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      1 //===-- ARMISelLowering.cpp - ARM DAG Lowering Implementation -------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines the interfaces that ARM uses to lower LLVM code into a
     11 // selection DAG.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #define DEBUG_TYPE "arm-isel"
     16 #include "ARM.h"
     17 #include "ARMAddressingModes.h"
     18 #include "ARMCallingConv.h"
     19 #include "ARMConstantPoolValue.h"
     20 #include "ARMISelLowering.h"
     21 #include "ARMMachineFunctionInfo.h"
     22 #include "ARMPerfectShuffle.h"
     23 #include "ARMRegisterInfo.h"
     24 #include "ARMSubtarget.h"
     25 #include "ARMTargetMachine.h"
     26 #include "ARMTargetObjectFile.h"
     27 #include "llvm/CallingConv.h"
     28 #include "llvm/Constants.h"
     29 #include "llvm/Function.h"
     30 #include "llvm/GlobalValue.h"
     31 #include "llvm/Instruction.h"
     32 #include "llvm/Instructions.h"
     33 #include "llvm/Intrinsics.h"
     34 #include "llvm/Type.h"
     35 #include "llvm/CodeGen/CallingConvLower.h"
     36 #include "llvm/CodeGen/IntrinsicLowering.h"
     37 #include "llvm/CodeGen/MachineBasicBlock.h"
     38 #include "llvm/CodeGen/MachineFrameInfo.h"
     39 #include "llvm/CodeGen/MachineFunction.h"
     40 #include "llvm/CodeGen/MachineInstrBuilder.h"
     41 #include "llvm/CodeGen/MachineRegisterInfo.h"
     42 #include "llvm/CodeGen/PseudoSourceValue.h"
     43 #include "llvm/CodeGen/SelectionDAG.h"
     44 #include "llvm/MC/MCSectionMachO.h"
     45 #include "llvm/Target/TargetOptions.h"
     46 #include "llvm/ADT/VectorExtras.h"
     47 #include "llvm/ADT/StringExtras.h"
     48 #include "llvm/ADT/Statistic.h"
     49 #include "llvm/Support/CommandLine.h"
     50 #include "llvm/Support/ErrorHandling.h"
     51 #include "llvm/Support/MathExtras.h"
     52 #include "llvm/Support/raw_ostream.h"
     53 #include <sstream>
     54 using namespace llvm;
     55 
     56 STATISTIC(NumTailCalls, "Number of tail calls");
     57 STATISTIC(NumMovwMovt, "Number of GAs materialized with movw + movt");
     58 
     59 // This option should go away when tail calls fully work.
     60 static cl::opt<bool>
     61 EnableARMTailCalls("arm-tail-calls", cl::Hidden,
     62   cl::desc("Generate tail calls (TEMPORARY OPTION)."),
     63   cl::init(false));
     64 
     65 cl::opt<bool>
     66 EnableARMLongCalls("arm-long-calls", cl::Hidden,
     67   cl::desc("Generate calls via indirect call instructions"),
     68   cl::init(false));
     69 
     70 static cl::opt<bool>
     71 ARMInterworking("arm-interworking", cl::Hidden,
     72   cl::desc("Enable / disable ARM interworking (for debugging only)"),
     73   cl::init(true));
     74 
     75 namespace llvm {
     76   class ARMCCState : public CCState {
     77   public:
     78     ARMCCState(CallingConv::ID CC, bool isVarArg, MachineFunction &MF,
     79                const TargetMachine &TM, SmallVector<CCValAssign, 16> &locs,
     80                LLVMContext &C, ParmContext PC)
     81         : CCState(CC, isVarArg, MF, TM, locs, C) {
     82       assert(((PC == Call) || (PC == Prologue)) &&
     83              "ARMCCState users must specify whether their context is call"
     84              "or prologue generation.");
     85       CallOrPrologue = PC;
     86     }
     87   };
     88 }
     89 
     90 // The APCS parameter registers.
     91 static const unsigned GPRArgRegs[] = {
     92   ARM::R0, ARM::R1, ARM::R2, ARM::R3
     93 };
     94 
     95 void ARMTargetLowering::addTypeForNEON(EVT VT, EVT PromotedLdStVT,
     96                                        EVT PromotedBitwiseVT) {
     97   if (VT != PromotedLdStVT) {
     98     setOperationAction(ISD::LOAD, VT.getSimpleVT(), Promote);
     99     AddPromotedToType (ISD::LOAD, VT.getSimpleVT(),
    100                        PromotedLdStVT.getSimpleVT());
    101 
    102     setOperationAction(ISD::STORE, VT.getSimpleVT(), Promote);
    103     AddPromotedToType (ISD::STORE, VT.getSimpleVT(),
    104                        PromotedLdStVT.getSimpleVT());
    105   }
    106 
    107   EVT ElemTy = VT.getVectorElementType();
    108   if (ElemTy != MVT::i64 && ElemTy != MVT::f64)
    109     setOperationAction(ISD::VSETCC, VT.getSimpleVT(), Custom);
    110   setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT.getSimpleVT(), Custom);
    111   if (ElemTy != MVT::i32) {
    112     setOperationAction(ISD::SINT_TO_FP, VT.getSimpleVT(), Expand);
    113     setOperationAction(ISD::UINT_TO_FP, VT.getSimpleVT(), Expand);
    114     setOperationAction(ISD::FP_TO_SINT, VT.getSimpleVT(), Expand);
    115     setOperationAction(ISD::FP_TO_UINT, VT.getSimpleVT(), Expand);
    116   }
    117   setOperationAction(ISD::BUILD_VECTOR, VT.getSimpleVT(), Custom);
    118   setOperationAction(ISD::VECTOR_SHUFFLE, VT.getSimpleVT(), Custom);
    119   setOperationAction(ISD::CONCAT_VECTORS, VT.getSimpleVT(), Legal);
    120   setOperationAction(ISD::EXTRACT_SUBVECTOR, VT.getSimpleVT(), Legal);
    121   setOperationAction(ISD::SELECT, VT.getSimpleVT(), Expand);
    122   setOperationAction(ISD::SELECT_CC, VT.getSimpleVT(), Expand);
    123   if (VT.isInteger()) {
    124     setOperationAction(ISD::SHL, VT.getSimpleVT(), Custom);
    125     setOperationAction(ISD::SRA, VT.getSimpleVT(), Custom);
    126     setOperationAction(ISD::SRL, VT.getSimpleVT(), Custom);
    127     setLoadExtAction(ISD::SEXTLOAD, VT.getSimpleVT(), Expand);
    128     setLoadExtAction(ISD::ZEXTLOAD, VT.getSimpleVT(), Expand);
    129     for (unsigned InnerVT = (unsigned)MVT::FIRST_VECTOR_VALUETYPE;
    130          InnerVT <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++InnerVT)
    131       setTruncStoreAction(VT.getSimpleVT(),
    132                           (MVT::SimpleValueType)InnerVT, Expand);
    133   }
    134   setLoadExtAction(ISD::EXTLOAD, VT.getSimpleVT(), Expand);
    135 
    136   // Promote all bit-wise operations.
    137   if (VT.isInteger() && VT != PromotedBitwiseVT) {
    138     setOperationAction(ISD::AND, VT.getSimpleVT(), Promote);
    139     AddPromotedToType (ISD::AND, VT.getSimpleVT(),
    140                        PromotedBitwiseVT.getSimpleVT());
    141     setOperationAction(ISD::OR,  VT.getSimpleVT(), Promote);
    142     AddPromotedToType (ISD::OR,  VT.getSimpleVT(),
    143                        PromotedBitwiseVT.getSimpleVT());
    144     setOperationAction(ISD::XOR, VT.getSimpleVT(), Promote);
    145     AddPromotedToType (ISD::XOR, VT.getSimpleVT(),
    146                        PromotedBitwiseVT.getSimpleVT());
    147   }
    148 
    149   // Neon does not support vector divide/remainder operations.
    150   setOperationAction(ISD::SDIV, VT.getSimpleVT(), Expand);
    151   setOperationAction(ISD::UDIV, VT.getSimpleVT(), Expand);
    152   setOperationAction(ISD::FDIV, VT.getSimpleVT(), Expand);
    153   setOperationAction(ISD::SREM, VT.getSimpleVT(), Expand);
    154   setOperationAction(ISD::UREM, VT.getSimpleVT(), Expand);
    155   setOperationAction(ISD::FREM, VT.getSimpleVT(), Expand);
    156 }
    157 
    158 void ARMTargetLowering::addDRTypeForNEON(EVT VT) {
    159   addRegisterClass(VT, ARM::DPRRegisterClass);
    160   addTypeForNEON(VT, MVT::f64, MVT::v2i32);
    161 }
    162 
    163 void ARMTargetLowering::addQRTypeForNEON(EVT VT) {
    164   addRegisterClass(VT, ARM::QPRRegisterClass);
    165   addTypeForNEON(VT, MVT::v2f64, MVT::v4i32);
    166 }
    167 
    168 static TargetLoweringObjectFile *createTLOF(TargetMachine &TM) {
    169   if (TM.getSubtarget<ARMSubtarget>().isTargetDarwin())
    170     return new TargetLoweringObjectFileMachO();
    171 
    172   return new ARMElfTargetObjectFile();
    173 }
    174 
    175 ARMTargetLowering::ARMTargetLowering(TargetMachine &TM)
    176     : TargetLowering(TM, createTLOF(TM)) {
    177   Subtarget = &TM.getSubtarget<ARMSubtarget>();
    178   RegInfo = TM.getRegisterInfo();
    179   Itins = TM.getInstrItineraryData();
    180 
    181   if (Subtarget->isTargetDarwin()) {
    182     // Uses VFP for Thumb libfuncs if available.
    183     if (Subtarget->isThumb() && Subtarget->hasVFP2()) {
    184       // Single-precision floating-point arithmetic.
    185       setLibcallName(RTLIB::ADD_F32, "__addsf3vfp");
    186       setLibcallName(RTLIB::SUB_F32, "__subsf3vfp");
    187       setLibcallName(RTLIB::MUL_F32, "__mulsf3vfp");
    188       setLibcallName(RTLIB::DIV_F32, "__divsf3vfp");
    189 
    190       // Double-precision floating-point arithmetic.
    191       setLibcallName(RTLIB::ADD_F64, "__adddf3vfp");
    192       setLibcallName(RTLIB::SUB_F64, "__subdf3vfp");
    193       setLibcallName(RTLIB::MUL_F64, "__muldf3vfp");
    194       setLibcallName(RTLIB::DIV_F64, "__divdf3vfp");
    195 
    196       // Single-precision comparisons.
    197       setLibcallName(RTLIB::OEQ_F32, "__eqsf2vfp");
    198       setLibcallName(RTLIB::UNE_F32, "__nesf2vfp");
    199       setLibcallName(RTLIB::OLT_F32, "__ltsf2vfp");
    200       setLibcallName(RTLIB::OLE_F32, "__lesf2vfp");
    201       setLibcallName(RTLIB::OGE_F32, "__gesf2vfp");
    202       setLibcallName(RTLIB::OGT_F32, "__gtsf2vfp");
    203       setLibcallName(RTLIB::UO_F32,  "__unordsf2vfp");
    204       setLibcallName(RTLIB::O_F32,   "__unordsf2vfp");
    205 
    206       setCmpLibcallCC(RTLIB::OEQ_F32, ISD::SETNE);
    207       setCmpLibcallCC(RTLIB::UNE_F32, ISD::SETNE);
    208       setCmpLibcallCC(RTLIB::OLT_F32, ISD::SETNE);
    209       setCmpLibcallCC(RTLIB::OLE_F32, ISD::SETNE);
    210       setCmpLibcallCC(RTLIB::OGE_F32, ISD::SETNE);
    211       setCmpLibcallCC(RTLIB::OGT_F32, ISD::SETNE);
    212       setCmpLibcallCC(RTLIB::UO_F32,  ISD::SETNE);
    213       setCmpLibcallCC(RTLIB::O_F32,   ISD::SETEQ);
    214 
    215       // Double-precision comparisons.
    216       setLibcallName(RTLIB::OEQ_F64, "__eqdf2vfp");
    217       setLibcallName(RTLIB::UNE_F64, "__nedf2vfp");
    218       setLibcallName(RTLIB::OLT_F64, "__ltdf2vfp");
    219       setLibcallName(RTLIB::OLE_F64, "__ledf2vfp");
    220       setLibcallName(RTLIB::OGE_F64, "__gedf2vfp");
    221       setLibcallName(RTLIB::OGT_F64, "__gtdf2vfp");
    222       setLibcallName(RTLIB::UO_F64,  "__unorddf2vfp");
    223       setLibcallName(RTLIB::O_F64,   "__unorddf2vfp");
    224 
    225       setCmpLibcallCC(RTLIB::OEQ_F64, ISD::SETNE);
    226       setCmpLibcallCC(RTLIB::UNE_F64, ISD::SETNE);
    227       setCmpLibcallCC(RTLIB::OLT_F64, ISD::SETNE);
    228       setCmpLibcallCC(RTLIB::OLE_F64, ISD::SETNE);
    229       setCmpLibcallCC(RTLIB::OGE_F64, ISD::SETNE);
    230       setCmpLibcallCC(RTLIB::OGT_F64, ISD::SETNE);
    231       setCmpLibcallCC(RTLIB::UO_F64,  ISD::SETNE);
    232       setCmpLibcallCC(RTLIB::O_F64,   ISD::SETEQ);
    233 
    234       // Floating-point to integer conversions.
    235       // i64 conversions are done via library routines even when generating VFP
    236       // instructions, so use the same ones.
    237       setLibcallName(RTLIB::FPTOSINT_F64_I32, "__fixdfsivfp");
    238       setLibcallName(RTLIB::FPTOUINT_F64_I32, "__fixunsdfsivfp");
    239       setLibcallName(RTLIB::FPTOSINT_F32_I32, "__fixsfsivfp");
    240       setLibcallName(RTLIB::FPTOUINT_F32_I32, "__fixunssfsivfp");
    241 
    242       // Conversions between floating types.
    243       setLibcallName(RTLIB::FPROUND_F64_F32, "__truncdfsf2vfp");
    244       setLibcallName(RTLIB::FPEXT_F32_F64,   "__extendsfdf2vfp");
    245 
    246       // Integer to floating-point conversions.
    247       // i64 conversions are done via library routines even when generating VFP
    248       // instructions, so use the same ones.
    249       // FIXME: There appears to be some naming inconsistency in ARM libgcc:
    250       // e.g., __floatunsidf vs. __floatunssidfvfp.
    251       setLibcallName(RTLIB::SINTTOFP_I32_F64, "__floatsidfvfp");
    252       setLibcallName(RTLIB::UINTTOFP_I32_F64, "__floatunssidfvfp");
    253       setLibcallName(RTLIB::SINTTOFP_I32_F32, "__floatsisfvfp");
    254       setLibcallName(RTLIB::UINTTOFP_I32_F32, "__floatunssisfvfp");
    255     }
    256   }
    257 
    258   // These libcalls are not available in 32-bit.
    259   setLibcallName(RTLIB::SHL_I128, 0);
    260   setLibcallName(RTLIB::SRL_I128, 0);
    261   setLibcallName(RTLIB::SRA_I128, 0);
    262 
    263   if (Subtarget->isAAPCS_ABI()) {
    264     // Double-precision floating-point arithmetic helper functions
    265     // RTABI chapter 4.1.2, Table 2
    266     setLibcallName(RTLIB::ADD_F64, "__aeabi_dadd");
    267     setLibcallName(RTLIB::DIV_F64, "__aeabi_ddiv");
    268     setLibcallName(RTLIB::MUL_F64, "__aeabi_dmul");
    269     setLibcallName(RTLIB::SUB_F64, "__aeabi_dsub");
    270     setLibcallCallingConv(RTLIB::ADD_F64, CallingConv::ARM_AAPCS);
    271     setLibcallCallingConv(RTLIB::DIV_F64, CallingConv::ARM_AAPCS);
    272     setLibcallCallingConv(RTLIB::MUL_F64, CallingConv::ARM_AAPCS);
    273     setLibcallCallingConv(RTLIB::SUB_F64, CallingConv::ARM_AAPCS);
    274 
    275     // Double-precision floating-point comparison helper functions
    276     // RTABI chapter 4.1.2, Table 3
    277     setLibcallName(RTLIB::OEQ_F64, "__aeabi_dcmpeq");
    278     setCmpLibcallCC(RTLIB::OEQ_F64, ISD::SETNE);
    279     setLibcallName(RTLIB::UNE_F64, "__aeabi_dcmpeq");
    280     setCmpLibcallCC(RTLIB::UNE_F64, ISD::SETEQ);
    281     setLibcallName(RTLIB::OLT_F64, "__aeabi_dcmplt");
    282     setCmpLibcallCC(RTLIB::OLT_F64, ISD::SETNE);
    283     setLibcallName(RTLIB::OLE_F64, "__aeabi_dcmple");
    284     setCmpLibcallCC(RTLIB::OLE_F64, ISD::SETNE);
    285     setLibcallName(RTLIB::OGE_F64, "__aeabi_dcmpge");
    286     setCmpLibcallCC(RTLIB::OGE_F64, ISD::SETNE);
    287     setLibcallName(RTLIB::OGT_F64, "__aeabi_dcmpgt");
    288     setCmpLibcallCC(RTLIB::OGT_F64, ISD::SETNE);
    289     setLibcallName(RTLIB::UO_F64,  "__aeabi_dcmpun");
    290     setCmpLibcallCC(RTLIB::UO_F64,  ISD::SETNE);
    291     setLibcallName(RTLIB::O_F64,   "__aeabi_dcmpun");
    292     setCmpLibcallCC(RTLIB::O_F64,   ISD::SETEQ);
    293     setLibcallCallingConv(RTLIB::OEQ_F64, CallingConv::ARM_AAPCS);
    294     setLibcallCallingConv(RTLIB::UNE_F64, CallingConv::ARM_AAPCS);
    295     setLibcallCallingConv(RTLIB::OLT_F64, CallingConv::ARM_AAPCS);
    296     setLibcallCallingConv(RTLIB::OLE_F64, CallingConv::ARM_AAPCS);
    297     setLibcallCallingConv(RTLIB::OGE_F64, CallingConv::ARM_AAPCS);
    298     setLibcallCallingConv(RTLIB::OGT_F64, CallingConv::ARM_AAPCS);
    299     setLibcallCallingConv(RTLIB::UO_F64, CallingConv::ARM_AAPCS);
    300     setLibcallCallingConv(RTLIB::O_F64, CallingConv::ARM_AAPCS);
    301 
    302     // Single-precision floating-point arithmetic helper functions
    303     // RTABI chapter 4.1.2, Table 4
    304     setLibcallName(RTLIB::ADD_F32, "__aeabi_fadd");
    305     setLibcallName(RTLIB::DIV_F32, "__aeabi_fdiv");
    306     setLibcallName(RTLIB::MUL_F32, "__aeabi_fmul");
    307     setLibcallName(RTLIB::SUB_F32, "__aeabi_fsub");
    308     setLibcallCallingConv(RTLIB::ADD_F32, CallingConv::ARM_AAPCS);
    309     setLibcallCallingConv(RTLIB::DIV_F32, CallingConv::ARM_AAPCS);
    310     setLibcallCallingConv(RTLIB::MUL_F32, CallingConv::ARM_AAPCS);
    311     setLibcallCallingConv(RTLIB::SUB_F32, CallingConv::ARM_AAPCS);
    312 
    313     // Single-precision floating-point comparison helper functions
    314     // RTABI chapter 4.1.2, Table 5
    315     setLibcallName(RTLIB::OEQ_F32, "__aeabi_fcmpeq");
    316     setCmpLibcallCC(RTLIB::OEQ_F32, ISD::SETNE);
    317     setLibcallName(RTLIB::UNE_F32, "__aeabi_fcmpeq");
    318     setCmpLibcallCC(RTLIB::UNE_F32, ISD::SETEQ);
    319     setLibcallName(RTLIB::OLT_F32, "__aeabi_fcmplt");
    320     setCmpLibcallCC(RTLIB::OLT_F32, ISD::SETNE);
    321     setLibcallName(RTLIB::OLE_F32, "__aeabi_fcmple");
    322     setCmpLibcallCC(RTLIB::OLE_F32, ISD::SETNE);
    323     setLibcallName(RTLIB::OGE_F32, "__aeabi_fcmpge");
    324     setCmpLibcallCC(RTLIB::OGE_F32, ISD::SETNE);
    325     setLibcallName(RTLIB::OGT_F32, "__aeabi_fcmpgt");
    326     setCmpLibcallCC(RTLIB::OGT_F32, ISD::SETNE);
    327     setLibcallName(RTLIB::UO_F32,  "__aeabi_fcmpun");
    328     setCmpLibcallCC(RTLIB::UO_F32,  ISD::SETNE);
    329     setLibcallName(RTLIB::O_F32,   "__aeabi_fcmpun");
    330     setCmpLibcallCC(RTLIB::O_F32,   ISD::SETEQ);
    331     setLibcallCallingConv(RTLIB::OEQ_F32, CallingConv::ARM_AAPCS);
    332     setLibcallCallingConv(RTLIB::UNE_F32, CallingConv::ARM_AAPCS);
    333     setLibcallCallingConv(RTLIB::OLT_F32, CallingConv::ARM_AAPCS);
    334     setLibcallCallingConv(RTLIB::OLE_F32, CallingConv::ARM_AAPCS);
    335     setLibcallCallingConv(RTLIB::OGE_F32, CallingConv::ARM_AAPCS);
    336     setLibcallCallingConv(RTLIB::OGT_F32, CallingConv::ARM_AAPCS);
    337     setLibcallCallingConv(RTLIB::UO_F32, CallingConv::ARM_AAPCS);
    338     setLibcallCallingConv(RTLIB::O_F32, CallingConv::ARM_AAPCS);
    339 
    340     // Floating-point to integer conversions.
    341     // RTABI chapter 4.1.2, Table 6
    342     setLibcallName(RTLIB::FPTOSINT_F64_I32, "__aeabi_d2iz");
    343     setLibcallName(RTLIB::FPTOUINT_F64_I32, "__aeabi_d2uiz");
    344     setLibcallName(RTLIB::FPTOSINT_F64_I64, "__aeabi_d2lz");
    345     setLibcallName(RTLIB::FPTOUINT_F64_I64, "__aeabi_d2ulz");
    346     setLibcallName(RTLIB::FPTOSINT_F32_I32, "__aeabi_f2iz");
    347     setLibcallName(RTLIB::FPTOUINT_F32_I32, "__aeabi_f2uiz");
    348     setLibcallName(RTLIB::FPTOSINT_F32_I64, "__aeabi_f2lz");
    349     setLibcallName(RTLIB::FPTOUINT_F32_I64, "__aeabi_f2ulz");
    350     setLibcallCallingConv(RTLIB::FPTOSINT_F64_I32, CallingConv::ARM_AAPCS);
    351     setLibcallCallingConv(RTLIB::FPTOUINT_F64_I32, CallingConv::ARM_AAPCS);
    352     setLibcallCallingConv(RTLIB::FPTOSINT_F64_I64, CallingConv::ARM_AAPCS);
    353     setLibcallCallingConv(RTLIB::FPTOUINT_F64_I64, CallingConv::ARM_AAPCS);
    354     setLibcallCallingConv(RTLIB::FPTOSINT_F32_I32, CallingConv::ARM_AAPCS);
    355     setLibcallCallingConv(RTLIB::FPTOUINT_F32_I32, CallingConv::ARM_AAPCS);
    356     setLibcallCallingConv(RTLIB::FPTOSINT_F32_I64, CallingConv::ARM_AAPCS);
    357     setLibcallCallingConv(RTLIB::FPTOUINT_F32_I64, CallingConv::ARM_AAPCS);
    358 
    359     // Conversions between floating types.
    360     // RTABI chapter 4.1.2, Table 7
    361     setLibcallName(RTLIB::FPROUND_F64_F32, "__aeabi_d2f");
    362     setLibcallName(RTLIB::FPEXT_F32_F64,   "__aeabi_f2d");
    363     setLibcallCallingConv(RTLIB::FPROUND_F64_F32, CallingConv::ARM_AAPCS);
    364     setLibcallCallingConv(RTLIB::FPEXT_F32_F64, CallingConv::ARM_AAPCS);
    365 
    366     // Integer to floating-point conversions.
    367     // RTABI chapter 4.1.2, Table 8
    368     setLibcallName(RTLIB::SINTTOFP_I32_F64, "__aeabi_i2d");
    369     setLibcallName(RTLIB::UINTTOFP_I32_F64, "__aeabi_ui2d");
    370     setLibcallName(RTLIB::SINTTOFP_I64_F64, "__aeabi_l2d");
    371     setLibcallName(RTLIB::UINTTOFP_I64_F64, "__aeabi_ul2d");
    372     setLibcallName(RTLIB::SINTTOFP_I32_F32, "__aeabi_i2f");
    373     setLibcallName(RTLIB::UINTTOFP_I32_F32, "__aeabi_ui2f");
    374     setLibcallName(RTLIB::SINTTOFP_I64_F32, "__aeabi_l2f");
    375     setLibcallName(RTLIB::UINTTOFP_I64_F32, "__aeabi_ul2f");
    376     setLibcallCallingConv(RTLIB::SINTTOFP_I32_F64, CallingConv::ARM_AAPCS);
    377     setLibcallCallingConv(RTLIB::UINTTOFP_I32_F64, CallingConv::ARM_AAPCS);
    378     setLibcallCallingConv(RTLIB::SINTTOFP_I64_F64, CallingConv::ARM_AAPCS);
    379     setLibcallCallingConv(RTLIB::UINTTOFP_I64_F64, CallingConv::ARM_AAPCS);
    380     setLibcallCallingConv(RTLIB::SINTTOFP_I32_F32, CallingConv::ARM_AAPCS);
    381     setLibcallCallingConv(RTLIB::UINTTOFP_I32_F32, CallingConv::ARM_AAPCS);
    382     setLibcallCallingConv(RTLIB::SINTTOFP_I64_F32, CallingConv::ARM_AAPCS);
    383     setLibcallCallingConv(RTLIB::UINTTOFP_I64_F32, CallingConv::ARM_AAPCS);
    384 
    385     // Long long helper functions
    386     // RTABI chapter 4.2, Table 9
    387     setLibcallName(RTLIB::MUL_I64,  "__aeabi_lmul");
    388     setLibcallName(RTLIB::SDIV_I64, "__aeabi_ldivmod");
    389     setLibcallName(RTLIB::UDIV_I64, "__aeabi_uldivmod");
    390     setLibcallName(RTLIB::SHL_I64, "__aeabi_llsl");
    391     setLibcallName(RTLIB::SRL_I64, "__aeabi_llsr");
    392     setLibcallName(RTLIB::SRA_I64, "__aeabi_lasr");
    393     setLibcallCallingConv(RTLIB::MUL_I64, CallingConv::ARM_AAPCS);
    394     setLibcallCallingConv(RTLIB::SDIV_I64, CallingConv::ARM_AAPCS);
    395     setLibcallCallingConv(RTLIB::UDIV_I64, CallingConv::ARM_AAPCS);
    396     setLibcallCallingConv(RTLIB::SHL_I64, CallingConv::ARM_AAPCS);
    397     setLibcallCallingConv(RTLIB::SRL_I64, CallingConv::ARM_AAPCS);
    398     setLibcallCallingConv(RTLIB::SRA_I64, CallingConv::ARM_AAPCS);
    399 
    400     // Integer division functions
    401     // RTABI chapter 4.3.1
    402     setLibcallName(RTLIB::SDIV_I8,  "__aeabi_idiv");
    403     setLibcallName(RTLIB::SDIV_I16, "__aeabi_idiv");
    404     setLibcallName(RTLIB::SDIV_I32, "__aeabi_idiv");
    405     setLibcallName(RTLIB::UDIV_I8,  "__aeabi_uidiv");
    406     setLibcallName(RTLIB::UDIV_I16, "__aeabi_uidiv");
    407     setLibcallName(RTLIB::UDIV_I32, "__aeabi_uidiv");
    408     setLibcallCallingConv(RTLIB::SDIV_I8, CallingConv::ARM_AAPCS);
    409     setLibcallCallingConv(RTLIB::SDIV_I16, CallingConv::ARM_AAPCS);
    410     setLibcallCallingConv(RTLIB::SDIV_I32, CallingConv::ARM_AAPCS);
    411     setLibcallCallingConv(RTLIB::UDIV_I8, CallingConv::ARM_AAPCS);
    412     setLibcallCallingConv(RTLIB::UDIV_I16, CallingConv::ARM_AAPCS);
    413     setLibcallCallingConv(RTLIB::UDIV_I32, CallingConv::ARM_AAPCS);
    414 
    415     // Memory operations
    416     // RTABI chapter 4.3.4
    417     setLibcallName(RTLIB::MEMCPY,  "__aeabi_memcpy");
    418     setLibcallName(RTLIB::MEMMOVE, "__aeabi_memmove");
    419     setLibcallName(RTLIB::MEMSET,  "__aeabi_memset");
    420   }
    421 
    422   if (Subtarget->isThumb1Only())
    423     addRegisterClass(MVT::i32, ARM::tGPRRegisterClass);
    424   else
    425     addRegisterClass(MVT::i32, ARM::GPRRegisterClass);
    426   if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
    427     addRegisterClass(MVT::f32, ARM::SPRRegisterClass);
    428     if (!Subtarget->isFPOnlySP())
    429       addRegisterClass(MVT::f64, ARM::DPRRegisterClass);
    430 
    431     setTruncStoreAction(MVT::f64, MVT::f32, Expand);
    432   }
    433 
    434   if (Subtarget->hasNEON()) {
    435     addDRTypeForNEON(MVT::v2f32);
    436     addDRTypeForNEON(MVT::v8i8);
    437     addDRTypeForNEON(MVT::v4i16);
    438     addDRTypeForNEON(MVT::v2i32);
    439     addDRTypeForNEON(MVT::v1i64);
    440 
    441     addQRTypeForNEON(MVT::v4f32);
    442     addQRTypeForNEON(MVT::v2f64);
    443     addQRTypeForNEON(MVT::v16i8);
    444     addQRTypeForNEON(MVT::v8i16);
    445     addQRTypeForNEON(MVT::v4i32);
    446     addQRTypeForNEON(MVT::v2i64);
    447 
    448     // v2f64 is legal so that QR subregs can be extracted as f64 elements, but
    449     // neither Neon nor VFP support any arithmetic operations on it.
    450     setOperationAction(ISD::FADD, MVT::v2f64, Expand);
    451     setOperationAction(ISD::FSUB, MVT::v2f64, Expand);
    452     setOperationAction(ISD::FMUL, MVT::v2f64, Expand);
    453     setOperationAction(ISD::FDIV, MVT::v2f64, Expand);
    454     setOperationAction(ISD::FREM, MVT::v2f64, Expand);
    455     setOperationAction(ISD::FCOPYSIGN, MVT::v2f64, Expand);
    456     setOperationAction(ISD::VSETCC, MVT::v2f64, Expand);
    457     setOperationAction(ISD::FNEG, MVT::v2f64, Expand);
    458     setOperationAction(ISD::FABS, MVT::v2f64, Expand);
    459     setOperationAction(ISD::FSQRT, MVT::v2f64, Expand);
    460     setOperationAction(ISD::FSIN, MVT::v2f64, Expand);
    461     setOperationAction(ISD::FCOS, MVT::v2f64, Expand);
    462     setOperationAction(ISD::FPOWI, MVT::v2f64, Expand);
    463     setOperationAction(ISD::FPOW, MVT::v2f64, Expand);
    464     setOperationAction(ISD::FLOG, MVT::v2f64, Expand);
    465     setOperationAction(ISD::FLOG2, MVT::v2f64, Expand);
    466     setOperationAction(ISD::FLOG10, MVT::v2f64, Expand);
    467     setOperationAction(ISD::FEXP, MVT::v2f64, Expand);
    468     setOperationAction(ISD::FEXP2, MVT::v2f64, Expand);
    469     setOperationAction(ISD::FCEIL, MVT::v2f64, Expand);
    470     setOperationAction(ISD::FTRUNC, MVT::v2f64, Expand);
    471     setOperationAction(ISD::FRINT, MVT::v2f64, Expand);
    472     setOperationAction(ISD::FNEARBYINT, MVT::v2f64, Expand);
    473     setOperationAction(ISD::FFLOOR, MVT::v2f64, Expand);
    474 
    475     setTruncStoreAction(MVT::v2f64, MVT::v2f32, Expand);
    476 
    477     // Neon does not support some operations on v1i64 and v2i64 types.
    478     setOperationAction(ISD::MUL, MVT::v1i64, Expand);
    479     // Custom handling for some quad-vector types to detect VMULL.
    480     setOperationAction(ISD::MUL, MVT::v8i16, Custom);
    481     setOperationAction(ISD::MUL, MVT::v4i32, Custom);
    482     setOperationAction(ISD::MUL, MVT::v2i64, Custom);
    483     // Custom handling for some vector types to avoid expensive expansions
    484     setOperationAction(ISD::SDIV, MVT::v4i16, Custom);
    485     setOperationAction(ISD::SDIV, MVT::v8i8, Custom);
    486     setOperationAction(ISD::UDIV, MVT::v4i16, Custom);
    487     setOperationAction(ISD::UDIV, MVT::v8i8, Custom);
    488     setOperationAction(ISD::VSETCC, MVT::v1i64, Expand);
    489     setOperationAction(ISD::VSETCC, MVT::v2i64, Expand);
    490     // Neon does not have single instruction SINT_TO_FP and UINT_TO_FP with
    491     // a destination type that is wider than the source.
    492     setOperationAction(ISD::SINT_TO_FP, MVT::v4i16, Custom);
    493     setOperationAction(ISD::UINT_TO_FP, MVT::v4i16, Custom);
    494 
    495     setTargetDAGCombine(ISD::INTRINSIC_VOID);
    496     setTargetDAGCombine(ISD::INTRINSIC_W_CHAIN);
    497     setTargetDAGCombine(ISD::INTRINSIC_WO_CHAIN);
    498     setTargetDAGCombine(ISD::SHL);
    499     setTargetDAGCombine(ISD::SRL);
    500     setTargetDAGCombine(ISD::SRA);
    501     setTargetDAGCombine(ISD::SIGN_EXTEND);
    502     setTargetDAGCombine(ISD::ZERO_EXTEND);
    503     setTargetDAGCombine(ISD::ANY_EXTEND);
    504     setTargetDAGCombine(ISD::SELECT_CC);
    505     setTargetDAGCombine(ISD::BUILD_VECTOR);
    506     setTargetDAGCombine(ISD::VECTOR_SHUFFLE);
    507     setTargetDAGCombine(ISD::INSERT_VECTOR_ELT);
    508     setTargetDAGCombine(ISD::STORE);
    509     setTargetDAGCombine(ISD::FP_TO_SINT);
    510     setTargetDAGCombine(ISD::FP_TO_UINT);
    511     setTargetDAGCombine(ISD::FDIV);
    512   }
    513 
    514   computeRegisterProperties();
    515 
    516   // ARM does not have f32 extending load.
    517   setLoadExtAction(ISD::EXTLOAD, MVT::f32, Expand);
    518 
    519   // ARM does not have i1 sign extending load.
    520   setLoadExtAction(ISD::SEXTLOAD, MVT::i1, Promote);
    521 
    522   // ARM supports all 4 flavors of integer indexed load / store.
    523   if (!Subtarget->isThumb1Only()) {
    524     for (unsigned im = (unsigned)ISD::PRE_INC;
    525          im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
    526       setIndexedLoadAction(im,  MVT::i1,  Legal);
    527       setIndexedLoadAction(im,  MVT::i8,  Legal);
    528       setIndexedLoadAction(im,  MVT::i16, Legal);
    529       setIndexedLoadAction(im,  MVT::i32, Legal);
    530       setIndexedStoreAction(im, MVT::i1,  Legal);
    531       setIndexedStoreAction(im, MVT::i8,  Legal);
    532       setIndexedStoreAction(im, MVT::i16, Legal);
    533       setIndexedStoreAction(im, MVT::i32, Legal);
    534     }
    535   }
    536 
    537   // i64 operation support.
    538   setOperationAction(ISD::MUL,     MVT::i64, Expand);
    539   setOperationAction(ISD::MULHU,   MVT::i32, Expand);
    540   if (Subtarget->isThumb1Only()) {
    541     setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
    542     setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
    543   }
    544   if (Subtarget->isThumb1Only() || !Subtarget->hasV6Ops()
    545       || (Subtarget->isThumb2() && !Subtarget->hasThumb2DSP()))
    546     setOperationAction(ISD::MULHS, MVT::i32, Expand);
    547 
    548   setOperationAction(ISD::SHL_PARTS, MVT::i32, Custom);
    549   setOperationAction(ISD::SRA_PARTS, MVT::i32, Custom);
    550   setOperationAction(ISD::SRL_PARTS, MVT::i32, Custom);
    551   setOperationAction(ISD::SRL,       MVT::i64, Custom);
    552   setOperationAction(ISD::SRA,       MVT::i64, Custom);
    553 
    554   // ARM does not have ROTL.
    555   setOperationAction(ISD::ROTL,  MVT::i32, Expand);
    556   setOperationAction(ISD::CTTZ,  MVT::i32, Custom);
    557   setOperationAction(ISD::CTPOP, MVT::i32, Expand);
    558   if (!Subtarget->hasV5TOps() || Subtarget->isThumb1Only())
    559     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
    560 
    561   // Only ARMv6 has BSWAP.
    562   if (!Subtarget->hasV6Ops())
    563     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
    564 
    565   // These are expanded into libcalls.
    566   if (!Subtarget->hasDivide() || !Subtarget->isThumb2()) {
    567     // v7M has a hardware divider
    568     setOperationAction(ISD::SDIV,  MVT::i32, Expand);
    569     setOperationAction(ISD::UDIV,  MVT::i32, Expand);
    570   }
    571   setOperationAction(ISD::SREM,  MVT::i32, Expand);
    572   setOperationAction(ISD::UREM,  MVT::i32, Expand);
    573   setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
    574   setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
    575 
    576   setOperationAction(ISD::GlobalAddress, MVT::i32,   Custom);
    577   setOperationAction(ISD::ConstantPool,  MVT::i32,   Custom);
    578   setOperationAction(ISD::GLOBAL_OFFSET_TABLE, MVT::i32, Custom);
    579   setOperationAction(ISD::GlobalTLSAddress, MVT::i32, Custom);
    580   setOperationAction(ISD::BlockAddress, MVT::i32, Custom);
    581 
    582   setOperationAction(ISD::TRAP, MVT::Other, Legal);
    583 
    584   // Use the default implementation.
    585   setOperationAction(ISD::VASTART,            MVT::Other, Custom);
    586   setOperationAction(ISD::VAARG,              MVT::Other, Expand);
    587   setOperationAction(ISD::VACOPY,             MVT::Other, Expand);
    588   setOperationAction(ISD::VAEND,              MVT::Other, Expand);
    589   setOperationAction(ISD::STACKSAVE,          MVT::Other, Expand);
    590   setOperationAction(ISD::STACKRESTORE,       MVT::Other, Expand);
    591   setOperationAction(ISD::EHSELECTION,        MVT::i32,   Expand);
    592   setOperationAction(ISD::EXCEPTIONADDR,      MVT::i32,   Expand);
    593   setExceptionPointerRegister(ARM::R0);
    594   setExceptionSelectorRegister(ARM::R1);
    595 
    596   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
    597   // ARMv6 Thumb1 (except for CPUs that support dmb / dsb) and earlier use
    598   // the default expansion.
    599   if (Subtarget->hasDataBarrier() ||
    600       (Subtarget->hasV6Ops() && !Subtarget->isThumb())) {
    601     // membarrier needs custom lowering; the rest are legal and handled
    602     // normally.
    603     setOperationAction(ISD::MEMBARRIER, MVT::Other, Custom);
    604   } else {
    605     // Set them all for expansion, which will force libcalls.
    606     setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand);
    607     setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i8,  Expand);
    608     setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i16, Expand);
    609     setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i32, Expand);
    610     setOperationAction(ISD::ATOMIC_SWAP,      MVT::i8,  Expand);
    611     setOperationAction(ISD::ATOMIC_SWAP,      MVT::i16, Expand);
    612     setOperationAction(ISD::ATOMIC_SWAP,      MVT::i32, Expand);
    613     setOperationAction(ISD::ATOMIC_LOAD_ADD,  MVT::i8,  Expand);
    614     setOperationAction(ISD::ATOMIC_LOAD_ADD,  MVT::i16, Expand);
    615     setOperationAction(ISD::ATOMIC_LOAD_ADD,  MVT::i32, Expand);
    616     setOperationAction(ISD::ATOMIC_LOAD_SUB,  MVT::i8,  Expand);
    617     setOperationAction(ISD::ATOMIC_LOAD_SUB,  MVT::i16, Expand);
    618     setOperationAction(ISD::ATOMIC_LOAD_SUB,  MVT::i32, Expand);
    619     setOperationAction(ISD::ATOMIC_LOAD_AND,  MVT::i8,  Expand);
    620     setOperationAction(ISD::ATOMIC_LOAD_AND,  MVT::i16, Expand);
    621     setOperationAction(ISD::ATOMIC_LOAD_AND,  MVT::i32, Expand);
    622     setOperationAction(ISD::ATOMIC_LOAD_OR,   MVT::i8,  Expand);
    623     setOperationAction(ISD::ATOMIC_LOAD_OR,   MVT::i16, Expand);
    624     setOperationAction(ISD::ATOMIC_LOAD_OR,   MVT::i32, Expand);
    625     setOperationAction(ISD::ATOMIC_LOAD_XOR,  MVT::i8,  Expand);
    626     setOperationAction(ISD::ATOMIC_LOAD_XOR,  MVT::i16, Expand);
    627     setOperationAction(ISD::ATOMIC_LOAD_XOR,  MVT::i32, Expand);
    628     setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i8,  Expand);
    629     setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i16, Expand);
    630     setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i32, Expand);
    631     setOperationAction(ISD::ATOMIC_LOAD_MIN, MVT::i8,  Expand);
    632     setOperationAction(ISD::ATOMIC_LOAD_MIN, MVT::i16, Expand);
    633     setOperationAction(ISD::ATOMIC_LOAD_MIN, MVT::i32, Expand);
    634     setOperationAction(ISD::ATOMIC_LOAD_MAX, MVT::i8,  Expand);
    635     setOperationAction(ISD::ATOMIC_LOAD_MAX, MVT::i16, Expand);
    636     setOperationAction(ISD::ATOMIC_LOAD_MAX, MVT::i32, Expand);
    637     setOperationAction(ISD::ATOMIC_LOAD_UMIN, MVT::i8,  Expand);
    638     setOperationAction(ISD::ATOMIC_LOAD_UMIN, MVT::i16, Expand);
    639     setOperationAction(ISD::ATOMIC_LOAD_UMIN, MVT::i32, Expand);
    640     setOperationAction(ISD::ATOMIC_LOAD_UMAX, MVT::i8,  Expand);
    641     setOperationAction(ISD::ATOMIC_LOAD_UMAX, MVT::i16, Expand);
    642     setOperationAction(ISD::ATOMIC_LOAD_UMAX, MVT::i32, Expand);
    643     // Since the libcalls include locking, fold in the fences
    644     setShouldFoldAtomicFences(true);
    645   }
    646   // 64-bit versions are always libcalls (for now)
    647   setOperationAction(ISD::ATOMIC_CMP_SWAP,  MVT::i64, Expand);
    648   setOperationAction(ISD::ATOMIC_SWAP,      MVT::i64, Expand);
    649   setOperationAction(ISD::ATOMIC_LOAD_ADD,  MVT::i64, Expand);
    650   setOperationAction(ISD::ATOMIC_LOAD_SUB,  MVT::i64, Expand);
    651   setOperationAction(ISD::ATOMIC_LOAD_AND,  MVT::i64, Expand);
    652   setOperationAction(ISD::ATOMIC_LOAD_OR,   MVT::i64, Expand);
    653   setOperationAction(ISD::ATOMIC_LOAD_XOR,  MVT::i64, Expand);
    654   setOperationAction(ISD::ATOMIC_LOAD_NAND, MVT::i64, Expand);
    655 
    656   setOperationAction(ISD::PREFETCH,         MVT::Other, Custom);
    657 
    658   // Requires SXTB/SXTH, available on v6 and up in both ARM and Thumb modes.
    659   if (!Subtarget->hasV6Ops()) {
    660     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
    661     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
    662   }
    663   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
    664 
    665   if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
    666     // Turn f64->i64 into VMOVRRD, i64 -> f64 to VMOVDRR
    667     // iff target supports vfp2.
    668     setOperationAction(ISD::BITCAST, MVT::i64, Custom);
    669     setOperationAction(ISD::FLT_ROUNDS_, MVT::i32, Custom);
    670   }
    671 
    672   // We want to custom lower some of our intrinsics.
    673   setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
    674   if (Subtarget->isTargetDarwin()) {
    675     setOperationAction(ISD::EH_SJLJ_SETJMP, MVT::i32, Custom);
    676     setOperationAction(ISD::EH_SJLJ_LONGJMP, MVT::Other, Custom);
    677     setOperationAction(ISD::EH_SJLJ_DISPATCHSETUP, MVT::Other, Custom);
    678     setLibcallName(RTLIB::UNWIND_RESUME, "_Unwind_SjLj_Resume");
    679   }
    680 
    681   setOperationAction(ISD::SETCC,     MVT::i32, Expand);
    682   setOperationAction(ISD::SETCC,     MVT::f32, Expand);
    683   setOperationAction(ISD::SETCC,     MVT::f64, Expand);
    684   setOperationAction(ISD::SELECT,    MVT::i32, Custom);
    685   setOperationAction(ISD::SELECT,    MVT::f32, Custom);
    686   setOperationAction(ISD::SELECT,    MVT::f64, Custom);
    687   setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
    688   setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
    689   setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
    690 
    691   setOperationAction(ISD::BRCOND,    MVT::Other, Expand);
    692   setOperationAction(ISD::BR_CC,     MVT::i32,   Custom);
    693   setOperationAction(ISD::BR_CC,     MVT::f32,   Custom);
    694   setOperationAction(ISD::BR_CC,     MVT::f64,   Custom);
    695   setOperationAction(ISD::BR_JT,     MVT::Other, Custom);
    696 
    697   // We don't support sin/cos/fmod/copysign/pow
    698   setOperationAction(ISD::FSIN,      MVT::f64, Expand);
    699   setOperationAction(ISD::FSIN,      MVT::f32, Expand);
    700   setOperationAction(ISD::FCOS,      MVT::f32, Expand);
    701   setOperationAction(ISD::FCOS,      MVT::f64, Expand);
    702   setOperationAction(ISD::FREM,      MVT::f64, Expand);
    703   setOperationAction(ISD::FREM,      MVT::f32, Expand);
    704   if (!UseSoftFloat && Subtarget->hasVFP2() && !Subtarget->isThumb1Only()) {
    705     setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
    706     setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
    707   }
    708   setOperationAction(ISD::FPOW,      MVT::f64, Expand);
    709   setOperationAction(ISD::FPOW,      MVT::f32, Expand);
    710 
    711   setOperationAction(ISD::FMA, MVT::f64, Expand);
    712   setOperationAction(ISD::FMA, MVT::f32, Expand);
    713 
    714   // Various VFP goodness
    715   if (!UseSoftFloat && !Subtarget->isThumb1Only()) {
    716     // int <-> fp are custom expanded into bit_convert + ARMISD ops.
    717     if (Subtarget->hasVFP2()) {
    718       setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
    719       setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
    720       setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
    721       setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
    722     }
    723     // Special handling for half-precision FP.
    724     if (!Subtarget->hasFP16()) {
    725       setOperationAction(ISD::FP16_TO_FP32, MVT::f32, Expand);
    726       setOperationAction(ISD::FP32_TO_FP16, MVT::i32, Expand);
    727     }
    728   }
    729 
    730   // We have target-specific dag combine patterns for the following nodes:
    731   // ARMISD::VMOVRRD  - No need to call setTargetDAGCombine
    732   setTargetDAGCombine(ISD::ADD);
    733   setTargetDAGCombine(ISD::SUB);
    734   setTargetDAGCombine(ISD::MUL);
    735 
    736   if (Subtarget->hasV6T2Ops() || Subtarget->hasNEON())
    737     setTargetDAGCombine(ISD::OR);
    738   if (Subtarget->hasNEON())
    739     setTargetDAGCombine(ISD::AND);
    740 
    741   setStackPointerRegisterToSaveRestore(ARM::SP);
    742 
    743   if (UseSoftFloat || Subtarget->isThumb1Only() || !Subtarget->hasVFP2())
    744     setSchedulingPreference(Sched::RegPressure);
    745   else
    746     setSchedulingPreference(Sched::Hybrid);
    747 
    748   //// temporary - rewrite interface to use type
    749   maxStoresPerMemcpy = maxStoresPerMemcpyOptSize = 1;
    750 
    751   // On ARM arguments smaller than 4 bytes are extended, so all arguments
    752   // are at least 4 bytes aligned.
    753   setMinStackArgumentAlignment(4);
    754 
    755   benefitFromCodePlacementOpt = true;
    756 
    757   setMinFunctionAlignment(Subtarget->isThumb() ? 1 : 2);
    758 }
    759 
    760 // FIXME: It might make sense to define the representative register class as the
    761 // nearest super-register that has a non-null superset. For example, DPR_VFP2 is
    762 // a super-register of SPR, and DPR is a superset if DPR_VFP2. Consequently,
    763 // SPR's representative would be DPR_VFP2. This should work well if register
    764 // pressure tracking were modified such that a register use would increment the
    765 // pressure of the register class's representative and all of it's super
    766 // classes' representatives transitively. We have not implemented this because
    767 // of the difficulty prior to coalescing of modeling operand register classes
    768 // due to the common occurrence of cross class copies and subregister insertions
    769 // and extractions.
    770 std::pair<const TargetRegisterClass*, uint8_t>
    771 ARMTargetLowering::findRepresentativeClass(EVT VT) const{
    772   const TargetRegisterClass *RRC = 0;
    773   uint8_t Cost = 1;
    774   switch (VT.getSimpleVT().SimpleTy) {
    775   default:
    776     return TargetLowering::findRepresentativeClass(VT);
    777   // Use DPR as representative register class for all floating point
    778   // and vector types. Since there are 32 SPR registers and 32 DPR registers so
    779   // the cost is 1 for both f32 and f64.
    780   case MVT::f32: case MVT::f64: case MVT::v8i8: case MVT::v4i16:
    781   case MVT::v2i32: case MVT::v1i64: case MVT::v2f32:
    782     RRC = ARM::DPRRegisterClass;
    783     // When NEON is used for SP, only half of the register file is available
    784     // because operations that define both SP and DP results will be constrained
    785     // to the VFP2 class (D0-D15). We currently model this constraint prior to
    786     // coalescing by double-counting the SP regs. See the FIXME above.
    787     if (Subtarget->useNEONForSinglePrecisionFP())
    788       Cost = 2;
    789     break;
    790   case MVT::v16i8: case MVT::v8i16: case MVT::v4i32: case MVT::v2i64:
    791   case MVT::v4f32: case MVT::v2f64:
    792     RRC = ARM::DPRRegisterClass;
    793     Cost = 2;
    794     break;
    795   case MVT::v4i64:
    796     RRC = ARM::DPRRegisterClass;
    797     Cost = 4;
    798     break;
    799   case MVT::v8i64:
    800     RRC = ARM::DPRRegisterClass;
    801     Cost = 8;
    802     break;
    803   }
    804   return std::make_pair(RRC, Cost);
    805 }
    806 
    807 const char *ARMTargetLowering::getTargetNodeName(unsigned Opcode) const {
    808   switch (Opcode) {
    809   default: return 0;
    810   case ARMISD::Wrapper:       return "ARMISD::Wrapper";
    811   case ARMISD::WrapperDYN:    return "ARMISD::WrapperDYN";
    812   case ARMISD::WrapperPIC:    return "ARMISD::WrapperPIC";
    813   case ARMISD::WrapperJT:     return "ARMISD::WrapperJT";
    814   case ARMISD::CALL:          return "ARMISD::CALL";
    815   case ARMISD::CALL_PRED:     return "ARMISD::CALL_PRED";
    816   case ARMISD::CALL_NOLINK:   return "ARMISD::CALL_NOLINK";
    817   case ARMISD::tCALL:         return "ARMISD::tCALL";
    818   case ARMISD::BRCOND:        return "ARMISD::BRCOND";
    819   case ARMISD::BR_JT:         return "ARMISD::BR_JT";
    820   case ARMISD::BR2_JT:        return "ARMISD::BR2_JT";
    821   case ARMISD::RET_FLAG:      return "ARMISD::RET_FLAG";
    822   case ARMISD::PIC_ADD:       return "ARMISD::PIC_ADD";
    823   case ARMISD::CMP:           return "ARMISD::CMP";
    824   case ARMISD::CMPZ:          return "ARMISD::CMPZ";
    825   case ARMISD::CMPFP:         return "ARMISD::CMPFP";
    826   case ARMISD::CMPFPw0:       return "ARMISD::CMPFPw0";
    827   case ARMISD::BCC_i64:       return "ARMISD::BCC_i64";
    828   case ARMISD::FMSTAT:        return "ARMISD::FMSTAT";
    829   case ARMISD::CMOV:          return "ARMISD::CMOV";
    830 
    831   case ARMISD::RBIT:          return "ARMISD::RBIT";
    832 
    833   case ARMISD::FTOSI:         return "ARMISD::FTOSI";
    834   case ARMISD::FTOUI:         return "ARMISD::FTOUI";
    835   case ARMISD::SITOF:         return "ARMISD::SITOF";
    836   case ARMISD::UITOF:         return "ARMISD::UITOF";
    837 
    838   case ARMISD::SRL_FLAG:      return "ARMISD::SRL_FLAG";
    839   case ARMISD::SRA_FLAG:      return "ARMISD::SRA_FLAG";
    840   case ARMISD::RRX:           return "ARMISD::RRX";
    841 
    842   case ARMISD::VMOVRRD:       return "ARMISD::VMOVRRD";
    843   case ARMISD::VMOVDRR:       return "ARMISD::VMOVDRR";
    844 
    845   case ARMISD::EH_SJLJ_SETJMP: return "ARMISD::EH_SJLJ_SETJMP";
    846   case ARMISD::EH_SJLJ_LONGJMP:return "ARMISD::EH_SJLJ_LONGJMP";
    847   case ARMISD::EH_SJLJ_DISPATCHSETUP:return "ARMISD::EH_SJLJ_DISPATCHSETUP";
    848 
    849   case ARMISD::TC_RETURN:     return "ARMISD::TC_RETURN";
    850 
    851   case ARMISD::THREAD_POINTER:return "ARMISD::THREAD_POINTER";
    852 
    853   case ARMISD::DYN_ALLOC:     return "ARMISD::DYN_ALLOC";
    854 
    855   case ARMISD::MEMBARRIER:    return "ARMISD::MEMBARRIER";
    856   case ARMISD::MEMBARRIER_MCR: return "ARMISD::MEMBARRIER_MCR";
    857 
    858   case ARMISD::PRELOAD:       return "ARMISD::PRELOAD";
    859 
    860   case ARMISD::VCEQ:          return "ARMISD::VCEQ";
    861   case ARMISD::VCEQZ:         return "ARMISD::VCEQZ";
    862   case ARMISD::VCGE:          return "ARMISD::VCGE";
    863   case ARMISD::VCGEZ:         return "ARMISD::VCGEZ";
    864   case ARMISD::VCLEZ:         return "ARMISD::VCLEZ";
    865   case ARMISD::VCGEU:         return "ARMISD::VCGEU";
    866   case ARMISD::VCGT:          return "ARMISD::VCGT";
    867   case ARMISD::VCGTZ:         return "ARMISD::VCGTZ";
    868   case ARMISD::VCLTZ:         return "ARMISD::VCLTZ";
    869   case ARMISD::VCGTU:         return "ARMISD::VCGTU";
    870   case ARMISD::VTST:          return "ARMISD::VTST";
    871 
    872   case ARMISD::VSHL:          return "ARMISD::VSHL";
    873   case ARMISD::VSHRs:         return "ARMISD::VSHRs";
    874   case ARMISD::VSHRu:         return "ARMISD::VSHRu";
    875   case ARMISD::VSHLLs:        return "ARMISD::VSHLLs";
    876   case ARMISD::VSHLLu:        return "ARMISD::VSHLLu";
    877   case ARMISD::VSHLLi:        return "ARMISD::VSHLLi";
    878   case ARMISD::VSHRN:         return "ARMISD::VSHRN";
    879   case ARMISD::VRSHRs:        return "ARMISD::VRSHRs";
    880   case ARMISD::VRSHRu:        return "ARMISD::VRSHRu";
    881   case ARMISD::VRSHRN:        return "ARMISD::VRSHRN";
    882   case ARMISD::VQSHLs:        return "ARMISD::VQSHLs";
    883   case ARMISD::VQSHLu:        return "ARMISD::VQSHLu";
    884   case ARMISD::VQSHLsu:       return "ARMISD::VQSHLsu";
    885   case ARMISD::VQSHRNs:       return "ARMISD::VQSHRNs";
    886   case ARMISD::VQSHRNu:       return "ARMISD::VQSHRNu";
    887   case ARMISD::VQSHRNsu:      return "ARMISD::VQSHRNsu";
    888   case ARMISD::VQRSHRNs:      return "ARMISD::VQRSHRNs";
    889   case ARMISD::VQRSHRNu:      return "ARMISD::VQRSHRNu";
    890   case ARMISD::VQRSHRNsu:     return "ARMISD::VQRSHRNsu";
    891   case ARMISD::VGETLANEu:     return "ARMISD::VGETLANEu";
    892   case ARMISD::VGETLANEs:     return "ARMISD::VGETLANEs";
    893   case ARMISD::VMOVIMM:       return "ARMISD::VMOVIMM";
    894   case ARMISD::VMVNIMM:       return "ARMISD::VMVNIMM";
    895   case ARMISD::VDUP:          return "ARMISD::VDUP";
    896   case ARMISD::VDUPLANE:      return "ARMISD::VDUPLANE";
    897   case ARMISD::VEXT:          return "ARMISD::VEXT";
    898   case ARMISD::VREV64:        return "ARMISD::VREV64";
    899   case ARMISD::VREV32:        return "ARMISD::VREV32";
    900   case ARMISD::VREV16:        return "ARMISD::VREV16";
    901   case ARMISD::VZIP:          return "ARMISD::VZIP";
    902   case ARMISD::VUZP:          return "ARMISD::VUZP";
    903   case ARMISD::VTRN:          return "ARMISD::VTRN";
    904   case ARMISD::VTBL1:         return "ARMISD::VTBL1";
    905   case ARMISD::VTBL2:         return "ARMISD::VTBL2";
    906   case ARMISD::VMULLs:        return "ARMISD::VMULLs";
    907   case ARMISD::VMULLu:        return "ARMISD::VMULLu";
    908   case ARMISD::BUILD_VECTOR:  return "ARMISD::BUILD_VECTOR";
    909   case ARMISD::FMAX:          return "ARMISD::FMAX";
    910   case ARMISD::FMIN:          return "ARMISD::FMIN";
    911   case ARMISD::BFI:           return "ARMISD::BFI";
    912   case ARMISD::VORRIMM:       return "ARMISD::VORRIMM";
    913   case ARMISD::VBICIMM:       return "ARMISD::VBICIMM";
    914   case ARMISD::VBSL:          return "ARMISD::VBSL";
    915   case ARMISD::VLD2DUP:       return "ARMISD::VLD2DUP";
    916   case ARMISD::VLD3DUP:       return "ARMISD::VLD3DUP";
    917   case ARMISD::VLD4DUP:       return "ARMISD::VLD4DUP";
    918   case ARMISD::VLD1_UPD:      return "ARMISD::VLD1_UPD";
    919   case ARMISD::VLD2_UPD:      return "ARMISD::VLD2_UPD";
    920   case ARMISD::VLD3_UPD:      return "ARMISD::VLD3_UPD";
    921   case ARMISD::VLD4_UPD:      return "ARMISD::VLD4_UPD";
    922   case ARMISD::VLD2LN_UPD:    return "ARMISD::VLD2LN_UPD";
    923   case ARMISD::VLD3LN_UPD:    return "ARMISD::VLD3LN_UPD";
    924   case ARMISD::VLD4LN_UPD:    return "ARMISD::VLD4LN_UPD";
    925   case ARMISD::VLD2DUP_UPD:   return "ARMISD::VLD2DUP_UPD";
    926   case ARMISD::VLD3DUP_UPD:   return "ARMISD::VLD3DUP_UPD";
    927   case ARMISD::VLD4DUP_UPD:   return "ARMISD::VLD4DUP_UPD";
    928   case ARMISD::VST1_UPD:      return "ARMISD::VST1_UPD";
    929   case ARMISD::VST2_UPD:      return "ARMISD::VST2_UPD";
    930   case ARMISD::VST3_UPD:      return "ARMISD::VST3_UPD";
    931   case ARMISD::VST4_UPD:      return "ARMISD::VST4_UPD";
    932   case ARMISD::VST2LN_UPD:    return "ARMISD::VST2LN_UPD";
    933   case ARMISD::VST3LN_UPD:    return "ARMISD::VST3LN_UPD";
    934   case ARMISD::VST4LN_UPD:    return "ARMISD::VST4LN_UPD";
    935   }
    936 }
    937 
    938 /// getRegClassFor - Return the register class that should be used for the
    939 /// specified value type.
    940 TargetRegisterClass *ARMTargetLowering::getRegClassFor(EVT VT) const {
    941   // Map v4i64 to QQ registers but do not make the type legal. Similarly map
    942   // v8i64 to QQQQ registers. v4i64 and v8i64 are only used for REG_SEQUENCE to
    943   // load / store 4 to 8 consecutive D registers.
    944   if (Subtarget->hasNEON()) {
    945     if (VT == MVT::v4i64)
    946       return ARM::QQPRRegisterClass;
    947     else if (VT == MVT::v8i64)
    948       return ARM::QQQQPRRegisterClass;
    949   }
    950   return TargetLowering::getRegClassFor(VT);
    951 }
    952 
    953 // Create a fast isel object.
    954 FastISel *
    955 ARMTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo) const {
    956   return ARM::createFastISel(funcInfo);
    957 }
    958 
    959 /// getMaximalGlobalOffset - Returns the maximal possible offset which can
    960 /// be used for loads / stores from the global.
    961 unsigned ARMTargetLowering::getMaximalGlobalOffset() const {
    962   return (Subtarget->isThumb1Only() ? 127 : 4095);
    963 }
    964 
    965 Sched::Preference ARMTargetLowering::getSchedulingPreference(SDNode *N) const {
    966   unsigned NumVals = N->getNumValues();
    967   if (!NumVals)
    968     return Sched::RegPressure;
    969 
    970   for (unsigned i = 0; i != NumVals; ++i) {
    971     EVT VT = N->getValueType(i);
    972     if (VT == MVT::Glue || VT == MVT::Other)
    973       continue;
    974     if (VT.isFloatingPoint() || VT.isVector())
    975       return Sched::Latency;
    976   }
    977 
    978   if (!N->isMachineOpcode())
    979     return Sched::RegPressure;
    980 
    981   // Load are scheduled for latency even if there instruction itinerary
    982   // is not available.
    983   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
    984   const MCInstrDesc &MCID = TII->get(N->getMachineOpcode());
    985 
    986   if (MCID.getNumDefs() == 0)
    987     return Sched::RegPressure;
    988   if (!Itins->isEmpty() &&
    989       Itins->getOperandCycle(MCID.getSchedClass(), 0) > 2)
    990     return Sched::Latency;
    991 
    992   return Sched::RegPressure;
    993 }
    994 
    995 //===----------------------------------------------------------------------===//
    996 // Lowering Code
    997 //===----------------------------------------------------------------------===//
    998 
    999 /// IntCCToARMCC - Convert a DAG integer condition code to an ARM CC
   1000 static ARMCC::CondCodes IntCCToARMCC(ISD::CondCode CC) {
   1001   switch (CC) {
   1002   default: llvm_unreachable("Unknown condition code!");
   1003   case ISD::SETNE:  return ARMCC::NE;
   1004   case ISD::SETEQ:  return ARMCC::EQ;
   1005   case ISD::SETGT:  return ARMCC::GT;
   1006   case ISD::SETGE:  return ARMCC::GE;
   1007   case ISD::SETLT:  return ARMCC::LT;
   1008   case ISD::SETLE:  return ARMCC::LE;
   1009   case ISD::SETUGT: return ARMCC::HI;
   1010   case ISD::SETUGE: return ARMCC::HS;
   1011   case ISD::SETULT: return ARMCC::LO;
   1012   case ISD::SETULE: return ARMCC::LS;
   1013   }
   1014 }
   1015 
   1016 /// FPCCToARMCC - Convert a DAG fp condition code to an ARM CC.
   1017 static void FPCCToARMCC(ISD::CondCode CC, ARMCC::CondCodes &CondCode,
   1018                         ARMCC::CondCodes &CondCode2) {
   1019   CondCode2 = ARMCC::AL;
   1020   switch (CC) {
   1021   default: llvm_unreachable("Unknown FP condition!");
   1022   case ISD::SETEQ:
   1023   case ISD::SETOEQ: CondCode = ARMCC::EQ; break;
   1024   case ISD::SETGT:
   1025   case ISD::SETOGT: CondCode = ARMCC::GT; break;
   1026   case ISD::SETGE:
   1027   case ISD::SETOGE: CondCode = ARMCC::GE; break;
   1028   case ISD::SETOLT: CondCode = ARMCC::MI; break;
   1029   case ISD::SETOLE: CondCode = ARMCC::LS; break;
   1030   case ISD::SETONE: CondCode = ARMCC::MI; CondCode2 = ARMCC::GT; break;
   1031   case ISD::SETO:   CondCode = ARMCC::VC; break;
   1032   case ISD::SETUO:  CondCode = ARMCC::VS; break;
   1033   case ISD::SETUEQ: CondCode = ARMCC::EQ; CondCode2 = ARMCC::VS; break;
   1034   case ISD::SETUGT: CondCode = ARMCC::HI; break;
   1035   case ISD::SETUGE: CondCode = ARMCC::PL; break;
   1036   case ISD::SETLT:
   1037   case ISD::SETULT: CondCode = ARMCC::LT; break;
   1038   case ISD::SETLE:
   1039   case ISD::SETULE: CondCode = ARMCC::LE; break;
   1040   case ISD::SETNE:
   1041   case ISD::SETUNE: CondCode = ARMCC::NE; break;
   1042   }
   1043 }
   1044 
   1045 //===----------------------------------------------------------------------===//
   1046 //                      Calling Convention Implementation
   1047 //===----------------------------------------------------------------------===//
   1048 
   1049 #include "ARMGenCallingConv.inc"
   1050 
   1051 /// CCAssignFnForNode - Selects the correct CCAssignFn for a the
   1052 /// given CallingConvention value.
   1053 CCAssignFn *ARMTargetLowering::CCAssignFnForNode(CallingConv::ID CC,
   1054                                                  bool Return,
   1055                                                  bool isVarArg) const {
   1056   switch (CC) {
   1057   default:
   1058     llvm_unreachable("Unsupported calling convention");
   1059   case CallingConv::Fast:
   1060     if (Subtarget->hasVFP2() && !isVarArg) {
   1061       if (!Subtarget->isAAPCS_ABI())
   1062         return (Return ? RetFastCC_ARM_APCS : FastCC_ARM_APCS);
   1063       // For AAPCS ABI targets, just use VFP variant of the calling convention.
   1064       return (Return ? RetCC_ARM_AAPCS_VFP : CC_ARM_AAPCS_VFP);
   1065     }
   1066     // Fallthrough
   1067   case CallingConv::C: {
   1068     // Use target triple & subtarget features to do actual dispatch.
   1069     if (!Subtarget->isAAPCS_ABI())
   1070       return (Return ? RetCC_ARM_APCS : CC_ARM_APCS);
   1071     else if (Subtarget->hasVFP2() &&
   1072              FloatABIType == FloatABI::Hard && !isVarArg)
   1073       return (Return ? RetCC_ARM_AAPCS_VFP : CC_ARM_AAPCS_VFP);
   1074     return (Return ? RetCC_ARM_AAPCS : CC_ARM_AAPCS);
   1075   }
   1076   case CallingConv::ARM_AAPCS_VFP:
   1077     return (Return ? RetCC_ARM_AAPCS_VFP : CC_ARM_AAPCS_VFP);
   1078   case CallingConv::ARM_AAPCS:
   1079     return (Return ? RetCC_ARM_AAPCS : CC_ARM_AAPCS);
   1080   case CallingConv::ARM_APCS:
   1081     return (Return ? RetCC_ARM_APCS : CC_ARM_APCS);
   1082   }
   1083 }
   1084 
   1085 /// LowerCallResult - Lower the result values of a call into the
   1086 /// appropriate copies out of appropriate physical registers.
   1087 SDValue
   1088 ARMTargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag,
   1089                                    CallingConv::ID CallConv, bool isVarArg,
   1090                                    const SmallVectorImpl<ISD::InputArg> &Ins,
   1091                                    DebugLoc dl, SelectionDAG &DAG,
   1092                                    SmallVectorImpl<SDValue> &InVals) const {
   1093 
   1094   // Assign locations to each value returned by this call.
   1095   SmallVector<CCValAssign, 16> RVLocs;
   1096   ARMCCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
   1097                     getTargetMachine(), RVLocs, *DAG.getContext(), Call);
   1098   CCInfo.AnalyzeCallResult(Ins,
   1099                            CCAssignFnForNode(CallConv, /* Return*/ true,
   1100                                              isVarArg));
   1101 
   1102   // Copy all of the result registers out of their specified physreg.
   1103   for (unsigned i = 0; i != RVLocs.size(); ++i) {
   1104     CCValAssign VA = RVLocs[i];
   1105 
   1106     SDValue Val;
   1107     if (VA.needsCustom()) {
   1108       // Handle f64 or half of a v2f64.
   1109       SDValue Lo = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32,
   1110                                       InFlag);
   1111       Chain = Lo.getValue(1);
   1112       InFlag = Lo.getValue(2);
   1113       VA = RVLocs[++i]; // skip ahead to next loc
   1114       SDValue Hi = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32,
   1115                                       InFlag);
   1116       Chain = Hi.getValue(1);
   1117       InFlag = Hi.getValue(2);
   1118       Val = DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi);
   1119 
   1120       if (VA.getLocVT() == MVT::v2f64) {
   1121         SDValue Vec = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
   1122         Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Vec, Val,
   1123                           DAG.getConstant(0, MVT::i32));
   1124 
   1125         VA = RVLocs[++i]; // skip ahead to next loc
   1126         Lo = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32, InFlag);
   1127         Chain = Lo.getValue(1);
   1128         InFlag = Lo.getValue(2);
   1129         VA = RVLocs[++i]; // skip ahead to next loc
   1130         Hi = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), MVT::i32, InFlag);
   1131         Chain = Hi.getValue(1);
   1132         InFlag = Hi.getValue(2);
   1133         Val = DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi);
   1134         Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Vec, Val,
   1135                           DAG.getConstant(1, MVT::i32));
   1136       }
   1137     } else {
   1138       Val = DAG.getCopyFromReg(Chain, dl, VA.getLocReg(), VA.getLocVT(),
   1139                                InFlag);
   1140       Chain = Val.getValue(1);
   1141       InFlag = Val.getValue(2);
   1142     }
   1143 
   1144     switch (VA.getLocInfo()) {
   1145     default: llvm_unreachable("Unknown loc info!");
   1146     case CCValAssign::Full: break;
   1147     case CCValAssign::BCvt:
   1148       Val = DAG.getNode(ISD::BITCAST, dl, VA.getValVT(), Val);
   1149       break;
   1150     }
   1151 
   1152     InVals.push_back(Val);
   1153   }
   1154 
   1155   return Chain;
   1156 }
   1157 
   1158 /// LowerMemOpCallTo - Store the argument to the stack.
   1159 SDValue
   1160 ARMTargetLowering::LowerMemOpCallTo(SDValue Chain,
   1161                                     SDValue StackPtr, SDValue Arg,
   1162                                     DebugLoc dl, SelectionDAG &DAG,
   1163                                     const CCValAssign &VA,
   1164                                     ISD::ArgFlagsTy Flags) const {
   1165   unsigned LocMemOffset = VA.getLocMemOffset();
   1166   SDValue PtrOff = DAG.getIntPtrConstant(LocMemOffset);
   1167   PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(), StackPtr, PtrOff);
   1168   return DAG.getStore(Chain, dl, Arg, PtrOff,
   1169                       MachinePointerInfo::getStack(LocMemOffset),
   1170                       false, false, 0);
   1171 }
   1172 
   1173 void ARMTargetLowering::PassF64ArgInRegs(DebugLoc dl, SelectionDAG &DAG,
   1174                                          SDValue Chain, SDValue &Arg,
   1175                                          RegsToPassVector &RegsToPass,
   1176                                          CCValAssign &VA, CCValAssign &NextVA,
   1177                                          SDValue &StackPtr,
   1178                                          SmallVector<SDValue, 8> &MemOpChains,
   1179                                          ISD::ArgFlagsTy Flags) const {
   1180 
   1181   SDValue fmrrd = DAG.getNode(ARMISD::VMOVRRD, dl,
   1182                               DAG.getVTList(MVT::i32, MVT::i32), Arg);
   1183   RegsToPass.push_back(std::make_pair(VA.getLocReg(), fmrrd));
   1184 
   1185   if (NextVA.isRegLoc())
   1186     RegsToPass.push_back(std::make_pair(NextVA.getLocReg(), fmrrd.getValue(1)));
   1187   else {
   1188     assert(NextVA.isMemLoc());
   1189     if (StackPtr.getNode() == 0)
   1190       StackPtr = DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy());
   1191 
   1192     MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, fmrrd.getValue(1),
   1193                                            dl, DAG, NextVA,
   1194                                            Flags));
   1195   }
   1196 }
   1197 
   1198 /// LowerCall - Lowering a call into a callseq_start <-
   1199 /// ARMISD:CALL <- callseq_end chain. Also add input and output parameter
   1200 /// nodes.
   1201 SDValue
   1202 ARMTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
   1203                              CallingConv::ID CallConv, bool isVarArg,
   1204                              bool &isTailCall,
   1205                              const SmallVectorImpl<ISD::OutputArg> &Outs,
   1206                              const SmallVectorImpl<SDValue> &OutVals,
   1207                              const SmallVectorImpl<ISD::InputArg> &Ins,
   1208                              DebugLoc dl, SelectionDAG &DAG,
   1209                              SmallVectorImpl<SDValue> &InVals) const {
   1210   MachineFunction &MF = DAG.getMachineFunction();
   1211   bool IsStructRet    = (Outs.empty()) ? false : Outs[0].Flags.isSRet();
   1212   bool IsSibCall = false;
   1213   // Temporarily disable tail calls so things don't break.
   1214   if (!EnableARMTailCalls)
   1215     isTailCall = false;
   1216   if (isTailCall) {
   1217     // Check if it's really possible to do a tail call.
   1218     isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv,
   1219                     isVarArg, IsStructRet, MF.getFunction()->hasStructRetAttr(),
   1220                                                    Outs, OutVals, Ins, DAG);
   1221     // We don't support GuaranteedTailCallOpt for ARM, only automatically
   1222     // detected sibcalls.
   1223     if (isTailCall) {
   1224       ++NumTailCalls;
   1225       IsSibCall = true;
   1226     }
   1227   }
   1228 
   1229   // Analyze operands of the call, assigning locations to each operand.
   1230   SmallVector<CCValAssign, 16> ArgLocs;
   1231   ARMCCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
   1232                  getTargetMachine(), ArgLocs, *DAG.getContext(), Call);
   1233   CCInfo.AnalyzeCallOperands(Outs,
   1234                              CCAssignFnForNode(CallConv, /* Return*/ false,
   1235                                                isVarArg));
   1236 
   1237   // Get a count of how many bytes are to be pushed on the stack.
   1238   unsigned NumBytes = CCInfo.getNextStackOffset();
   1239 
   1240   // For tail calls, memory operands are available in our caller's stack.
   1241   if (IsSibCall)
   1242     NumBytes = 0;
   1243 
   1244   // Adjust the stack pointer for the new arguments...
   1245   // These operations are automatically eliminated by the prolog/epilog pass
   1246   if (!IsSibCall)
   1247     Chain = DAG.getCALLSEQ_START(Chain, DAG.getIntPtrConstant(NumBytes, true));
   1248 
   1249   SDValue StackPtr = DAG.getCopyFromReg(Chain, dl, ARM::SP, getPointerTy());
   1250 
   1251   RegsToPassVector RegsToPass;
   1252   SmallVector<SDValue, 8> MemOpChains;
   1253 
   1254   // Walk the register/memloc assignments, inserting copies/loads.  In the case
   1255   // of tail call optimization, arguments are handled later.
   1256   for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size();
   1257        i != e;
   1258        ++i, ++realArgIdx) {
   1259     CCValAssign &VA = ArgLocs[i];
   1260     SDValue Arg = OutVals[realArgIdx];
   1261     ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
   1262     bool isByVal = Flags.isByVal();
   1263 
   1264     // Promote the value if needed.
   1265     switch (VA.getLocInfo()) {
   1266     default: llvm_unreachable("Unknown loc info!");
   1267     case CCValAssign::Full: break;
   1268     case CCValAssign::SExt:
   1269       Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
   1270       break;
   1271     case CCValAssign::ZExt:
   1272       Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
   1273       break;
   1274     case CCValAssign::AExt:
   1275       Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), Arg);
   1276       break;
   1277     case CCValAssign::BCvt:
   1278       Arg = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), Arg);
   1279       break;
   1280     }
   1281 
   1282     // f64 and v2f64 might be passed in i32 pairs and must be split into pieces
   1283     if (VA.needsCustom()) {
   1284       if (VA.getLocVT() == MVT::v2f64) {
   1285         SDValue Op0 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
   1286                                   DAG.getConstant(0, MVT::i32));
   1287         SDValue Op1 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
   1288                                   DAG.getConstant(1, MVT::i32));
   1289 
   1290         PassF64ArgInRegs(dl, DAG, Chain, Op0, RegsToPass,
   1291                          VA, ArgLocs[++i], StackPtr, MemOpChains, Flags);
   1292 
   1293         VA = ArgLocs[++i]; // skip ahead to next loc
   1294         if (VA.isRegLoc()) {
   1295           PassF64ArgInRegs(dl, DAG, Chain, Op1, RegsToPass,
   1296                            VA, ArgLocs[++i], StackPtr, MemOpChains, Flags);
   1297         } else {
   1298           assert(VA.isMemLoc());
   1299 
   1300           MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, Op1,
   1301                                                  dl, DAG, VA, Flags));
   1302         }
   1303       } else {
   1304         PassF64ArgInRegs(dl, DAG, Chain, Arg, RegsToPass, VA, ArgLocs[++i],
   1305                          StackPtr, MemOpChains, Flags);
   1306       }
   1307     } else if (VA.isRegLoc()) {
   1308       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
   1309     } else if (isByVal) {
   1310       assert(VA.isMemLoc());
   1311       unsigned offset = 0;
   1312 
   1313       // True if this byval aggregate will be split between registers
   1314       // and memory.
   1315       if (CCInfo.isFirstByValRegValid()) {
   1316         EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
   1317         unsigned int i, j;
   1318         for (i = 0, j = CCInfo.getFirstByValReg(); j < ARM::R4; i++, j++) {
   1319           SDValue Const = DAG.getConstant(4*i, MVT::i32);
   1320           SDValue AddArg = DAG.getNode(ISD::ADD, dl, PtrVT, Arg, Const);
   1321           SDValue Load = DAG.getLoad(PtrVT, dl, Chain, AddArg,
   1322                                      MachinePointerInfo(),
   1323                                      false, false, 0);
   1324           MemOpChains.push_back(Load.getValue(1));
   1325           RegsToPass.push_back(std::make_pair(j, Load));
   1326         }
   1327         offset = ARM::R4 - CCInfo.getFirstByValReg();
   1328         CCInfo.clearFirstByValReg();
   1329       }
   1330 
   1331       unsigned LocMemOffset = VA.getLocMemOffset();
   1332       SDValue StkPtrOff = DAG.getIntPtrConstant(LocMemOffset);
   1333       SDValue Dst = DAG.getNode(ISD::ADD, dl, getPointerTy(), StackPtr,
   1334                                 StkPtrOff);
   1335       SDValue SrcOffset = DAG.getIntPtrConstant(4*offset);
   1336       SDValue Src = DAG.getNode(ISD::ADD, dl, getPointerTy(), Arg, SrcOffset);
   1337       SDValue SizeNode = DAG.getConstant(Flags.getByValSize() - 4*offset,
   1338                                          MVT::i32);
   1339       MemOpChains.push_back(DAG.getMemcpy(Chain, dl, Dst, Src, SizeNode,
   1340                                           Flags.getByValAlign(),
   1341                                           /*isVolatile=*/false,
   1342                                           /*AlwaysInline=*/false,
   1343                                           MachinePointerInfo(0),
   1344                                           MachinePointerInfo(0)));
   1345 
   1346     } else if (!IsSibCall) {
   1347       assert(VA.isMemLoc());
   1348 
   1349       MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, Arg,
   1350                                              dl, DAG, VA, Flags));
   1351     }
   1352   }
   1353 
   1354   if (!MemOpChains.empty())
   1355     Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
   1356                         &MemOpChains[0], MemOpChains.size());
   1357 
   1358   // Build a sequence of copy-to-reg nodes chained together with token chain
   1359   // and flag operands which copy the outgoing args into the appropriate regs.
   1360   SDValue InFlag;
   1361   // Tail call byval lowering might overwrite argument registers so in case of
   1362   // tail call optimization the copies to registers are lowered later.
   1363   if (!isTailCall)
   1364     for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
   1365       Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
   1366                                RegsToPass[i].second, InFlag);
   1367       InFlag = Chain.getValue(1);
   1368     }
   1369 
   1370   // For tail calls lower the arguments to the 'real' stack slot.
   1371   if (isTailCall) {
   1372     // Force all the incoming stack arguments to be loaded from the stack
   1373     // before any new outgoing arguments are stored to the stack, because the
   1374     // outgoing stack slots may alias the incoming argument stack slots, and
   1375     // the alias isn't otherwise explicit. This is slightly more conservative
   1376     // than necessary, because it means that each store effectively depends
   1377     // on every argument instead of just those arguments it would clobber.
   1378 
   1379     // Do not flag preceding copytoreg stuff together with the following stuff.
   1380     InFlag = SDValue();
   1381     for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
   1382       Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
   1383                                RegsToPass[i].second, InFlag);
   1384       InFlag = Chain.getValue(1);
   1385     }
   1386     InFlag =SDValue();
   1387   }
   1388 
   1389   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
   1390   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
   1391   // node so that legalize doesn't hack it.
   1392   bool isDirect = false;
   1393   bool isARMFunc = false;
   1394   bool isLocalARMFunc = false;
   1395   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   1396 
   1397   if (EnableARMLongCalls) {
   1398     assert (getTargetMachine().getRelocationModel() == Reloc::Static
   1399             && "long-calls with non-static relocation model!");
   1400     // Handle a global address or an external symbol. If it's not one of
   1401     // those, the target's already in a register, so we don't need to do
   1402     // anything extra.
   1403     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
   1404       const GlobalValue *GV = G->getGlobal();
   1405       // Create a constant pool entry for the callee address
   1406       unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
   1407       ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV,
   1408                                                            ARMPCLabelIndex,
   1409                                                            ARMCP::CPValue, 0);
   1410       // Get the address of the callee into a register
   1411       SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
   1412       CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   1413       Callee = DAG.getLoad(getPointerTy(), dl,
   1414                            DAG.getEntryNode(), CPAddr,
   1415                            MachinePointerInfo::getConstantPool(),
   1416                            false, false, 0);
   1417     } else if (ExternalSymbolSDNode *S=dyn_cast<ExternalSymbolSDNode>(Callee)) {
   1418       const char *Sym = S->getSymbol();
   1419 
   1420       // Create a constant pool entry for the callee address
   1421       unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
   1422       ARMConstantPoolValue *CPV = new ARMConstantPoolValue(*DAG.getContext(),
   1423                                                        Sym, ARMPCLabelIndex, 0);
   1424       // Get the address of the callee into a register
   1425       SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
   1426       CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   1427       Callee = DAG.getLoad(getPointerTy(), dl,
   1428                            DAG.getEntryNode(), CPAddr,
   1429                            MachinePointerInfo::getConstantPool(),
   1430                            false, false, 0);
   1431     }
   1432   } else if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
   1433     const GlobalValue *GV = G->getGlobal();
   1434     isDirect = true;
   1435     bool isExt = GV->isDeclaration() || GV->isWeakForLinker();
   1436     bool isStub = (isExt && Subtarget->isTargetDarwin()) &&
   1437                    getTargetMachine().getRelocationModel() != Reloc::Static;
   1438     isARMFunc = !Subtarget->isThumb() || isStub;
   1439     // ARM call to a local ARM function is predicable.
   1440     isLocalARMFunc = !Subtarget->isThumb() && (!isExt || !ARMInterworking);
   1441     // tBX takes a register source operand.
   1442     if (isARMFunc && Subtarget->isThumb1Only() && !Subtarget->hasV5TOps()) {
   1443       unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
   1444       ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV,
   1445                                                            ARMPCLabelIndex,
   1446                                                            ARMCP::CPValue, 4);
   1447       SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
   1448       CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   1449       Callee = DAG.getLoad(getPointerTy(), dl,
   1450                            DAG.getEntryNode(), CPAddr,
   1451                            MachinePointerInfo::getConstantPool(),
   1452                            false, false, 0);
   1453       SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
   1454       Callee = DAG.getNode(ARMISD::PIC_ADD, dl,
   1455                            getPointerTy(), Callee, PICLabel);
   1456     } else {
   1457       // On ELF targets for PIC code, direct calls should go through the PLT
   1458       unsigned OpFlags = 0;
   1459       if (Subtarget->isTargetELF() &&
   1460                   getTargetMachine().getRelocationModel() == Reloc::PIC_)
   1461         OpFlags = ARMII::MO_PLT;
   1462       Callee = DAG.getTargetGlobalAddress(GV, dl, getPointerTy(), 0, OpFlags);
   1463     }
   1464   } else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
   1465     isDirect = true;
   1466     bool isStub = Subtarget->isTargetDarwin() &&
   1467                   getTargetMachine().getRelocationModel() != Reloc::Static;
   1468     isARMFunc = !Subtarget->isThumb() || isStub;
   1469     // tBX takes a register source operand.
   1470     const char *Sym = S->getSymbol();
   1471     if (isARMFunc && Subtarget->isThumb1Only() && !Subtarget->hasV5TOps()) {
   1472       unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
   1473       ARMConstantPoolValue *CPV = new ARMConstantPoolValue(*DAG.getContext(),
   1474                                                        Sym, ARMPCLabelIndex, 4);
   1475       SDValue CPAddr = DAG.getTargetConstantPool(CPV, getPointerTy(), 4);
   1476       CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   1477       Callee = DAG.getLoad(getPointerTy(), dl,
   1478                            DAG.getEntryNode(), CPAddr,
   1479                            MachinePointerInfo::getConstantPool(),
   1480                            false, false, 0);
   1481       SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
   1482       Callee = DAG.getNode(ARMISD::PIC_ADD, dl,
   1483                            getPointerTy(), Callee, PICLabel);
   1484     } else {
   1485       unsigned OpFlags = 0;
   1486       // On ELF targets for PIC code, direct calls should go through the PLT
   1487       if (Subtarget->isTargetELF() &&
   1488                   getTargetMachine().getRelocationModel() == Reloc::PIC_)
   1489         OpFlags = ARMII::MO_PLT;
   1490       Callee = DAG.getTargetExternalSymbol(Sym, getPointerTy(), OpFlags);
   1491     }
   1492   }
   1493 
   1494   // FIXME: handle tail calls differently.
   1495   unsigned CallOpc;
   1496   if (Subtarget->isThumb()) {
   1497     if ((!isDirect || isARMFunc) && !Subtarget->hasV5TOps())
   1498       CallOpc = ARMISD::CALL_NOLINK;
   1499     else
   1500       CallOpc = isARMFunc ? ARMISD::CALL : ARMISD::tCALL;
   1501   } else {
   1502     CallOpc = (isDirect || Subtarget->hasV5TOps())
   1503       ? (isLocalARMFunc ? ARMISD::CALL_PRED : ARMISD::CALL)
   1504       : ARMISD::CALL_NOLINK;
   1505   }
   1506 
   1507   std::vector<SDValue> Ops;
   1508   Ops.push_back(Chain);
   1509   Ops.push_back(Callee);
   1510 
   1511   // Add argument registers to the end of the list so that they are known live
   1512   // into the call.
   1513   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
   1514     Ops.push_back(DAG.getRegister(RegsToPass[i].first,
   1515                                   RegsToPass[i].second.getValueType()));
   1516 
   1517   if (InFlag.getNode())
   1518     Ops.push_back(InFlag);
   1519 
   1520   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
   1521   if (isTailCall)
   1522     return DAG.getNode(ARMISD::TC_RETURN, dl, NodeTys, &Ops[0], Ops.size());
   1523 
   1524   // Returns a chain and a flag for retval copy to use.
   1525   Chain = DAG.getNode(CallOpc, dl, NodeTys, &Ops[0], Ops.size());
   1526   InFlag = Chain.getValue(1);
   1527 
   1528   Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(NumBytes, true),
   1529                              DAG.getIntPtrConstant(0, true), InFlag);
   1530   if (!Ins.empty())
   1531     InFlag = Chain.getValue(1);
   1532 
   1533   // Handle result values, copying them out of physregs into vregs that we
   1534   // return.
   1535   return LowerCallResult(Chain, InFlag, CallConv, isVarArg, Ins,
   1536                          dl, DAG, InVals);
   1537 }
   1538 
   1539 /// HandleByVal - Every parameter *after* a byval parameter is passed
   1540 /// on the stack.  Remember the next parameter register to allocate,
   1541 /// and then confiscate the rest of the parameter registers to insure
   1542 /// this.
   1543 void
   1544 llvm::ARMTargetLowering::HandleByVal(CCState *State, unsigned &size) const {
   1545   unsigned reg = State->AllocateReg(GPRArgRegs, 4);
   1546   assert((State->getCallOrPrologue() == Prologue ||
   1547           State->getCallOrPrologue() == Call) &&
   1548          "unhandled ParmContext");
   1549   if ((!State->isFirstByValRegValid()) &&
   1550       (ARM::R0 <= reg) && (reg <= ARM::R3)) {
   1551     State->setFirstByValReg(reg);
   1552     // At a call site, a byval parameter that is split between
   1553     // registers and memory needs its size truncated here.  In a
   1554     // function prologue, such byval parameters are reassembled in
   1555     // memory, and are not truncated.
   1556     if (State->getCallOrPrologue() == Call) {
   1557       unsigned excess = 4 * (ARM::R4 - reg);
   1558       assert(size >= excess && "expected larger existing stack allocation");
   1559       size -= excess;
   1560     }
   1561   }
   1562   // Confiscate any remaining parameter registers to preclude their
   1563   // assignment to subsequent parameters.
   1564   while (State->AllocateReg(GPRArgRegs, 4))
   1565     ;
   1566 }
   1567 
   1568 /// MatchingStackOffset - Return true if the given stack call argument is
   1569 /// already available in the same position (relatively) of the caller's
   1570 /// incoming argument stack.
   1571 static
   1572 bool MatchingStackOffset(SDValue Arg, unsigned Offset, ISD::ArgFlagsTy Flags,
   1573                          MachineFrameInfo *MFI, const MachineRegisterInfo *MRI,
   1574                          const ARMInstrInfo *TII) {
   1575   unsigned Bytes = Arg.getValueType().getSizeInBits() / 8;
   1576   int FI = INT_MAX;
   1577   if (Arg.getOpcode() == ISD::CopyFromReg) {
   1578     unsigned VR = cast<RegisterSDNode>(Arg.getOperand(1))->getReg();
   1579     if (!TargetRegisterInfo::isVirtualRegister(VR))
   1580       return false;
   1581     MachineInstr *Def = MRI->getVRegDef(VR);
   1582     if (!Def)
   1583       return false;
   1584     if (!Flags.isByVal()) {
   1585       if (!TII->isLoadFromStackSlot(Def, FI))
   1586         return false;
   1587     } else {
   1588       return false;
   1589     }
   1590   } else if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Arg)) {
   1591     if (Flags.isByVal())
   1592       // ByVal argument is passed in as a pointer but it's now being
   1593       // dereferenced. e.g.
   1594       // define @foo(%struct.X* %A) {
   1595       //   tail call @bar(%struct.X* byval %A)
   1596       // }
   1597       return false;
   1598     SDValue Ptr = Ld->getBasePtr();
   1599     FrameIndexSDNode *FINode = dyn_cast<FrameIndexSDNode>(Ptr);
   1600     if (!FINode)
   1601       return false;
   1602     FI = FINode->getIndex();
   1603   } else
   1604     return false;
   1605 
   1606   assert(FI != INT_MAX);
   1607   if (!MFI->isFixedObjectIndex(FI))
   1608     return false;
   1609   return Offset == MFI->getObjectOffset(FI) && Bytes == MFI->getObjectSize(FI);
   1610 }
   1611 
   1612 /// IsEligibleForTailCallOptimization - Check whether the call is eligible
   1613 /// for tail call optimization. Targets which want to do tail call
   1614 /// optimization should implement this function.
   1615 bool
   1616 ARMTargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
   1617                                                      CallingConv::ID CalleeCC,
   1618                                                      bool isVarArg,
   1619                                                      bool isCalleeStructRet,
   1620                                                      bool isCallerStructRet,
   1621                                     const SmallVectorImpl<ISD::OutputArg> &Outs,
   1622                                     const SmallVectorImpl<SDValue> &OutVals,
   1623                                     const SmallVectorImpl<ISD::InputArg> &Ins,
   1624                                                      SelectionDAG& DAG) const {
   1625   const Function *CallerF = DAG.getMachineFunction().getFunction();
   1626   CallingConv::ID CallerCC = CallerF->getCallingConv();
   1627   bool CCMatch = CallerCC == CalleeCC;
   1628 
   1629   // Look for obvious safe cases to perform tail call optimization that do not
   1630   // require ABI changes. This is what gcc calls sibcall.
   1631 
   1632   // Do not sibcall optimize vararg calls unless the call site is not passing
   1633   // any arguments.
   1634   if (isVarArg && !Outs.empty())
   1635     return false;
   1636 
   1637   // Also avoid sibcall optimization if either caller or callee uses struct
   1638   // return semantics.
   1639   if (isCalleeStructRet || isCallerStructRet)
   1640     return false;
   1641 
   1642   // FIXME: Completely disable sibcall for Thumb1 since Thumb1RegisterInfo::
   1643   // emitEpilogue is not ready for them. Thumb tail calls also use t2B, as
   1644   // the Thumb1 16-bit unconditional branch doesn't have sufficient relocation
   1645   // support in the assembler and linker to be used. This would need to be
   1646   // fixed to fully support tail calls in Thumb1.
   1647   //
   1648   // Doing this is tricky, since the LDM/POP instruction on Thumb doesn't take
   1649   // LR.  This means if we need to reload LR, it takes an extra instructions,
   1650   // which outweighs the value of the tail call; but here we don't know yet
   1651   // whether LR is going to be used.  Probably the right approach is to
   1652   // generate the tail call here and turn it back into CALL/RET in
   1653   // emitEpilogue if LR is used.
   1654 
   1655   // Thumb1 PIC calls to external symbols use BX, so they can be tail calls,
   1656   // but we need to make sure there are enough registers; the only valid
   1657   // registers are the 4 used for parameters.  We don't currently do this
   1658   // case.
   1659   if (Subtarget->isThumb1Only())
   1660     return false;
   1661 
   1662   // If the calling conventions do not match, then we'd better make sure the
   1663   // results are returned in the same way as what the caller expects.
   1664   if (!CCMatch) {
   1665     SmallVector<CCValAssign, 16> RVLocs1;
   1666     ARMCCState CCInfo1(CalleeCC, false, DAG.getMachineFunction(),
   1667                        getTargetMachine(), RVLocs1, *DAG.getContext(), Call);
   1668     CCInfo1.AnalyzeCallResult(Ins, CCAssignFnForNode(CalleeCC, true, isVarArg));
   1669 
   1670     SmallVector<CCValAssign, 16> RVLocs2;
   1671     ARMCCState CCInfo2(CallerCC, false, DAG.getMachineFunction(),
   1672                        getTargetMachine(), RVLocs2, *DAG.getContext(), Call);
   1673     CCInfo2.AnalyzeCallResult(Ins, CCAssignFnForNode(CallerCC, true, isVarArg));
   1674 
   1675     if (RVLocs1.size() != RVLocs2.size())
   1676       return false;
   1677     for (unsigned i = 0, e = RVLocs1.size(); i != e; ++i) {
   1678       if (RVLocs1[i].isRegLoc() != RVLocs2[i].isRegLoc())
   1679         return false;
   1680       if (RVLocs1[i].getLocInfo() != RVLocs2[i].getLocInfo())
   1681         return false;
   1682       if (RVLocs1[i].isRegLoc()) {
   1683         if (RVLocs1[i].getLocReg() != RVLocs2[i].getLocReg())
   1684           return false;
   1685       } else {
   1686         if (RVLocs1[i].getLocMemOffset() != RVLocs2[i].getLocMemOffset())
   1687           return false;
   1688       }
   1689     }
   1690   }
   1691 
   1692   // If the callee takes no arguments then go on to check the results of the
   1693   // call.
   1694   if (!Outs.empty()) {
   1695     // Check if stack adjustment is needed. For now, do not do this if any
   1696     // argument is passed on the stack.
   1697     SmallVector<CCValAssign, 16> ArgLocs;
   1698     ARMCCState CCInfo(CalleeCC, isVarArg, DAG.getMachineFunction(),
   1699                       getTargetMachine(), ArgLocs, *DAG.getContext(), Call);
   1700     CCInfo.AnalyzeCallOperands(Outs,
   1701                                CCAssignFnForNode(CalleeCC, false, isVarArg));
   1702     if (CCInfo.getNextStackOffset()) {
   1703       MachineFunction &MF = DAG.getMachineFunction();
   1704 
   1705       // Check if the arguments are already laid out in the right way as
   1706       // the caller's fixed stack objects.
   1707       MachineFrameInfo *MFI = MF.getFrameInfo();
   1708       const MachineRegisterInfo *MRI = &MF.getRegInfo();
   1709       const ARMInstrInfo *TII =
   1710         ((ARMTargetMachine&)getTargetMachine()).getInstrInfo();
   1711       for (unsigned i = 0, realArgIdx = 0, e = ArgLocs.size();
   1712            i != e;
   1713            ++i, ++realArgIdx) {
   1714         CCValAssign &VA = ArgLocs[i];
   1715         EVT RegVT = VA.getLocVT();
   1716         SDValue Arg = OutVals[realArgIdx];
   1717         ISD::ArgFlagsTy Flags = Outs[realArgIdx].Flags;
   1718         if (VA.getLocInfo() == CCValAssign::Indirect)
   1719           return false;
   1720         if (VA.needsCustom()) {
   1721           // f64 and vector types are split into multiple registers or
   1722           // register/stack-slot combinations.  The types will not match
   1723           // the registers; give up on memory f64 refs until we figure
   1724           // out what to do about this.
   1725           if (!VA.isRegLoc())
   1726             return false;
   1727           if (!ArgLocs[++i].isRegLoc())
   1728             return false;
   1729           if (RegVT == MVT::v2f64) {
   1730             if (!ArgLocs[++i].isRegLoc())
   1731               return false;
   1732             if (!ArgLocs[++i].isRegLoc())
   1733               return false;
   1734           }
   1735         } else if (!VA.isRegLoc()) {
   1736           if (!MatchingStackOffset(Arg, VA.getLocMemOffset(), Flags,
   1737                                    MFI, MRI, TII))
   1738             return false;
   1739         }
   1740       }
   1741     }
   1742   }
   1743 
   1744   return true;
   1745 }
   1746 
   1747 SDValue
   1748 ARMTargetLowering::LowerReturn(SDValue Chain,
   1749                                CallingConv::ID CallConv, bool isVarArg,
   1750                                const SmallVectorImpl<ISD::OutputArg> &Outs,
   1751                                const SmallVectorImpl<SDValue> &OutVals,
   1752                                DebugLoc dl, SelectionDAG &DAG) const {
   1753 
   1754   // CCValAssign - represent the assignment of the return value to a location.
   1755   SmallVector<CCValAssign, 16> RVLocs;
   1756 
   1757   // CCState - Info about the registers and stack slots.
   1758   ARMCCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
   1759                     getTargetMachine(), RVLocs, *DAG.getContext(), Call);
   1760 
   1761   // Analyze outgoing return values.
   1762   CCInfo.AnalyzeReturn(Outs, CCAssignFnForNode(CallConv, /* Return */ true,
   1763                                                isVarArg));
   1764 
   1765   // If this is the first return lowered for this function, add
   1766   // the regs to the liveout set for the function.
   1767   if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
   1768     for (unsigned i = 0; i != RVLocs.size(); ++i)
   1769       if (RVLocs[i].isRegLoc())
   1770         DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
   1771   }
   1772 
   1773   SDValue Flag;
   1774 
   1775   // Copy the result values into the output registers.
   1776   for (unsigned i = 0, realRVLocIdx = 0;
   1777        i != RVLocs.size();
   1778        ++i, ++realRVLocIdx) {
   1779     CCValAssign &VA = RVLocs[i];
   1780     assert(VA.isRegLoc() && "Can only return in registers!");
   1781 
   1782     SDValue Arg = OutVals[realRVLocIdx];
   1783 
   1784     switch (VA.getLocInfo()) {
   1785     default: llvm_unreachable("Unknown loc info!");
   1786     case CCValAssign::Full: break;
   1787     case CCValAssign::BCvt:
   1788       Arg = DAG.getNode(ISD::BITCAST, dl, VA.getLocVT(), Arg);
   1789       break;
   1790     }
   1791 
   1792     if (VA.needsCustom()) {
   1793       if (VA.getLocVT() == MVT::v2f64) {
   1794         // Extract the first half and return it in two registers.
   1795         SDValue Half = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
   1796                                    DAG.getConstant(0, MVT::i32));
   1797         SDValue HalfGPRs = DAG.getNode(ARMISD::VMOVRRD, dl,
   1798                                        DAG.getVTList(MVT::i32, MVT::i32), Half);
   1799 
   1800         Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), HalfGPRs, Flag);
   1801         Flag = Chain.getValue(1);
   1802         VA = RVLocs[++i]; // skip ahead to next loc
   1803         Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
   1804                                  HalfGPRs.getValue(1), Flag);
   1805         Flag = Chain.getValue(1);
   1806         VA = RVLocs[++i]; // skip ahead to next loc
   1807 
   1808         // Extract the 2nd half and fall through to handle it as an f64 value.
   1809         Arg = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
   1810                           DAG.getConstant(1, MVT::i32));
   1811       }
   1812       // Legalize ret f64 -> ret 2 x i32.  We always have fmrrd if f64 is
   1813       // available.
   1814       SDValue fmrrd = DAG.getNode(ARMISD::VMOVRRD, dl,
   1815                                   DAG.getVTList(MVT::i32, MVT::i32), &Arg, 1);
   1816       Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), fmrrd, Flag);
   1817       Flag = Chain.getValue(1);
   1818       VA = RVLocs[++i]; // skip ahead to next loc
   1819       Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), fmrrd.getValue(1),
   1820                                Flag);
   1821     } else
   1822       Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), Arg, Flag);
   1823 
   1824     // Guarantee that all emitted copies are
   1825     // stuck together, avoiding something bad.
   1826     Flag = Chain.getValue(1);
   1827   }
   1828 
   1829   SDValue result;
   1830   if (Flag.getNode())
   1831     result = DAG.getNode(ARMISD::RET_FLAG, dl, MVT::Other, Chain, Flag);
   1832   else // Return Void
   1833     result = DAG.getNode(ARMISD::RET_FLAG, dl, MVT::Other, Chain);
   1834 
   1835   return result;
   1836 }
   1837 
   1838 bool ARMTargetLowering::isUsedByReturnOnly(SDNode *N) const {
   1839   if (N->getNumValues() != 1)
   1840     return false;
   1841   if (!N->hasNUsesOfValue(1, 0))
   1842     return false;
   1843 
   1844   unsigned NumCopies = 0;
   1845   SDNode* Copies[2];
   1846   SDNode *Use = *N->use_begin();
   1847   if (Use->getOpcode() == ISD::CopyToReg) {
   1848     Copies[NumCopies++] = Use;
   1849   } else if (Use->getOpcode() == ARMISD::VMOVRRD) {
   1850     // f64 returned in a pair of GPRs.
   1851     for (SDNode::use_iterator UI = Use->use_begin(), UE = Use->use_end();
   1852          UI != UE; ++UI) {
   1853       if (UI->getOpcode() != ISD::CopyToReg)
   1854         return false;
   1855       Copies[UI.getUse().getResNo()] = *UI;
   1856       ++NumCopies;
   1857     }
   1858   } else if (Use->getOpcode() == ISD::BITCAST) {
   1859     // f32 returned in a single GPR.
   1860     if (!Use->hasNUsesOfValue(1, 0))
   1861       return false;
   1862     Use = *Use->use_begin();
   1863     if (Use->getOpcode() != ISD::CopyToReg || !Use->hasNUsesOfValue(1, 0))
   1864       return false;
   1865     Copies[NumCopies++] = Use;
   1866   } else {
   1867     return false;
   1868   }
   1869 
   1870   if (NumCopies != 1 && NumCopies != 2)
   1871     return false;
   1872 
   1873   bool HasRet = false;
   1874   for (unsigned i = 0; i < NumCopies; ++i) {
   1875     SDNode *Copy = Copies[i];
   1876     for (SDNode::use_iterator UI = Copy->use_begin(), UE = Copy->use_end();
   1877          UI != UE; ++UI) {
   1878       if (UI->getOpcode() == ISD::CopyToReg) {
   1879         SDNode *Use = *UI;
   1880         if (Use == Copies[0] || Use == Copies[1])
   1881           continue;
   1882         return false;
   1883       }
   1884       if (UI->getOpcode() != ARMISD::RET_FLAG)
   1885         return false;
   1886       HasRet = true;
   1887     }
   1888   }
   1889 
   1890   return HasRet;
   1891 }
   1892 
   1893 bool ARMTargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
   1894   if (!EnableARMTailCalls)
   1895     return false;
   1896 
   1897   if (!CI->isTailCall())
   1898     return false;
   1899 
   1900   return !Subtarget->isThumb1Only();
   1901 }
   1902 
   1903 // ConstantPool, JumpTable, GlobalAddress, and ExternalSymbol are lowered as
   1904 // their target counterpart wrapped in the ARMISD::Wrapper node. Suppose N is
   1905 // one of the above mentioned nodes. It has to be wrapped because otherwise
   1906 // Select(N) returns N. So the raw TargetGlobalAddress nodes, etc. can only
   1907 // be used to form addressing mode. These wrapped nodes will be selected
   1908 // into MOVi.
   1909 static SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) {
   1910   EVT PtrVT = Op.getValueType();
   1911   // FIXME there is no actual debug info here
   1912   DebugLoc dl = Op.getDebugLoc();
   1913   ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
   1914   SDValue Res;
   1915   if (CP->isMachineConstantPoolEntry())
   1916     Res = DAG.getTargetConstantPool(CP->getMachineCPVal(), PtrVT,
   1917                                     CP->getAlignment());
   1918   else
   1919     Res = DAG.getTargetConstantPool(CP->getConstVal(), PtrVT,
   1920                                     CP->getAlignment());
   1921   return DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Res);
   1922 }
   1923 
   1924 unsigned ARMTargetLowering::getJumpTableEncoding() const {
   1925   return MachineJumpTableInfo::EK_Inline;
   1926 }
   1927 
   1928 SDValue ARMTargetLowering::LowerBlockAddress(SDValue Op,
   1929                                              SelectionDAG &DAG) const {
   1930   MachineFunction &MF = DAG.getMachineFunction();
   1931   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   1932   unsigned ARMPCLabelIndex = 0;
   1933   DebugLoc DL = Op.getDebugLoc();
   1934   EVT PtrVT = getPointerTy();
   1935   const BlockAddress *BA = cast<BlockAddressSDNode>(Op)->getBlockAddress();
   1936   Reloc::Model RelocM = getTargetMachine().getRelocationModel();
   1937   SDValue CPAddr;
   1938   if (RelocM == Reloc::Static) {
   1939     CPAddr = DAG.getTargetConstantPool(BA, PtrVT, 4);
   1940   } else {
   1941     unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
   1942     ARMPCLabelIndex = AFI->createPICLabelUId();
   1943     ARMConstantPoolValue *CPV = new ARMConstantPoolValue(BA, ARMPCLabelIndex,
   1944                                                          ARMCP::CPBlockAddress,
   1945                                                          PCAdj);
   1946     CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
   1947   }
   1948   CPAddr = DAG.getNode(ARMISD::Wrapper, DL, PtrVT, CPAddr);
   1949   SDValue Result = DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), CPAddr,
   1950                                MachinePointerInfo::getConstantPool(),
   1951                                false, false, 0);
   1952   if (RelocM == Reloc::Static)
   1953     return Result;
   1954   SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
   1955   return DAG.getNode(ARMISD::PIC_ADD, DL, PtrVT, Result, PICLabel);
   1956 }
   1957 
   1958 // Lower ISD::GlobalTLSAddress using the "general dynamic" model
   1959 SDValue
   1960 ARMTargetLowering::LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
   1961                                                  SelectionDAG &DAG) const {
   1962   DebugLoc dl = GA->getDebugLoc();
   1963   EVT PtrVT = getPointerTy();
   1964   unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
   1965   MachineFunction &MF = DAG.getMachineFunction();
   1966   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   1967   unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
   1968   ARMConstantPoolValue *CPV =
   1969     new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex,
   1970                              ARMCP::CPValue, PCAdj, ARMCP::TLSGD, true);
   1971   SDValue Argument = DAG.getTargetConstantPool(CPV, PtrVT, 4);
   1972   Argument = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Argument);
   1973   Argument = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), Argument,
   1974                          MachinePointerInfo::getConstantPool(),
   1975                          false, false, 0);
   1976   SDValue Chain = Argument.getValue(1);
   1977 
   1978   SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
   1979   Argument = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Argument, PICLabel);
   1980 
   1981   // call __tls_get_addr.
   1982   ArgListTy Args;
   1983   ArgListEntry Entry;
   1984   Entry.Node = Argument;
   1985   Entry.Ty = (Type *) Type::getInt32Ty(*DAG.getContext());
   1986   Args.push_back(Entry);
   1987   // FIXME: is there useful debug info available here?
   1988   std::pair<SDValue, SDValue> CallResult =
   1989     LowerCallTo(Chain, (Type *) Type::getInt32Ty(*DAG.getContext()),
   1990                 false, false, false, false,
   1991                 0, CallingConv::C, false, /*isReturnValueUsed=*/true,
   1992                 DAG.getExternalSymbol("__tls_get_addr", PtrVT), Args, DAG, dl);
   1993   return CallResult.first;
   1994 }
   1995 
   1996 // Lower ISD::GlobalTLSAddress using the "initial exec" or
   1997 // "local exec" model.
   1998 SDValue
   1999 ARMTargetLowering::LowerToTLSExecModels(GlobalAddressSDNode *GA,
   2000                                         SelectionDAG &DAG) const {
   2001   const GlobalValue *GV = GA->getGlobal();
   2002   DebugLoc dl = GA->getDebugLoc();
   2003   SDValue Offset;
   2004   SDValue Chain = DAG.getEntryNode();
   2005   EVT PtrVT = getPointerTy();
   2006   // Get the Thread Pointer
   2007   SDValue ThreadPointer = DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
   2008 
   2009   if (GV->isDeclaration()) {
   2010     MachineFunction &MF = DAG.getMachineFunction();
   2011     ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   2012     unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
   2013     // Initial exec model.
   2014     unsigned char PCAdj = Subtarget->isThumb() ? 4 : 8;
   2015     ARMConstantPoolValue *CPV =
   2016       new ARMConstantPoolValue(GA->getGlobal(), ARMPCLabelIndex,
   2017                                ARMCP::CPValue, PCAdj, ARMCP::GOTTPOFF, true);
   2018     Offset = DAG.getTargetConstantPool(CPV, PtrVT, 4);
   2019     Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
   2020     Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
   2021                          MachinePointerInfo::getConstantPool(),
   2022                          false, false, 0);
   2023     Chain = Offset.getValue(1);
   2024 
   2025     SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
   2026     Offset = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Offset, PICLabel);
   2027 
   2028     Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
   2029                          MachinePointerInfo::getConstantPool(),
   2030                          false, false, 0);
   2031   } else {
   2032     // local exec model
   2033     ARMConstantPoolValue *CPV = new ARMConstantPoolValue(GV, ARMCP::TPOFF);
   2034     Offset = DAG.getTargetConstantPool(CPV, PtrVT, 4);
   2035     Offset = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, Offset);
   2036     Offset = DAG.getLoad(PtrVT, dl, Chain, Offset,
   2037                          MachinePointerInfo::getConstantPool(),
   2038                          false, false, 0);
   2039   }
   2040 
   2041   // The address of the thread local variable is the add of the thread
   2042   // pointer with the offset of the variable.
   2043   return DAG.getNode(ISD::ADD, dl, PtrVT, ThreadPointer, Offset);
   2044 }
   2045 
   2046 SDValue
   2047 ARMTargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
   2048   // TODO: implement the "local dynamic" model
   2049   assert(Subtarget->isTargetELF() &&
   2050          "TLS not implemented for non-ELF targets");
   2051   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
   2052   // If the relocation model is PIC, use the "General Dynamic" TLS Model,
   2053   // otherwise use the "Local Exec" TLS Model
   2054   if (getTargetMachine().getRelocationModel() == Reloc::PIC_)
   2055     return LowerToTLSGeneralDynamicModel(GA, DAG);
   2056   else
   2057     return LowerToTLSExecModels(GA, DAG);
   2058 }
   2059 
   2060 SDValue ARMTargetLowering::LowerGlobalAddressELF(SDValue Op,
   2061                                                  SelectionDAG &DAG) const {
   2062   EVT PtrVT = getPointerTy();
   2063   DebugLoc dl = Op.getDebugLoc();
   2064   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
   2065   Reloc::Model RelocM = getTargetMachine().getRelocationModel();
   2066   if (RelocM == Reloc::PIC_) {
   2067     bool UseGOTOFF = GV->hasLocalLinkage() || GV->hasHiddenVisibility();
   2068     ARMConstantPoolValue *CPV =
   2069       new ARMConstantPoolValue(GV, UseGOTOFF ? ARMCP::GOTOFF : ARMCP::GOT);
   2070     SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
   2071     CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   2072     SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(),
   2073                                  CPAddr,
   2074                                  MachinePointerInfo::getConstantPool(),
   2075                                  false, false, 0);
   2076     SDValue Chain = Result.getValue(1);
   2077     SDValue GOT = DAG.getGLOBAL_OFFSET_TABLE(PtrVT);
   2078     Result = DAG.getNode(ISD::ADD, dl, PtrVT, Result, GOT);
   2079     if (!UseGOTOFF)
   2080       Result = DAG.getLoad(PtrVT, dl, Chain, Result,
   2081                            MachinePointerInfo::getGOT(), false, false, 0);
   2082     return Result;
   2083   }
   2084 
   2085   // If we have T2 ops, we can materialize the address directly via movt/movw
   2086   // pair. This is always cheaper.
   2087   if (Subtarget->useMovt()) {
   2088     ++NumMovwMovt;
   2089     // FIXME: Once remat is capable of dealing with instructions with register
   2090     // operands, expand this into two nodes.
   2091     return DAG.getNode(ARMISD::Wrapper, dl, PtrVT,
   2092                        DAG.getTargetGlobalAddress(GV, dl, PtrVT));
   2093   } else {
   2094     SDValue CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 4);
   2095     CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   2096     return DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
   2097                        MachinePointerInfo::getConstantPool(),
   2098                        false, false, 0);
   2099   }
   2100 }
   2101 
   2102 SDValue ARMTargetLowering::LowerGlobalAddressDarwin(SDValue Op,
   2103                                                     SelectionDAG &DAG) const {
   2104   EVT PtrVT = getPointerTy();
   2105   DebugLoc dl = Op.getDebugLoc();
   2106   const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
   2107   Reloc::Model RelocM = getTargetMachine().getRelocationModel();
   2108   MachineFunction &MF = DAG.getMachineFunction();
   2109   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   2110 
   2111   // FIXME: Enable this for static codegen when tool issues are fixed.
   2112   if (Subtarget->useMovt() && RelocM != Reloc::Static) {
   2113     ++NumMovwMovt;
   2114     // FIXME: Once remat is capable of dealing with instructions with register
   2115     // operands, expand this into two nodes.
   2116     if (RelocM == Reloc::Static)
   2117       return DAG.getNode(ARMISD::Wrapper, dl, PtrVT,
   2118                                  DAG.getTargetGlobalAddress(GV, dl, PtrVT));
   2119 
   2120     unsigned Wrapper = (RelocM == Reloc::PIC_)
   2121       ? ARMISD::WrapperPIC : ARMISD::WrapperDYN;
   2122     SDValue Result = DAG.getNode(Wrapper, dl, PtrVT,
   2123                                  DAG.getTargetGlobalAddress(GV, dl, PtrVT));
   2124     if (Subtarget->GVIsIndirectSymbol(GV, RelocM))
   2125       Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), Result,
   2126                            MachinePointerInfo::getGOT(), false, false, 0);
   2127     return Result;
   2128   }
   2129 
   2130   unsigned ARMPCLabelIndex = 0;
   2131   SDValue CPAddr;
   2132   if (RelocM == Reloc::Static) {
   2133     CPAddr = DAG.getTargetConstantPool(GV, PtrVT, 4);
   2134   } else {
   2135     ARMPCLabelIndex = AFI->createPICLabelUId();
   2136     unsigned PCAdj = (RelocM != Reloc::PIC_) ? 0 : (Subtarget->isThumb()?4:8);
   2137     ARMConstantPoolValue *CPV =
   2138       new ARMConstantPoolValue(GV, ARMPCLabelIndex, ARMCP::CPValue, PCAdj);
   2139     CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
   2140   }
   2141   CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   2142 
   2143   SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
   2144                                MachinePointerInfo::getConstantPool(),
   2145                                false, false, 0);
   2146   SDValue Chain = Result.getValue(1);
   2147 
   2148   if (RelocM == Reloc::PIC_) {
   2149     SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
   2150     Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
   2151   }
   2152 
   2153   if (Subtarget->GVIsIndirectSymbol(GV, RelocM))
   2154     Result = DAG.getLoad(PtrVT, dl, Chain, Result, MachinePointerInfo::getGOT(),
   2155                          false, false, 0);
   2156 
   2157   return Result;
   2158 }
   2159 
   2160 SDValue ARMTargetLowering::LowerGLOBAL_OFFSET_TABLE(SDValue Op,
   2161                                                     SelectionDAG &DAG) const {
   2162   assert(Subtarget->isTargetELF() &&
   2163          "GLOBAL OFFSET TABLE not implemented for non-ELF targets");
   2164   MachineFunction &MF = DAG.getMachineFunction();
   2165   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   2166   unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
   2167   EVT PtrVT = getPointerTy();
   2168   DebugLoc dl = Op.getDebugLoc();
   2169   unsigned PCAdj = Subtarget->isThumb() ? 4 : 8;
   2170   ARMConstantPoolValue *CPV = new ARMConstantPoolValue(*DAG.getContext(),
   2171                                                        "_GLOBAL_OFFSET_TABLE_",
   2172                                                        ARMPCLabelIndex, PCAdj);
   2173   SDValue CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
   2174   CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   2175   SDValue Result = DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
   2176                                MachinePointerInfo::getConstantPool(),
   2177                                false, false, 0);
   2178   SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
   2179   return DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
   2180 }
   2181 
   2182 SDValue
   2183 ARMTargetLowering::LowerEH_SJLJ_DISPATCHSETUP(SDValue Op, SelectionDAG &DAG)
   2184   const {
   2185   DebugLoc dl = Op.getDebugLoc();
   2186   return DAG.getNode(ARMISD::EH_SJLJ_DISPATCHSETUP, dl, MVT::Other,
   2187                      Op.getOperand(0), Op.getOperand(1));
   2188 }
   2189 
   2190 SDValue
   2191 ARMTargetLowering::LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const {
   2192   DebugLoc dl = Op.getDebugLoc();
   2193   SDValue Val = DAG.getConstant(0, MVT::i32);
   2194   return DAG.getNode(ARMISD::EH_SJLJ_SETJMP, dl, MVT::i32, Op.getOperand(0),
   2195                      Op.getOperand(1), Val);
   2196 }
   2197 
   2198 SDValue
   2199 ARMTargetLowering::LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const {
   2200   DebugLoc dl = Op.getDebugLoc();
   2201   return DAG.getNode(ARMISD::EH_SJLJ_LONGJMP, dl, MVT::Other, Op.getOperand(0),
   2202                      Op.getOperand(1), DAG.getConstant(0, MVT::i32));
   2203 }
   2204 
   2205 SDValue
   2206 ARMTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
   2207                                           const ARMSubtarget *Subtarget) const {
   2208   unsigned IntNo = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
   2209   DebugLoc dl = Op.getDebugLoc();
   2210   switch (IntNo) {
   2211   default: return SDValue();    // Don't custom lower most intrinsics.
   2212   case Intrinsic::arm_thread_pointer: {
   2213     EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
   2214     return DAG.getNode(ARMISD::THREAD_POINTER, dl, PtrVT);
   2215   }
   2216   case Intrinsic::eh_sjlj_lsda: {
   2217     MachineFunction &MF = DAG.getMachineFunction();
   2218     ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   2219     unsigned ARMPCLabelIndex = AFI->createPICLabelUId();
   2220     EVT PtrVT = getPointerTy();
   2221     DebugLoc dl = Op.getDebugLoc();
   2222     Reloc::Model RelocM = getTargetMachine().getRelocationModel();
   2223     SDValue CPAddr;
   2224     unsigned PCAdj = (RelocM != Reloc::PIC_)
   2225       ? 0 : (Subtarget->isThumb() ? 4 : 8);
   2226     ARMConstantPoolValue *CPV =
   2227       new ARMConstantPoolValue(MF.getFunction(), ARMPCLabelIndex,
   2228                                ARMCP::CPLSDA, PCAdj);
   2229     CPAddr = DAG.getTargetConstantPool(CPV, PtrVT, 4);
   2230     CPAddr = DAG.getNode(ARMISD::Wrapper, dl, MVT::i32, CPAddr);
   2231     SDValue Result =
   2232       DAG.getLoad(PtrVT, dl, DAG.getEntryNode(), CPAddr,
   2233                   MachinePointerInfo::getConstantPool(),
   2234                   false, false, 0);
   2235 
   2236     if (RelocM == Reloc::PIC_) {
   2237       SDValue PICLabel = DAG.getConstant(ARMPCLabelIndex, MVT::i32);
   2238       Result = DAG.getNode(ARMISD::PIC_ADD, dl, PtrVT, Result, PICLabel);
   2239     }
   2240     return Result;
   2241   }
   2242   case Intrinsic::arm_neon_vmulls:
   2243   case Intrinsic::arm_neon_vmullu: {
   2244     unsigned NewOpc = (IntNo == Intrinsic::arm_neon_vmulls)
   2245       ? ARMISD::VMULLs : ARMISD::VMULLu;
   2246     return DAG.getNode(NewOpc, Op.getDebugLoc(), Op.getValueType(),
   2247                        Op.getOperand(1), Op.getOperand(2));
   2248   }
   2249   }
   2250 }
   2251 
   2252 static SDValue LowerMEMBARRIER(SDValue Op, SelectionDAG &DAG,
   2253                                const ARMSubtarget *Subtarget) {
   2254   DebugLoc dl = Op.getDebugLoc();
   2255   if (!Subtarget->hasDataBarrier()) {
   2256     // Some ARMv6 cpus can support data barriers with an mcr instruction.
   2257     // Thumb1 and pre-v6 ARM mode use a libcall instead and should never get
   2258     // here.
   2259     assert(Subtarget->hasV6Ops() && !Subtarget->isThumb() &&
   2260            "Unexpected ISD::MEMBARRIER encountered. Should be libcall!");
   2261     return DAG.getNode(ARMISD::MEMBARRIER_MCR, dl, MVT::Other, Op.getOperand(0),
   2262                        DAG.getConstant(0, MVT::i32));
   2263   }
   2264 
   2265   SDValue Op5 = Op.getOperand(5);
   2266   bool isDeviceBarrier = cast<ConstantSDNode>(Op5)->getZExtValue() != 0;
   2267   unsigned isLL = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
   2268   unsigned isLS = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue();
   2269   bool isOnlyStoreBarrier = (isLL == 0 && isLS == 0);
   2270 
   2271   ARM_MB::MemBOpt DMBOpt;
   2272   if (isDeviceBarrier)
   2273     DMBOpt = isOnlyStoreBarrier ? ARM_MB::ST : ARM_MB::SY;
   2274   else
   2275     DMBOpt = isOnlyStoreBarrier ? ARM_MB::ISHST : ARM_MB::ISH;
   2276   return DAG.getNode(ARMISD::MEMBARRIER, dl, MVT::Other, Op.getOperand(0),
   2277                      DAG.getConstant(DMBOpt, MVT::i32));
   2278 }
   2279 
   2280 static SDValue LowerPREFETCH(SDValue Op, SelectionDAG &DAG,
   2281                              const ARMSubtarget *Subtarget) {
   2282   // ARM pre v5TE and Thumb1 does not have preload instructions.
   2283   if (!(Subtarget->isThumb2() ||
   2284         (!Subtarget->isThumb1Only() && Subtarget->hasV5TEOps())))
   2285     // Just preserve the chain.
   2286     return Op.getOperand(0);
   2287 
   2288   DebugLoc dl = Op.getDebugLoc();
   2289   unsigned isRead = ~cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue() & 1;
   2290   if (!isRead &&
   2291       (!Subtarget->hasV7Ops() || !Subtarget->hasMPExtension()))
   2292     // ARMv7 with MP extension has PLDW.
   2293     return Op.getOperand(0);
   2294 
   2295   unsigned isData = cast<ConstantSDNode>(Op.getOperand(4))->getZExtValue();
   2296   if (Subtarget->isThumb()) {
   2297     // Invert the bits.
   2298     isRead = ~isRead & 1;
   2299     isData = ~isData & 1;
   2300   }
   2301 
   2302   return DAG.getNode(ARMISD::PRELOAD, dl, MVT::Other, Op.getOperand(0),
   2303                      Op.getOperand(1), DAG.getConstant(isRead, MVT::i32),
   2304                      DAG.getConstant(isData, MVT::i32));
   2305 }
   2306 
   2307 static SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) {
   2308   MachineFunction &MF = DAG.getMachineFunction();
   2309   ARMFunctionInfo *FuncInfo = MF.getInfo<ARMFunctionInfo>();
   2310 
   2311   // vastart just stores the address of the VarArgsFrameIndex slot into the
   2312   // memory location argument.
   2313   DebugLoc dl = Op.getDebugLoc();
   2314   EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
   2315   SDValue FR = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), PtrVT);
   2316   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
   2317   return DAG.getStore(Op.getOperand(0), dl, FR, Op.getOperand(1),
   2318                       MachinePointerInfo(SV), false, false, 0);
   2319 }
   2320 
   2321 SDValue
   2322 ARMTargetLowering::GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
   2323                                         SDValue &Root, SelectionDAG &DAG,
   2324                                         DebugLoc dl) const {
   2325   MachineFunction &MF = DAG.getMachineFunction();
   2326   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   2327 
   2328   TargetRegisterClass *RC;
   2329   if (AFI->isThumb1OnlyFunction())
   2330     RC = ARM::tGPRRegisterClass;
   2331   else
   2332     RC = ARM::GPRRegisterClass;
   2333 
   2334   // Transform the arguments stored in physical registers into virtual ones.
   2335   unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
   2336   SDValue ArgValue = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
   2337 
   2338   SDValue ArgValue2;
   2339   if (NextVA.isMemLoc()) {
   2340     MachineFrameInfo *MFI = MF.getFrameInfo();
   2341     int FI = MFI->CreateFixedObject(4, NextVA.getLocMemOffset(), true);
   2342 
   2343     // Create load node to retrieve arguments from the stack.
   2344     SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
   2345     ArgValue2 = DAG.getLoad(MVT::i32, dl, Root, FIN,
   2346                             MachinePointerInfo::getFixedStack(FI),
   2347                             false, false, 0);
   2348   } else {
   2349     Reg = MF.addLiveIn(NextVA.getLocReg(), RC);
   2350     ArgValue2 = DAG.getCopyFromReg(Root, dl, Reg, MVT::i32);
   2351   }
   2352 
   2353   return DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, ArgValue, ArgValue2);
   2354 }
   2355 
   2356 void
   2357 ARMTargetLowering::computeRegArea(CCState &CCInfo, MachineFunction &MF,
   2358                                   unsigned &VARegSize, unsigned &VARegSaveSize)
   2359   const {
   2360   unsigned NumGPRs;
   2361   if (CCInfo.isFirstByValRegValid())
   2362     NumGPRs = ARM::R4 - CCInfo.getFirstByValReg();
   2363   else {
   2364     unsigned int firstUnalloced;
   2365     firstUnalloced = CCInfo.getFirstUnallocated(GPRArgRegs,
   2366                                                 sizeof(GPRArgRegs) /
   2367                                                 sizeof(GPRArgRegs[0]));
   2368     NumGPRs = (firstUnalloced <= 3) ? (4 - firstUnalloced) : 0;
   2369   }
   2370 
   2371   unsigned Align = MF.getTarget().getFrameLowering()->getStackAlignment();
   2372   VARegSize = NumGPRs * 4;
   2373   VARegSaveSize = (VARegSize + Align - 1) & ~(Align - 1);
   2374 }
   2375 
   2376 // The remaining GPRs hold either the beginning of variable-argument
   2377 // data, or the beginning of an aggregate passed by value (usuall
   2378 // byval).  Either way, we allocate stack slots adjacent to the data
   2379 // provided by our caller, and store the unallocated registers there.
   2380 // If this is a variadic function, the va_list pointer will begin with
   2381 // these values; otherwise, this reassembles a (byval) structure that
   2382 // was split between registers and memory.
   2383 void
   2384 ARMTargetLowering::VarArgStyleRegisters(CCState &CCInfo, SelectionDAG &DAG,
   2385                                         DebugLoc dl, SDValue &Chain,
   2386                                         unsigned ArgOffset) const {
   2387   MachineFunction &MF = DAG.getMachineFunction();
   2388   MachineFrameInfo *MFI = MF.getFrameInfo();
   2389   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   2390   unsigned firstRegToSaveIndex;
   2391   if (CCInfo.isFirstByValRegValid())
   2392     firstRegToSaveIndex = CCInfo.getFirstByValReg() - ARM::R0;
   2393   else {
   2394     firstRegToSaveIndex = CCInfo.getFirstUnallocated
   2395       (GPRArgRegs, sizeof(GPRArgRegs) / sizeof(GPRArgRegs[0]));
   2396   }
   2397 
   2398   unsigned VARegSize, VARegSaveSize;
   2399   computeRegArea(CCInfo, MF, VARegSize, VARegSaveSize);
   2400   if (VARegSaveSize) {
   2401     // If this function is vararg, store any remaining integer argument regs
   2402     // to their spots on the stack so that they may be loaded by deferencing
   2403     // the result of va_next.
   2404     AFI->setVarArgsRegSaveSize(VARegSaveSize);
   2405     AFI->setVarArgsFrameIndex(MFI->CreateFixedObject(VARegSaveSize,
   2406                                                      ArgOffset + VARegSaveSize
   2407                                                      - VARegSize,
   2408                                                      false));
   2409     SDValue FIN = DAG.getFrameIndex(AFI->getVarArgsFrameIndex(),
   2410                                     getPointerTy());
   2411 
   2412     SmallVector<SDValue, 4> MemOps;
   2413     for (; firstRegToSaveIndex < 4; ++firstRegToSaveIndex) {
   2414       TargetRegisterClass *RC;
   2415       if (AFI->isThumb1OnlyFunction())
   2416         RC = ARM::tGPRRegisterClass;
   2417       else
   2418         RC = ARM::GPRRegisterClass;
   2419 
   2420       unsigned VReg = MF.addLiveIn(GPRArgRegs[firstRegToSaveIndex], RC);
   2421       SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i32);
   2422       SDValue Store =
   2423         DAG.getStore(Val.getValue(1), dl, Val, FIN,
   2424                  MachinePointerInfo::getFixedStack(AFI->getVarArgsFrameIndex()),
   2425                      false, false, 0);
   2426       MemOps.push_back(Store);
   2427       FIN = DAG.getNode(ISD::ADD, dl, getPointerTy(), FIN,
   2428                         DAG.getConstant(4, getPointerTy()));
   2429     }
   2430     if (!MemOps.empty())
   2431       Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
   2432                           &MemOps[0], MemOps.size());
   2433   } else
   2434     // This will point to the next argument passed via stack.
   2435     AFI->setVarArgsFrameIndex(MFI->CreateFixedObject(4, ArgOffset, true));
   2436 }
   2437 
   2438 SDValue
   2439 ARMTargetLowering::LowerFormalArguments(SDValue Chain,
   2440                                         CallingConv::ID CallConv, bool isVarArg,
   2441                                         const SmallVectorImpl<ISD::InputArg>
   2442                                           &Ins,
   2443                                         DebugLoc dl, SelectionDAG &DAG,
   2444                                         SmallVectorImpl<SDValue> &InVals)
   2445                                           const {
   2446   MachineFunction &MF = DAG.getMachineFunction();
   2447   MachineFrameInfo *MFI = MF.getFrameInfo();
   2448 
   2449   ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
   2450 
   2451   // Assign locations to all of the incoming arguments.
   2452   SmallVector<CCValAssign, 16> ArgLocs;
   2453   ARMCCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
   2454                     getTargetMachine(), ArgLocs, *DAG.getContext(), Prologue);
   2455   CCInfo.AnalyzeFormalArguments(Ins,
   2456                                 CCAssignFnForNode(CallConv, /* Return*/ false,
   2457                                                   isVarArg));
   2458 
   2459   SmallVector<SDValue, 16> ArgValues;
   2460   int lastInsIndex = -1;
   2461 
   2462   SDValue ArgValue;
   2463   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
   2464     CCValAssign &VA = ArgLocs[i];
   2465 
   2466     // Arguments stored in registers.
   2467     if (VA.isRegLoc()) {
   2468       EVT RegVT = VA.getLocVT();
   2469 
   2470       if (VA.needsCustom()) {
   2471         // f64 and vector types are split up into multiple registers or
   2472         // combinations of registers and stack slots.
   2473         if (VA.getLocVT() == MVT::v2f64) {
   2474           SDValue ArgValue1 = GetF64FormalArgument(VA, ArgLocs[++i],
   2475                                                    Chain, DAG, dl);
   2476           VA = ArgLocs[++i]; // skip ahead to next loc
   2477           SDValue ArgValue2;
   2478           if (VA.isMemLoc()) {
   2479             int FI = MFI->CreateFixedObject(8, VA.getLocMemOffset(), true);
   2480             SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
   2481             ArgValue2 = DAG.getLoad(MVT::f64, dl, Chain, FIN,
   2482                                     MachinePointerInfo::getFixedStack(FI),
   2483                                     false, false, 0);
   2484           } else {
   2485             ArgValue2 = GetF64FormalArgument(VA, ArgLocs[++i],
   2486                                              Chain, DAG, dl);
   2487           }
   2488           ArgValue = DAG.getNode(ISD::UNDEF, dl, MVT::v2f64);
   2489           ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64,
   2490                                  ArgValue, ArgValue1, DAG.getIntPtrConstant(0));
   2491           ArgValue = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64,
   2492                                  ArgValue, ArgValue2, DAG.getIntPtrConstant(1));
   2493         } else
   2494           ArgValue = GetF64FormalArgument(VA, ArgLocs[++i], Chain, DAG, dl);
   2495 
   2496       } else {
   2497         TargetRegisterClass *RC;
   2498 
   2499         if (RegVT == MVT::f32)
   2500           RC = ARM::SPRRegisterClass;
   2501         else if (RegVT == MVT::f64)
   2502           RC = ARM::DPRRegisterClass;
   2503         else if (RegVT == MVT::v2f64)
   2504           RC = ARM::QPRRegisterClass;
   2505         else if (RegVT == MVT::i32)
   2506           RC = (AFI->isThumb1OnlyFunction() ?
   2507                 ARM::tGPRRegisterClass : ARM::GPRRegisterClass);
   2508         else
   2509           llvm_unreachable("RegVT not supported by FORMAL_ARGUMENTS Lowering");
   2510 
   2511         // Transform the arguments in physical registers into virtual ones.
   2512         unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
   2513         ArgValue = DAG.getCopyFromReg(Chain, dl, Reg, RegVT);
   2514       }
   2515 
   2516       // If this is an 8 or 16-bit value, it is really passed promoted
   2517       // to 32 bits.  Insert an assert[sz]ext to capture this, then
   2518       // truncate to the right size.
   2519       switch (VA.getLocInfo()) {
   2520       default: llvm_unreachable("Unknown loc info!");
   2521       case CCValAssign::Full: break;
   2522       case CCValAssign::BCvt:
   2523         ArgValue = DAG.getNode(ISD::BITCAST, dl, VA.getValVT(), ArgValue);
   2524         break;
   2525       case CCValAssign::SExt:
   2526         ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
   2527                                DAG.getValueType(VA.getValVT()));
   2528         ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
   2529         break;
   2530       case CCValAssign::ZExt:
   2531         ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
   2532                                DAG.getValueType(VA.getValVT()));
   2533         ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
   2534         break;
   2535       }
   2536 
   2537       InVals.push_back(ArgValue);
   2538 
   2539     } else { // VA.isRegLoc()
   2540 
   2541       // sanity check
   2542       assert(VA.isMemLoc());
   2543       assert(VA.getValVT() != MVT::i64 && "i64 should already be lowered");
   2544 
   2545       int index = ArgLocs[i].getValNo();
   2546 
   2547       // Some Ins[] entries become multiple ArgLoc[] entries.
   2548       // Process them only once.
   2549       if (index != lastInsIndex)
   2550         {
   2551           ISD::ArgFlagsTy Flags = Ins[index].Flags;
   2552           // FIXME: For now, all byval parameter objects are marked mutable.
   2553           // This can be changed with more analysis.
   2554           // In case of tail call optimization mark all arguments mutable.
   2555           // Since they could be overwritten by lowering of arguments in case of
   2556           // a tail call.
   2557           if (Flags.isByVal()) {
   2558             unsigned VARegSize, VARegSaveSize;
   2559             computeRegArea(CCInfo, MF, VARegSize, VARegSaveSize);
   2560             VarArgStyleRegisters(CCInfo, DAG, dl, Chain, 0);
   2561             unsigned Bytes = Flags.getByValSize() - VARegSize;
   2562             if (Bytes == 0) Bytes = 1; // Don't create zero-sized stack objects.
   2563             int FI = MFI->CreateFixedObject(Bytes,
   2564                                             VA.getLocMemOffset(), false);
   2565             InVals.push_back(DAG.getFrameIndex(FI, getPointerTy()));
   2566           } else {
   2567             int FI = MFI->CreateFixedObject(VA.getLocVT().getSizeInBits()/8,
   2568                                             VA.getLocMemOffset(), true);
   2569 
   2570             // Create load nodes to retrieve arguments from the stack.
   2571             SDValue FIN = DAG.getFrameIndex(FI, getPointerTy());
   2572             InVals.push_back(DAG.getLoad(VA.getValVT(), dl, Chain, FIN,
   2573                                          MachinePointerInfo::getFixedStack(FI),
   2574                                          false, false, 0));
   2575           }
   2576           lastInsIndex = index;
   2577         }
   2578     }
   2579   }
   2580 
   2581   // varargs
   2582   if (isVarArg)
   2583     VarArgStyleRegisters(CCInfo, DAG, dl, Chain, CCInfo.getNextStackOffset());
   2584 
   2585   return Chain;
   2586 }
   2587 
   2588 /// isFloatingPointZero - Return true if this is +0.0.
   2589 static bool isFloatingPointZero(SDValue Op) {
   2590   if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Op))
   2591     return CFP->getValueAPF().isPosZero();
   2592   else if (ISD::isEXTLoad(Op.getNode()) || ISD::isNON_EXTLoad(Op.getNode())) {
   2593     // Maybe this has already been legalized into the constant pool?
   2594     if (Op.getOperand(1).getOpcode() == ARMISD::Wrapper) {
   2595       SDValue WrapperOp = Op.getOperand(1).getOperand(0);
   2596       if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(WrapperOp))
   2597         if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CP->getConstVal()))
   2598           return CFP->getValueAPF().isPosZero();
   2599     }
   2600   }
   2601   return false;
   2602 }
   2603 
   2604 /// Returns appropriate ARM CMP (cmp) and corresponding condition code for
   2605 /// the given operands.
   2606 SDValue
   2607 ARMTargetLowering::getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
   2608                              SDValue &ARMcc, SelectionDAG &DAG,
   2609                              DebugLoc dl) const {
   2610   if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
   2611     unsigned C = RHSC->getZExtValue();
   2612     if (!isLegalICmpImmediate(C)) {
   2613       // Constant does not fit, try adjusting it by one?
   2614       switch (CC) {
   2615       default: break;
   2616       case ISD::SETLT:
   2617       case ISD::SETGE:
   2618         if (C != 0x80000000 && isLegalICmpImmediate(C-1)) {
   2619           CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
   2620           RHS = DAG.getConstant(C-1, MVT::i32);
   2621         }
   2622         break;
   2623       case ISD::SETULT:
   2624       case ISD::SETUGE:
   2625         if (C != 0 && isLegalICmpImmediate(C-1)) {
   2626           CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
   2627           RHS = DAG.getConstant(C-1, MVT::i32);
   2628         }
   2629         break;
   2630       case ISD::SETLE:
   2631       case ISD::SETGT:
   2632         if (C != 0x7fffffff && isLegalICmpImmediate(C+1)) {
   2633           CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
   2634           RHS = DAG.getConstant(C+1, MVT::i32);
   2635         }
   2636         break;
   2637       case ISD::SETULE:
   2638       case ISD::SETUGT:
   2639         if (C != 0xffffffff && isLegalICmpImmediate(C+1)) {
   2640           CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
   2641           RHS = DAG.getConstant(C+1, MVT::i32);
   2642         }
   2643         break;
   2644       }
   2645     }
   2646   }
   2647 
   2648   ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
   2649   ARMISD::NodeType CompareType;
   2650   switch (CondCode) {
   2651   default:
   2652     CompareType = ARMISD::CMP;
   2653     break;
   2654   case ARMCC::EQ:
   2655   case ARMCC::NE:
   2656     // Uses only Z Flag
   2657     CompareType = ARMISD::CMPZ;
   2658     break;
   2659   }
   2660   ARMcc = DAG.getConstant(CondCode, MVT::i32);
   2661   return DAG.getNode(CompareType, dl, MVT::Glue, LHS, RHS);
   2662 }
   2663 
   2664 /// Returns a appropriate VFP CMP (fcmp{s|d}+fmstat) for the given operands.
   2665 SDValue
   2666 ARMTargetLowering::getVFPCmp(SDValue LHS, SDValue RHS, SelectionDAG &DAG,
   2667                              DebugLoc dl) const {
   2668   SDValue Cmp;
   2669   if (!isFloatingPointZero(RHS))
   2670     Cmp = DAG.getNode(ARMISD::CMPFP, dl, MVT::Glue, LHS, RHS);
   2671   else
   2672     Cmp = DAG.getNode(ARMISD::CMPFPw0, dl, MVT::Glue, LHS);
   2673   return DAG.getNode(ARMISD::FMSTAT, dl, MVT::Glue, Cmp);
   2674 }
   2675 
   2676 /// duplicateCmp - Glue values can have only one use, so this function
   2677 /// duplicates a comparison node.
   2678 SDValue
   2679 ARMTargetLowering::duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const {
   2680   unsigned Opc = Cmp.getOpcode();
   2681   DebugLoc DL = Cmp.getDebugLoc();
   2682   if (Opc == ARMISD::CMP || Opc == ARMISD::CMPZ)
   2683     return DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0),Cmp.getOperand(1));
   2684 
   2685   assert(Opc == ARMISD::FMSTAT && "unexpected comparison operation");
   2686   Cmp = Cmp.getOperand(0);
   2687   Opc = Cmp.getOpcode();
   2688   if (Opc == ARMISD::CMPFP)
   2689     Cmp = DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0),Cmp.getOperand(1));
   2690   else {
   2691     assert(Opc == ARMISD::CMPFPw0 && "unexpected operand of FMSTAT");
   2692     Cmp = DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0));
   2693   }
   2694   return DAG.getNode(ARMISD::FMSTAT, DL, MVT::Glue, Cmp);
   2695 }
   2696 
   2697 SDValue ARMTargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const {
   2698   SDValue Cond = Op.getOperand(0);
   2699   SDValue SelectTrue = Op.getOperand(1);
   2700   SDValue SelectFalse = Op.getOperand(2);
   2701   DebugLoc dl = Op.getDebugLoc();
   2702 
   2703   // Convert:
   2704   //
   2705   //   (select (cmov 1, 0, cond), t, f) -> (cmov t, f, cond)
   2706   //   (select (cmov 0, 1, cond), t, f) -> (cmov f, t, cond)
   2707   //
   2708   if (Cond.getOpcode() == ARMISD::CMOV && Cond.hasOneUse()) {
   2709     const ConstantSDNode *CMOVTrue =
   2710       dyn_cast<ConstantSDNode>(Cond.getOperand(0));
   2711     const ConstantSDNode *CMOVFalse =
   2712       dyn_cast<ConstantSDNode>(Cond.getOperand(1));
   2713 
   2714     if (CMOVTrue && CMOVFalse) {
   2715       unsigned CMOVTrueVal = CMOVTrue->getZExtValue();
   2716       unsigned CMOVFalseVal = CMOVFalse->getZExtValue();
   2717 
   2718       SDValue True;
   2719       SDValue False;
   2720       if (CMOVTrueVal == 1 && CMOVFalseVal == 0) {
   2721         True = SelectTrue;
   2722         False = SelectFalse;
   2723       } else if (CMOVTrueVal == 0 && CMOVFalseVal == 1) {
   2724         True = SelectFalse;
   2725         False = SelectTrue;
   2726       }
   2727 
   2728       if (True.getNode() && False.getNode()) {
   2729         EVT VT = Op.getValueType();
   2730         SDValue ARMcc = Cond.getOperand(2);
   2731         SDValue CCR = Cond.getOperand(3);
   2732         SDValue Cmp = duplicateCmp(Cond.getOperand(4), DAG);
   2733         assert(True.getValueType() == VT);
   2734         return DAG.getNode(ARMISD::CMOV, dl, VT, True, False, ARMcc, CCR, Cmp);
   2735       }
   2736     }
   2737   }
   2738 
   2739   return DAG.getSelectCC(dl, Cond,
   2740                          DAG.getConstant(0, Cond.getValueType()),
   2741                          SelectTrue, SelectFalse, ISD::SETNE);
   2742 }
   2743 
   2744 SDValue ARMTargetLowering::LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const {
   2745   EVT VT = Op.getValueType();
   2746   SDValue LHS = Op.getOperand(0);
   2747   SDValue RHS = Op.getOperand(1);
   2748   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
   2749   SDValue TrueVal = Op.getOperand(2);
   2750   SDValue FalseVal = Op.getOperand(3);
   2751   DebugLoc dl = Op.getDebugLoc();
   2752 
   2753   if (LHS.getValueType() == MVT::i32) {
   2754     SDValue ARMcc;
   2755     SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
   2756     SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMcc, DAG, dl);
   2757     return DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal, ARMcc, CCR, Cmp);
   2758   }
   2759 
   2760   ARMCC::CondCodes CondCode, CondCode2;
   2761   FPCCToARMCC(CC, CondCode, CondCode2);
   2762 
   2763   SDValue ARMcc = DAG.getConstant(CondCode, MVT::i32);
   2764   SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl);
   2765   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
   2766   SDValue Result = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal,
   2767                                ARMcc, CCR, Cmp);
   2768   if (CondCode2 != ARMCC::AL) {
   2769     SDValue ARMcc2 = DAG.getConstant(CondCode2, MVT::i32);
   2770     // FIXME: Needs another CMP because flag can have but one use.
   2771     SDValue Cmp2 = getVFPCmp(LHS, RHS, DAG, dl);
   2772     Result = DAG.getNode(ARMISD::CMOV, dl, VT,
   2773                          Result, TrueVal, ARMcc2, CCR, Cmp2);
   2774   }
   2775   return Result;
   2776 }
   2777 
   2778 /// canChangeToInt - Given the fp compare operand, return true if it is suitable
   2779 /// to morph to an integer compare sequence.
   2780 static bool canChangeToInt(SDValue Op, bool &SeenZero,
   2781                            const ARMSubtarget *Subtarget) {
   2782   SDNode *N = Op.getNode();
   2783   if (!N->hasOneUse())
   2784     // Otherwise it requires moving the value from fp to integer registers.
   2785     return false;
   2786   if (!N->getNumValues())
   2787     return false;
   2788   EVT VT = Op.getValueType();
   2789   if (VT != MVT::f32 && !Subtarget->isFPBrccSlow())
   2790     // f32 case is generally profitable. f64 case only makes sense when vcmpe +
   2791     // vmrs are very slow, e.g. cortex-a8.
   2792     return false;
   2793 
   2794   if (isFloatingPointZero(Op)) {
   2795     SeenZero = true;
   2796     return true;
   2797   }
   2798   return ISD::isNormalLoad(N);
   2799 }
   2800 
   2801 static SDValue bitcastf32Toi32(SDValue Op, SelectionDAG &DAG) {
   2802   if (isFloatingPointZero(Op))
   2803     return DAG.getConstant(0, MVT::i32);
   2804 
   2805   if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Op))
   2806     return DAG.getLoad(MVT::i32, Op.getDebugLoc(),
   2807                        Ld->getChain(), Ld->getBasePtr(), Ld->getPointerInfo(),
   2808                        Ld->isVolatile(), Ld->isNonTemporal(),
   2809                        Ld->getAlignment());
   2810 
   2811   llvm_unreachable("Unknown VFP cmp argument!");
   2812 }
   2813 
   2814 static void expandf64Toi32(SDValue Op, SelectionDAG &DAG,
   2815                            SDValue &RetVal1, SDValue &RetVal2) {
   2816   if (isFloatingPointZero(Op)) {
   2817     RetVal1 = DAG.getConstant(0, MVT::i32);
   2818     RetVal2 = DAG.getConstant(0, MVT::i32);
   2819     return;
   2820   }
   2821 
   2822   if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Op)) {
   2823     SDValue Ptr = Ld->getBasePtr();
   2824     RetVal1 = DAG.getLoad(MVT::i32, Op.getDebugLoc(),
   2825                           Ld->getChain(), Ptr,
   2826                           Ld->getPointerInfo(),
   2827                           Ld->isVolatile(), Ld->isNonTemporal(),
   2828                           Ld->getAlignment());
   2829 
   2830     EVT PtrType = Ptr.getValueType();
   2831     unsigned NewAlign = MinAlign(Ld->getAlignment(), 4);
   2832     SDValue NewPtr = DAG.getNode(ISD::ADD, Op.getDebugLoc(),
   2833                                  PtrType, Ptr, DAG.getConstant(4, PtrType));
   2834     RetVal2 = DAG.getLoad(MVT::i32, Op.getDebugLoc(),
   2835                           Ld->getChain(), NewPtr,
   2836                           Ld->getPointerInfo().getWithOffset(4),
   2837                           Ld->isVolatile(), Ld->isNonTemporal(),
   2838                           NewAlign);
   2839     return;
   2840   }
   2841 
   2842   llvm_unreachable("Unknown VFP cmp argument!");
   2843 }
   2844 
   2845 /// OptimizeVFPBrcond - With -enable-unsafe-fp-math, it's legal to optimize some
   2846 /// f32 and even f64 comparisons to integer ones.
   2847 SDValue
   2848 ARMTargetLowering::OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const {
   2849   SDValue Chain = Op.getOperand(0);
   2850   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
   2851   SDValue LHS = Op.getOperand(2);
   2852   SDValue RHS = Op.getOperand(3);
   2853   SDValue Dest = Op.getOperand(4);
   2854   DebugLoc dl = Op.getDebugLoc();
   2855 
   2856   bool SeenZero = false;
   2857   if (canChangeToInt(LHS, SeenZero, Subtarget) &&
   2858       canChangeToInt(RHS, SeenZero, Subtarget) &&
   2859       // If one of the operand is zero, it's safe to ignore the NaN case since
   2860       // we only care about equality comparisons.
   2861       (SeenZero || (DAG.isKnownNeverNaN(LHS) && DAG.isKnownNeverNaN(RHS)))) {
   2862     // If unsafe fp math optimization is enabled and there are no other uses of
   2863     // the CMP operands, and the condition code is EQ or NE, we can optimize it
   2864     // to an integer comparison.
   2865     if (CC == ISD::SETOEQ)
   2866       CC = ISD::SETEQ;
   2867     else if (CC == ISD::SETUNE)
   2868       CC = ISD::SETNE;
   2869 
   2870     SDValue ARMcc;
   2871     if (LHS.getValueType() == MVT::f32) {
   2872       LHS = bitcastf32Toi32(LHS, DAG);
   2873       RHS = bitcastf32Toi32(RHS, DAG);
   2874       SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMcc, DAG, dl);
   2875       SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
   2876       return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other,
   2877                          Chain, Dest, ARMcc, CCR, Cmp);
   2878     }
   2879 
   2880     SDValue LHS1, LHS2;
   2881     SDValue RHS1, RHS2;
   2882     expandf64Toi32(LHS, DAG, LHS1, LHS2);
   2883     expandf64Toi32(RHS, DAG, RHS1, RHS2);
   2884     ARMCC::CondCodes CondCode = IntCCToARMCC(CC);
   2885     ARMcc = DAG.getConstant(CondCode, MVT::i32);
   2886     SDVTList VTList = DAG.getVTList(MVT::Other, MVT::Glue);
   2887     SDValue Ops[] = { Chain, ARMcc, LHS1, LHS2, RHS1, RHS2, Dest };
   2888     return DAG.getNode(ARMISD::BCC_i64, dl, VTList, Ops, 7);
   2889   }
   2890 
   2891   return SDValue();
   2892 }
   2893 
   2894 SDValue ARMTargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
   2895   SDValue Chain = Op.getOperand(0);
   2896   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
   2897   SDValue LHS = Op.getOperand(2);
   2898   SDValue RHS = Op.getOperand(3);
   2899   SDValue Dest = Op.getOperand(4);
   2900   DebugLoc dl = Op.getDebugLoc();
   2901 
   2902   if (LHS.getValueType() == MVT::i32) {
   2903     SDValue ARMcc;
   2904     SDValue Cmp = getARMCmp(LHS, RHS, CC, ARMcc, DAG, dl);
   2905     SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
   2906     return DAG.getNode(ARMISD::BRCOND, dl, MVT::Other,
   2907                        Chain, Dest, ARMcc, CCR, Cmp);
   2908   }
   2909 
   2910   assert(LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
   2911 
   2912   if (UnsafeFPMath &&
   2913       (CC == ISD::SETEQ || CC == ISD::SETOEQ ||
   2914        CC == ISD::SETNE || CC == ISD::SETUNE)) {
   2915     SDValue Result = OptimizeVFPBrcond(Op, DAG);
   2916     if (Result.getNode())
   2917       return Result;
   2918   }
   2919 
   2920   ARMCC::CondCodes CondCode, CondCode2;
   2921   FPCCToARMCC(CC, CondCode, CondCode2);
   2922 
   2923   SDValue ARMcc = DAG.getConstant(CondCode, MVT::i32);
   2924   SDValue Cmp = getVFPCmp(LHS, RHS, DAG, dl);
   2925   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
   2926   SDVTList VTList = DAG.getVTList(MVT::Other, MVT::Glue);
   2927   SDValue Ops[] = { Chain, Dest, ARMcc, CCR, Cmp };
   2928   SDValue Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops, 5);
   2929   if (CondCode2 != ARMCC::AL) {
   2930     ARMcc = DAG.getConstant(CondCode2, MVT::i32);
   2931     SDValue Ops[] = { Res, Dest, ARMcc, CCR, Res.getValue(1) };
   2932     Res = DAG.getNode(ARMISD::BRCOND, dl, VTList, Ops, 5);
   2933   }
   2934   return Res;
   2935 }
   2936 
   2937 SDValue ARMTargetLowering::LowerBR_JT(SDValue Op, SelectionDAG &DAG) const {
   2938   SDValue Chain = Op.getOperand(0);
   2939   SDValue Table = Op.getOperand(1);
   2940   SDValue Index = Op.getOperand(2);
   2941   DebugLoc dl = Op.getDebugLoc();
   2942 
   2943   EVT PTy = getPointerTy();
   2944   JumpTableSDNode *JT = cast<JumpTableSDNode>(Table);
   2945   ARMFunctionInfo *AFI = DAG.getMachineFunction().getInfo<ARMFunctionInfo>();
   2946   SDValue UId = DAG.getConstant(AFI->createJumpTableUId(), PTy);
   2947   SDValue JTI = DAG.getTargetJumpTable(JT->getIndex(), PTy);
   2948   Table = DAG.getNode(ARMISD::WrapperJT, dl, MVT::i32, JTI, UId);
   2949   Index = DAG.getNode(ISD::MUL, dl, PTy, Index, DAG.getConstant(4, PTy));
   2950   SDValue Addr = DAG.getNode(ISD::ADD, dl, PTy, Index, Table);
   2951   if (Subtarget->isThumb2()) {
   2952     // Thumb2 uses a two-level jump. That is, it jumps into the jump table
   2953     // which does another jump to the destination. This also makes it easier
   2954     // to translate it to TBB / TBH later.
   2955     // FIXME: This might not work if the function is extremely large.
   2956     return DAG.getNode(ARMISD::BR2_JT, dl, MVT::Other, Chain,
   2957                        Addr, Op.getOperand(2), JTI, UId);
   2958   }
   2959   if (getTargetMachine().getRelocationModel() == Reloc::PIC_) {
   2960     Addr = DAG.getLoad((EVT)MVT::i32, dl, Chain, Addr,
   2961                        MachinePointerInfo::getJumpTable(),
   2962                        false, false, 0);
   2963     Chain = Addr.getValue(1);
   2964     Addr = DAG.getNode(ISD::ADD, dl, PTy, Addr, Table);
   2965     return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI, UId);
   2966   } else {
   2967     Addr = DAG.getLoad(PTy, dl, Chain, Addr,
   2968                        MachinePointerInfo::getJumpTable(), false, false, 0);
   2969     Chain = Addr.getValue(1);
   2970     return DAG.getNode(ARMISD::BR_JT, dl, MVT::Other, Chain, Addr, JTI, UId);
   2971   }
   2972 }
   2973 
   2974 static SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) {
   2975   DebugLoc dl = Op.getDebugLoc();
   2976   unsigned Opc;
   2977 
   2978   switch (Op.getOpcode()) {
   2979   default:
   2980     assert(0 && "Invalid opcode!");
   2981   case ISD::FP_TO_SINT:
   2982     Opc = ARMISD::FTOSI;
   2983     break;
   2984   case ISD::FP_TO_UINT:
   2985     Opc = ARMISD::FTOUI;
   2986     break;
   2987   }
   2988   Op = DAG.getNode(Opc, dl, MVT::f32, Op.getOperand(0));
   2989   return DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
   2990 }
   2991 
   2992 static SDValue LowerVectorINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
   2993   EVT VT = Op.getValueType();
   2994   DebugLoc dl = Op.getDebugLoc();
   2995 
   2996   EVT OperandVT = Op.getOperand(0).getValueType();
   2997   assert(OperandVT == MVT::v4i16 && "Invalid type for custom lowering!");
   2998   if (VT != MVT::v4f32)
   2999     return DAG.UnrollVectorOp(Op.getNode());
   3000 
   3001   unsigned CastOpc;
   3002   unsigned Opc;
   3003   switch (Op.getOpcode()) {
   3004   default:
   3005     assert(0 && "Invalid opcode!");
   3006   case ISD::SINT_TO_FP:
   3007     CastOpc = ISD::SIGN_EXTEND;
   3008     Opc = ISD::SINT_TO_FP;
   3009     break;
   3010   case ISD::UINT_TO_FP:
   3011     CastOpc = ISD::ZERO_EXTEND;
   3012     Opc = ISD::UINT_TO_FP;
   3013     break;
   3014   }
   3015 
   3016   Op = DAG.getNode(CastOpc, dl, MVT::v4i32, Op.getOperand(0));
   3017   return DAG.getNode(Opc, dl, VT, Op);
   3018 }
   3019 
   3020 static SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) {
   3021   EVT VT = Op.getValueType();
   3022   if (VT.isVector())
   3023     return LowerVectorINT_TO_FP(Op, DAG);
   3024 
   3025   DebugLoc dl = Op.getDebugLoc();
   3026   unsigned Opc;
   3027 
   3028   switch (Op.getOpcode()) {
   3029   default:
   3030     assert(0 && "Invalid opcode!");
   3031   case ISD::SINT_TO_FP:
   3032     Opc = ARMISD::SITOF;
   3033     break;
   3034   case ISD::UINT_TO_FP:
   3035     Opc = ARMISD::UITOF;
   3036     break;
   3037   }
   3038 
   3039   Op = DAG.getNode(ISD::BITCAST, dl, MVT::f32, Op.getOperand(0));
   3040   return DAG.getNode(Opc, dl, VT, Op);
   3041 }
   3042 
   3043 SDValue ARMTargetLowering::LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
   3044   // Implement fcopysign with a fabs and a conditional fneg.
   3045   SDValue Tmp0 = Op.getOperand(0);
   3046   SDValue Tmp1 = Op.getOperand(1);
   3047   DebugLoc dl = Op.getDebugLoc();
   3048   EVT VT = Op.getValueType();
   3049   EVT SrcVT = Tmp1.getValueType();
   3050   bool InGPR = Tmp0.getOpcode() == ISD::BITCAST ||
   3051     Tmp0.getOpcode() == ARMISD::VMOVDRR;
   3052   bool UseNEON = !InGPR && Subtarget->hasNEON();
   3053 
   3054   if (UseNEON) {
   3055     // Use VBSL to copy the sign bit.
   3056     unsigned EncodedVal = ARM_AM::createNEONModImm(0x6, 0x80);
   3057     SDValue Mask = DAG.getNode(ARMISD::VMOVIMM, dl, MVT::v2i32,
   3058                                DAG.getTargetConstant(EncodedVal, MVT::i32));
   3059     EVT OpVT = (VT == MVT::f32) ? MVT::v2i32 : MVT::v1i64;
   3060     if (VT == MVT::f64)
   3061       Mask = DAG.getNode(ARMISD::VSHL, dl, OpVT,
   3062                          DAG.getNode(ISD::BITCAST, dl, OpVT, Mask),
   3063                          DAG.getConstant(32, MVT::i32));
   3064     else /*if (VT == MVT::f32)*/
   3065       Tmp0 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2f32, Tmp0);
   3066     if (SrcVT == MVT::f32) {
   3067       Tmp1 = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, MVT::v2f32, Tmp1);
   3068       if (VT == MVT::f64)
   3069         Tmp1 = DAG.getNode(ARMISD::VSHL, dl, OpVT,
   3070                            DAG.getNode(ISD::BITCAST, dl, OpVT, Tmp1),
   3071                            DAG.getConstant(32, MVT::i32));
   3072     } else if (VT == MVT::f32)
   3073       Tmp1 = DAG.getNode(ARMISD::VSHRu, dl, MVT::v1i64,
   3074                          DAG.getNode(ISD::BITCAST, dl, MVT::v1i64, Tmp1),
   3075                          DAG.getConstant(32, MVT::i32));
   3076     Tmp0 = DAG.getNode(ISD::BITCAST, dl, OpVT, Tmp0);
   3077     Tmp1 = DAG.getNode(ISD::BITCAST, dl, OpVT, Tmp1);
   3078 
   3079     SDValue AllOnes = DAG.getTargetConstant(ARM_AM::createNEONModImm(0xe, 0xff),
   3080                                             MVT::i32);
   3081     AllOnes = DAG.getNode(ARMISD::VMOVIMM, dl, MVT::v8i8, AllOnes);
   3082     SDValue MaskNot = DAG.getNode(ISD::XOR, dl, OpVT, Mask,
   3083                                   DAG.getNode(ISD::BITCAST, dl, OpVT, AllOnes));
   3084 
   3085     SDValue Res = DAG.getNode(ISD::OR, dl, OpVT,
   3086                               DAG.getNode(ISD::AND, dl, OpVT, Tmp1, Mask),
   3087                               DAG.getNode(ISD::AND, dl, OpVT, Tmp0, MaskNot));
   3088     if (VT == MVT::f32) {
   3089       Res = DAG.getNode(ISD::BITCAST, dl, MVT::v2f32, Res);
   3090       Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f32, Res,
   3091                         DAG.getConstant(0, MVT::i32));
   3092     } else {
   3093       Res = DAG.getNode(ISD::BITCAST, dl, MVT::f64, Res);
   3094     }
   3095 
   3096     return Res;
   3097   }
   3098 
   3099   // Bitcast operand 1 to i32.
   3100   if (SrcVT == MVT::f64)
   3101     Tmp1 = DAG.getNode(ARMISD::VMOVRRD, dl, DAG.getVTList(MVT::i32, MVT::i32),
   3102                        &Tmp1, 1).getValue(1);
   3103   Tmp1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Tmp1);
   3104 
   3105   // Or in the signbit with integer operations.
   3106   SDValue Mask1 = DAG.getConstant(0x80000000, MVT::i32);
   3107   SDValue Mask2 = DAG.getConstant(0x7fffffff, MVT::i32);
   3108   Tmp1 = DAG.getNode(ISD::AND, dl, MVT::i32, Tmp1, Mask1);
   3109   if (VT == MVT::f32) {
   3110     Tmp0 = DAG.getNode(ISD::AND, dl, MVT::i32,
   3111                        DAG.getNode(ISD::BITCAST, dl, MVT::i32, Tmp0), Mask2);
   3112     return DAG.getNode(ISD::BITCAST, dl, MVT::f32,
   3113                        DAG.getNode(ISD::OR, dl, MVT::i32, Tmp0, Tmp1));
   3114   }
   3115 
   3116   // f64: Or the high part with signbit and then combine two parts.
   3117   Tmp0 = DAG.getNode(ARMISD::VMOVRRD, dl, DAG.getVTList(MVT::i32, MVT::i32),
   3118                      &Tmp0, 1);
   3119   SDValue Lo = Tmp0.getValue(0);
   3120   SDValue Hi = DAG.getNode(ISD::AND, dl, MVT::i32, Tmp0.getValue(1), Mask2);
   3121   Hi = DAG.getNode(ISD::OR, dl, MVT::i32, Hi, Tmp1);
   3122   return DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi);
   3123 }
   3124 
   3125 SDValue ARMTargetLowering::LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const{
   3126   MachineFunction &MF = DAG.getMachineFunction();
   3127   MachineFrameInfo *MFI = MF.getFrameInfo();
   3128   MFI->setReturnAddressIsTaken(true);
   3129 
   3130   EVT VT = Op.getValueType();
   3131   DebugLoc dl = Op.getDebugLoc();
   3132   unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
   3133   if (Depth) {
   3134     SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
   3135     SDValue Offset = DAG.getConstant(4, MVT::i32);
   3136     return DAG.getLoad(VT, dl, DAG.getEntryNode(),
   3137                        DAG.getNode(ISD::ADD, dl, VT, FrameAddr, Offset),
   3138                        MachinePointerInfo(), false, false, 0);
   3139   }
   3140 
   3141   // Return LR, which contains the return address. Mark it an implicit live-in.
   3142   unsigned Reg = MF.addLiveIn(ARM::LR, getRegClassFor(MVT::i32));
   3143   return DAG.getCopyFromReg(DAG.getEntryNode(), dl, Reg, VT);
   3144 }
   3145 
   3146 SDValue ARMTargetLowering::LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
   3147   MachineFrameInfo *MFI = DAG.getMachineFunction().getFrameInfo();
   3148   MFI->setFrameAddressIsTaken(true);
   3149 
   3150   EVT VT = Op.getValueType();
   3151   DebugLoc dl = Op.getDebugLoc();  // FIXME probably not meaningful
   3152   unsigned Depth = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
   3153   unsigned FrameReg = (Subtarget->isThumb() || Subtarget->isTargetDarwin())
   3154     ? ARM::R7 : ARM::R11;
   3155   SDValue FrameAddr = DAG.getCopyFromReg(DAG.getEntryNode(), dl, FrameReg, VT);
   3156   while (Depth--)
   3157     FrameAddr = DAG.getLoad(VT, dl, DAG.getEntryNode(), FrameAddr,
   3158                             MachinePointerInfo(),
   3159                             false, false, 0);
   3160   return FrameAddr;
   3161 }
   3162 
   3163 /// ExpandBITCAST - If the target supports VFP, this function is called to
   3164 /// expand a bit convert where either the source or destination type is i64 to
   3165 /// use a VMOVDRR or VMOVRRD node.  This should not be done when the non-i64
   3166 /// operand type is illegal (e.g., v2f32 for a target that doesn't support
   3167 /// vectors), since the legalizer won't know what to do with that.
   3168 static SDValue ExpandBITCAST(SDNode *N, SelectionDAG &DAG) {
   3169   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   3170   DebugLoc dl = N->getDebugLoc();
   3171   SDValue Op = N->getOperand(0);
   3172 
   3173   // This function is only supposed to be called for i64 types, either as the
   3174   // source or destination of the bit convert.
   3175   EVT SrcVT = Op.getValueType();
   3176   EVT DstVT = N->getValueType(0);
   3177   assert((SrcVT == MVT::i64 || DstVT == MVT::i64) &&
   3178          "ExpandBITCAST called for non-i64 type");
   3179 
   3180   // Turn i64->f64 into VMOVDRR.
   3181   if (SrcVT == MVT::i64 && TLI.isTypeLegal(DstVT)) {
   3182     SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Op,
   3183                              DAG.getConstant(0, MVT::i32));
   3184     SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, Op,
   3185                              DAG.getConstant(1, MVT::i32));
   3186     return DAG.getNode(ISD::BITCAST, dl, DstVT,
   3187                        DAG.getNode(ARMISD::VMOVDRR, dl, MVT::f64, Lo, Hi));
   3188   }
   3189 
   3190   // Turn f64->i64 into VMOVRRD.
   3191   if (DstVT == MVT::i64 && TLI.isTypeLegal(SrcVT)) {
   3192     SDValue Cvt = DAG.getNode(ARMISD::VMOVRRD, dl,
   3193                               DAG.getVTList(MVT::i32, MVT::i32), &Op, 1);
   3194     // Merge the pieces into a single i64 value.
   3195     return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Cvt, Cvt.getValue(1));
   3196   }
   3197 
   3198   return SDValue();
   3199 }
   3200 
   3201 /// getZeroVector - Returns a vector of specified type with all zero elements.
   3202 /// Zero vectors are used to represent vector negation and in those cases
   3203 /// will be implemented with the NEON VNEG instruction.  However, VNEG does
   3204 /// not support i64 elements, so sometimes the zero vectors will need to be
   3205 /// explicitly constructed.  Regardless, use a canonical VMOV to create the
   3206 /// zero vector.
   3207 static SDValue getZeroVector(EVT VT, SelectionDAG &DAG, DebugLoc dl) {
   3208   assert(VT.isVector() && "Expected a vector type");
   3209   // The canonical modified immediate encoding of a zero vector is....0!
   3210   SDValue EncodedVal = DAG.getTargetConstant(0, MVT::i32);
   3211   EVT VmovVT = VT.is128BitVector() ? MVT::v4i32 : MVT::v2i32;
   3212   SDValue Vmov = DAG.getNode(ARMISD::VMOVIMM, dl, VmovVT, EncodedVal);
   3213   return DAG.getNode(ISD::BITCAST, dl, VT, Vmov);
   3214 }
   3215 
   3216 /// LowerShiftRightParts - Lower SRA_PARTS, which returns two
   3217 /// i32 values and take a 2 x i32 value to shift plus a shift amount.
   3218 SDValue ARMTargetLowering::LowerShiftRightParts(SDValue Op,
   3219                                                 SelectionDAG &DAG) const {
   3220   assert(Op.getNumOperands() == 3 && "Not a double-shift!");
   3221   EVT VT = Op.getValueType();
   3222   unsigned VTBits = VT.getSizeInBits();
   3223   DebugLoc dl = Op.getDebugLoc();
   3224   SDValue ShOpLo = Op.getOperand(0);
   3225   SDValue ShOpHi = Op.getOperand(1);
   3226   SDValue ShAmt  = Op.getOperand(2);
   3227   SDValue ARMcc;
   3228   unsigned Opc = (Op.getOpcode() == ISD::SRA_PARTS) ? ISD::SRA : ISD::SRL;
   3229 
   3230   assert(Op.getOpcode() == ISD::SRA_PARTS || Op.getOpcode() == ISD::SRL_PARTS);
   3231 
   3232   SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
   3233                                  DAG.getConstant(VTBits, MVT::i32), ShAmt);
   3234   SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, ShAmt);
   3235   SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32, ShAmt,
   3236                                    DAG.getConstant(VTBits, MVT::i32));
   3237   SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, RevShAmt);
   3238   SDValue FalseVal = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
   3239   SDValue TrueVal = DAG.getNode(Opc, dl, VT, ShOpHi, ExtraShAmt);
   3240 
   3241   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
   3242   SDValue Cmp = getARMCmp(ExtraShAmt, DAG.getConstant(0, MVT::i32), ISD::SETGE,
   3243                           ARMcc, DAG, dl);
   3244   SDValue Hi = DAG.getNode(Opc, dl, VT, ShOpHi, ShAmt);
   3245   SDValue Lo = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, TrueVal, ARMcc,
   3246                            CCR, Cmp);
   3247 
   3248   SDValue Ops[2] = { Lo, Hi };
   3249   return DAG.getMergeValues(Ops, 2, dl);
   3250 }
   3251 
   3252 /// LowerShiftLeftParts - Lower SHL_PARTS, which returns two
   3253 /// i32 values and take a 2 x i32 value to shift plus a shift amount.
   3254 SDValue ARMTargetLowering::LowerShiftLeftParts(SDValue Op,
   3255                                                SelectionDAG &DAG) const {
   3256   assert(Op.getNumOperands() == 3 && "Not a double-shift!");
   3257   EVT VT = Op.getValueType();
   3258   unsigned VTBits = VT.getSizeInBits();
   3259   DebugLoc dl = Op.getDebugLoc();
   3260   SDValue ShOpLo = Op.getOperand(0);
   3261   SDValue ShOpHi = Op.getOperand(1);
   3262   SDValue ShAmt  = Op.getOperand(2);
   3263   SDValue ARMcc;
   3264 
   3265   assert(Op.getOpcode() == ISD::SHL_PARTS);
   3266   SDValue RevShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32,
   3267                                  DAG.getConstant(VTBits, MVT::i32), ShAmt);
   3268   SDValue Tmp1 = DAG.getNode(ISD::SRL, dl, VT, ShOpLo, RevShAmt);
   3269   SDValue ExtraShAmt = DAG.getNode(ISD::SUB, dl, MVT::i32, ShAmt,
   3270                                    DAG.getConstant(VTBits, MVT::i32));
   3271   SDValue Tmp2 = DAG.getNode(ISD::SHL, dl, VT, ShOpHi, ShAmt);
   3272   SDValue Tmp3 = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ExtraShAmt);
   3273 
   3274   SDValue FalseVal = DAG.getNode(ISD::OR, dl, VT, Tmp1, Tmp2);
   3275   SDValue CCR = DAG.getRegister(ARM::CPSR, MVT::i32);
   3276   SDValue Cmp = getARMCmp(ExtraShAmt, DAG.getConstant(0, MVT::i32), ISD::SETGE,
   3277                           ARMcc, DAG, dl);
   3278   SDValue Lo = DAG.getNode(ISD::SHL, dl, VT, ShOpLo, ShAmt);
   3279   SDValue Hi = DAG.getNode(ARMISD::CMOV, dl, VT, FalseVal, Tmp3, ARMcc,
   3280                            CCR, Cmp);
   3281 
   3282   SDValue Ops[2] = { Lo, Hi };
   3283   return DAG.getMergeValues(Ops, 2, dl);
   3284 }
   3285 
   3286 SDValue ARMTargetLowering::LowerFLT_ROUNDS_(SDValue Op,
   3287                                             SelectionDAG &DAG) const {
   3288   // The rounding mode is in bits 23:22 of the FPSCR.
   3289   // The ARM rounding mode value to FLT_ROUNDS mapping is 0->1, 1->2, 2->3, 3->0
   3290   // The formula we use to implement this is (((FPSCR + 1 << 22) >> 22) & 3)
   3291   // so that the shift + and get folded into a bitfield extract.
   3292   DebugLoc dl = Op.getDebugLoc();
   3293   SDValue FPSCR = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::i32,
   3294                               DAG.getConstant(Intrinsic::arm_get_fpscr,
   3295                                               MVT::i32));
   3296   SDValue FltRounds = DAG.getNode(ISD::ADD, dl, MVT::i32, FPSCR,
   3297                                   DAG.getConstant(1U << 22, MVT::i32));
   3298   SDValue RMODE = DAG.getNode(ISD::SRL, dl, MVT::i32, FltRounds,
   3299                               DAG.getConstant(22, MVT::i32));
   3300   return DAG.getNode(ISD::AND, dl, MVT::i32, RMODE,
   3301                      DAG.getConstant(3, MVT::i32));
   3302 }
   3303 
   3304 static SDValue LowerCTTZ(SDNode *N, SelectionDAG &DAG,
   3305                          const ARMSubtarget *ST) {
   3306   EVT VT = N->getValueType(0);
   3307   DebugLoc dl = N->getDebugLoc();
   3308 
   3309   if (!ST->hasV6T2Ops())
   3310     return SDValue();
   3311 
   3312   SDValue rbit = DAG.getNode(ARMISD::RBIT, dl, VT, N->getOperand(0));
   3313   return DAG.getNode(ISD::CTLZ, dl, VT, rbit);
   3314 }
   3315 
   3316 static SDValue LowerShift(SDNode *N, SelectionDAG &DAG,
   3317                           const ARMSubtarget *ST) {
   3318   EVT VT = N->getValueType(0);
   3319   DebugLoc dl = N->getDebugLoc();
   3320 
   3321   if (!VT.isVector())
   3322     return SDValue();
   3323 
   3324   // Lower vector shifts on NEON to use VSHL.
   3325   assert(ST->hasNEON() && "unexpected vector shift");
   3326 
   3327   // Left shifts translate directly to the vshiftu intrinsic.
   3328   if (N->getOpcode() == ISD::SHL)
   3329     return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
   3330                        DAG.getConstant(Intrinsic::arm_neon_vshiftu, MVT::i32),
   3331                        N->getOperand(0), N->getOperand(1));
   3332 
   3333   assert((N->getOpcode() == ISD::SRA ||
   3334           N->getOpcode() == ISD::SRL) && "unexpected vector shift opcode");
   3335 
   3336   // NEON uses the same intrinsics for both left and right shifts.  For
   3337   // right shifts, the shift amounts are negative, so negate the vector of
   3338   // shift amounts.
   3339   EVT ShiftVT = N->getOperand(1).getValueType();
   3340   SDValue NegatedCount = DAG.getNode(ISD::SUB, dl, ShiftVT,
   3341                                      getZeroVector(ShiftVT, DAG, dl),
   3342                                      N->getOperand(1));
   3343   Intrinsic::ID vshiftInt = (N->getOpcode() == ISD::SRA ?
   3344                              Intrinsic::arm_neon_vshifts :
   3345                              Intrinsic::arm_neon_vshiftu);
   3346   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
   3347                      DAG.getConstant(vshiftInt, MVT::i32),
   3348                      N->getOperand(0), NegatedCount);
   3349 }
   3350 
   3351 static SDValue Expand64BitShift(SDNode *N, SelectionDAG &DAG,
   3352                                 const ARMSubtarget *ST) {
   3353   EVT VT = N->getValueType(0);
   3354   DebugLoc dl = N->getDebugLoc();
   3355 
   3356   // We can get here for a node like i32 = ISD::SHL i32, i64
   3357   if (VT != MVT::i64)
   3358     return SDValue();
   3359 
   3360   assert((N->getOpcode() == ISD::SRL || N->getOpcode() == ISD::SRA) &&
   3361          "Unknown shift to lower!");
   3362 
   3363   // We only lower SRA, SRL of 1 here, all others use generic lowering.
   3364   if (!isa<ConstantSDNode>(N->getOperand(1)) ||
   3365       cast<ConstantSDNode>(N->getOperand(1))->getZExtValue() != 1)
   3366     return SDValue();
   3367 
   3368   // If we are in thumb mode, we don't have RRX.
   3369   if (ST->isThumb1Only()) return SDValue();
   3370 
   3371   // Okay, we have a 64-bit SRA or SRL of 1.  Lower this to an RRX expr.
   3372   SDValue Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, N->getOperand(0),
   3373                            DAG.getConstant(0, MVT::i32));
   3374   SDValue Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, MVT::i32, N->getOperand(0),
   3375                            DAG.getConstant(1, MVT::i32));
   3376 
   3377   // First, build a SRA_FLAG/SRL_FLAG op, which shifts the top part by one and
   3378   // captures the result into a carry flag.
   3379   unsigned Opc = N->getOpcode() == ISD::SRL ? ARMISD::SRL_FLAG:ARMISD::SRA_FLAG;
   3380   Hi = DAG.getNode(Opc, dl, DAG.getVTList(MVT::i32, MVT::Glue), &Hi, 1);
   3381 
   3382   // The low part is an ARMISD::RRX operand, which shifts the carry in.
   3383   Lo = DAG.getNode(ARMISD::RRX, dl, MVT::i32, Lo, Hi.getValue(1));
   3384 
   3385   // Merge the pieces into a single i64 value.
   3386  return DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, Lo, Hi);
   3387 }
   3388 
   3389 static SDValue LowerVSETCC(SDValue Op, SelectionDAG &DAG) {
   3390   SDValue TmpOp0, TmpOp1;
   3391   bool Invert = false;
   3392   bool Swap = false;
   3393   unsigned Opc = 0;
   3394 
   3395   SDValue Op0 = Op.getOperand(0);
   3396   SDValue Op1 = Op.getOperand(1);
   3397   SDValue CC = Op.getOperand(2);
   3398   EVT VT = Op.getValueType();
   3399   ISD::CondCode SetCCOpcode = cast<CondCodeSDNode>(CC)->get();
   3400   DebugLoc dl = Op.getDebugLoc();
   3401 
   3402   if (Op.getOperand(1).getValueType().isFloatingPoint()) {
   3403     switch (SetCCOpcode) {
   3404     default: llvm_unreachable("Illegal FP comparison"); break;
   3405     case ISD::SETUNE:
   3406     case ISD::SETNE:  Invert = true; // Fallthrough
   3407     case ISD::SETOEQ:
   3408     case ISD::SETEQ:  Opc = ARMISD::VCEQ; break;
   3409     case ISD::SETOLT:
   3410     case ISD::SETLT: Swap = true; // Fallthrough
   3411     case ISD::SETOGT:
   3412     case ISD::SETGT:  Opc = ARMISD::VCGT; break;
   3413     case ISD::SETOLE:
   3414     case ISD::SETLE:  Swap = true; // Fallthrough
   3415     case ISD::SETOGE:
   3416     case ISD::SETGE: Opc = ARMISD::VCGE; break;
   3417     case ISD::SETUGE: Swap = true; // Fallthrough
   3418     case ISD::SETULE: Invert = true; Opc = ARMISD::VCGT; break;
   3419     case ISD::SETUGT: Swap = true; // Fallthrough
   3420     case ISD::SETULT: Invert = true; Opc = ARMISD::VCGE; break;
   3421     case ISD::SETUEQ: Invert = true; // Fallthrough
   3422     case ISD::SETONE:
   3423       // Expand this to (OLT | OGT).
   3424       TmpOp0 = Op0;
   3425       TmpOp1 = Op1;
   3426       Opc = ISD::OR;
   3427       Op0 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp1, TmpOp0);
   3428       Op1 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp0, TmpOp1);
   3429       break;
   3430     case ISD::SETUO: Invert = true; // Fallthrough
   3431     case ISD::SETO:
   3432       // Expand this to (OLT | OGE).
   3433       TmpOp0 = Op0;
   3434       TmpOp1 = Op1;
   3435       Opc = ISD::OR;
   3436       Op0 = DAG.getNode(ARMISD::VCGT, dl, VT, TmpOp1, TmpOp0);
   3437       Op1 = DAG.getNode(ARMISD::VCGE, dl, VT, TmpOp0, TmpOp1);
   3438       break;
   3439     }
   3440   } else {
   3441     // Integer comparisons.
   3442     switch (SetCCOpcode) {
   3443     default: llvm_unreachable("Illegal integer comparison"); break;
   3444     case ISD::SETNE:  Invert = true;
   3445     case ISD::SETEQ:  Opc = ARMISD::VCEQ; break;
   3446     case ISD::SETLT:  Swap = true;
   3447     case ISD::SETGT:  Opc = ARMISD::VCGT; break;
   3448     case ISD::SETLE:  Swap = true;
   3449     case ISD::SETGE:  Opc = ARMISD::VCGE; break;
   3450     case ISD::SETULT: Swap = true;
   3451     case ISD::SETUGT: Opc = ARMISD::VCGTU; break;
   3452     case ISD::SETULE: Swap = true;
   3453     case ISD::SETUGE: Opc = ARMISD::VCGEU; break;
   3454     }
   3455 
   3456     // Detect VTST (Vector Test Bits) = icmp ne (and (op0, op1), zero).
   3457     if (Opc == ARMISD::VCEQ) {
   3458 
   3459       SDValue AndOp;
   3460       if (ISD::isBuildVectorAllZeros(Op1.getNode()))
   3461         AndOp = Op0;
   3462       else if (ISD::isBuildVectorAllZeros(Op0.getNode()))
   3463         AndOp = Op1;
   3464 
   3465       // Ignore bitconvert.
   3466       if (AndOp.getNode() && AndOp.getOpcode() == ISD::BITCAST)
   3467         AndOp = AndOp.getOperand(0);
   3468 
   3469       if (AndOp.getNode() && AndOp.getOpcode() == ISD::AND) {
   3470         Opc = ARMISD::VTST;
   3471         Op0 = DAG.getNode(ISD::BITCAST, dl, VT, AndOp.getOperand(0));
   3472         Op1 = DAG.getNode(ISD::BITCAST, dl, VT, AndOp.getOperand(1));
   3473         Invert = !Invert;
   3474       }
   3475     }
   3476   }
   3477 
   3478   if (Swap)
   3479     std::swap(Op0, Op1);
   3480 
   3481   // If one of the operands is a constant vector zero, attempt to fold the
   3482   // comparison to a specialized compare-against-zero form.
   3483   SDValue SingleOp;
   3484   if (ISD::isBuildVectorAllZeros(Op1.getNode()))
   3485     SingleOp = Op0;
   3486   else if (ISD::isBuildVectorAllZeros(Op0.getNode())) {
   3487     if (Opc == ARMISD::VCGE)
   3488       Opc = ARMISD::VCLEZ;
   3489     else if (Opc == ARMISD::VCGT)
   3490       Opc = ARMISD::VCLTZ;
   3491     SingleOp = Op1;
   3492   }
   3493 
   3494   SDValue Result;
   3495   if (SingleOp.getNode()) {
   3496     switch (Opc) {
   3497     case ARMISD::VCEQ:
   3498       Result = DAG.getNode(ARMISD::VCEQZ, dl, VT, SingleOp); break;
   3499     case ARMISD::VCGE:
   3500       Result = DAG.getNode(ARMISD::VCGEZ, dl, VT, SingleOp); break;
   3501     case ARMISD::VCLEZ:
   3502       Result = DAG.getNode(ARMISD::VCLEZ, dl, VT, SingleOp); break;
   3503     case ARMISD::VCGT:
   3504       Result = DAG.getNode(ARMISD::VCGTZ, dl, VT, SingleOp); break;
   3505     case ARMISD::VCLTZ:
   3506       Result = DAG.getNode(ARMISD::VCLTZ, dl, VT, SingleOp); break;
   3507     default:
   3508       Result = DAG.getNode(Opc, dl, VT, Op0, Op1);
   3509     }
   3510   } else {
   3511      Result = DAG.getNode(Opc, dl, VT, Op0, Op1);
   3512   }
   3513 
   3514   if (Invert)
   3515     Result = DAG.getNOT(dl, Result, VT);
   3516 
   3517   return Result;
   3518 }
   3519 
   3520 /// isNEONModifiedImm - Check if the specified splat value corresponds to a
   3521 /// valid vector constant for a NEON instruction with a "modified immediate"
   3522 /// operand (e.g., VMOV).  If so, return the encoded value.
   3523 static SDValue isNEONModifiedImm(uint64_t SplatBits, uint64_t SplatUndef,
   3524                                  unsigned SplatBitSize, SelectionDAG &DAG,
   3525                                  EVT &VT, bool is128Bits, NEONModImmType type) {
   3526   unsigned OpCmode, Imm;
   3527 
   3528   // SplatBitSize is set to the smallest size that splats the vector, so a
   3529   // zero vector will always have SplatBitSize == 8.  However, NEON modified
   3530   // immediate instructions others than VMOV do not support the 8-bit encoding
   3531   // of a zero vector, and the default encoding of zero is supposed to be the
   3532   // 32-bit version.
   3533   if (SplatBits == 0)
   3534     SplatBitSize = 32;
   3535 
   3536   switch (SplatBitSize) {
   3537   case 8:
   3538     if (type != VMOVModImm)
   3539       return SDValue();
   3540     // Any 1-byte value is OK.  Op=0, Cmode=1110.
   3541     assert((SplatBits & ~0xff) == 0 && "one byte splat value is too big");
   3542     OpCmode = 0xe;
   3543     Imm = SplatBits;
   3544     VT = is128Bits ? MVT::v16i8 : MVT::v8i8;
   3545     break;
   3546 
   3547   case 16:
   3548     // NEON's 16-bit VMOV supports splat values where only one byte is nonzero.
   3549     VT = is128Bits ? MVT::v8i16 : MVT::v4i16;
   3550     if ((SplatBits & ~0xff) == 0) {
   3551       // Value = 0x00nn: Op=x, Cmode=100x.
   3552       OpCmode = 0x8;
   3553       Imm = SplatBits;
   3554       break;
   3555     }
   3556     if ((SplatBits & ~0xff00) == 0) {
   3557       // Value = 0xnn00: Op=x, Cmode=101x.
   3558       OpCmode = 0xa;
   3559       Imm = SplatBits >> 8;
   3560       break;
   3561     }
   3562     return SDValue();
   3563 
   3564   case 32:
   3565     // NEON's 32-bit VMOV supports splat values where:
   3566     // * only one byte is nonzero, or
   3567     // * the least significant byte is 0xff and the second byte is nonzero, or
   3568     // * the least significant 2 bytes are 0xff and the third is nonzero.
   3569     VT = is128Bits ? MVT::v4i32 : MVT::v2i32;
   3570     if ((SplatBits & ~0xff) == 0) {
   3571       // Value = 0x000000nn: Op=x, Cmode=000x.
   3572       OpCmode = 0;
   3573       Imm = SplatBits;
   3574       break;
   3575     }
   3576     if ((SplatBits & ~0xff00) == 0) {
   3577       // Value = 0x0000nn00: Op=x, Cmode=001x.
   3578       OpCmode = 0x2;
   3579       Imm = SplatBits >> 8;
   3580       break;
   3581     }
   3582     if ((SplatBits & ~0xff0000) == 0) {
   3583       // Value = 0x00nn0000: Op=x, Cmode=010x.
   3584       OpCmode = 0x4;
   3585       Imm = SplatBits >> 16;
   3586       break;
   3587     }
   3588     if ((SplatBits & ~0xff000000) == 0) {
   3589       // Value = 0xnn000000: Op=x, Cmode=011x.
   3590       OpCmode = 0x6;
   3591       Imm = SplatBits >> 24;
   3592       break;
   3593     }
   3594 
   3595     // cmode == 0b1100 and cmode == 0b1101 are not supported for VORR or VBIC
   3596     if (type == OtherModImm) return SDValue();
   3597 
   3598     if ((SplatBits & ~0xffff) == 0 &&
   3599         ((SplatBits | SplatUndef) & 0xff) == 0xff) {
   3600       // Value = 0x0000nnff: Op=x, Cmode=1100.
   3601       OpCmode = 0xc;
   3602       Imm = SplatBits >> 8;
   3603       SplatBits |= 0xff;
   3604       break;
   3605     }
   3606 
   3607     if ((SplatBits & ~0xffffff) == 0 &&
   3608         ((SplatBits | SplatUndef) & 0xffff) == 0xffff) {
   3609       // Value = 0x00nnffff: Op=x, Cmode=1101.
   3610       OpCmode = 0xd;
   3611       Imm = SplatBits >> 16;
   3612       SplatBits |= 0xffff;
   3613       break;
   3614     }
   3615 
   3616     // Note: there are a few 32-bit splat values (specifically: 00ffff00,
   3617     // ff000000, ff0000ff, and ffff00ff) that are valid for VMOV.I64 but not
   3618     // VMOV.I32.  A (very) minor optimization would be to replicate the value
   3619     // and fall through here to test for a valid 64-bit splat.  But, then the
   3620     // caller would also need to check and handle the change in size.
   3621     return SDValue();
   3622 
   3623   case 64: {
   3624     if (type != VMOVModImm)
   3625       return SDValue();
   3626     // NEON has a 64-bit VMOV splat where each byte is either 0 or 0xff.
   3627     uint64_t BitMask = 0xff;
   3628     uint64_t Val = 0;
   3629     unsigned ImmMask = 1;
   3630     Imm = 0;
   3631     for (int ByteNum = 0; ByteNum < 8; ++ByteNum) {
   3632       if (((SplatBits | SplatUndef) & BitMask) == BitMask) {
   3633         Val |= BitMask;
   3634         Imm |= ImmMask;
   3635       } else if ((SplatBits & BitMask) != 0) {
   3636         return SDValue();
   3637       }
   3638       BitMask <<= 8;
   3639       ImmMask <<= 1;
   3640     }
   3641     // Op=1, Cmode=1110.
   3642     OpCmode = 0x1e;
   3643     SplatBits = Val;
   3644     VT = is128Bits ? MVT::v2i64 : MVT::v1i64;
   3645     break;
   3646   }
   3647 
   3648   default:
   3649     llvm_unreachable("unexpected size for isNEONModifiedImm");
   3650     return SDValue();
   3651   }
   3652 
   3653   unsigned EncodedVal = ARM_AM::createNEONModImm(OpCmode, Imm);
   3654   return DAG.getTargetConstant(EncodedVal, MVT::i32);
   3655 }
   3656 
   3657 static bool isVEXTMask(const SmallVectorImpl<int> &M, EVT VT,
   3658                        bool &ReverseVEXT, unsigned &Imm) {
   3659   unsigned NumElts = VT.getVectorNumElements();
   3660   ReverseVEXT = false;
   3661 
   3662   // Assume that the first shuffle index is not UNDEF.  Fail if it is.
   3663   if (M[0] < 0)
   3664     return false;
   3665 
   3666   Imm = M[0];
   3667 
   3668   // If this is a VEXT shuffle, the immediate value is the index of the first
   3669   // element.  The other shuffle indices must be the successive elements after
   3670   // the first one.
   3671   unsigned ExpectedElt = Imm;
   3672   for (unsigned i = 1; i < NumElts; ++i) {
   3673     // Increment the expected index.  If it wraps around, it may still be
   3674     // a VEXT but the source vectors must be swapped.
   3675     ExpectedElt += 1;
   3676     if (ExpectedElt == NumElts * 2) {
   3677       ExpectedElt = 0;
   3678       ReverseVEXT = true;
   3679     }
   3680 
   3681     if (M[i] < 0) continue; // ignore UNDEF indices
   3682     if (ExpectedElt != static_cast<unsigned>(M[i]))
   3683       return false;
   3684   }
   3685 
   3686   // Adjust the index value if the source operands will be swapped.
   3687   if (ReverseVEXT)
   3688     Imm -= NumElts;
   3689 
   3690   return true;
   3691 }
   3692 
   3693 /// isVREVMask - Check if a vector shuffle corresponds to a VREV
   3694 /// instruction with the specified blocksize.  (The order of the elements
   3695 /// within each block of the vector is reversed.)
   3696 static bool isVREVMask(const SmallVectorImpl<int> &M, EVT VT,
   3697                        unsigned BlockSize) {
   3698   assert((BlockSize==16 || BlockSize==32 || BlockSize==64) &&
   3699          "Only possible block sizes for VREV are: 16, 32, 64");
   3700 
   3701   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
   3702   if (EltSz == 64)
   3703     return false;
   3704 
   3705   unsigned NumElts = VT.getVectorNumElements();
   3706   unsigned BlockElts = M[0] + 1;
   3707   // If the first shuffle index is UNDEF, be optimistic.
   3708   if (M[0] < 0)
   3709     BlockElts = BlockSize / EltSz;
   3710 
   3711   if (BlockSize <= EltSz || BlockSize != BlockElts * EltSz)
   3712     return false;
   3713 
   3714   for (unsigned i = 0; i < NumElts; ++i) {
   3715     if (M[i] < 0) continue; // ignore UNDEF indices
   3716     if ((unsigned) M[i] != (i - i%BlockElts) + (BlockElts - 1 - i%BlockElts))
   3717       return false;
   3718   }
   3719 
   3720   return true;
   3721 }
   3722 
   3723 static bool isVTBLMask(const SmallVectorImpl<int> &M, EVT VT) {
   3724   // We can handle <8 x i8> vector shuffles. If the index in the mask is out of
   3725   // range, then 0 is placed into the resulting vector. So pretty much any mask
   3726   // of 8 elements can work here.
   3727   return VT == MVT::v8i8 && M.size() == 8;
   3728 }
   3729 
   3730 static bool isVTRNMask(const SmallVectorImpl<int> &M, EVT VT,
   3731                        unsigned &WhichResult) {
   3732   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
   3733   if (EltSz == 64)
   3734     return false;
   3735 
   3736   unsigned NumElts = VT.getVectorNumElements();
   3737   WhichResult = (M[0] == 0 ? 0 : 1);
   3738   for (unsigned i = 0; i < NumElts; i += 2) {
   3739     if ((M[i] >= 0 && (unsigned) M[i] != i + WhichResult) ||
   3740         (M[i+1] >= 0 && (unsigned) M[i+1] != i + NumElts + WhichResult))
   3741       return false;
   3742   }
   3743   return true;
   3744 }
   3745 
   3746 /// isVTRN_v_undef_Mask - Special case of isVTRNMask for canonical form of
   3747 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
   3748 /// Mask is e.g., <0, 0, 2, 2> instead of <0, 4, 2, 6>.
   3749 static bool isVTRN_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
   3750                                 unsigned &WhichResult) {
   3751   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
   3752   if (EltSz == 64)
   3753     return false;
   3754 
   3755   unsigned NumElts = VT.getVectorNumElements();
   3756   WhichResult = (M[0] == 0 ? 0 : 1);
   3757   for (unsigned i = 0; i < NumElts; i += 2) {
   3758     if ((M[i] >= 0 && (unsigned) M[i] != i + WhichResult) ||
   3759         (M[i+1] >= 0 && (unsigned) M[i+1] != i + WhichResult))
   3760       return false;
   3761   }
   3762   return true;
   3763 }
   3764 
   3765 static bool isVUZPMask(const SmallVectorImpl<int> &M, EVT VT,
   3766                        unsigned &WhichResult) {
   3767   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
   3768   if (EltSz == 64)
   3769     return false;
   3770 
   3771   unsigned NumElts = VT.getVectorNumElements();
   3772   WhichResult = (M[0] == 0 ? 0 : 1);
   3773   for (unsigned i = 0; i != NumElts; ++i) {
   3774     if (M[i] < 0) continue; // ignore UNDEF indices
   3775     if ((unsigned) M[i] != 2 * i + WhichResult)
   3776       return false;
   3777   }
   3778 
   3779   // VUZP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
   3780   if (VT.is64BitVector() && EltSz == 32)
   3781     return false;
   3782 
   3783   return true;
   3784 }
   3785 
   3786 /// isVUZP_v_undef_Mask - Special case of isVUZPMask for canonical form of
   3787 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
   3788 /// Mask is e.g., <0, 2, 0, 2> instead of <0, 2, 4, 6>,
   3789 static bool isVUZP_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
   3790                                 unsigned &WhichResult) {
   3791   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
   3792   if (EltSz == 64)
   3793     return false;
   3794 
   3795   unsigned Half = VT.getVectorNumElements() / 2;
   3796   WhichResult = (M[0] == 0 ? 0 : 1);
   3797   for (unsigned j = 0; j != 2; ++j) {
   3798     unsigned Idx = WhichResult;
   3799     for (unsigned i = 0; i != Half; ++i) {
   3800       int MIdx = M[i + j * Half];
   3801       if (MIdx >= 0 && (unsigned) MIdx != Idx)
   3802         return false;
   3803       Idx += 2;
   3804     }
   3805   }
   3806 
   3807   // VUZP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
   3808   if (VT.is64BitVector() && EltSz == 32)
   3809     return false;
   3810 
   3811   return true;
   3812 }
   3813 
   3814 static bool isVZIPMask(const SmallVectorImpl<int> &M, EVT VT,
   3815                        unsigned &WhichResult) {
   3816   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
   3817   if (EltSz == 64)
   3818     return false;
   3819 
   3820   unsigned NumElts = VT.getVectorNumElements();
   3821   WhichResult = (M[0] == 0 ? 0 : 1);
   3822   unsigned Idx = WhichResult * NumElts / 2;
   3823   for (unsigned i = 0; i != NumElts; i += 2) {
   3824     if ((M[i] >= 0 && (unsigned) M[i] != Idx) ||
   3825         (M[i+1] >= 0 && (unsigned) M[i+1] != Idx + NumElts))
   3826       return false;
   3827     Idx += 1;
   3828   }
   3829 
   3830   // VZIP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
   3831   if (VT.is64BitVector() && EltSz == 32)
   3832     return false;
   3833 
   3834   return true;
   3835 }
   3836 
   3837 /// isVZIP_v_undef_Mask - Special case of isVZIPMask for canonical form of
   3838 /// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
   3839 /// Mask is e.g., <0, 0, 1, 1> instead of <0, 4, 1, 5>.
   3840 static bool isVZIP_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
   3841                                 unsigned &WhichResult) {
   3842   unsigned EltSz = VT.getVectorElementType().getSizeInBits();
   3843   if (EltSz == 64)
   3844     return false;
   3845 
   3846   unsigned NumElts = VT.getVectorNumElements();
   3847   WhichResult = (M[0] == 0 ? 0 : 1);
   3848   unsigned Idx = WhichResult * NumElts / 2;
   3849   for (unsigned i = 0; i != NumElts; i += 2) {
   3850     if ((M[i] >= 0 && (unsigned) M[i] != Idx) ||
   3851         (M[i+1] >= 0 && (unsigned) M[i+1] != Idx))
   3852       return false;
   3853     Idx += 1;
   3854   }
   3855 
   3856   // VZIP.32 for 64-bit vectors is a pseudo-instruction alias for VTRN.32.
   3857   if (VT.is64BitVector() && EltSz == 32)
   3858     return false;
   3859 
   3860   return true;
   3861 }
   3862 
   3863 // If N is an integer constant that can be moved into a register in one
   3864 // instruction, return an SDValue of such a constant (will become a MOV
   3865 // instruction).  Otherwise return null.
   3866 static SDValue IsSingleInstrConstant(SDValue N, SelectionDAG &DAG,
   3867                                      const ARMSubtarget *ST, DebugLoc dl) {
   3868   uint64_t Val;
   3869   if (!isa<ConstantSDNode>(N))
   3870     return SDValue();
   3871   Val = cast<ConstantSDNode>(N)->getZExtValue();
   3872 
   3873   if (ST->isThumb1Only()) {
   3874     if (Val <= 255 || ~Val <= 255)
   3875       return DAG.getConstant(Val, MVT::i32);
   3876   } else {
   3877     if (ARM_AM::getSOImmVal(Val) != -1 || ARM_AM::getSOImmVal(~Val) != -1)
   3878       return DAG.getConstant(Val, MVT::i32);
   3879   }
   3880   return SDValue();
   3881 }
   3882 
   3883 // If this is a case we can't handle, return null and let the default
   3884 // expansion code take care of it.
   3885 SDValue ARMTargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
   3886                                              const ARMSubtarget *ST) const {
   3887   BuildVectorSDNode *BVN = cast<BuildVectorSDNode>(Op.getNode());
   3888   DebugLoc dl = Op.getDebugLoc();
   3889   EVT VT = Op.getValueType();
   3890 
   3891   APInt SplatBits, SplatUndef;
   3892   unsigned SplatBitSize;
   3893   bool HasAnyUndefs;
   3894   if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
   3895     if (SplatBitSize <= 64) {
   3896       // Check if an immediate VMOV works.
   3897       EVT VmovVT;
   3898       SDValue Val = isNEONModifiedImm(SplatBits.getZExtValue(),
   3899                                       SplatUndef.getZExtValue(), SplatBitSize,
   3900                                       DAG, VmovVT, VT.is128BitVector(),
   3901                                       VMOVModImm);
   3902       if (Val.getNode()) {
   3903         SDValue Vmov = DAG.getNode(ARMISD::VMOVIMM, dl, VmovVT, Val);
   3904         return DAG.getNode(ISD::BITCAST, dl, VT, Vmov);
   3905       }
   3906 
   3907       // Try an immediate VMVN.
   3908       uint64_t NegatedImm = (SplatBits.getZExtValue() ^
   3909                              ((1LL << SplatBitSize) - 1));
   3910       Val = isNEONModifiedImm(NegatedImm,
   3911                                       SplatUndef.getZExtValue(), SplatBitSize,
   3912                                       DAG, VmovVT, VT.is128BitVector(),
   3913                                       VMVNModImm);
   3914       if (Val.getNode()) {
   3915         SDValue Vmov = DAG.getNode(ARMISD::VMVNIMM, dl, VmovVT, Val);
   3916         return DAG.getNode(ISD::BITCAST, dl, VT, Vmov);
   3917       }
   3918     }
   3919   }
   3920 
   3921   // Scan through the operands to see if only one value is used.
   3922   unsigned NumElts = VT.getVectorNumElements();
   3923   bool isOnlyLowElement = true;
   3924   bool usesOnlyOneValue = true;
   3925   bool isConstant = true;
   3926   SDValue Value;
   3927   for (unsigned i = 0; i < NumElts; ++i) {
   3928     SDValue V = Op.getOperand(i);
   3929     if (V.getOpcode() == ISD::UNDEF)
   3930       continue;
   3931     if (i > 0)
   3932       isOnlyLowElement = false;
   3933     if (!isa<ConstantFPSDNode>(V) && !isa<ConstantSDNode>(V))
   3934       isConstant = false;
   3935 
   3936     if (!Value.getNode())
   3937       Value = V;
   3938     else if (V != Value)
   3939       usesOnlyOneValue = false;
   3940   }
   3941 
   3942   if (!Value.getNode())
   3943     return DAG.getUNDEF(VT);
   3944 
   3945   if (isOnlyLowElement)
   3946     return DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, VT, Value);
   3947 
   3948   unsigned EltSize = VT.getVectorElementType().getSizeInBits();
   3949 
   3950   // Use VDUP for non-constant splats.  For f32 constant splats, reduce to
   3951   // i32 and try again.
   3952   if (usesOnlyOneValue && EltSize <= 32) {
   3953     if (!isConstant)
   3954       return DAG.getNode(ARMISD::VDUP, dl, VT, Value);
   3955     if (VT.getVectorElementType().isFloatingPoint()) {
   3956       SmallVector<SDValue, 8> Ops;
   3957       for (unsigned i = 0; i < NumElts; ++i)
   3958         Ops.push_back(DAG.getNode(ISD::BITCAST, dl, MVT::i32,
   3959                                   Op.getOperand(i)));
   3960       EVT VecVT = EVT::getVectorVT(*DAG.getContext(), MVT::i32, NumElts);
   3961       SDValue Val = DAG.getNode(ISD::BUILD_VECTOR, dl, VecVT, &Ops[0], NumElts);
   3962       Val = LowerBUILD_VECTOR(Val, DAG, ST);
   3963       if (Val.getNode())
   3964         return DAG.getNode(ISD::BITCAST, dl, VT, Val);
   3965     }
   3966     SDValue Val = IsSingleInstrConstant(Value, DAG, ST, dl);
   3967     if (Val.getNode())
   3968       return DAG.getNode(ARMISD::VDUP, dl, VT, Val);
   3969   }
   3970 
   3971   // If all elements are constants and the case above didn't get hit, fall back
   3972   // to the default expansion, which will generate a load from the constant
   3973   // pool.
   3974   if (isConstant)
   3975     return SDValue();
   3976 
   3977   // Empirical tests suggest this is rarely worth it for vectors of length <= 2.
   3978   if (NumElts >= 4) {
   3979     SDValue shuffle = ReconstructShuffle(Op, DAG);
   3980     if (shuffle != SDValue())
   3981       return shuffle;
   3982   }
   3983 
   3984   // Vectors with 32- or 64-bit elements can be built by directly assigning
   3985   // the subregisters.  Lower it to an ARMISD::BUILD_VECTOR so the operands
   3986   // will be legalized.
   3987   if (EltSize >= 32) {
   3988     // Do the expansion with floating-point types, since that is what the VFP
   3989     // registers are defined to use, and since i64 is not legal.
   3990     EVT EltVT = EVT::getFloatingPointVT(EltSize);
   3991     EVT VecVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts);
   3992     SmallVector<SDValue, 8> Ops;
   3993     for (unsigned i = 0; i < NumElts; ++i)
   3994       Ops.push_back(DAG.getNode(ISD::BITCAST, dl, EltVT, Op.getOperand(i)));
   3995     SDValue Val = DAG.getNode(ARMISD::BUILD_VECTOR, dl, VecVT, &Ops[0],NumElts);
   3996     return DAG.getNode(ISD::BITCAST, dl, VT, Val);
   3997   }
   3998 
   3999   return SDValue();
   4000 }
   4001 
   4002 // Gather data to see if the operation can be modelled as a
   4003 // shuffle in combination with VEXTs.
   4004 SDValue ARMTargetLowering::ReconstructShuffle(SDValue Op,
   4005                                               SelectionDAG &DAG) const {
   4006   DebugLoc dl = Op.getDebugLoc();
   4007   EVT VT = Op.getValueType();
   4008   unsigned NumElts = VT.getVectorNumElements();
   4009 
   4010   SmallVector<SDValue, 2> SourceVecs;
   4011   SmallVector<unsigned, 2> MinElts;
   4012   SmallVector<unsigned, 2> MaxElts;
   4013 
   4014   for (unsigned i = 0; i < NumElts; ++i) {
   4015     SDValue V = Op.getOperand(i);
   4016     if (V.getOpcode() == ISD::UNDEF)
   4017       continue;
   4018     else if (V.getOpcode() != ISD::EXTRACT_VECTOR_ELT) {
   4019       // A shuffle can only come from building a vector from various
   4020       // elements of other vectors.
   4021       return SDValue();
   4022     }
   4023 
   4024     // Record this extraction against the appropriate vector if possible...
   4025     SDValue SourceVec = V.getOperand(0);
   4026     unsigned EltNo = cast<ConstantSDNode>(V.getOperand(1))->getZExtValue();
   4027     bool FoundSource = false;
   4028     for (unsigned j = 0; j < SourceVecs.size(); ++j) {
   4029       if (SourceVecs[j] == SourceVec) {
   4030         if (MinElts[j] > EltNo)
   4031           MinElts[j] = EltNo;
   4032         if (MaxElts[j] < EltNo)
   4033           MaxElts[j] = EltNo;
   4034         FoundSource = true;
   4035         break;
   4036       }
   4037     }
   4038 
   4039     // Or record a new source if not...
   4040     if (!FoundSource) {
   4041       SourceVecs.push_back(SourceVec);
   4042       MinElts.push_back(EltNo);
   4043       MaxElts.push_back(EltNo);
   4044     }
   4045   }
   4046 
   4047   // Currently only do something sane when at most two source vectors
   4048   // involved.
   4049   if (SourceVecs.size() > 2)
   4050     return SDValue();
   4051 
   4052   SDValue ShuffleSrcs[2] = {DAG.getUNDEF(VT), DAG.getUNDEF(VT) };
   4053   int VEXTOffsets[2] = {0, 0};
   4054 
   4055   // This loop extracts the usage patterns of the source vectors
   4056   // and prepares appropriate SDValues for a shuffle if possible.
   4057   for (unsigned i = 0; i < SourceVecs.size(); ++i) {
   4058     if (SourceVecs[i].getValueType() == VT) {
   4059       // No VEXT necessary
   4060       ShuffleSrcs[i] = SourceVecs[i];
   4061       VEXTOffsets[i] = 0;
   4062       continue;
   4063     } else if (SourceVecs[i].getValueType().getVectorNumElements() < NumElts) {
   4064       // It probably isn't worth padding out a smaller vector just to
   4065       // break it down again in a shuffle.
   4066       return SDValue();
   4067     }
   4068 
   4069     // Since only 64-bit and 128-bit vectors are legal on ARM and
   4070     // we've eliminated the other cases...
   4071     assert(SourceVecs[i].getValueType().getVectorNumElements() == 2*NumElts &&
   4072            "unexpected vector sizes in ReconstructShuffle");
   4073 
   4074     if (MaxElts[i] - MinElts[i] >= NumElts) {
   4075       // Span too large for a VEXT to cope
   4076       return SDValue();
   4077     }
   4078 
   4079     if (MinElts[i] >= NumElts) {
   4080       // The extraction can just take the second half
   4081       VEXTOffsets[i] = NumElts;
   4082       ShuffleSrcs[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT,
   4083                                    SourceVecs[i],
   4084                                    DAG.getIntPtrConstant(NumElts));
   4085     } else if (MaxElts[i] < NumElts) {
   4086       // The extraction can just take the first half
   4087       VEXTOffsets[i] = 0;
   4088       ShuffleSrcs[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT,
   4089                                    SourceVecs[i],
   4090                                    DAG.getIntPtrConstant(0));
   4091     } else {
   4092       // An actual VEXT is needed
   4093       VEXTOffsets[i] = MinElts[i];
   4094       SDValue VEXTSrc1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT,
   4095                                      SourceVecs[i],
   4096                                      DAG.getIntPtrConstant(0));
   4097       SDValue VEXTSrc2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, VT,
   4098                                      SourceVecs[i],
   4099                                      DAG.getIntPtrConstant(NumElts));
   4100       ShuffleSrcs[i] = DAG.getNode(ARMISD::VEXT, dl, VT, VEXTSrc1, VEXTSrc2,
   4101                                    DAG.getConstant(VEXTOffsets[i], MVT::i32));
   4102     }
   4103   }
   4104 
   4105   SmallVector<int, 8> Mask;
   4106 
   4107   for (unsigned i = 0; i < NumElts; ++i) {
   4108     SDValue Entry = Op.getOperand(i);
   4109     if (Entry.getOpcode() == ISD::UNDEF) {
   4110       Mask.push_back(-1);
   4111       continue;
   4112     }
   4113 
   4114     SDValue ExtractVec = Entry.getOperand(0);
   4115     int ExtractElt = cast<ConstantSDNode>(Op.getOperand(i)
   4116                                           .getOperand(1))->getSExtValue();
   4117     if (ExtractVec == SourceVecs[0]) {
   4118       Mask.push_back(ExtractElt - VEXTOffsets[0]);
   4119     } else {
   4120       Mask.push_back(ExtractElt + NumElts - VEXTOffsets[1]);
   4121     }
   4122   }
   4123 
   4124   // Final check before we try to produce nonsense...
   4125   if (isShuffleMaskLegal(Mask, VT))
   4126     return DAG.getVectorShuffle(VT, dl, ShuffleSrcs[0], ShuffleSrcs[1],
   4127                                 &Mask[0]);
   4128 
   4129   return SDValue();
   4130 }
   4131 
   4132 /// isShuffleMaskLegal - Targets can use this to indicate that they only
   4133 /// support *some* VECTOR_SHUFFLE operations, those with specific masks.
   4134 /// By default, if a target supports the VECTOR_SHUFFLE node, all mask values
   4135 /// are assumed to be legal.
   4136 bool
   4137 ARMTargetLowering::isShuffleMaskLegal(const SmallVectorImpl<int> &M,
   4138                                       EVT VT) const {
   4139   if (VT.getVectorNumElements() == 4 &&
   4140       (VT.is128BitVector() || VT.is64BitVector())) {
   4141     unsigned PFIndexes[4];
   4142     for (unsigned i = 0; i != 4; ++i) {
   4143       if (M[i] < 0)
   4144         PFIndexes[i] = 8;
   4145       else
   4146         PFIndexes[i] = M[i];
   4147     }
   4148 
   4149     // Compute the index in the perfect shuffle table.
   4150     unsigned PFTableIndex =
   4151       PFIndexes[0]*9*9*9+PFIndexes[1]*9*9+PFIndexes[2]*9+PFIndexes[3];
   4152     unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
   4153     unsigned Cost = (PFEntry >> 30);
   4154 
   4155     if (Cost <= 4)
   4156       return true;
   4157   }
   4158 
   4159   bool ReverseVEXT;
   4160   unsigned Imm, WhichResult;
   4161 
   4162   unsigned EltSize = VT.getVectorElementType().getSizeInBits();
   4163   return (EltSize >= 32 ||
   4164           ShuffleVectorSDNode::isSplatMask(&M[0], VT) ||
   4165           isVREVMask(M, VT, 64) ||
   4166           isVREVMask(M, VT, 32) ||
   4167           isVREVMask(M, VT, 16) ||
   4168           isVEXTMask(M, VT, ReverseVEXT, Imm) ||
   4169           isVTBLMask(M, VT) ||
   4170           isVTRNMask(M, VT, WhichResult) ||
   4171           isVUZPMask(M, VT, WhichResult) ||
   4172           isVZIPMask(M, VT, WhichResult) ||
   4173           isVTRN_v_undef_Mask(M, VT, WhichResult) ||
   4174           isVUZP_v_undef_Mask(M, VT, WhichResult) ||
   4175           isVZIP_v_undef_Mask(M, VT, WhichResult));
   4176 }
   4177 
   4178 /// GeneratePerfectShuffle - Given an entry in the perfect-shuffle table, emit
   4179 /// the specified operations to build the shuffle.
   4180 static SDValue GeneratePerfectShuffle(unsigned PFEntry, SDValue LHS,
   4181                                       SDValue RHS, SelectionDAG &DAG,
   4182                                       DebugLoc dl) {
   4183   unsigned OpNum = (PFEntry >> 26) & 0x0F;
   4184   unsigned LHSID = (PFEntry >> 13) & ((1 << 13)-1);
   4185   unsigned RHSID = (PFEntry >>  0) & ((1 << 13)-1);
   4186 
   4187   enum {
   4188     OP_COPY = 0, // Copy, used for things like <u,u,u,3> to say it is <0,1,2,3>
   4189     OP_VREV,
   4190     OP_VDUP0,
   4191     OP_VDUP1,
   4192     OP_VDUP2,
   4193     OP_VDUP3,
   4194     OP_VEXT1,
   4195     OP_VEXT2,
   4196     OP_VEXT3,
   4197     OP_VUZPL, // VUZP, left result
   4198     OP_VUZPR, // VUZP, right result
   4199     OP_VZIPL, // VZIP, left result
   4200     OP_VZIPR, // VZIP, right result
   4201     OP_VTRNL, // VTRN, left result
   4202     OP_VTRNR  // VTRN, right result
   4203   };
   4204 
   4205   if (OpNum == OP_COPY) {
   4206     if (LHSID == (1*9+2)*9+3) return LHS;
   4207     assert(LHSID == ((4*9+5)*9+6)*9+7 && "Illegal OP_COPY!");
   4208     return RHS;
   4209   }
   4210 
   4211   SDValue OpLHS, OpRHS;
   4212   OpLHS = GeneratePerfectShuffle(PerfectShuffleTable[LHSID], LHS, RHS, DAG, dl);
   4213   OpRHS = GeneratePerfectShuffle(PerfectShuffleTable[RHSID], LHS, RHS, DAG, dl);
   4214   EVT VT = OpLHS.getValueType();
   4215 
   4216   switch (OpNum) {
   4217   default: llvm_unreachable("Unknown shuffle opcode!");
   4218   case OP_VREV:
   4219     // VREV divides the vector in half and swaps within the half.
   4220     if (VT.getVectorElementType() == MVT::i32 ||
   4221         VT.getVectorElementType() == MVT::f32)
   4222       return DAG.getNode(ARMISD::VREV64, dl, VT, OpLHS);
   4223     // vrev <4 x i16> -> VREV32
   4224     if (VT.getVectorElementType() == MVT::i16)
   4225       return DAG.getNode(ARMISD::VREV32, dl, VT, OpLHS);
   4226     // vrev <4 x i8> -> VREV16
   4227     assert(VT.getVectorElementType() == MVT::i8);
   4228     return DAG.getNode(ARMISD::VREV16, dl, VT, OpLHS);
   4229   case OP_VDUP0:
   4230   case OP_VDUP1:
   4231   case OP_VDUP2:
   4232   case OP_VDUP3:
   4233     return DAG.getNode(ARMISD::VDUPLANE, dl, VT,
   4234                        OpLHS, DAG.getConstant(OpNum-OP_VDUP0, MVT::i32));
   4235   case OP_VEXT1:
   4236   case OP_VEXT2:
   4237   case OP_VEXT3:
   4238     return DAG.getNode(ARMISD::VEXT, dl, VT,
   4239                        OpLHS, OpRHS,
   4240                        DAG.getConstant(OpNum-OP_VEXT1+1, MVT::i32));
   4241   case OP_VUZPL:
   4242   case OP_VUZPR:
   4243     return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
   4244                        OpLHS, OpRHS).getValue(OpNum-OP_VUZPL);
   4245   case OP_VZIPL:
   4246   case OP_VZIPR:
   4247     return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
   4248                        OpLHS, OpRHS).getValue(OpNum-OP_VZIPL);
   4249   case OP_VTRNL:
   4250   case OP_VTRNR:
   4251     return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
   4252                        OpLHS, OpRHS).getValue(OpNum-OP_VTRNL);
   4253   }
   4254 }
   4255 
   4256 static SDValue LowerVECTOR_SHUFFLEv8i8(SDValue Op,
   4257                                        SmallVectorImpl<int> &ShuffleMask,
   4258                                        SelectionDAG &DAG) {
   4259   // Check to see if we can use the VTBL instruction.
   4260   SDValue V1 = Op.getOperand(0);
   4261   SDValue V2 = Op.getOperand(1);
   4262   DebugLoc DL = Op.getDebugLoc();
   4263 
   4264   SmallVector<SDValue, 8> VTBLMask;
   4265   for (SmallVectorImpl<int>::iterator
   4266          I = ShuffleMask.begin(), E = ShuffleMask.end(); I != E; ++I)
   4267     VTBLMask.push_back(DAG.getConstant(*I, MVT::i32));
   4268 
   4269   if (V2.getNode()->getOpcode() == ISD::UNDEF)
   4270     return DAG.getNode(ARMISD::VTBL1, DL, MVT::v8i8, V1,
   4271                        DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v8i8,
   4272                                    &VTBLMask[0], 8));
   4273 
   4274   return DAG.getNode(ARMISD::VTBL2, DL, MVT::v8i8, V1, V2,
   4275                      DAG.getNode(ISD::BUILD_VECTOR, DL, MVT::v8i8,
   4276                                  &VTBLMask[0], 8));
   4277 }
   4278 
   4279 static SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) {
   4280   SDValue V1 = Op.getOperand(0);
   4281   SDValue V2 = Op.getOperand(1);
   4282   DebugLoc dl = Op.getDebugLoc();
   4283   EVT VT = Op.getValueType();
   4284   ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
   4285   SmallVector<int, 8> ShuffleMask;
   4286 
   4287   // Convert shuffles that are directly supported on NEON to target-specific
   4288   // DAG nodes, instead of keeping them as shuffles and matching them again
   4289   // during code selection.  This is more efficient and avoids the possibility
   4290   // of inconsistencies between legalization and selection.
   4291   // FIXME: floating-point vectors should be canonicalized to integer vectors
   4292   // of the same time so that they get CSEd properly.
   4293   SVN->getMask(ShuffleMask);
   4294 
   4295   unsigned EltSize = VT.getVectorElementType().getSizeInBits();
   4296   if (EltSize <= 32) {
   4297     if (ShuffleVectorSDNode::isSplatMask(&ShuffleMask[0], VT)) {
   4298       int Lane = SVN->getSplatIndex();
   4299       // If this is undef splat, generate it via "just" vdup, if possible.
   4300       if (Lane == -1) Lane = 0;
   4301 
   4302       if (Lane == 0 && V1.getOpcode() == ISD::SCALAR_TO_VECTOR) {
   4303         return DAG.getNode(ARMISD::VDUP, dl, VT, V1.getOperand(0));
   4304       }
   4305       return DAG.getNode(ARMISD::VDUPLANE, dl, VT, V1,
   4306                          DAG.getConstant(Lane, MVT::i32));
   4307     }
   4308 
   4309     bool ReverseVEXT;
   4310     unsigned Imm;
   4311     if (isVEXTMask(ShuffleMask, VT, ReverseVEXT, Imm)) {
   4312       if (ReverseVEXT)
   4313         std::swap(V1, V2);
   4314       return DAG.getNode(ARMISD::VEXT, dl, VT, V1, V2,
   4315                          DAG.getConstant(Imm, MVT::i32));
   4316     }
   4317 
   4318     if (isVREVMask(ShuffleMask, VT, 64))
   4319       return DAG.getNode(ARMISD::VREV64, dl, VT, V1);
   4320     if (isVREVMask(ShuffleMask, VT, 32))
   4321       return DAG.getNode(ARMISD::VREV32, dl, VT, V1);
   4322     if (isVREVMask(ShuffleMask, VT, 16))
   4323       return DAG.getNode(ARMISD::VREV16, dl, VT, V1);
   4324 
   4325     // Check for Neon shuffles that modify both input vectors in place.
   4326     // If both results are used, i.e., if there are two shuffles with the same
   4327     // source operands and with masks corresponding to both results of one of
   4328     // these operations, DAG memoization will ensure that a single node is
   4329     // used for both shuffles.
   4330     unsigned WhichResult;
   4331     if (isVTRNMask(ShuffleMask, VT, WhichResult))
   4332       return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
   4333                          V1, V2).getValue(WhichResult);
   4334     if (isVUZPMask(ShuffleMask, VT, WhichResult))
   4335       return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
   4336                          V1, V2).getValue(WhichResult);
   4337     if (isVZIPMask(ShuffleMask, VT, WhichResult))
   4338       return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
   4339                          V1, V2).getValue(WhichResult);
   4340 
   4341     if (isVTRN_v_undef_Mask(ShuffleMask, VT, WhichResult))
   4342       return DAG.getNode(ARMISD::VTRN, dl, DAG.getVTList(VT, VT),
   4343                          V1, V1).getValue(WhichResult);
   4344     if (isVUZP_v_undef_Mask(ShuffleMask, VT, WhichResult))
   4345       return DAG.getNode(ARMISD::VUZP, dl, DAG.getVTList(VT, VT),
   4346                          V1, V1).getValue(WhichResult);
   4347     if (isVZIP_v_undef_Mask(ShuffleMask, VT, WhichResult))
   4348       return DAG.getNode(ARMISD::VZIP, dl, DAG.getVTList(VT, VT),
   4349                          V1, V1).getValue(WhichResult);
   4350   }
   4351 
   4352   // If the shuffle is not directly supported and it has 4 elements, use
   4353   // the PerfectShuffle-generated table to synthesize it from other shuffles.
   4354   unsigned NumElts = VT.getVectorNumElements();
   4355   if (NumElts == 4) {
   4356     unsigned PFIndexes[4];
   4357     for (unsigned i = 0; i != 4; ++i) {
   4358       if (ShuffleMask[i] < 0)
   4359         PFIndexes[i] = 8;
   4360       else
   4361         PFIndexes[i] = ShuffleMask[i];
   4362     }
   4363 
   4364     // Compute the index in the perfect shuffle table.
   4365     unsigned PFTableIndex =
   4366       PFIndexes[0]*9*9*9+PFIndexes[1]*9*9+PFIndexes[2]*9+PFIndexes[3];
   4367     unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
   4368     unsigned Cost = (PFEntry >> 30);
   4369 
   4370     if (Cost <= 4)
   4371       return GeneratePerfectShuffle(PFEntry, V1, V2, DAG, dl);
   4372   }
   4373 
   4374   // Implement shuffles with 32- or 64-bit elements as ARMISD::BUILD_VECTORs.
   4375   if (EltSize >= 32) {
   4376     // Do the expansion with floating-point types, since that is what the VFP
   4377     // registers are defined to use, and since i64 is not legal.
   4378     EVT EltVT = EVT::getFloatingPointVT(EltSize);
   4379     EVT VecVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts);
   4380     V1 = DAG.getNode(ISD::BITCAST, dl, VecVT, V1);
   4381     V2 = DAG.getNode(ISD::BITCAST, dl, VecVT, V2);
   4382     SmallVector<SDValue, 8> Ops;
   4383     for (unsigned i = 0; i < NumElts; ++i) {
   4384       if (ShuffleMask[i] < 0)
   4385         Ops.push_back(DAG.getUNDEF(EltVT));
   4386       else
   4387         Ops.push_back(DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, EltVT,
   4388                                   ShuffleMask[i] < (int)NumElts ? V1 : V2,
   4389                                   DAG.getConstant(ShuffleMask[i] & (NumElts-1),
   4390                                                   MVT::i32)));
   4391     }
   4392     SDValue Val = DAG.getNode(ARMISD::BUILD_VECTOR, dl, VecVT, &Ops[0],NumElts);
   4393     return DAG.getNode(ISD::BITCAST, dl, VT, Val);
   4394   }
   4395 
   4396   if (VT == MVT::v8i8) {
   4397     SDValue NewOp = LowerVECTOR_SHUFFLEv8i8(Op, ShuffleMask, DAG);
   4398     if (NewOp.getNode())
   4399       return NewOp;
   4400   }
   4401 
   4402   return SDValue();
   4403 }
   4404 
   4405 static SDValue LowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) {
   4406   // EXTRACT_VECTOR_ELT is legal only for immediate indexes.
   4407   SDValue Lane = Op.getOperand(1);
   4408   if (!isa<ConstantSDNode>(Lane))
   4409     return SDValue();
   4410 
   4411   SDValue Vec = Op.getOperand(0);
   4412   if (Op.getValueType() == MVT::i32 &&
   4413       Vec.getValueType().getVectorElementType().getSizeInBits() < 32) {
   4414     DebugLoc dl = Op.getDebugLoc();
   4415     return DAG.getNode(ARMISD::VGETLANEu, dl, MVT::i32, Vec, Lane);
   4416   }
   4417 
   4418   return Op;
   4419 }
   4420 
   4421 static SDValue LowerCONCAT_VECTORS(SDValue Op, SelectionDAG &DAG) {
   4422   // The only time a CONCAT_VECTORS operation can have legal types is when
   4423   // two 64-bit vectors are concatenated to a 128-bit vector.
   4424   assert(Op.getValueType().is128BitVector() && Op.getNumOperands() == 2 &&
   4425          "unexpected CONCAT_VECTORS");
   4426   DebugLoc dl = Op.getDebugLoc();
   4427   SDValue Val = DAG.getUNDEF(MVT::v2f64);
   4428   SDValue Op0 = Op.getOperand(0);
   4429   SDValue Op1 = Op.getOperand(1);
   4430   if (Op0.getOpcode() != ISD::UNDEF)
   4431     Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Val,
   4432                       DAG.getNode(ISD::BITCAST, dl, MVT::f64, Op0),
   4433                       DAG.getIntPtrConstant(0));
   4434   if (Op1.getOpcode() != ISD::UNDEF)
   4435     Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, MVT::v2f64, Val,
   4436                       DAG.getNode(ISD::BITCAST, dl, MVT::f64, Op1),
   4437                       DAG.getIntPtrConstant(1));
   4438   return DAG.getNode(ISD::BITCAST, dl, Op.getValueType(), Val);
   4439 }
   4440 
   4441 /// isExtendedBUILD_VECTOR - Check if N is a constant BUILD_VECTOR where each
   4442 /// element has been zero/sign-extended, depending on the isSigned parameter,
   4443 /// from an integer type half its size.
   4444 static bool isExtendedBUILD_VECTOR(SDNode *N, SelectionDAG &DAG,
   4445                                    bool isSigned) {
   4446   // A v2i64 BUILD_VECTOR will have been legalized to a BITCAST from v4i32.
   4447   EVT VT = N->getValueType(0);
   4448   if (VT == MVT::v2i64 && N->getOpcode() == ISD::BITCAST) {
   4449     SDNode *BVN = N->getOperand(0).getNode();
   4450     if (BVN->getValueType(0) != MVT::v4i32 ||
   4451         BVN->getOpcode() != ISD::BUILD_VECTOR)
   4452       return false;
   4453     unsigned LoElt = DAG.getTargetLoweringInfo().isBigEndian() ? 1 : 0;
   4454     unsigned HiElt = 1 - LoElt;
   4455     ConstantSDNode *Lo0 = dyn_cast<ConstantSDNode>(BVN->getOperand(LoElt));
   4456     ConstantSDNode *Hi0 = dyn_cast<ConstantSDNode>(BVN->getOperand(HiElt));
   4457     ConstantSDNode *Lo1 = dyn_cast<ConstantSDNode>(BVN->getOperand(LoElt+2));
   4458     ConstantSDNode *Hi1 = dyn_cast<ConstantSDNode>(BVN->getOperand(HiElt+2));
   4459     if (!Lo0 || !Hi0 || !Lo1 || !Hi1)
   4460       return false;
   4461     if (isSigned) {
   4462       if (Hi0->getSExtValue() == Lo0->getSExtValue() >> 32 &&
   4463           Hi1->getSExtValue() == Lo1->getSExtValue() >> 32)
   4464         return true;
   4465     } else {
   4466       if (Hi0->isNullValue() && Hi1->isNullValue())
   4467         return true;
   4468     }
   4469     return false;
   4470   }
   4471 
   4472   if (N->getOpcode() != ISD::BUILD_VECTOR)
   4473     return false;
   4474 
   4475   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
   4476     SDNode *Elt = N->getOperand(i).getNode();
   4477     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Elt)) {
   4478       unsigned EltSize = VT.getVectorElementType().getSizeInBits();
   4479       unsigned HalfSize = EltSize / 2;
   4480       if (isSigned) {
   4481         int64_t SExtVal = C->getSExtValue();
   4482         if ((SExtVal >> HalfSize) != (SExtVal >> EltSize))
   4483           return false;
   4484       } else {
   4485         if ((C->getZExtValue() >> HalfSize) != 0)
   4486           return false;
   4487       }
   4488       continue;
   4489     }
   4490     return false;
   4491   }
   4492 
   4493   return true;
   4494 }
   4495 
   4496 /// isSignExtended - Check if a node is a vector value that is sign-extended
   4497 /// or a constant BUILD_VECTOR with sign-extended elements.
   4498 static bool isSignExtended(SDNode *N, SelectionDAG &DAG) {
   4499   if (N->getOpcode() == ISD::SIGN_EXTEND || ISD::isSEXTLoad(N))
   4500     return true;
   4501   if (isExtendedBUILD_VECTOR(N, DAG, true))
   4502     return true;
   4503   return false;
   4504 }
   4505 
   4506 /// isZeroExtended - Check if a node is a vector value that is zero-extended
   4507 /// or a constant BUILD_VECTOR with zero-extended elements.
   4508 static bool isZeroExtended(SDNode *N, SelectionDAG &DAG) {
   4509   if (N->getOpcode() == ISD::ZERO_EXTEND || ISD::isZEXTLoad(N))
   4510     return true;
   4511   if (isExtendedBUILD_VECTOR(N, DAG, false))
   4512     return true;
   4513   return false;
   4514 }
   4515 
   4516 /// SkipExtension - For a node that is a SIGN_EXTEND, ZERO_EXTEND, extending
   4517 /// load, or BUILD_VECTOR with extended elements, return the unextended value.
   4518 static SDValue SkipExtension(SDNode *N, SelectionDAG &DAG) {
   4519   if (N->getOpcode() == ISD::SIGN_EXTEND || N->getOpcode() == ISD::ZERO_EXTEND)
   4520     return N->getOperand(0);
   4521   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N))
   4522     return DAG.getLoad(LD->getMemoryVT(), N->getDebugLoc(), LD->getChain(),
   4523                        LD->getBasePtr(), LD->getPointerInfo(), LD->isVolatile(),
   4524                        LD->isNonTemporal(), LD->getAlignment());
   4525   // Otherwise, the value must be a BUILD_VECTOR.  For v2i64, it will
   4526   // have been legalized as a BITCAST from v4i32.
   4527   if (N->getOpcode() == ISD::BITCAST) {
   4528     SDNode *BVN = N->getOperand(0).getNode();
   4529     assert(BVN->getOpcode() == ISD::BUILD_VECTOR &&
   4530            BVN->getValueType(0) == MVT::v4i32 && "expected v4i32 BUILD_VECTOR");
   4531     unsigned LowElt = DAG.getTargetLoweringInfo().isBigEndian() ? 1 : 0;
   4532     return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), MVT::v2i32,
   4533                        BVN->getOperand(LowElt), BVN->getOperand(LowElt+2));
   4534   }
   4535   // Construct a new BUILD_VECTOR with elements truncated to half the size.
   4536   assert(N->getOpcode() == ISD::BUILD_VECTOR && "expected BUILD_VECTOR");
   4537   EVT VT = N->getValueType(0);
   4538   unsigned EltSize = VT.getVectorElementType().getSizeInBits() / 2;
   4539   unsigned NumElts = VT.getVectorNumElements();
   4540   MVT TruncVT = MVT::getIntegerVT(EltSize);
   4541   SmallVector<SDValue, 8> Ops;
   4542   for (unsigned i = 0; i != NumElts; ++i) {
   4543     ConstantSDNode *C = cast<ConstantSDNode>(N->getOperand(i));
   4544     const APInt &CInt = C->getAPIntValue();
   4545     Ops.push_back(DAG.getConstant(CInt.trunc(EltSize), TruncVT));
   4546   }
   4547   return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(),
   4548                      MVT::getVectorVT(TruncVT, NumElts), Ops.data(), NumElts);
   4549 }
   4550 
   4551 static bool isAddSubSExt(SDNode *N, SelectionDAG &DAG) {
   4552   unsigned Opcode = N->getOpcode();
   4553   if (Opcode == ISD::ADD || Opcode == ISD::SUB) {
   4554     SDNode *N0 = N->getOperand(0).getNode();
   4555     SDNode *N1 = N->getOperand(1).getNode();
   4556     return N0->hasOneUse() && N1->hasOneUse() &&
   4557       isSignExtended(N0, DAG) && isSignExtended(N1, DAG);
   4558   }
   4559   return false;
   4560 }
   4561 
   4562 static bool isAddSubZExt(SDNode *N, SelectionDAG &DAG) {
   4563   unsigned Opcode = N->getOpcode();
   4564   if (Opcode == ISD::ADD || Opcode == ISD::SUB) {
   4565     SDNode *N0 = N->getOperand(0).getNode();
   4566     SDNode *N1 = N->getOperand(1).getNode();
   4567     return N0->hasOneUse() && N1->hasOneUse() &&
   4568       isZeroExtended(N0, DAG) && isZeroExtended(N1, DAG);
   4569   }
   4570   return false;
   4571 }
   4572 
   4573 static SDValue LowerMUL(SDValue Op, SelectionDAG &DAG) {
   4574   // Multiplications are only custom-lowered for 128-bit vectors so that
   4575   // VMULL can be detected.  Otherwise v2i64 multiplications are not legal.
   4576   EVT VT = Op.getValueType();
   4577   assert(VT.is128BitVector() && "unexpected type for custom-lowering ISD::MUL");
   4578   SDNode *N0 = Op.getOperand(0).getNode();
   4579   SDNode *N1 = Op.getOperand(1).getNode();
   4580   unsigned NewOpc = 0;
   4581   bool isMLA = false;
   4582   bool isN0SExt = isSignExtended(N0, DAG);
   4583   bool isN1SExt = isSignExtended(N1, DAG);
   4584   if (isN0SExt && isN1SExt)
   4585     NewOpc = ARMISD::VMULLs;
   4586   else {
   4587     bool isN0ZExt = isZeroExtended(N0, DAG);
   4588     bool isN1ZExt = isZeroExtended(N1, DAG);
   4589     if (isN0ZExt && isN1ZExt)
   4590       NewOpc = ARMISD::VMULLu;
   4591     else if (isN1SExt || isN1ZExt) {
   4592       // Look for (s/zext A + s/zext B) * (s/zext C). We want to turn these
   4593       // into (s/zext A * s/zext C) + (s/zext B * s/zext C)
   4594       if (isN1SExt && isAddSubSExt(N0, DAG)) {
   4595         NewOpc = ARMISD::VMULLs;
   4596         isMLA = true;
   4597       } else if (isN1ZExt && isAddSubZExt(N0, DAG)) {
   4598         NewOpc = ARMISD::VMULLu;
   4599         isMLA = true;
   4600       } else if (isN0ZExt && isAddSubZExt(N1, DAG)) {
   4601         std::swap(N0, N1);
   4602         NewOpc = ARMISD::VMULLu;
   4603         isMLA = true;
   4604       }
   4605     }
   4606 
   4607     if (!NewOpc) {
   4608       if (VT == MVT::v2i64)
   4609         // Fall through to expand this.  It is not legal.
   4610         return SDValue();
   4611       else
   4612         // Other vector multiplications are legal.
   4613         return Op;
   4614     }
   4615   }
   4616 
   4617   // Legalize to a VMULL instruction.
   4618   DebugLoc DL = Op.getDebugLoc();
   4619   SDValue Op0;
   4620   SDValue Op1 = SkipExtension(N1, DAG);
   4621   if (!isMLA) {
   4622     Op0 = SkipExtension(N0, DAG);
   4623     assert(Op0.getValueType().is64BitVector() &&
   4624            Op1.getValueType().is64BitVector() &&
   4625            "unexpected types for extended operands to VMULL");
   4626     return DAG.getNode(NewOpc, DL, VT, Op0, Op1);
   4627   }
   4628 
   4629   // Optimizing (zext A + zext B) * C, to (VMULL A, C) + (VMULL B, C) during
   4630   // isel lowering to take advantage of no-stall back to back vmul + vmla.
   4631   //   vmull q0, d4, d6
   4632   //   vmlal q0, d5, d6
   4633   // is faster than
   4634   //   vaddl q0, d4, d5
   4635   //   vmovl q1, d6
   4636   //   vmul  q0, q0, q1
   4637   SDValue N00 = SkipExtension(N0->getOperand(0).getNode(), DAG);
   4638   SDValue N01 = SkipExtension(N0->getOperand(1).getNode(), DAG);
   4639   EVT Op1VT = Op1.getValueType();
   4640   return DAG.getNode(N0->getOpcode(), DL, VT,
   4641                      DAG.getNode(NewOpc, DL, VT,
   4642                                DAG.getNode(ISD::BITCAST, DL, Op1VT, N00), Op1),
   4643                      DAG.getNode(NewOpc, DL, VT,
   4644                                DAG.getNode(ISD::BITCAST, DL, Op1VT, N01), Op1));
   4645 }
   4646 
   4647 static SDValue
   4648 LowerSDIV_v4i8(SDValue X, SDValue Y, DebugLoc dl, SelectionDAG &DAG) {
   4649   // Convert to float
   4650   // float4 xf = vcvt_f32_s32(vmovl_s16(a.lo));
   4651   // float4 yf = vcvt_f32_s32(vmovl_s16(b.lo));
   4652   X = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i32, X);
   4653   Y = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i32, Y);
   4654   X = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, X);
   4655   Y = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, Y);
   4656   // Get reciprocal estimate.
   4657   // float4 recip = vrecpeq_f32(yf);
   4658   Y = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
   4659                    DAG.getConstant(Intrinsic::arm_neon_vrecpe, MVT::i32), Y);
   4660   // Because char has a smaller range than uchar, we can actually get away
   4661   // without any newton steps.  This requires that we use a weird bias
   4662   // of 0xb000, however (again, this has been exhaustively tested).
   4663   // float4 result = as_float4(as_int4(xf*recip) + 0xb000);
   4664   X = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, X, Y);
   4665   X = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, X);
   4666   Y = DAG.getConstant(0xb000, MVT::i32);
   4667   Y = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, Y, Y, Y, Y);
   4668   X = DAG.getNode(ISD::ADD, dl, MVT::v4i32, X, Y);
   4669   X = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, X);
   4670   // Convert back to short.
   4671   X = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::v4i32, X);
   4672   X = DAG.getNode(ISD::TRUNCATE, dl, MVT::v4i16, X);
   4673   return X;
   4674 }
   4675 
   4676 static SDValue
   4677 LowerSDIV_v4i16(SDValue N0, SDValue N1, DebugLoc dl, SelectionDAG &DAG) {
   4678   SDValue N2;
   4679   // Convert to float.
   4680   // float4 yf = vcvt_f32_s32(vmovl_s16(y));
   4681   // float4 xf = vcvt_f32_s32(vmovl_s16(x));
   4682   N0 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i32, N0);
   4683   N1 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v4i32, N1);
   4684   N0 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, N0);
   4685   N1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, N1);
   4686 
   4687   // Use reciprocal estimate and one refinement step.
   4688   // float4 recip = vrecpeq_f32(yf);
   4689   // recip *= vrecpsq_f32(yf, recip);
   4690   N2 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
   4691                    DAG.getConstant(Intrinsic::arm_neon_vrecpe, MVT::i32), N1);
   4692   N1 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
   4693                    DAG.getConstant(Intrinsic::arm_neon_vrecps, MVT::i32),
   4694                    N1, N2);
   4695   N2 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N1, N2);
   4696   // Because short has a smaller range than ushort, we can actually get away
   4697   // with only a single newton step.  This requires that we use a weird bias
   4698   // of 89, however (again, this has been exhaustively tested).
   4699   // float4 result = as_float4(as_int4(xf*recip) + 0x89);
   4700   N0 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N0, N2);
   4701   N0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, N0);
   4702   N1 = DAG.getConstant(0x89, MVT::i32);
   4703   N1 = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, N1, N1, N1, N1);
   4704   N0 = DAG.getNode(ISD::ADD, dl, MVT::v4i32, N0, N1);
   4705   N0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, N0);
   4706   // Convert back to integer and return.
   4707   // return vmovn_s32(vcvt_s32_f32(result));
   4708   N0 = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::v4i32, N0);
   4709   N0 = DAG.getNode(ISD::TRUNCATE, dl, MVT::v4i16, N0);
   4710   return N0;
   4711 }
   4712 
   4713 static SDValue LowerSDIV(SDValue Op, SelectionDAG &DAG) {
   4714   EVT VT = Op.getValueType();
   4715   assert((VT == MVT::v4i16 || VT == MVT::v8i8) &&
   4716          "unexpected type for custom-lowering ISD::SDIV");
   4717 
   4718   DebugLoc dl = Op.getDebugLoc();
   4719   SDValue N0 = Op.getOperand(0);
   4720   SDValue N1 = Op.getOperand(1);
   4721   SDValue N2, N3;
   4722 
   4723   if (VT == MVT::v8i8) {
   4724     N0 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v8i16, N0);
   4725     N1 = DAG.getNode(ISD::SIGN_EXTEND, dl, MVT::v8i16, N1);
   4726 
   4727     N2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N0,
   4728                      DAG.getIntPtrConstant(4));
   4729     N3 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N1,
   4730                      DAG.getIntPtrConstant(4));
   4731     N0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N0,
   4732                      DAG.getIntPtrConstant(0));
   4733     N1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N1,
   4734                      DAG.getIntPtrConstant(0));
   4735 
   4736     N0 = LowerSDIV_v4i8(N0, N1, dl, DAG); // v4i16
   4737     N2 = LowerSDIV_v4i8(N2, N3, dl, DAG); // v4i16
   4738 
   4739     N0 = DAG.getNode(ISD::CONCAT_VECTORS, dl, MVT::v8i16, N0, N2);
   4740     N0 = LowerCONCAT_VECTORS(N0, DAG);
   4741 
   4742     N0 = DAG.getNode(ISD::TRUNCATE, dl, MVT::v8i8, N0);
   4743     return N0;
   4744   }
   4745   return LowerSDIV_v4i16(N0, N1, dl, DAG);
   4746 }
   4747 
   4748 static SDValue LowerUDIV(SDValue Op, SelectionDAG &DAG) {
   4749   EVT VT = Op.getValueType();
   4750   assert((VT == MVT::v4i16 || VT == MVT::v8i8) &&
   4751          "unexpected type for custom-lowering ISD::UDIV");
   4752 
   4753   DebugLoc dl = Op.getDebugLoc();
   4754   SDValue N0 = Op.getOperand(0);
   4755   SDValue N1 = Op.getOperand(1);
   4756   SDValue N2, N3;
   4757 
   4758   if (VT == MVT::v8i8) {
   4759     N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v8i16, N0);
   4760     N1 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v8i16, N1);
   4761 
   4762     N2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N0,
   4763                      DAG.getIntPtrConstant(4));
   4764     N3 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N1,
   4765                      DAG.getIntPtrConstant(4));
   4766     N0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N0,
   4767                      DAG.getIntPtrConstant(0));
   4768     N1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl, MVT::v4i16, N1,
   4769                      DAG.getIntPtrConstant(0));
   4770 
   4771     N0 = LowerSDIV_v4i16(N0, N1, dl, DAG); // v4i16
   4772     N2 = LowerSDIV_v4i16(N2, N3, dl, DAG); // v4i16
   4773 
   4774     N0 = DAG.getNode(ISD::CONCAT_VECTORS, dl, MVT::v8i16, N0, N2);
   4775     N0 = LowerCONCAT_VECTORS(N0, DAG);
   4776 
   4777     N0 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v8i8,
   4778                      DAG.getConstant(Intrinsic::arm_neon_vqmovnsu, MVT::i32),
   4779                      N0);
   4780     return N0;
   4781   }
   4782 
   4783   // v4i16 sdiv ... Convert to float.
   4784   // float4 yf = vcvt_f32_s32(vmovl_u16(y));
   4785   // float4 xf = vcvt_f32_s32(vmovl_u16(x));
   4786   N0 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v4i32, N0);
   4787   N1 = DAG.getNode(ISD::ZERO_EXTEND, dl, MVT::v4i32, N1);
   4788   N0 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, N0);
   4789   SDValue BN1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::v4f32, N1);
   4790 
   4791   // Use reciprocal estimate and two refinement steps.
   4792   // float4 recip = vrecpeq_f32(yf);
   4793   // recip *= vrecpsq_f32(yf, recip);
   4794   // recip *= vrecpsq_f32(yf, recip);
   4795   N2 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
   4796                    DAG.getConstant(Intrinsic::arm_neon_vrecpe, MVT::i32), BN1);
   4797   N1 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
   4798                    DAG.getConstant(Intrinsic::arm_neon_vrecps, MVT::i32),
   4799                    BN1, N2);
   4800   N2 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N1, N2);
   4801   N1 = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, MVT::v4f32,
   4802                    DAG.getConstant(Intrinsic::arm_neon_vrecps, MVT::i32),
   4803                    BN1, N2);
   4804   N2 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N1, N2);
   4805   // Simply multiplying by the reciprocal estimate can leave us a few ulps
   4806   // too low, so we add 2 ulps (exhaustive testing shows that this is enough,
   4807   // and that it will never cause us to return an answer too large).
   4808   // float4 result = as_float4(as_int4(xf*recip) + 2);
   4809   N0 = DAG.getNode(ISD::FMUL, dl, MVT::v4f32, N0, N2);
   4810   N0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4i32, N0);
   4811   N1 = DAG.getConstant(2, MVT::i32);
   4812   N1 = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, N1, N1, N1, N1);
   4813   N0 = DAG.getNode(ISD::ADD, dl, MVT::v4i32, N0, N1);
   4814   N0 = DAG.getNode(ISD::BITCAST, dl, MVT::v4f32, N0);
   4815   // Convert back to integer and return.
   4816   // return vmovn_u32(vcvt_s32_f32(result));
   4817   N0 = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::v4i32, N0);
   4818   N0 = DAG.getNode(ISD::TRUNCATE, dl, MVT::v4i16, N0);
   4819   return N0;
   4820 }
   4821 
   4822 SDValue ARMTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
   4823   switch (Op.getOpcode()) {
   4824   default: llvm_unreachable("Don't know how to custom lower this!");
   4825   case ISD::ConstantPool:  return LowerConstantPool(Op, DAG);
   4826   case ISD::BlockAddress:  return LowerBlockAddress(Op, DAG);
   4827   case ISD::GlobalAddress:
   4828     return Subtarget->isTargetDarwin() ? LowerGlobalAddressDarwin(Op, DAG) :
   4829       LowerGlobalAddressELF(Op, DAG);
   4830   case ISD::GlobalTLSAddress: return LowerGlobalTLSAddress(Op, DAG);
   4831   case ISD::SELECT:        return LowerSELECT(Op, DAG);
   4832   case ISD::SELECT_CC:     return LowerSELECT_CC(Op, DAG);
   4833   case ISD::BR_CC:         return LowerBR_CC(Op, DAG);
   4834   case ISD::BR_JT:         return LowerBR_JT(Op, DAG);
   4835   case ISD::VASTART:       return LowerVASTART(Op, DAG);
   4836   case ISD::MEMBARRIER:    return LowerMEMBARRIER(Op, DAG, Subtarget);
   4837   case ISD::PREFETCH:      return LowerPREFETCH(Op, DAG, Subtarget);
   4838   case ISD::SINT_TO_FP:
   4839   case ISD::UINT_TO_FP:    return LowerINT_TO_FP(Op, DAG);
   4840   case ISD::FP_TO_SINT:
   4841   case ISD::FP_TO_UINT:    return LowerFP_TO_INT(Op, DAG);
   4842   case ISD::FCOPYSIGN:     return LowerFCOPYSIGN(Op, DAG);
   4843   case ISD::RETURNADDR:    return LowerRETURNADDR(Op, DAG);
   4844   case ISD::FRAMEADDR:     return LowerFRAMEADDR(Op, DAG);
   4845   case ISD::GLOBAL_OFFSET_TABLE: return LowerGLOBAL_OFFSET_TABLE(Op, DAG);
   4846   case ISD::EH_SJLJ_SETJMP: return LowerEH_SJLJ_SETJMP(Op, DAG);
   4847   case ISD::EH_SJLJ_LONGJMP: return LowerEH_SJLJ_LONGJMP(Op, DAG);
   4848   case ISD::EH_SJLJ_DISPATCHSETUP: return LowerEH_SJLJ_DISPATCHSETUP(Op, DAG);
   4849   case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG,
   4850                                                                Subtarget);
   4851   case ISD::BITCAST:       return ExpandBITCAST(Op.getNode(), DAG);
   4852   case ISD::SHL:
   4853   case ISD::SRL:
   4854   case ISD::SRA:           return LowerShift(Op.getNode(), DAG, Subtarget);
   4855   case ISD::SHL_PARTS:     return LowerShiftLeftParts(Op, DAG);
   4856   case ISD::SRL_PARTS:
   4857   case ISD::SRA_PARTS:     return LowerShiftRightParts(Op, DAG);
   4858   case ISD::CTTZ:          return LowerCTTZ(Op.getNode(), DAG, Subtarget);
   4859   case ISD::VSETCC:        return LowerVSETCC(Op, DAG);
   4860   case ISD::BUILD_VECTOR:  return LowerBUILD_VECTOR(Op, DAG, Subtarget);
   4861   case ISD::VECTOR_SHUFFLE: return LowerVECTOR_SHUFFLE(Op, DAG);
   4862   case ISD::EXTRACT_VECTOR_ELT: return LowerEXTRACT_VECTOR_ELT(Op, DAG);
   4863   case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
   4864   case ISD::FLT_ROUNDS_:   return LowerFLT_ROUNDS_(Op, DAG);
   4865   case ISD::MUL:           return LowerMUL(Op, DAG);
   4866   case ISD::SDIV:          return LowerSDIV(Op, DAG);
   4867   case ISD::UDIV:          return LowerUDIV(Op, DAG);
   4868   }
   4869   return SDValue();
   4870 }
   4871 
   4872 /// ReplaceNodeResults - Replace the results of node with an illegal result
   4873 /// type with new values built out of custom code.
   4874 void ARMTargetLowering::ReplaceNodeResults(SDNode *N,
   4875                                            SmallVectorImpl<SDValue>&Results,
   4876                                            SelectionDAG &DAG) const {
   4877   SDValue Res;
   4878   switch (N->getOpcode()) {
   4879   default:
   4880     llvm_unreachable("Don't know how to custom expand this!");
   4881     break;
   4882   case ISD::BITCAST:
   4883     Res = ExpandBITCAST(N, DAG);
   4884     break;
   4885   case ISD::SRL:
   4886   case ISD::SRA:
   4887     Res = Expand64BitShift(N, DAG, Subtarget);
   4888     break;
   4889   }
   4890   if (Res.getNode())
   4891     Results.push_back(Res);
   4892 }
   4893 
   4894 //===----------------------------------------------------------------------===//
   4895 //                           ARM Scheduler Hooks
   4896 //===----------------------------------------------------------------------===//
   4897 
   4898 MachineBasicBlock *
   4899 ARMTargetLowering::EmitAtomicCmpSwap(MachineInstr *MI,
   4900                                      MachineBasicBlock *BB,
   4901                                      unsigned Size) const {
   4902   unsigned dest    = MI->getOperand(0).getReg();
   4903   unsigned ptr     = MI->getOperand(1).getReg();
   4904   unsigned oldval  = MI->getOperand(2).getReg();
   4905   unsigned newval  = MI->getOperand(3).getReg();
   4906   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
   4907   DebugLoc dl = MI->getDebugLoc();
   4908   bool isThumb2 = Subtarget->isThumb2();
   4909 
   4910   MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
   4911   unsigned scratch =
   4912     MRI.createVirtualRegister(isThumb2 ? ARM::rGPRRegisterClass
   4913                                        : ARM::GPRRegisterClass);
   4914 
   4915   if (isThumb2) {
   4916     MRI.constrainRegClass(dest, ARM::rGPRRegisterClass);
   4917     MRI.constrainRegClass(oldval, ARM::rGPRRegisterClass);
   4918     MRI.constrainRegClass(newval, ARM::rGPRRegisterClass);
   4919   }
   4920 
   4921   unsigned ldrOpc, strOpc;
   4922   switch (Size) {
   4923   default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
   4924   case 1:
   4925     ldrOpc = isThumb2 ? ARM::t2LDREXB : ARM::LDREXB;
   4926     strOpc = isThumb2 ? ARM::t2STREXB : ARM::STREXB;
   4927     break;
   4928   case 2:
   4929     ldrOpc = isThumb2 ? ARM::t2LDREXH : ARM::LDREXH;
   4930     strOpc = isThumb2 ? ARM::t2STREXH : ARM::STREXH;
   4931     break;
   4932   case 4:
   4933     ldrOpc = isThumb2 ? ARM::t2LDREX : ARM::LDREX;
   4934     strOpc = isThumb2 ? ARM::t2STREX : ARM::STREX;
   4935     break;
   4936   }
   4937 
   4938   MachineFunction *MF = BB->getParent();
   4939   const BasicBlock *LLVM_BB = BB->getBasicBlock();
   4940   MachineFunction::iterator It = BB;
   4941   ++It; // insert the new blocks after the current block
   4942 
   4943   MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
   4944   MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
   4945   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
   4946   MF->insert(It, loop1MBB);
   4947   MF->insert(It, loop2MBB);
   4948   MF->insert(It, exitMBB);
   4949 
   4950   // Transfer the remainder of BB and its successor edges to exitMBB.
   4951   exitMBB->splice(exitMBB->begin(), BB,
   4952                   llvm::next(MachineBasicBlock::iterator(MI)),
   4953                   BB->end());
   4954   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
   4955 
   4956   //  thisMBB:
   4957   //   ...
   4958   //   fallthrough --> loop1MBB
   4959   BB->addSuccessor(loop1MBB);
   4960 
   4961   // loop1MBB:
   4962   //   ldrex dest, [ptr]
   4963   //   cmp dest, oldval
   4964   //   bne exitMBB
   4965   BB = loop1MBB;
   4966   AddDefaultPred(BuildMI(BB, dl, TII->get(ldrOpc), dest).addReg(ptr));
   4967   AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPrr : ARM::CMPrr))
   4968                  .addReg(dest).addReg(oldval));
   4969   BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
   4970     .addMBB(exitMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
   4971   BB->addSuccessor(loop2MBB);
   4972   BB->addSuccessor(exitMBB);
   4973 
   4974   // loop2MBB:
   4975   //   strex scratch, newval, [ptr]
   4976   //   cmp scratch, #0
   4977   //   bne loop1MBB
   4978   BB = loop2MBB;
   4979   AddDefaultPred(BuildMI(BB, dl, TII->get(strOpc), scratch).addReg(newval)
   4980                  .addReg(ptr));
   4981   AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
   4982                  .addReg(scratch).addImm(0));
   4983   BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
   4984     .addMBB(loop1MBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
   4985   BB->addSuccessor(loop1MBB);
   4986   BB->addSuccessor(exitMBB);
   4987 
   4988   //  exitMBB:
   4989   //   ...
   4990   BB = exitMBB;
   4991 
   4992   MI->eraseFromParent();   // The instruction is gone now.
   4993 
   4994   return BB;
   4995 }
   4996 
   4997 MachineBasicBlock *
   4998 ARMTargetLowering::EmitAtomicBinary(MachineInstr *MI, MachineBasicBlock *BB,
   4999                                     unsigned Size, unsigned BinOpcode) const {
   5000   // This also handles ATOMIC_SWAP, indicated by BinOpcode==0.
   5001   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
   5002 
   5003   const BasicBlock *LLVM_BB = BB->getBasicBlock();
   5004   MachineFunction *MF = BB->getParent();
   5005   MachineFunction::iterator It = BB;
   5006   ++It;
   5007 
   5008   unsigned dest = MI->getOperand(0).getReg();
   5009   unsigned ptr = MI->getOperand(1).getReg();
   5010   unsigned incr = MI->getOperand(2).getReg();
   5011   DebugLoc dl = MI->getDebugLoc();
   5012   bool isThumb2 = Subtarget->isThumb2();
   5013 
   5014   MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
   5015   if (isThumb2) {
   5016     MRI.constrainRegClass(dest, ARM::rGPRRegisterClass);
   5017     MRI.constrainRegClass(ptr, ARM::rGPRRegisterClass);
   5018   }
   5019 
   5020   unsigned ldrOpc, strOpc;
   5021   switch (Size) {
   5022   default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
   5023   case 1:
   5024     ldrOpc = isThumb2 ? ARM::t2LDREXB : ARM::LDREXB;
   5025     strOpc = isThumb2 ? ARM::t2STREXB : ARM::STREXB;
   5026     break;
   5027   case 2:
   5028     ldrOpc = isThumb2 ? ARM::t2LDREXH : ARM::LDREXH;
   5029     strOpc = isThumb2 ? ARM::t2STREXH : ARM::STREXH;
   5030     break;
   5031   case 4:
   5032     ldrOpc = isThumb2 ? ARM::t2LDREX : ARM::LDREX;
   5033     strOpc = isThumb2 ? ARM::t2STREX : ARM::STREX;
   5034     break;
   5035   }
   5036 
   5037   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
   5038   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
   5039   MF->insert(It, loopMBB);
   5040   MF->insert(It, exitMBB);
   5041 
   5042   // Transfer the remainder of BB and its successor edges to exitMBB.
   5043   exitMBB->splice(exitMBB->begin(), BB,
   5044                   llvm::next(MachineBasicBlock::iterator(MI)),
   5045                   BB->end());
   5046   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
   5047 
   5048   TargetRegisterClass *TRC =
   5049     isThumb2 ? ARM::tGPRRegisterClass : ARM::GPRRegisterClass;
   5050   unsigned scratch = MRI.createVirtualRegister(TRC);
   5051   unsigned scratch2 = (!BinOpcode) ? incr : MRI.createVirtualRegister(TRC);
   5052 
   5053   //  thisMBB:
   5054   //   ...
   5055   //   fallthrough --> loopMBB
   5056   BB->addSuccessor(loopMBB);
   5057 
   5058   //  loopMBB:
   5059   //   ldrex dest, ptr
   5060   //   <binop> scratch2, dest, incr
   5061   //   strex scratch, scratch2, ptr
   5062   //   cmp scratch, #0
   5063   //   bne- loopMBB
   5064   //   fallthrough --> exitMBB
   5065   BB = loopMBB;
   5066   AddDefaultPred(BuildMI(BB, dl, TII->get(ldrOpc), dest).addReg(ptr));
   5067   if (BinOpcode) {
   5068     // operand order needs to go the other way for NAND
   5069     if (BinOpcode == ARM::BICrr || BinOpcode == ARM::t2BICrr)
   5070       AddDefaultPred(BuildMI(BB, dl, TII->get(BinOpcode), scratch2).
   5071                      addReg(incr).addReg(dest)).addReg(0);
   5072     else
   5073       AddDefaultPred(BuildMI(BB, dl, TII->get(BinOpcode), scratch2).
   5074                      addReg(dest).addReg(incr)).addReg(0);
   5075   }
   5076 
   5077   AddDefaultPred(BuildMI(BB, dl, TII->get(strOpc), scratch).addReg(scratch2)
   5078                  .addReg(ptr));
   5079   AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
   5080                  .addReg(scratch).addImm(0));
   5081   BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
   5082     .addMBB(loopMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
   5083 
   5084   BB->addSuccessor(loopMBB);
   5085   BB->addSuccessor(exitMBB);
   5086 
   5087   //  exitMBB:
   5088   //   ...
   5089   BB = exitMBB;
   5090 
   5091   MI->eraseFromParent();   // The instruction is gone now.
   5092 
   5093   return BB;
   5094 }
   5095 
   5096 MachineBasicBlock *
   5097 ARMTargetLowering::EmitAtomicBinaryMinMax(MachineInstr *MI,
   5098                                           MachineBasicBlock *BB,
   5099                                           unsigned Size,
   5100                                           bool signExtend,
   5101                                           ARMCC::CondCodes Cond) const {
   5102   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
   5103 
   5104   const BasicBlock *LLVM_BB = BB->getBasicBlock();
   5105   MachineFunction *MF = BB->getParent();
   5106   MachineFunction::iterator It = BB;
   5107   ++It;
   5108 
   5109   unsigned dest = MI->getOperand(0).getReg();
   5110   unsigned ptr = MI->getOperand(1).getReg();
   5111   unsigned incr = MI->getOperand(2).getReg();
   5112   unsigned oldval = dest;
   5113   DebugLoc dl = MI->getDebugLoc();
   5114   bool isThumb2 = Subtarget->isThumb2();
   5115 
   5116   MachineRegisterInfo &MRI = BB->getParent()->getRegInfo();
   5117   if (isThumb2) {
   5118     MRI.constrainRegClass(dest, ARM::rGPRRegisterClass);
   5119     MRI.constrainRegClass(ptr, ARM::rGPRRegisterClass);
   5120   }
   5121 
   5122   unsigned ldrOpc, strOpc, extendOpc;
   5123   switch (Size) {
   5124   default: llvm_unreachable("unsupported size for AtomicCmpSwap!");
   5125   case 1:
   5126     ldrOpc = isThumb2 ? ARM::t2LDREXB : ARM::LDREXB;
   5127     strOpc = isThumb2 ? ARM::t2STREXB : ARM::STREXB;
   5128     extendOpc = isThumb2 ? ARM::t2SXTBr : ARM::SXTBr;
   5129     break;
   5130   case 2:
   5131     ldrOpc = isThumb2 ? ARM::t2LDREXH : ARM::LDREXH;
   5132     strOpc = isThumb2 ? ARM::t2STREXH : ARM::STREXH;
   5133     extendOpc = isThumb2 ? ARM::t2SXTHr : ARM::SXTHr;
   5134     break;
   5135   case 4:
   5136     ldrOpc = isThumb2 ? ARM::t2LDREX : ARM::LDREX;
   5137     strOpc = isThumb2 ? ARM::t2STREX : ARM::STREX;
   5138     extendOpc = 0;
   5139     break;
   5140   }
   5141 
   5142   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
   5143   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
   5144   MF->insert(It, loopMBB);
   5145   MF->insert(It, exitMBB);
   5146 
   5147   // Transfer the remainder of BB and its successor edges to exitMBB.
   5148   exitMBB->splice(exitMBB->begin(), BB,
   5149                   llvm::next(MachineBasicBlock::iterator(MI)),
   5150                   BB->end());
   5151   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
   5152 
   5153   TargetRegisterClass *TRC =
   5154     isThumb2 ? ARM::tGPRRegisterClass : ARM::GPRRegisterClass;
   5155   unsigned scratch = MRI.createVirtualRegister(TRC);
   5156   unsigned scratch2 = MRI.createVirtualRegister(TRC);
   5157 
   5158   //  thisMBB:
   5159   //   ...
   5160   //   fallthrough --> loopMBB
   5161   BB->addSuccessor(loopMBB);
   5162 
   5163   //  loopMBB:
   5164   //   ldrex dest, ptr
   5165   //   (sign extend dest, if required)
   5166   //   cmp dest, incr
   5167   //   cmov.cond scratch2, dest, incr
   5168   //   strex scratch, scratch2, ptr
   5169   //   cmp scratch, #0
   5170   //   bne- loopMBB
   5171   //   fallthrough --> exitMBB
   5172   BB = loopMBB;
   5173   AddDefaultPred(BuildMI(BB, dl, TII->get(ldrOpc), dest).addReg(ptr));
   5174 
   5175   // Sign extend the value, if necessary.
   5176   if (signExtend && extendOpc) {
   5177     oldval = MRI.createVirtualRegister(ARM::GPRRegisterClass);
   5178     AddDefaultPred(BuildMI(BB, dl, TII->get(extendOpc), oldval).addReg(dest));
   5179   }
   5180 
   5181   // Build compare and cmov instructions.
   5182   AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPrr : ARM::CMPrr))
   5183                  .addReg(oldval).addReg(incr));
   5184   BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2MOVCCr : ARM::MOVCCr), scratch2)
   5185          .addReg(oldval).addReg(incr).addImm(Cond).addReg(ARM::CPSR);
   5186 
   5187   AddDefaultPred(BuildMI(BB, dl, TII->get(strOpc), scratch).addReg(scratch2)
   5188                  .addReg(ptr));
   5189   AddDefaultPred(BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
   5190                  .addReg(scratch).addImm(0));
   5191   BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
   5192     .addMBB(loopMBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
   5193 
   5194   BB->addSuccessor(loopMBB);
   5195   BB->addSuccessor(exitMBB);
   5196 
   5197   //  exitMBB:
   5198   //   ...
   5199   BB = exitMBB;
   5200 
   5201   MI->eraseFromParent();   // The instruction is gone now.
   5202 
   5203   return BB;
   5204 }
   5205 
   5206 static
   5207 MachineBasicBlock *OtherSucc(MachineBasicBlock *MBB, MachineBasicBlock *Succ) {
   5208   for (MachineBasicBlock::succ_iterator I = MBB->succ_begin(),
   5209        E = MBB->succ_end(); I != E; ++I)
   5210     if (*I != Succ)
   5211       return *I;
   5212   llvm_unreachable("Expecting a BB with two successors!");
   5213 }
   5214 
   5215 // FIXME: This opcode table should obviously be expressed in the target
   5216 // description. We probably just need a "machine opcode" value in the pseudo
   5217 // instruction. But the ideal solution maybe to simply remove the "S" version
   5218 // of the opcode altogether.
   5219 struct AddSubFlagsOpcodePair {
   5220   unsigned PseudoOpc;
   5221   unsigned MachineOpc;
   5222 };
   5223 
   5224 static AddSubFlagsOpcodePair AddSubFlagsOpcodeMap[] = {
   5225   {ARM::ADCSri, ARM::ADCri},
   5226   {ARM::ADCSrr, ARM::ADCrr},
   5227   {ARM::ADCSrs, ARM::ADCrs},
   5228   {ARM::SBCSri, ARM::SBCri},
   5229   {ARM::SBCSrr, ARM::SBCrr},
   5230   {ARM::SBCSrs, ARM::SBCrs},
   5231   {ARM::RSBSri, ARM::RSBri},
   5232   {ARM::RSBSrr, ARM::RSBrr},
   5233   {ARM::RSBSrs, ARM::RSBrs},
   5234   {ARM::RSCSri, ARM::RSCri},
   5235   {ARM::RSCSrs, ARM::RSCrs},
   5236   {ARM::t2ADCSri, ARM::t2ADCri},
   5237   {ARM::t2ADCSrr, ARM::t2ADCrr},
   5238   {ARM::t2ADCSrs, ARM::t2ADCrs},
   5239   {ARM::t2SBCSri, ARM::t2SBCri},
   5240   {ARM::t2SBCSrr, ARM::t2SBCrr},
   5241   {ARM::t2SBCSrs, ARM::t2SBCrs},
   5242   {ARM::t2RSBSri, ARM::t2RSBri},
   5243   {ARM::t2RSBSrs, ARM::t2RSBrs},
   5244 };
   5245 
   5246 // Convert and Add or Subtract with Carry and Flags to a generic opcode with
   5247 // CPSR<def> operand. e.g. ADCS (...) -> ADC (... CPSR<def>).
   5248 //
   5249 // FIXME: Somewhere we should assert that CPSR<def> is in the correct
   5250 // position to be recognized by the target descrition as the 'S' bit.
   5251 bool ARMTargetLowering::RemapAddSubWithFlags(MachineInstr *MI,
   5252                                              MachineBasicBlock *BB) const {
   5253   unsigned OldOpc = MI->getOpcode();
   5254   unsigned NewOpc = 0;
   5255 
   5256   // This is only called for instructions that need remapping, so iterating over
   5257   // the tiny opcode table is not costly.
   5258   static const int NPairs =
   5259     sizeof(AddSubFlagsOpcodeMap) / sizeof(AddSubFlagsOpcodePair);
   5260   for (AddSubFlagsOpcodePair *Pair = &AddSubFlagsOpcodeMap[0],
   5261          *End = &AddSubFlagsOpcodeMap[NPairs]; Pair != End; ++Pair) {
   5262     if (OldOpc == Pair->PseudoOpc) {
   5263       NewOpc = Pair->MachineOpc;
   5264       break;
   5265     }
   5266   }
   5267   if (!NewOpc)
   5268     return false;
   5269 
   5270   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
   5271   DebugLoc dl = MI->getDebugLoc();
   5272   MachineInstrBuilder MIB = BuildMI(*BB, MI, dl, TII->get(NewOpc));
   5273   for (unsigned i = 0; i < MI->getNumOperands(); ++i)
   5274     MIB.addOperand(MI->getOperand(i));
   5275   AddDefaultPred(MIB);
   5276   MIB.addReg(ARM::CPSR, RegState::Define); // S bit
   5277   MI->eraseFromParent();
   5278   return true;
   5279 }
   5280 
   5281 MachineBasicBlock *
   5282 ARMTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
   5283                                                MachineBasicBlock *BB) const {
   5284   const TargetInstrInfo *TII = getTargetMachine().getInstrInfo();
   5285   DebugLoc dl = MI->getDebugLoc();
   5286   bool isThumb2 = Subtarget->isThumb2();
   5287   switch (MI->getOpcode()) {
   5288   default: {
   5289     if (RemapAddSubWithFlags(MI, BB))
   5290       return BB;
   5291 
   5292     MI->dump();
   5293     llvm_unreachable("Unexpected instr type to insert");
   5294   }
   5295   case ARM::ATOMIC_LOAD_ADD_I8:
   5296      return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
   5297   case ARM::ATOMIC_LOAD_ADD_I16:
   5298      return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
   5299   case ARM::ATOMIC_LOAD_ADD_I32:
   5300      return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ADDrr : ARM::ADDrr);
   5301 
   5302   case ARM::ATOMIC_LOAD_AND_I8:
   5303      return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
   5304   case ARM::ATOMIC_LOAD_AND_I16:
   5305      return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
   5306   case ARM::ATOMIC_LOAD_AND_I32:
   5307      return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ANDrr : ARM::ANDrr);
   5308 
   5309   case ARM::ATOMIC_LOAD_OR_I8:
   5310      return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
   5311   case ARM::ATOMIC_LOAD_OR_I16:
   5312      return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
   5313   case ARM::ATOMIC_LOAD_OR_I32:
   5314      return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2ORRrr : ARM::ORRrr);
   5315 
   5316   case ARM::ATOMIC_LOAD_XOR_I8:
   5317      return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
   5318   case ARM::ATOMIC_LOAD_XOR_I16:
   5319      return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
   5320   case ARM::ATOMIC_LOAD_XOR_I32:
   5321      return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2EORrr : ARM::EORrr);
   5322 
   5323   case ARM::ATOMIC_LOAD_NAND_I8:
   5324      return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
   5325   case ARM::ATOMIC_LOAD_NAND_I16:
   5326      return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
   5327   case ARM::ATOMIC_LOAD_NAND_I32:
   5328      return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2BICrr : ARM::BICrr);
   5329 
   5330   case ARM::ATOMIC_LOAD_SUB_I8:
   5331      return EmitAtomicBinary(MI, BB, 1, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
   5332   case ARM::ATOMIC_LOAD_SUB_I16:
   5333      return EmitAtomicBinary(MI, BB, 2, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
   5334   case ARM::ATOMIC_LOAD_SUB_I32:
   5335      return EmitAtomicBinary(MI, BB, 4, isThumb2 ? ARM::t2SUBrr : ARM::SUBrr);
   5336 
   5337   case ARM::ATOMIC_LOAD_MIN_I8:
   5338      return EmitAtomicBinaryMinMax(MI, BB, 1, true, ARMCC::LT);
   5339   case ARM::ATOMIC_LOAD_MIN_I16:
   5340      return EmitAtomicBinaryMinMax(MI, BB, 2, true, ARMCC::LT);
   5341   case ARM::ATOMIC_LOAD_MIN_I32:
   5342      return EmitAtomicBinaryMinMax(MI, BB, 4, true, ARMCC::LT);
   5343 
   5344   case ARM::ATOMIC_LOAD_MAX_I8:
   5345      return EmitAtomicBinaryMinMax(MI, BB, 1, true, ARMCC::GT);
   5346   case ARM::ATOMIC_LOAD_MAX_I16:
   5347      return EmitAtomicBinaryMinMax(MI, BB, 2, true, ARMCC::GT);
   5348   case ARM::ATOMIC_LOAD_MAX_I32:
   5349      return EmitAtomicBinaryMinMax(MI, BB, 4, true, ARMCC::GT);
   5350 
   5351   case ARM::ATOMIC_LOAD_UMIN_I8:
   5352      return EmitAtomicBinaryMinMax(MI, BB, 1, false, ARMCC::LO);
   5353   case ARM::ATOMIC_LOAD_UMIN_I16:
   5354      return EmitAtomicBinaryMinMax(MI, BB, 2, false, ARMCC::LO);
   5355   case ARM::ATOMIC_LOAD_UMIN_I32:
   5356      return EmitAtomicBinaryMinMax(MI, BB, 4, false, ARMCC::LO);
   5357 
   5358   case ARM::ATOMIC_LOAD_UMAX_I8:
   5359      return EmitAtomicBinaryMinMax(MI, BB, 1, false, ARMCC::HI);
   5360   case ARM::ATOMIC_LOAD_UMAX_I16:
   5361      return EmitAtomicBinaryMinMax(MI, BB, 2, false, ARMCC::HI);
   5362   case ARM::ATOMIC_LOAD_UMAX_I32:
   5363      return EmitAtomicBinaryMinMax(MI, BB, 4, false, ARMCC::HI);
   5364 
   5365   case ARM::ATOMIC_SWAP_I8:  return EmitAtomicBinary(MI, BB, 1, 0);
   5366   case ARM::ATOMIC_SWAP_I16: return EmitAtomicBinary(MI, BB, 2, 0);
   5367   case ARM::ATOMIC_SWAP_I32: return EmitAtomicBinary(MI, BB, 4, 0);
   5368 
   5369   case ARM::ATOMIC_CMP_SWAP_I8:  return EmitAtomicCmpSwap(MI, BB, 1);
   5370   case ARM::ATOMIC_CMP_SWAP_I16: return EmitAtomicCmpSwap(MI, BB, 2);
   5371   case ARM::ATOMIC_CMP_SWAP_I32: return EmitAtomicCmpSwap(MI, BB, 4);
   5372 
   5373   case ARM::tMOVCCr_pseudo: {
   5374     // To "insert" a SELECT_CC instruction, we actually have to insert the
   5375     // diamond control-flow pattern.  The incoming instruction knows the
   5376     // destination vreg to set, the condition code register to branch on, the
   5377     // true/false values to select between, and a branch opcode to use.
   5378     const BasicBlock *LLVM_BB = BB->getBasicBlock();
   5379     MachineFunction::iterator It = BB;
   5380     ++It;
   5381 
   5382     //  thisMBB:
   5383     //  ...
   5384     //   TrueVal = ...
   5385     //   cmpTY ccX, r1, r2
   5386     //   bCC copy1MBB
   5387     //   fallthrough --> copy0MBB
   5388     MachineBasicBlock *thisMBB  = BB;
   5389     MachineFunction *F = BB->getParent();
   5390     MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
   5391     MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
   5392     F->insert(It, copy0MBB);
   5393     F->insert(It, sinkMBB);
   5394 
   5395     // Transfer the remainder of BB and its successor edges to sinkMBB.
   5396     sinkMBB->splice(sinkMBB->begin(), BB,
   5397                     llvm::next(MachineBasicBlock::iterator(MI)),
   5398                     BB->end());
   5399     sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
   5400 
   5401     BB->addSuccessor(copy0MBB);
   5402     BB->addSuccessor(sinkMBB);
   5403 
   5404     BuildMI(BB, dl, TII->get(ARM::tBcc)).addMBB(sinkMBB)
   5405       .addImm(MI->getOperand(3).getImm()).addReg(MI->getOperand(4).getReg());
   5406 
   5407     //  copy0MBB:
   5408     //   %FalseValue = ...
   5409     //   # fallthrough to sinkMBB
   5410     BB = copy0MBB;
   5411 
   5412     // Update machine-CFG edges
   5413     BB->addSuccessor(sinkMBB);
   5414 
   5415     //  sinkMBB:
   5416     //   %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, thisMBB ]
   5417     //  ...
   5418     BB = sinkMBB;
   5419     BuildMI(*BB, BB->begin(), dl,
   5420             TII->get(ARM::PHI), MI->getOperand(0).getReg())
   5421       .addReg(MI->getOperand(1).getReg()).addMBB(copy0MBB)
   5422       .addReg(MI->getOperand(2).getReg()).addMBB(thisMBB);
   5423 
   5424     MI->eraseFromParent();   // The pseudo instruction is gone now.
   5425     return BB;
   5426   }
   5427 
   5428   case ARM::BCCi64:
   5429   case ARM::BCCZi64: {
   5430     // If there is an unconditional branch to the other successor, remove it.
   5431     BB->erase(llvm::next(MachineBasicBlock::iterator(MI)), BB->end());
   5432 
   5433     // Compare both parts that make up the double comparison separately for
   5434     // equality.
   5435     bool RHSisZero = MI->getOpcode() == ARM::BCCZi64;
   5436 
   5437     unsigned LHS1 = MI->getOperand(1).getReg();
   5438     unsigned LHS2 = MI->getOperand(2).getReg();
   5439     if (RHSisZero) {
   5440       AddDefaultPred(BuildMI(BB, dl,
   5441                              TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
   5442                      .addReg(LHS1).addImm(0));
   5443       BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPri : ARM::CMPri))
   5444         .addReg(LHS2).addImm(0)
   5445         .addImm(ARMCC::EQ).addReg(ARM::CPSR);
   5446     } else {
   5447       unsigned RHS1 = MI->getOperand(3).getReg();
   5448       unsigned RHS2 = MI->getOperand(4).getReg();
   5449       AddDefaultPred(BuildMI(BB, dl,
   5450                              TII->get(isThumb2 ? ARM::t2CMPrr : ARM::CMPrr))
   5451                      .addReg(LHS1).addReg(RHS1));
   5452       BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2CMPrr : ARM::CMPrr))
   5453         .addReg(LHS2).addReg(RHS2)
   5454         .addImm(ARMCC::EQ).addReg(ARM::CPSR);
   5455     }
   5456 
   5457     MachineBasicBlock *destMBB = MI->getOperand(RHSisZero ? 3 : 5).getMBB();
   5458     MachineBasicBlock *exitMBB = OtherSucc(BB, destMBB);
   5459     if (MI->getOperand(0).getImm() == ARMCC::NE)
   5460       std::swap(destMBB, exitMBB);
   5461 
   5462     BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2Bcc : ARM::Bcc))
   5463       .addMBB(destMBB).addImm(ARMCC::EQ).addReg(ARM::CPSR);
   5464     BuildMI(BB, dl, TII->get(isThumb2 ? ARM::t2B : ARM::B))
   5465       .addMBB(exitMBB);
   5466 
   5467     MI->eraseFromParent();   // The pseudo instruction is gone now.
   5468     return BB;
   5469   }
   5470   }
   5471 }
   5472 
   5473 //===----------------------------------------------------------------------===//
   5474 //                           ARM Optimization Hooks
   5475 //===----------------------------------------------------------------------===//
   5476 
   5477 static
   5478 SDValue combineSelectAndUse(SDNode *N, SDValue Slct, SDValue OtherOp,
   5479                             TargetLowering::DAGCombinerInfo &DCI) {
   5480   SelectionDAG &DAG = DCI.DAG;
   5481   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   5482   EVT VT = N->getValueType(0);
   5483   unsigned Opc = N->getOpcode();
   5484   bool isSlctCC = Slct.getOpcode() == ISD::SELECT_CC;
   5485   SDValue LHS = isSlctCC ? Slct.getOperand(2) : Slct.getOperand(1);
   5486   SDValue RHS = isSlctCC ? Slct.getOperand(3) : Slct.getOperand(2);
   5487   ISD::CondCode CC = ISD::SETCC_INVALID;
   5488 
   5489   if (isSlctCC) {
   5490     CC = cast<CondCodeSDNode>(Slct.getOperand(4))->get();
   5491   } else {
   5492     SDValue CCOp = Slct.getOperand(0);
   5493     if (CCOp.getOpcode() == ISD::SETCC)
   5494       CC = cast<CondCodeSDNode>(CCOp.getOperand(2))->get();
   5495   }
   5496 
   5497   bool DoXform = false;
   5498   bool InvCC = false;
   5499   assert ((Opc == ISD::ADD || (Opc == ISD::SUB && Slct == N->getOperand(1))) &&
   5500           "Bad input!");
   5501 
   5502   if (LHS.getOpcode() == ISD::Constant &&
   5503       cast<ConstantSDNode>(LHS)->isNullValue()) {
   5504     DoXform = true;
   5505   } else if (CC != ISD::SETCC_INVALID &&
   5506              RHS.getOpcode() == ISD::Constant &&
   5507              cast<ConstantSDNode>(RHS)->isNullValue()) {
   5508     std::swap(LHS, RHS);
   5509     SDValue Op0 = Slct.getOperand(0);
   5510     EVT OpVT = isSlctCC ? Op0.getValueType() :
   5511                           Op0.getOperand(0).getValueType();
   5512     bool isInt = OpVT.isInteger();
   5513     CC = ISD::getSetCCInverse(CC, isInt);
   5514 
   5515     if (!TLI.isCondCodeLegal(CC, OpVT))
   5516       return SDValue();         // Inverse operator isn't legal.
   5517 
   5518     DoXform = true;
   5519     InvCC = true;
   5520   }
   5521 
   5522   if (DoXform) {
   5523     SDValue Result = DAG.getNode(Opc, RHS.getDebugLoc(), VT, OtherOp, RHS);
   5524     if (isSlctCC)
   5525       return DAG.getSelectCC(N->getDebugLoc(), OtherOp, Result,
   5526                              Slct.getOperand(0), Slct.getOperand(1), CC);
   5527     SDValue CCOp = Slct.getOperand(0);
   5528     if (InvCC)
   5529       CCOp = DAG.getSetCC(Slct.getDebugLoc(), CCOp.getValueType(),
   5530                           CCOp.getOperand(0), CCOp.getOperand(1), CC);
   5531     return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
   5532                        CCOp, OtherOp, Result);
   5533   }
   5534   return SDValue();
   5535 }
   5536 
   5537 // AddCombineToVPADDL- For pair-wise add on neon, use the vpaddl instruction
   5538 // (only after legalization).
   5539 static SDValue AddCombineToVPADDL(SDNode *N, SDValue N0, SDValue N1,
   5540                                  TargetLowering::DAGCombinerInfo &DCI,
   5541                                  const ARMSubtarget *Subtarget) {
   5542 
   5543   // Only perform optimization if after legalize, and if NEON is available. We
   5544   // also expected both operands to be BUILD_VECTORs.
   5545   if (DCI.isBeforeLegalize() || !Subtarget->hasNEON()
   5546       || N0.getOpcode() != ISD::BUILD_VECTOR
   5547       || N1.getOpcode() != ISD::BUILD_VECTOR)
   5548     return SDValue();
   5549 
   5550   // Check output type since VPADDL operand elements can only be 8, 16, or 32.
   5551   EVT VT = N->getValueType(0);
   5552   if (!VT.isInteger() || VT.getVectorElementType() == MVT::i64)
   5553     return SDValue();
   5554 
   5555   // Check that the vector operands are of the right form.
   5556   // N0 and N1 are BUILD_VECTOR nodes with N number of EXTRACT_VECTOR
   5557   // operands, where N is the size of the formed vector.
   5558   // Each EXTRACT_VECTOR should have the same input vector and odd or even
   5559   // index such that we have a pair wise add pattern.
   5560 
   5561   // Grab the vector that all EXTRACT_VECTOR nodes should be referencing.
   5562   if (N0->getOperand(0)->getOpcode() != ISD::EXTRACT_VECTOR_ELT)
   5563     return SDValue();
   5564   SDValue Vec = N0->getOperand(0)->getOperand(0);
   5565   SDNode *V = Vec.getNode();
   5566   unsigned nextIndex = 0;
   5567 
   5568   // For each operands to the ADD which are BUILD_VECTORs,
   5569   // check to see if each of their operands are an EXTRACT_VECTOR with
   5570   // the same vector and appropriate index.
   5571   for (unsigned i = 0, e = N0->getNumOperands(); i != e; ++i) {
   5572     if (N0->getOperand(i)->getOpcode() == ISD::EXTRACT_VECTOR_ELT
   5573         && N1->getOperand(i)->getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
   5574 
   5575       SDValue ExtVec0 = N0->getOperand(i);
   5576       SDValue ExtVec1 = N1->getOperand(i);
   5577 
   5578       // First operand is the vector, verify its the same.
   5579       if (V != ExtVec0->getOperand(0).getNode() ||
   5580           V != ExtVec1->getOperand(0).getNode())
   5581         return SDValue();
   5582 
   5583       // Second is the constant, verify its correct.
   5584       ConstantSDNode *C0 = dyn_cast<ConstantSDNode>(ExtVec0->getOperand(1));
   5585       ConstantSDNode *C1 = dyn_cast<ConstantSDNode>(ExtVec1->getOperand(1));
   5586 
   5587       // For the constant, we want to see all the even or all the odd.
   5588       if (!C0 || !C1 || C0->getZExtValue() != nextIndex
   5589           || C1->getZExtValue() != nextIndex+1)
   5590         return SDValue();
   5591 
   5592       // Increment index.
   5593       nextIndex+=2;
   5594     } else
   5595       return SDValue();
   5596   }
   5597 
   5598   // Create VPADDL node.
   5599   SelectionDAG &DAG = DCI.DAG;
   5600   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   5601 
   5602   // Build operand list.
   5603   SmallVector<SDValue, 8> Ops;
   5604   Ops.push_back(DAG.getConstant(Intrinsic::arm_neon_vpaddls,
   5605                                 TLI.getPointerTy()));
   5606 
   5607   // Input is the vector.
   5608   Ops.push_back(Vec);
   5609 
   5610   // Get widened type and narrowed type.
   5611   MVT widenType;
   5612   unsigned numElem = VT.getVectorNumElements();
   5613   switch (VT.getVectorElementType().getSimpleVT().SimpleTy) {
   5614     case MVT::i8: widenType = MVT::getVectorVT(MVT::i16, numElem); break;
   5615     case MVT::i16: widenType = MVT::getVectorVT(MVT::i32, numElem); break;
   5616     case MVT::i32: widenType = MVT::getVectorVT(MVT::i64, numElem); break;
   5617     default:
   5618       assert(0 && "Invalid vector element type for padd optimization.");
   5619   }
   5620 
   5621   SDValue tmp = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, N->getDebugLoc(),
   5622                             widenType, &Ops[0], Ops.size());
   5623   return DAG.getNode(ISD::TRUNCATE, N->getDebugLoc(), VT, tmp);
   5624 }
   5625 
   5626 /// PerformADDCombineWithOperands - Try DAG combinations for an ADD with
   5627 /// operands N0 and N1.  This is a helper for PerformADDCombine that is
   5628 /// called with the default operands, and if that fails, with commuted
   5629 /// operands.
   5630 static SDValue PerformADDCombineWithOperands(SDNode *N, SDValue N0, SDValue N1,
   5631                                           TargetLowering::DAGCombinerInfo &DCI,
   5632                                           const ARMSubtarget *Subtarget){
   5633 
   5634   // Attempt to create vpaddl for this add.
   5635   SDValue Result = AddCombineToVPADDL(N, N0, N1, DCI, Subtarget);
   5636   if (Result.getNode())
   5637     return Result;
   5638 
   5639   // fold (add (select cc, 0, c), x) -> (select cc, x, (add, x, c))
   5640   if (N0.getOpcode() == ISD::SELECT && N0.getNode()->hasOneUse()) {
   5641     SDValue Result = combineSelectAndUse(N, N0, N1, DCI);
   5642     if (Result.getNode()) return Result;
   5643   }
   5644   return SDValue();
   5645 }
   5646 
   5647 /// PerformADDCombine - Target-specific dag combine xforms for ISD::ADD.
   5648 ///
   5649 static SDValue PerformADDCombine(SDNode *N,
   5650                                  TargetLowering::DAGCombinerInfo &DCI,
   5651                                  const ARMSubtarget *Subtarget) {
   5652   SDValue N0 = N->getOperand(0);
   5653   SDValue N1 = N->getOperand(1);
   5654 
   5655   // First try with the default operand order.
   5656   SDValue Result = PerformADDCombineWithOperands(N, N0, N1, DCI, Subtarget);
   5657   if (Result.getNode())
   5658     return Result;
   5659 
   5660   // If that didn't work, try again with the operands commuted.
   5661   return PerformADDCombineWithOperands(N, N1, N0, DCI, Subtarget);
   5662 }
   5663 
   5664 /// PerformSUBCombine - Target-specific dag combine xforms for ISD::SUB.
   5665 ///
   5666 static SDValue PerformSUBCombine(SDNode *N,
   5667                                  TargetLowering::DAGCombinerInfo &DCI) {
   5668   SDValue N0 = N->getOperand(0);
   5669   SDValue N1 = N->getOperand(1);
   5670 
   5671   // fold (sub x, (select cc, 0, c)) -> (select cc, x, (sub, x, c))
   5672   if (N1.getOpcode() == ISD::SELECT && N1.getNode()->hasOneUse()) {
   5673     SDValue Result = combineSelectAndUse(N, N1, N0, DCI);
   5674     if (Result.getNode()) return Result;
   5675   }
   5676 
   5677   return SDValue();
   5678 }
   5679 
   5680 /// PerformVMULCombine
   5681 /// Distribute (A + B) * C to (A * C) + (B * C) to take advantage of the
   5682 /// special multiplier accumulator forwarding.
   5683 ///   vmul d3, d0, d2
   5684 ///   vmla d3, d1, d2
   5685 /// is faster than
   5686 ///   vadd d3, d0, d1
   5687 ///   vmul d3, d3, d2
   5688 static SDValue PerformVMULCombine(SDNode *N,
   5689                                   TargetLowering::DAGCombinerInfo &DCI,
   5690                                   const ARMSubtarget *Subtarget) {
   5691   if (!Subtarget->hasVMLxForwarding())
   5692     return SDValue();
   5693 
   5694   SelectionDAG &DAG = DCI.DAG;
   5695   SDValue N0 = N->getOperand(0);
   5696   SDValue N1 = N->getOperand(1);
   5697   unsigned Opcode = N0.getOpcode();
   5698   if (Opcode != ISD::ADD && Opcode != ISD::SUB &&
   5699       Opcode != ISD::FADD && Opcode != ISD::FSUB) {
   5700     Opcode = N1.getOpcode();
   5701     if (Opcode != ISD::ADD && Opcode != ISD::SUB &&
   5702         Opcode != ISD::FADD && Opcode != ISD::FSUB)
   5703       return SDValue();
   5704     std::swap(N0, N1);
   5705   }
   5706 
   5707   EVT VT = N->getValueType(0);
   5708   DebugLoc DL = N->getDebugLoc();
   5709   SDValue N00 = N0->getOperand(0);
   5710   SDValue N01 = N0->getOperand(1);
   5711   return DAG.getNode(Opcode, DL, VT,
   5712                      DAG.getNode(ISD::MUL, DL, VT, N00, N1),
   5713                      DAG.getNode(ISD::MUL, DL, VT, N01, N1));
   5714 }
   5715 
   5716 static SDValue PerformMULCombine(SDNode *N,
   5717                                  TargetLowering::DAGCombinerInfo &DCI,
   5718                                  const ARMSubtarget *Subtarget) {
   5719   SelectionDAG &DAG = DCI.DAG;
   5720 
   5721   if (Subtarget->isThumb1Only())
   5722     return SDValue();
   5723 
   5724   if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
   5725     return SDValue();
   5726 
   5727   EVT VT = N->getValueType(0);
   5728   if (VT.is64BitVector() || VT.is128BitVector())
   5729     return PerformVMULCombine(N, DCI, Subtarget);
   5730   if (VT != MVT::i32)
   5731     return SDValue();
   5732 
   5733   ConstantSDNode *C = dyn_cast<ConstantSDNode>(N->getOperand(1));
   5734   if (!C)
   5735     return SDValue();
   5736 
   5737   uint64_t MulAmt = C->getZExtValue();
   5738   unsigned ShiftAmt = CountTrailingZeros_64(MulAmt);
   5739   ShiftAmt = ShiftAmt & (32 - 1);
   5740   SDValue V = N->getOperand(0);
   5741   DebugLoc DL = N->getDebugLoc();
   5742 
   5743   SDValue Res;
   5744   MulAmt >>= ShiftAmt;
   5745   if (isPowerOf2_32(MulAmt - 1)) {
   5746     // (mul x, 2^N + 1) => (add (shl x, N), x)
   5747     Res = DAG.getNode(ISD::ADD, DL, VT,
   5748                       V, DAG.getNode(ISD::SHL, DL, VT,
   5749                                      V, DAG.getConstant(Log2_32(MulAmt-1),
   5750                                                         MVT::i32)));
   5751   } else if (isPowerOf2_32(MulAmt + 1)) {
   5752     // (mul x, 2^N - 1) => (sub (shl x, N), x)
   5753     Res = DAG.getNode(ISD::SUB, DL, VT,
   5754                       DAG.getNode(ISD::SHL, DL, VT,
   5755                                   V, DAG.getConstant(Log2_32(MulAmt+1),
   5756                                                      MVT::i32)),
   5757                                                      V);
   5758   } else
   5759     return SDValue();
   5760 
   5761   if (ShiftAmt != 0)
   5762     Res = DAG.getNode(ISD::SHL, DL, VT, Res,
   5763                       DAG.getConstant(ShiftAmt, MVT::i32));
   5764 
   5765   // Do not add new nodes to DAG combiner worklist.
   5766   DCI.CombineTo(N, Res, false);
   5767   return SDValue();
   5768 }
   5769 
   5770 static SDValue PerformANDCombine(SDNode *N,
   5771                                 TargetLowering::DAGCombinerInfo &DCI) {
   5772 
   5773   // Attempt to use immediate-form VBIC
   5774   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N->getOperand(1));
   5775   DebugLoc dl = N->getDebugLoc();
   5776   EVT VT = N->getValueType(0);
   5777   SelectionDAG &DAG = DCI.DAG;
   5778 
   5779   if(!DAG.getTargetLoweringInfo().isTypeLegal(VT))
   5780     return SDValue();
   5781 
   5782   APInt SplatBits, SplatUndef;
   5783   unsigned SplatBitSize;
   5784   bool HasAnyUndefs;
   5785   if (BVN &&
   5786       BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
   5787     if (SplatBitSize <= 64) {
   5788       EVT VbicVT;
   5789       SDValue Val = isNEONModifiedImm((~SplatBits).getZExtValue(),
   5790                                       SplatUndef.getZExtValue(), SplatBitSize,
   5791                                       DAG, VbicVT, VT.is128BitVector(),
   5792                                       OtherModImm);
   5793       if (Val.getNode()) {
   5794         SDValue Input =
   5795           DAG.getNode(ISD::BITCAST, dl, VbicVT, N->getOperand(0));
   5796         SDValue Vbic = DAG.getNode(ARMISD::VBICIMM, dl, VbicVT, Input, Val);
   5797         return DAG.getNode(ISD::BITCAST, dl, VT, Vbic);
   5798       }
   5799     }
   5800   }
   5801 
   5802   return SDValue();
   5803 }
   5804 
   5805 /// PerformORCombine - Target-specific dag combine xforms for ISD::OR
   5806 static SDValue PerformORCombine(SDNode *N,
   5807                                 TargetLowering::DAGCombinerInfo &DCI,
   5808                                 const ARMSubtarget *Subtarget) {
   5809   // Attempt to use immediate-form VORR
   5810   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(N->getOperand(1));
   5811   DebugLoc dl = N->getDebugLoc();
   5812   EVT VT = N->getValueType(0);
   5813   SelectionDAG &DAG = DCI.DAG;
   5814 
   5815   if(!DAG.getTargetLoweringInfo().isTypeLegal(VT))
   5816     return SDValue();
   5817 
   5818   APInt SplatBits, SplatUndef;
   5819   unsigned SplatBitSize;
   5820   bool HasAnyUndefs;
   5821   if (BVN && Subtarget->hasNEON() &&
   5822       BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
   5823     if (SplatBitSize <= 64) {
   5824       EVT VorrVT;
   5825       SDValue Val = isNEONModifiedImm(SplatBits.getZExtValue(),
   5826                                       SplatUndef.getZExtValue(), SplatBitSize,
   5827                                       DAG, VorrVT, VT.is128BitVector(),
   5828                                       OtherModImm);
   5829       if (Val.getNode()) {
   5830         SDValue Input =
   5831           DAG.getNode(ISD::BITCAST, dl, VorrVT, N->getOperand(0));
   5832         SDValue Vorr = DAG.getNode(ARMISD::VORRIMM, dl, VorrVT, Input, Val);
   5833         return DAG.getNode(ISD::BITCAST, dl, VT, Vorr);
   5834       }
   5835     }
   5836   }
   5837 
   5838   SDValue N0 = N->getOperand(0);
   5839   if (N0.getOpcode() != ISD::AND)
   5840     return SDValue();
   5841   SDValue N1 = N->getOperand(1);
   5842 
   5843   // (or (and B, A), (and C, ~A)) => (VBSL A, B, C) when A is a constant.
   5844   if (Subtarget->hasNEON() && N1.getOpcode() == ISD::AND && VT.isVector() &&
   5845       DAG.getTargetLoweringInfo().isTypeLegal(VT)) {
   5846     APInt SplatUndef;
   5847     unsigned SplatBitSize;
   5848     bool HasAnyUndefs;
   5849 
   5850     BuildVectorSDNode *BVN0 = dyn_cast<BuildVectorSDNode>(N0->getOperand(1));
   5851     APInt SplatBits0;
   5852     if (BVN0 && BVN0->isConstantSplat(SplatBits0, SplatUndef, SplatBitSize,
   5853                                   HasAnyUndefs) && !HasAnyUndefs) {
   5854       BuildVectorSDNode *BVN1 = dyn_cast<BuildVectorSDNode>(N1->getOperand(1));
   5855       APInt SplatBits1;
   5856       if (BVN1 && BVN1->isConstantSplat(SplatBits1, SplatUndef, SplatBitSize,
   5857                                     HasAnyUndefs) && !HasAnyUndefs &&
   5858           SplatBits0 == ~SplatBits1) {
   5859         // Canonicalize the vector type to make instruction selection simpler.
   5860         EVT CanonicalVT = VT.is128BitVector() ? MVT::v4i32 : MVT::v2i32;
   5861         SDValue Result = DAG.getNode(ARMISD::VBSL, dl, CanonicalVT,
   5862                                      N0->getOperand(1), N0->getOperand(0),
   5863                                      N1->getOperand(0));
   5864         return DAG.getNode(ISD::BITCAST, dl, VT, Result);
   5865       }
   5866     }
   5867   }
   5868 
   5869   // Try to use the ARM/Thumb2 BFI (bitfield insert) instruction when
   5870   // reasonable.
   5871 
   5872   // BFI is only available on V6T2+
   5873   if (Subtarget->isThumb1Only() || !Subtarget->hasV6T2Ops())
   5874     return SDValue();
   5875 
   5876   DebugLoc DL = N->getDebugLoc();
   5877   // 1) or (and A, mask), val => ARMbfi A, val, mask
   5878   //      iff (val & mask) == val
   5879   //
   5880   // 2) or (and A, mask), (and B, mask2) => ARMbfi A, (lsr B, amt), mask
   5881   //  2a) iff isBitFieldInvertedMask(mask) && isBitFieldInvertedMask(~mask2)
   5882   //          && mask == ~mask2
   5883   //  2b) iff isBitFieldInvertedMask(~mask) && isBitFieldInvertedMask(mask2)
   5884   //          && ~mask == mask2
   5885   //  (i.e., copy a bitfield value into another bitfield of the same width)
   5886 
   5887   if (VT != MVT::i32)
   5888     return SDValue();
   5889 
   5890   SDValue N00 = N0.getOperand(0);
   5891 
   5892   // The value and the mask need to be constants so we can verify this is
   5893   // actually a bitfield set. If the mask is 0xffff, we can do better
   5894   // via a movt instruction, so don't use BFI in that case.
   5895   SDValue MaskOp = N0.getOperand(1);
   5896   ConstantSDNode *MaskC = dyn_cast<ConstantSDNode>(MaskOp);
   5897   if (!MaskC)
   5898     return SDValue();
   5899   unsigned Mask = MaskC->getZExtValue();
   5900   if (Mask == 0xffff)
   5901     return SDValue();
   5902   SDValue Res;
   5903   // Case (1): or (and A, mask), val => ARMbfi A, val, mask
   5904   ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
   5905   if (N1C) {
   5906     unsigned Val = N1C->getZExtValue();
   5907     if ((Val & ~Mask) != Val)
   5908       return SDValue();
   5909 
   5910     if (ARM::isBitFieldInvertedMask(Mask)) {
   5911       Val >>= CountTrailingZeros_32(~Mask);
   5912 
   5913       Res = DAG.getNode(ARMISD::BFI, DL, VT, N00,
   5914                         DAG.getConstant(Val, MVT::i32),
   5915                         DAG.getConstant(Mask, MVT::i32));
   5916 
   5917       // Do not add new nodes to DAG combiner worklist.
   5918       DCI.CombineTo(N, Res, false);
   5919       return SDValue();
   5920     }
   5921   } else if (N1.getOpcode() == ISD::AND) {
   5922     // case (2) or (and A, mask), (and B, mask2) => ARMbfi A, (lsr B, amt), mask
   5923     ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
   5924     if (!N11C)
   5925       return SDValue();
   5926     unsigned Mask2 = N11C->getZExtValue();
   5927 
   5928     // Mask and ~Mask2 (or reverse) must be equivalent for the BFI pattern
   5929     // as is to match.
   5930     if (ARM::isBitFieldInvertedMask(Mask) &&
   5931         (Mask == ~Mask2)) {
   5932       // The pack halfword instruction works better for masks that fit it,
   5933       // so use that when it's available.
   5934       if (Subtarget->hasT2ExtractPack() &&
   5935           (Mask == 0xffff || Mask == 0xffff0000))
   5936         return SDValue();
   5937       // 2a
   5938       unsigned amt = CountTrailingZeros_32(Mask2);
   5939       Res = DAG.getNode(ISD::SRL, DL, VT, N1.getOperand(0),
   5940                         DAG.getConstant(amt, MVT::i32));
   5941       Res = DAG.getNode(ARMISD::BFI, DL, VT, N00, Res,
   5942                         DAG.getConstant(Mask, MVT::i32));
   5943       // Do not add new nodes to DAG combiner worklist.
   5944       DCI.CombineTo(N, Res, false);
   5945       return SDValue();
   5946     } else if (ARM::isBitFieldInvertedMask(~Mask) &&
   5947                (~Mask == Mask2)) {
   5948       // The pack halfword instruction works better for masks that fit it,
   5949       // so use that when it's available.
   5950       if (Subtarget->hasT2ExtractPack() &&
   5951           (Mask2 == 0xffff || Mask2 == 0xffff0000))
   5952         return SDValue();
   5953       // 2b
   5954       unsigned lsb = CountTrailingZeros_32(Mask);
   5955       Res = DAG.getNode(ISD::SRL, DL, VT, N00,
   5956                         DAG.getConstant(lsb, MVT::i32));
   5957       Res = DAG.getNode(ARMISD::BFI, DL, VT, N1.getOperand(0), Res,
   5958                         DAG.getConstant(Mask2, MVT::i32));
   5959       // Do not add new nodes to DAG combiner worklist.
   5960       DCI.CombineTo(N, Res, false);
   5961       return SDValue();
   5962     }
   5963   }
   5964 
   5965   if (DAG.MaskedValueIsZero(N1, MaskC->getAPIntValue()) &&
   5966       N00.getOpcode() == ISD::SHL && isa<ConstantSDNode>(N00.getOperand(1)) &&
   5967       ARM::isBitFieldInvertedMask(~Mask)) {
   5968     // Case (3): or (and (shl A, #shamt), mask), B => ARMbfi B, A, ~mask
   5969     // where lsb(mask) == #shamt and masked bits of B are known zero.
   5970     SDValue ShAmt = N00.getOperand(1);
   5971     unsigned ShAmtC = cast<ConstantSDNode>(ShAmt)->getZExtValue();
   5972     unsigned LSB = CountTrailingZeros_32(Mask);
   5973     if (ShAmtC != LSB)
   5974       return SDValue();
   5975 
   5976     Res = DAG.getNode(ARMISD::BFI, DL, VT, N1, N00.getOperand(0),
   5977                       DAG.getConstant(~Mask, MVT::i32));
   5978 
   5979     // Do not add new nodes to DAG combiner worklist.
   5980     DCI.CombineTo(N, Res, false);
   5981   }
   5982 
   5983   return SDValue();
   5984 }
   5985 
   5986 /// PerformBFICombine - (bfi A, (and B, Mask1), Mask2) -> (bfi A, B, Mask2) iff
   5987 /// the bits being cleared by the AND are not demanded by the BFI.
   5988 static SDValue PerformBFICombine(SDNode *N,
   5989                                  TargetLowering::DAGCombinerInfo &DCI) {
   5990   SDValue N1 = N->getOperand(1);
   5991   if (N1.getOpcode() == ISD::AND) {
   5992     ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
   5993     if (!N11C)
   5994       return SDValue();
   5995     unsigned InvMask = cast<ConstantSDNode>(N->getOperand(2))->getZExtValue();
   5996     unsigned LSB = CountTrailingZeros_32(~InvMask);
   5997     unsigned Width = (32 - CountLeadingZeros_32(~InvMask)) - LSB;
   5998     unsigned Mask = (1 << Width)-1;
   5999     unsigned Mask2 = N11C->getZExtValue();
   6000     if ((Mask & (~Mask2)) == 0)
   6001       return DCI.DAG.getNode(ARMISD::BFI, N->getDebugLoc(), N->getValueType(0),
   6002                              N->getOperand(0), N1.getOperand(0),
   6003                              N->getOperand(2));
   6004   }
   6005   return SDValue();
   6006 }
   6007 
   6008 /// PerformVMOVRRDCombine - Target-specific dag combine xforms for
   6009 /// ARMISD::VMOVRRD.
   6010 static SDValue PerformVMOVRRDCombine(SDNode *N,
   6011                                      TargetLowering::DAGCombinerInfo &DCI) {
   6012   // vmovrrd(vmovdrr x, y) -> x,y
   6013   SDValue InDouble = N->getOperand(0);
   6014   if (InDouble.getOpcode() == ARMISD::VMOVDRR)
   6015     return DCI.CombineTo(N, InDouble.getOperand(0), InDouble.getOperand(1));
   6016 
   6017   // vmovrrd(load f64) -> (load i32), (load i32)
   6018   SDNode *InNode = InDouble.getNode();
   6019   if (ISD::isNormalLoad(InNode) && InNode->hasOneUse() &&
   6020       InNode->getValueType(0) == MVT::f64 &&
   6021       InNode->getOperand(1).getOpcode() == ISD::FrameIndex &&
   6022       !cast<LoadSDNode>(InNode)->isVolatile()) {
   6023     // TODO: Should this be done for non-FrameIndex operands?
   6024     LoadSDNode *LD = cast<LoadSDNode>(InNode);
   6025 
   6026     SelectionDAG &DAG = DCI.DAG;
   6027     DebugLoc DL = LD->getDebugLoc();
   6028     SDValue BasePtr = LD->getBasePtr();
   6029     SDValue NewLD1 = DAG.getLoad(MVT::i32, DL, LD->getChain(), BasePtr,
   6030                                  LD->getPointerInfo(), LD->isVolatile(),
   6031                                  LD->isNonTemporal(), LD->getAlignment());
   6032 
   6033     SDValue OffsetPtr = DAG.getNode(ISD::ADD, DL, MVT::i32, BasePtr,
   6034                                     DAG.getConstant(4, MVT::i32));
   6035     SDValue NewLD2 = DAG.getLoad(MVT::i32, DL, NewLD1.getValue(1), OffsetPtr,
   6036                                  LD->getPointerInfo(), LD->isVolatile(),
   6037                                  LD->isNonTemporal(),
   6038                                  std::min(4U, LD->getAlignment() / 2));
   6039 
   6040     DAG.ReplaceAllUsesOfValueWith(SDValue(LD, 1), NewLD2.getValue(1));
   6041     SDValue Result = DCI.CombineTo(N, NewLD1, NewLD2);
   6042     DCI.RemoveFromWorklist(LD);
   6043     DAG.DeleteNode(LD);
   6044     return Result;
   6045   }
   6046 
   6047   return SDValue();
   6048 }
   6049 
   6050 /// PerformVMOVDRRCombine - Target-specific dag combine xforms for
   6051 /// ARMISD::VMOVDRR.  This is also used for BUILD_VECTORs with 2 operands.
   6052 static SDValue PerformVMOVDRRCombine(SDNode *N, SelectionDAG &DAG) {
   6053   // N=vmovrrd(X); vmovdrr(N:0, N:1) -> bit_convert(X)
   6054   SDValue Op0 = N->getOperand(0);
   6055   SDValue Op1 = N->getOperand(1);
   6056   if (Op0.getOpcode() == ISD::BITCAST)
   6057     Op0 = Op0.getOperand(0);
   6058   if (Op1.getOpcode() == ISD::BITCAST)
   6059     Op1 = Op1.getOperand(0);
   6060   if (Op0.getOpcode() == ARMISD::VMOVRRD &&
   6061       Op0.getNode() == Op1.getNode() &&
   6062       Op0.getResNo() == 0 && Op1.getResNo() == 1)
   6063     return DAG.getNode(ISD::BITCAST, N->getDebugLoc(),
   6064                        N->getValueType(0), Op0.getOperand(0));
   6065   return SDValue();
   6066 }
   6067 
   6068 /// PerformSTORECombine - Target-specific dag combine xforms for
   6069 /// ISD::STORE.
   6070 static SDValue PerformSTORECombine(SDNode *N,
   6071                                    TargetLowering::DAGCombinerInfo &DCI) {
   6072   // Bitcast an i64 store extracted from a vector to f64.
   6073   // Otherwise, the i64 value will be legalized to a pair of i32 values.
   6074   StoreSDNode *St = cast<StoreSDNode>(N);
   6075   SDValue StVal = St->getValue();
   6076   if (!ISD::isNormalStore(St) || St->isVolatile())
   6077     return SDValue();
   6078 
   6079   if (StVal.getNode()->getOpcode() == ARMISD::VMOVDRR &&
   6080       StVal.getNode()->hasOneUse() && !St->isVolatile()) {
   6081     SelectionDAG  &DAG = DCI.DAG;
   6082     DebugLoc DL = St->getDebugLoc();
   6083     SDValue BasePtr = St->getBasePtr();
   6084     SDValue NewST1 = DAG.getStore(St->getChain(), DL,
   6085                                   StVal.getNode()->getOperand(0), BasePtr,
   6086                                   St->getPointerInfo(), St->isVolatile(),
   6087                                   St->isNonTemporal(), St->getAlignment());
   6088 
   6089     SDValue OffsetPtr = DAG.getNode(ISD::ADD, DL, MVT::i32, BasePtr,
   6090                                     DAG.getConstant(4, MVT::i32));
   6091     return DAG.getStore(NewST1.getValue(0), DL, StVal.getNode()->getOperand(1),
   6092                         OffsetPtr, St->getPointerInfo(), St->isVolatile(),
   6093                         St->isNonTemporal(),
   6094                         std::min(4U, St->getAlignment() / 2));
   6095   }
   6096 
   6097   if (StVal.getValueType() != MVT::i64 ||
   6098       StVal.getNode()->getOpcode() != ISD::EXTRACT_VECTOR_ELT)
   6099     return SDValue();
   6100 
   6101   SelectionDAG &DAG = DCI.DAG;
   6102   DebugLoc dl = StVal.getDebugLoc();
   6103   SDValue IntVec = StVal.getOperand(0);
   6104   EVT FloatVT = EVT::getVectorVT(*DAG.getContext(), MVT::f64,
   6105                                  IntVec.getValueType().getVectorNumElements());
   6106   SDValue Vec = DAG.getNode(ISD::BITCAST, dl, FloatVT, IntVec);
   6107   SDValue ExtElt = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64,
   6108                                Vec, StVal.getOperand(1));
   6109   dl = N->getDebugLoc();
   6110   SDValue V = DAG.getNode(ISD::BITCAST, dl, MVT::i64, ExtElt);
   6111   // Make the DAGCombiner fold the bitcasts.
   6112   DCI.AddToWorklist(Vec.getNode());
   6113   DCI.AddToWorklist(ExtElt.getNode());
   6114   DCI.AddToWorklist(V.getNode());
   6115   return DAG.getStore(St->getChain(), dl, V, St->getBasePtr(),
   6116                       St->getPointerInfo(), St->isVolatile(),
   6117                       St->isNonTemporal(), St->getAlignment(),
   6118                       St->getTBAAInfo());
   6119 }
   6120 
   6121 /// hasNormalLoadOperand - Check if any of the operands of a BUILD_VECTOR node
   6122 /// are normal, non-volatile loads.  If so, it is profitable to bitcast an
   6123 /// i64 vector to have f64 elements, since the value can then be loaded
   6124 /// directly into a VFP register.
   6125 static bool hasNormalLoadOperand(SDNode *N) {
   6126   unsigned NumElts = N->getValueType(0).getVectorNumElements();
   6127   for (unsigned i = 0; i < NumElts; ++i) {
   6128     SDNode *Elt = N->getOperand(i).getNode();
   6129     if (ISD::isNormalLoad(Elt) && !cast<LoadSDNode>(Elt)->isVolatile())
   6130       return true;
   6131   }
   6132   return false;
   6133 }
   6134 
   6135 /// PerformBUILD_VECTORCombine - Target-specific dag combine xforms for
   6136 /// ISD::BUILD_VECTOR.
   6137 static SDValue PerformBUILD_VECTORCombine(SDNode *N,
   6138                                           TargetLowering::DAGCombinerInfo &DCI){
   6139   // build_vector(N=ARMISD::VMOVRRD(X), N:1) -> bit_convert(X):
   6140   // VMOVRRD is introduced when legalizing i64 types.  It forces the i64 value
   6141   // into a pair of GPRs, which is fine when the value is used as a scalar,
   6142   // but if the i64 value is converted to a vector, we need to undo the VMOVRRD.
   6143   SelectionDAG &DAG = DCI.DAG;
   6144   if (N->getNumOperands() == 2) {
   6145     SDValue RV = PerformVMOVDRRCombine(N, DAG);
   6146     if (RV.getNode())
   6147       return RV;
   6148   }
   6149 
   6150   // Load i64 elements as f64 values so that type legalization does not split
   6151   // them up into i32 values.
   6152   EVT VT = N->getValueType(0);
   6153   if (VT.getVectorElementType() != MVT::i64 || !hasNormalLoadOperand(N))
   6154     return SDValue();
   6155   DebugLoc dl = N->getDebugLoc();
   6156   SmallVector<SDValue, 8> Ops;
   6157   unsigned NumElts = VT.getVectorNumElements();
   6158   for (unsigned i = 0; i < NumElts; ++i) {
   6159     SDValue V = DAG.getNode(ISD::BITCAST, dl, MVT::f64, N->getOperand(i));
   6160     Ops.push_back(V);
   6161     // Make the DAGCombiner fold the bitcast.
   6162     DCI.AddToWorklist(V.getNode());
   6163   }
   6164   EVT FloatVT = EVT::getVectorVT(*DAG.getContext(), MVT::f64, NumElts);
   6165   SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, dl, FloatVT, Ops.data(), NumElts);
   6166   return DAG.getNode(ISD::BITCAST, dl, VT, BV);
   6167 }
   6168 
   6169 /// PerformInsertEltCombine - Target-specific dag combine xforms for
   6170 /// ISD::INSERT_VECTOR_ELT.
   6171 static SDValue PerformInsertEltCombine(SDNode *N,
   6172                                        TargetLowering::DAGCombinerInfo &DCI) {
   6173   // Bitcast an i64 load inserted into a vector to f64.
   6174   // Otherwise, the i64 value will be legalized to a pair of i32 values.
   6175   EVT VT = N->getValueType(0);
   6176   SDNode *Elt = N->getOperand(1).getNode();
   6177   if (VT.getVectorElementType() != MVT::i64 ||
   6178       !ISD::isNormalLoad(Elt) || cast<LoadSDNode>(Elt)->isVolatile())
   6179     return SDValue();
   6180 
   6181   SelectionDAG &DAG = DCI.DAG;
   6182   DebugLoc dl = N->getDebugLoc();
   6183   EVT FloatVT = EVT::getVectorVT(*DAG.getContext(), MVT::f64,
   6184                                  VT.getVectorNumElements());
   6185   SDValue Vec = DAG.getNode(ISD::BITCAST, dl, FloatVT, N->getOperand(0));
   6186   SDValue V = DAG.getNode(ISD::BITCAST, dl, MVT::f64, N->getOperand(1));
   6187   // Make the DAGCombiner fold the bitcasts.
   6188   DCI.AddToWorklist(Vec.getNode());
   6189   DCI.AddToWorklist(V.getNode());
   6190   SDValue InsElt = DAG.getNode(ISD::INSERT_VECTOR_ELT, dl, FloatVT,
   6191                                Vec, V, N->getOperand(2));
   6192   return DAG.getNode(ISD::BITCAST, dl, VT, InsElt);
   6193 }
   6194 
   6195 /// PerformVECTOR_SHUFFLECombine - Target-specific dag combine xforms for
   6196 /// ISD::VECTOR_SHUFFLE.
   6197 static SDValue PerformVECTOR_SHUFFLECombine(SDNode *N, SelectionDAG &DAG) {
   6198   // The LLVM shufflevector instruction does not require the shuffle mask
   6199   // length to match the operand vector length, but ISD::VECTOR_SHUFFLE does
   6200   // have that requirement.  When translating to ISD::VECTOR_SHUFFLE, if the
   6201   // operands do not match the mask length, they are extended by concatenating
   6202   // them with undef vectors.  That is probably the right thing for other
   6203   // targets, but for NEON it is better to concatenate two double-register
   6204   // size vector operands into a single quad-register size vector.  Do that
   6205   // transformation here:
   6206   //   shuffle(concat(v1, undef), concat(v2, undef)) ->
   6207   //   shuffle(concat(v1, v2), undef)
   6208   SDValue Op0 = N->getOperand(0);
   6209   SDValue Op1 = N->getOperand(1);
   6210   if (Op0.getOpcode() != ISD::CONCAT_VECTORS ||
   6211       Op1.getOpcode() != ISD::CONCAT_VECTORS ||
   6212       Op0.getNumOperands() != 2 ||
   6213       Op1.getNumOperands() != 2)
   6214     return SDValue();
   6215   SDValue Concat0Op1 = Op0.getOperand(1);
   6216   SDValue Concat1Op1 = Op1.getOperand(1);
   6217   if (Concat0Op1.getOpcode() != ISD::UNDEF ||
   6218       Concat1Op1.getOpcode() != ISD::UNDEF)
   6219     return SDValue();
   6220   // Skip the transformation if any of the types are illegal.
   6221   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   6222   EVT VT = N->getValueType(0);
   6223   if (!TLI.isTypeLegal(VT) ||
   6224       !TLI.isTypeLegal(Concat0Op1.getValueType()) ||
   6225       !TLI.isTypeLegal(Concat1Op1.getValueType()))
   6226     return SDValue();
   6227 
   6228   SDValue NewConcat = DAG.getNode(ISD::CONCAT_VECTORS, N->getDebugLoc(), VT,
   6229                                   Op0.getOperand(0), Op1.getOperand(0));
   6230   // Translate the shuffle mask.
   6231   SmallVector<int, 16> NewMask;
   6232   unsigned NumElts = VT.getVectorNumElements();
   6233   unsigned HalfElts = NumElts/2;
   6234   ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
   6235   for (unsigned n = 0; n < NumElts; ++n) {
   6236     int MaskElt = SVN->getMaskElt(n);
   6237     int NewElt = -1;
   6238     if (MaskElt < (int)HalfElts)
   6239       NewElt = MaskElt;
   6240     else if (MaskElt >= (int)NumElts && MaskElt < (int)(NumElts + HalfElts))
   6241       NewElt = HalfElts + MaskElt - NumElts;
   6242     NewMask.push_back(NewElt);
   6243   }
   6244   return DAG.getVectorShuffle(VT, N->getDebugLoc(), NewConcat,
   6245                               DAG.getUNDEF(VT), NewMask.data());
   6246 }
   6247 
   6248 /// CombineBaseUpdate - Target-specific DAG combine function for VLDDUP and
   6249 /// NEON load/store intrinsics to merge base address updates.
   6250 static SDValue CombineBaseUpdate(SDNode *N,
   6251                                  TargetLowering::DAGCombinerInfo &DCI) {
   6252   if (DCI.isBeforeLegalize() || DCI.isCalledByLegalizer())
   6253     return SDValue();
   6254 
   6255   SelectionDAG &DAG = DCI.DAG;
   6256   bool isIntrinsic = (N->getOpcode() == ISD::INTRINSIC_VOID ||
   6257                       N->getOpcode() == ISD::INTRINSIC_W_CHAIN);
   6258   unsigned AddrOpIdx = (isIntrinsic ? 2 : 1);
   6259   SDValue Addr = N->getOperand(AddrOpIdx);
   6260 
   6261   // Search for a use of the address operand that is an increment.
   6262   for (SDNode::use_iterator UI = Addr.getNode()->use_begin(),
   6263          UE = Addr.getNode()->use_end(); UI != UE; ++UI) {
   6264     SDNode *User = *UI;
   6265     if (User->getOpcode() != ISD::ADD ||
   6266         UI.getUse().getResNo() != Addr.getResNo())
   6267       continue;
   6268 
   6269     // Check that the add is independent of the load/store.  Otherwise, folding
   6270     // it would create a cycle.
   6271     if (User->isPredecessorOf(N) || N->isPredecessorOf(User))
   6272       continue;
   6273 
   6274     // Find the new opcode for the updating load/store.
   6275     bool isLoad = true;
   6276     bool isLaneOp = false;
   6277     unsigned NewOpc = 0;
   6278     unsigned NumVecs = 0;
   6279     if (isIntrinsic) {
   6280       unsigned IntNo = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
   6281       switch (IntNo) {
   6282       default: assert(0 && "unexpected intrinsic for Neon base update");
   6283       case Intrinsic::arm_neon_vld1:     NewOpc = ARMISD::VLD1_UPD;
   6284         NumVecs = 1; break;
   6285       case Intrinsic::arm_neon_vld2:     NewOpc = ARMISD::VLD2_UPD;
   6286         NumVecs = 2; break;
   6287       case Intrinsic::arm_neon_vld3:     NewOpc = ARMISD::VLD3_UPD;
   6288         NumVecs = 3; break;
   6289       case Intrinsic::arm_neon_vld4:     NewOpc = ARMISD::VLD4_UPD;
   6290         NumVecs = 4; break;
   6291       case Intrinsic::arm_neon_vld2lane: NewOpc = ARMISD::VLD2LN_UPD;
   6292         NumVecs = 2; isLaneOp = true; break;
   6293       case Intrinsic::arm_neon_vld3lane: NewOpc = ARMISD::VLD3LN_UPD;
   6294         NumVecs = 3; isLaneOp = true; break;
   6295       case Intrinsic::arm_neon_vld4lane: NewOpc = ARMISD::VLD4LN_UPD;
   6296         NumVecs = 4; isLaneOp = true; break;
   6297       case Intrinsic::arm_neon_vst1:     NewOpc = ARMISD::VST1_UPD;
   6298         NumVecs = 1; isLoad = false; break;
   6299       case Intrinsic::arm_neon_vst2:     NewOpc = ARMISD::VST2_UPD;
   6300         NumVecs = 2; isLoad = false; break;
   6301       case Intrinsic::arm_neon_vst3:     NewOpc = ARMISD::VST3_UPD;
   6302         NumVecs = 3; isLoad = false; break;
   6303       case Intrinsic::arm_neon_vst4:     NewOpc = ARMISD::VST4_UPD;
   6304         NumVecs = 4; isLoad = false; break;
   6305       case Intrinsic::arm_neon_vst2lane: NewOpc = ARMISD::VST2LN_UPD;
   6306         NumVecs = 2; isLoad = false; isLaneOp = true; break;
   6307       case Intrinsic::arm_neon_vst3lane: NewOpc = ARMISD::VST3LN_UPD;
   6308         NumVecs = 3; isLoad = false; isLaneOp = true; break;
   6309       case Intrinsic::arm_neon_vst4lane: NewOpc = ARMISD::VST4LN_UPD;
   6310         NumVecs = 4; isLoad = false; isLaneOp = true; break;
   6311       }
   6312     } else {
   6313       isLaneOp = true;
   6314       switch (N->getOpcode()) {
   6315       default: assert(0 && "unexpected opcode for Neon base update");
   6316       case ARMISD::VLD2DUP: NewOpc = ARMISD::VLD2DUP_UPD; NumVecs = 2; break;
   6317       case ARMISD::VLD3DUP: NewOpc = ARMISD::VLD3DUP_UPD; NumVecs = 3; break;
   6318       case ARMISD::VLD4DUP: NewOpc = ARMISD::VLD4DUP_UPD; NumVecs = 4; break;
   6319       }
   6320     }
   6321 
   6322     // Find the size of memory referenced by the load/store.
   6323     EVT VecTy;
   6324     if (isLoad)
   6325       VecTy = N->getValueType(0);
   6326     else
   6327       VecTy = N->getOperand(AddrOpIdx+1).getValueType();
   6328     unsigned NumBytes = NumVecs * VecTy.getSizeInBits() / 8;
   6329     if (isLaneOp)
   6330       NumBytes /= VecTy.getVectorNumElements();
   6331 
   6332     // If the increment is a constant, it must match the memory ref size.
   6333     SDValue Inc = User->getOperand(User->getOperand(0) == Addr ? 1 : 0);
   6334     if (ConstantSDNode *CInc = dyn_cast<ConstantSDNode>(Inc.getNode())) {
   6335       uint64_t IncVal = CInc->getZExtValue();
   6336       if (IncVal != NumBytes)
   6337         continue;
   6338     } else if (NumBytes >= 3 * 16) {
   6339       // VLD3/4 and VST3/4 for 128-bit vectors are implemented with two
   6340       // separate instructions that make it harder to use a non-constant update.
   6341       continue;
   6342     }
   6343 
   6344     // Create the new updating load/store node.
   6345     EVT Tys[6];
   6346     unsigned NumResultVecs = (isLoad ? NumVecs : 0);
   6347     unsigned n;
   6348     for (n = 0; n < NumResultVecs; ++n)
   6349       Tys[n] = VecTy;
   6350     Tys[n++] = MVT::i32;
   6351     Tys[n] = MVT::Other;
   6352     SDVTList SDTys = DAG.getVTList(Tys, NumResultVecs+2);
   6353     SmallVector<SDValue, 8> Ops;
   6354     Ops.push_back(N->getOperand(0)); // incoming chain
   6355     Ops.push_back(N->getOperand(AddrOpIdx));
   6356     Ops.push_back(Inc);
   6357     for (unsigned i = AddrOpIdx + 1; i < N->getNumOperands(); ++i) {
   6358       Ops.push_back(N->getOperand(i));
   6359     }
   6360     MemIntrinsicSDNode *MemInt = cast<MemIntrinsicSDNode>(N);
   6361     SDValue UpdN = DAG.getMemIntrinsicNode(NewOpc, N->getDebugLoc(), SDTys,
   6362                                            Ops.data(), Ops.size(),
   6363                                            MemInt->getMemoryVT(),
   6364                                            MemInt->getMemOperand());
   6365 
   6366     // Update the uses.
   6367     std::vector<SDValue> NewResults;
   6368     for (unsigned i = 0; i < NumResultVecs; ++i) {
   6369       NewResults.push_back(SDValue(UpdN.getNode(), i));
   6370     }
   6371     NewResults.push_back(SDValue(UpdN.getNode(), NumResultVecs+1)); // chain
   6372     DCI.CombineTo(N, NewResults);
   6373     DCI.CombineTo(User, SDValue(UpdN.getNode(), NumResultVecs));
   6374 
   6375     break;
   6376   }
   6377   return SDValue();
   6378 }
   6379 
   6380 /// CombineVLDDUP - For a VDUPLANE node N, check if its source operand is a
   6381 /// vldN-lane (N > 1) intrinsic, and if all the other uses of that intrinsic
   6382 /// are also VDUPLANEs.  If so, combine them to a vldN-dup operation and
   6383 /// return true.
   6384 static bool CombineVLDDUP(SDNode *N, TargetLowering::DAGCombinerInfo &DCI) {
   6385   SelectionDAG &DAG = DCI.DAG;
   6386   EVT VT = N->getValueType(0);
   6387   // vldN-dup instructions only support 64-bit vectors for N > 1.
   6388   if (!VT.is64BitVector())
   6389     return false;
   6390 
   6391   // Check if the VDUPLANE operand is a vldN-dup intrinsic.
   6392   SDNode *VLD = N->getOperand(0).getNode();
   6393   if (VLD->getOpcode() != ISD::INTRINSIC_W_CHAIN)
   6394     return false;
   6395   unsigned NumVecs = 0;
   6396   unsigned NewOpc = 0;
   6397   unsigned IntNo = cast<ConstantSDNode>(VLD->getOperand(1))->getZExtValue();
   6398   if (IntNo == Intrinsic::arm_neon_vld2lane) {
   6399     NumVecs = 2;
   6400     NewOpc = ARMISD::VLD2DUP;
   6401   } else if (IntNo == Intrinsic::arm_neon_vld3lane) {
   6402     NumVecs = 3;
   6403     NewOpc = ARMISD::VLD3DUP;
   6404   } else if (IntNo == Intrinsic::arm_neon_vld4lane) {
   6405     NumVecs = 4;
   6406     NewOpc = ARMISD::VLD4DUP;
   6407   } else {
   6408     return false;
   6409   }
   6410 
   6411   // First check that all the vldN-lane uses are VDUPLANEs and that the lane
   6412   // numbers match the load.
   6413   unsigned VLDLaneNo =
   6414     cast<ConstantSDNode>(VLD->getOperand(NumVecs+3))->getZExtValue();
   6415   for (SDNode::use_iterator UI = VLD->use_begin(), UE = VLD->use_end();
   6416        UI != UE; ++UI) {
   6417     // Ignore uses of the chain result.
   6418     if (UI.getUse().getResNo() == NumVecs)
   6419       continue;
   6420     SDNode *User = *UI;
   6421     if (User->getOpcode() != ARMISD::VDUPLANE ||
   6422         VLDLaneNo != cast<ConstantSDNode>(User->getOperand(1))->getZExtValue())
   6423       return false;
   6424   }
   6425 
   6426   // Create the vldN-dup node.
   6427   EVT Tys[5];
   6428   unsigned n;
   6429   for (n = 0; n < NumVecs; ++n)
   6430     Tys[n] = VT;
   6431   Tys[n] = MVT::Other;
   6432   SDVTList SDTys = DAG.getVTList(Tys, NumVecs+1);
   6433   SDValue Ops[] = { VLD->getOperand(0), VLD->getOperand(2) };
   6434   MemIntrinsicSDNode *VLDMemInt = cast<MemIntrinsicSDNode>(VLD);
   6435   SDValue VLDDup = DAG.getMemIntrinsicNode(NewOpc, VLD->getDebugLoc(), SDTys,
   6436                                            Ops, 2, VLDMemInt->getMemoryVT(),
   6437                                            VLDMemInt->getMemOperand());
   6438 
   6439   // Update the uses.
   6440   for (SDNode::use_iterator UI = VLD->use_begin(), UE = VLD->use_end();
   6441        UI != UE; ++UI) {
   6442     unsigned ResNo = UI.getUse().getResNo();
   6443     // Ignore uses of the chain result.
   6444     if (ResNo == NumVecs)
   6445       continue;
   6446     SDNode *User = *UI;
   6447     DCI.CombineTo(User, SDValue(VLDDup.getNode(), ResNo));
   6448   }
   6449 
   6450   // Now the vldN-lane intrinsic is dead except for its chain result.
   6451   // Update uses of the chain.
   6452   std::vector<SDValue> VLDDupResults;
   6453   for (unsigned n = 0; n < NumVecs; ++n)
   6454     VLDDupResults.push_back(SDValue(VLDDup.getNode(), n));
   6455   VLDDupResults.push_back(SDValue(VLDDup.getNode(), NumVecs));
   6456   DCI.CombineTo(VLD, VLDDupResults);
   6457 
   6458   return true;
   6459 }
   6460 
   6461 /// PerformVDUPLANECombine - Target-specific dag combine xforms for
   6462 /// ARMISD::VDUPLANE.
   6463 static SDValue PerformVDUPLANECombine(SDNode *N,
   6464                                       TargetLowering::DAGCombinerInfo &DCI) {
   6465   SDValue Op = N->getOperand(0);
   6466 
   6467   // If the source is a vldN-lane (N > 1) intrinsic, and all the other uses
   6468   // of that intrinsic are also VDUPLANEs, combine them to a vldN-dup operation.
   6469   if (CombineVLDDUP(N, DCI))
   6470     return SDValue(N, 0);
   6471 
   6472   // If the source is already a VMOVIMM or VMVNIMM splat, the VDUPLANE is
   6473   // redundant.  Ignore bit_converts for now; element sizes are checked below.
   6474   while (Op.getOpcode() == ISD::BITCAST)
   6475     Op = Op.getOperand(0);
   6476   if (Op.getOpcode() != ARMISD::VMOVIMM && Op.getOpcode() != ARMISD::VMVNIMM)
   6477     return SDValue();
   6478 
   6479   // Make sure the VMOV element size is not bigger than the VDUPLANE elements.
   6480   unsigned EltSize = Op.getValueType().getVectorElementType().getSizeInBits();
   6481   // The canonical VMOV for a zero vector uses a 32-bit element size.
   6482   unsigned Imm = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
   6483   unsigned EltBits;
   6484   if (ARM_AM::decodeNEONModImm(Imm, EltBits) == 0)
   6485     EltSize = 8;
   6486   EVT VT = N->getValueType(0);
   6487   if (EltSize > VT.getVectorElementType().getSizeInBits())
   6488     return SDValue();
   6489 
   6490   return DCI.DAG.getNode(ISD::BITCAST, N->getDebugLoc(), VT, Op);
   6491 }
   6492 
   6493 // isConstVecPow2 - Return true if each vector element is a power of 2, all
   6494 // elements are the same constant, C, and Log2(C) ranges from 1 to 32.
   6495 static bool isConstVecPow2(SDValue ConstVec, bool isSigned, uint64_t &C)
   6496 {
   6497   integerPart cN;
   6498   integerPart c0 = 0;
   6499   for (unsigned I = 0, E = ConstVec.getValueType().getVectorNumElements();
   6500        I != E; I++) {
   6501     ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(ConstVec.getOperand(I));
   6502     if (!C)
   6503       return false;
   6504 
   6505     bool isExact;
   6506     APFloat APF = C->getValueAPF();
   6507     if (APF.convertToInteger(&cN, 64, isSigned, APFloat::rmTowardZero, &isExact)
   6508         != APFloat::opOK || !isExact)
   6509       return false;
   6510 
   6511     c0 = (I == 0) ? cN : c0;
   6512     if (!isPowerOf2_64(cN) || c0 != cN || Log2_64(c0) < 1 || Log2_64(c0) > 32)
   6513       return false;
   6514   }
   6515   C = c0;
   6516   return true;
   6517 }
   6518 
   6519 /// PerformVCVTCombine - VCVT (floating-point to fixed-point, Advanced SIMD)
   6520 /// can replace combinations of VMUL and VCVT (floating-point to integer)
   6521 /// when the VMUL has a constant operand that is a power of 2.
   6522 ///
   6523 /// Example (assume d17 = <float 8.000000e+00, float 8.000000e+00>):
   6524 ///  vmul.f32        d16, d17, d16
   6525 ///  vcvt.s32.f32    d16, d16
   6526 /// becomes:
   6527 ///  vcvt.s32.f32    d16, d16, #3
   6528 static SDValue PerformVCVTCombine(SDNode *N,
   6529                                   TargetLowering::DAGCombinerInfo &DCI,
   6530                                   const ARMSubtarget *Subtarget) {
   6531   SelectionDAG &DAG = DCI.DAG;
   6532   SDValue Op = N->getOperand(0);
   6533 
   6534   if (!Subtarget->hasNEON() || !Op.getValueType().isVector() ||
   6535       Op.getOpcode() != ISD::FMUL)
   6536     return SDValue();
   6537 
   6538   uint64_t C;
   6539   SDValue N0 = Op->getOperand(0);
   6540   SDValue ConstVec = Op->getOperand(1);
   6541   bool isSigned = N->getOpcode() == ISD::FP_TO_SINT;
   6542 
   6543   if (ConstVec.getOpcode() != ISD::BUILD_VECTOR ||
   6544       !isConstVecPow2(ConstVec, isSigned, C))
   6545     return SDValue();
   6546 
   6547   unsigned IntrinsicOpcode = isSigned ? Intrinsic::arm_neon_vcvtfp2fxs :
   6548     Intrinsic::arm_neon_vcvtfp2fxu;
   6549   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, N->getDebugLoc(),
   6550                      N->getValueType(0),
   6551                      DAG.getConstant(IntrinsicOpcode, MVT::i32), N0,
   6552                      DAG.getConstant(Log2_64(C), MVT::i32));
   6553 }
   6554 
   6555 /// PerformVDIVCombine - VCVT (fixed-point to floating-point, Advanced SIMD)
   6556 /// can replace combinations of VCVT (integer to floating-point) and VDIV
   6557 /// when the VDIV has a constant operand that is a power of 2.
   6558 ///
   6559 /// Example (assume d17 = <float 8.000000e+00, float 8.000000e+00>):
   6560 ///  vcvt.f32.s32    d16, d16
   6561 ///  vdiv.f32        d16, d17, d16
   6562 /// becomes:
   6563 ///  vcvt.f32.s32    d16, d16, #3
   6564 static SDValue PerformVDIVCombine(SDNode *N,
   6565                                   TargetLowering::DAGCombinerInfo &DCI,
   6566                                   const ARMSubtarget *Subtarget) {
   6567   SelectionDAG &DAG = DCI.DAG;
   6568   SDValue Op = N->getOperand(0);
   6569   unsigned OpOpcode = Op.getNode()->getOpcode();
   6570 
   6571   if (!Subtarget->hasNEON() || !N->getValueType(0).isVector() ||
   6572       (OpOpcode != ISD::SINT_TO_FP && OpOpcode != ISD::UINT_TO_FP))
   6573     return SDValue();
   6574 
   6575   uint64_t C;
   6576   SDValue ConstVec = N->getOperand(1);
   6577   bool isSigned = OpOpcode == ISD::SINT_TO_FP;
   6578 
   6579   if (ConstVec.getOpcode() != ISD::BUILD_VECTOR ||
   6580       !isConstVecPow2(ConstVec, isSigned, C))
   6581     return SDValue();
   6582 
   6583   unsigned IntrinsicOpcode = isSigned ? Intrinsic::arm_neon_vcvtfxs2fp :
   6584     Intrinsic::arm_neon_vcvtfxu2fp;
   6585   return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, N->getDebugLoc(),
   6586                      Op.getValueType(),
   6587                      DAG.getConstant(IntrinsicOpcode, MVT::i32),
   6588                      Op.getOperand(0), DAG.getConstant(Log2_64(C), MVT::i32));
   6589 }
   6590 
   6591 /// Getvshiftimm - Check if this is a valid build_vector for the immediate
   6592 /// operand of a vector shift operation, where all the elements of the
   6593 /// build_vector must have the same constant integer value.
   6594 static bool getVShiftImm(SDValue Op, unsigned ElementBits, int64_t &Cnt) {
   6595   // Ignore bit_converts.
   6596   while (Op.getOpcode() == ISD::BITCAST)
   6597     Op = Op.getOperand(0);
   6598   BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
   6599   APInt SplatBits, SplatUndef;
   6600   unsigned SplatBitSize;
   6601   bool HasAnyUndefs;
   6602   if (! BVN || ! BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
   6603                                       HasAnyUndefs, ElementBits) ||
   6604       SplatBitSize > ElementBits)
   6605     return false;
   6606   Cnt = SplatBits.getSExtValue();
   6607   return true;
   6608 }
   6609 
   6610 /// isVShiftLImm - Check if this is a valid build_vector for the immediate
   6611 /// operand of a vector shift left operation.  That value must be in the range:
   6612 ///   0 <= Value < ElementBits for a left shift; or
   6613 ///   0 <= Value <= ElementBits for a long left shift.
   6614 static bool isVShiftLImm(SDValue Op, EVT VT, bool isLong, int64_t &Cnt) {
   6615   assert(VT.isVector() && "vector shift count is not a vector type");
   6616   unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
   6617   if (! getVShiftImm(Op, ElementBits, Cnt))
   6618     return false;
   6619   return (Cnt >= 0 && (isLong ? Cnt-1 : Cnt) < ElementBits);
   6620 }
   6621 
   6622 /// isVShiftRImm - Check if this is a valid build_vector for the immediate
   6623 /// operand of a vector shift right operation.  For a shift opcode, the value
   6624 /// is positive, but for an intrinsic the value count must be negative. The
   6625 /// absolute value must be in the range:
   6626 ///   1 <= |Value| <= ElementBits for a right shift; or
   6627 ///   1 <= |Value| <= ElementBits/2 for a narrow right shift.
   6628 static bool isVShiftRImm(SDValue Op, EVT VT, bool isNarrow, bool isIntrinsic,
   6629                          int64_t &Cnt) {
   6630   assert(VT.isVector() && "vector shift count is not a vector type");
   6631   unsigned ElementBits = VT.getVectorElementType().getSizeInBits();
   6632   if (! getVShiftImm(Op, ElementBits, Cnt))
   6633     return false;
   6634   if (isIntrinsic)
   6635     Cnt = -Cnt;
   6636   return (Cnt >= 1 && Cnt <= (isNarrow ? ElementBits/2 : ElementBits));
   6637 }
   6638 
   6639 /// PerformIntrinsicCombine - ARM-specific DAG combining for intrinsics.
   6640 static SDValue PerformIntrinsicCombine(SDNode *N, SelectionDAG &DAG) {
   6641   unsigned IntNo = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
   6642   switch (IntNo) {
   6643   default:
   6644     // Don't do anything for most intrinsics.
   6645     break;
   6646 
   6647   // Vector shifts: check for immediate versions and lower them.
   6648   // Note: This is done during DAG combining instead of DAG legalizing because
   6649   // the build_vectors for 64-bit vector element shift counts are generally
   6650   // not legal, and it is hard to see their values after they get legalized to
   6651   // loads from a constant pool.
   6652   case Intrinsic::arm_neon_vshifts:
   6653   case Intrinsic::arm_neon_vshiftu:
   6654   case Intrinsic::arm_neon_vshiftls:
   6655   case Intrinsic::arm_neon_vshiftlu:
   6656   case Intrinsic::arm_neon_vshiftn:
   6657   case Intrinsic::arm_neon_vrshifts:
   6658   case Intrinsic::arm_neon_vrshiftu:
   6659   case Intrinsic::arm_neon_vrshiftn:
   6660   case Intrinsic::arm_neon_vqshifts:
   6661   case Intrinsic::arm_neon_vqshiftu:
   6662   case Intrinsic::arm_neon_vqshiftsu:
   6663   case Intrinsic::arm_neon_vqshiftns:
   6664   case Intrinsic::arm_neon_vqshiftnu:
   6665   case Intrinsic::arm_neon_vqshiftnsu:
   6666   case Intrinsic::arm_neon_vqrshiftns:
   6667   case Intrinsic::arm_neon_vqrshiftnu:
   6668   case Intrinsic::arm_neon_vqrshiftnsu: {
   6669     EVT VT = N->getOperand(1).getValueType();
   6670     int64_t Cnt;
   6671     unsigned VShiftOpc = 0;
   6672 
   6673     switch (IntNo) {
   6674     case Intrinsic::arm_neon_vshifts:
   6675     case Intrinsic::arm_neon_vshiftu:
   6676       if (isVShiftLImm(N->getOperand(2), VT, false, Cnt)) {
   6677         VShiftOpc = ARMISD::VSHL;
   6678         break;
   6679       }
   6680       if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt)) {
   6681         VShiftOpc = (IntNo == Intrinsic::arm_neon_vshifts ?
   6682                      ARMISD::VSHRs : ARMISD::VSHRu);
   6683         break;
   6684       }
   6685       return SDValue();
   6686 
   6687     case Intrinsic::arm_neon_vshiftls:
   6688     case Intrinsic::arm_neon_vshiftlu:
   6689       if (isVShiftLImm(N->getOperand(2), VT, true, Cnt))
   6690         break;
   6691       llvm_unreachable("invalid shift count for vshll intrinsic");
   6692 
   6693     case Intrinsic::arm_neon_vrshifts:
   6694     case Intrinsic::arm_neon_vrshiftu:
   6695       if (isVShiftRImm(N->getOperand(2), VT, false, true, Cnt))
   6696         break;
   6697       return SDValue();
   6698 
   6699     case Intrinsic::arm_neon_vqshifts:
   6700     case Intrinsic::arm_neon_vqshiftu:
   6701       if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
   6702         break;
   6703       return SDValue();
   6704 
   6705     case Intrinsic::arm_neon_vqshiftsu:
   6706       if (isVShiftLImm(N->getOperand(2), VT, false, Cnt))
   6707         break;
   6708       llvm_unreachable("invalid shift count for vqshlu intrinsic");
   6709 
   6710     case Intrinsic::arm_neon_vshiftn:
   6711     case Intrinsic::arm_neon_vrshiftn:
   6712     case Intrinsic::arm_neon_vqshiftns:
   6713     case Intrinsic::arm_neon_vqshiftnu:
   6714     case Intrinsic::arm_neon_vqshiftnsu:
   6715     case Intrinsic::arm_neon_vqrshiftns:
   6716     case Intrinsic::arm_neon_vqrshiftnu:
   6717     case Intrinsic::arm_neon_vqrshiftnsu:
   6718       // Narrowing shifts require an immediate right shift.
   6719       if (isVShiftRImm(N->getOperand(2), VT, true, true, Cnt))
   6720         break;
   6721       llvm_unreachable("invalid shift count for narrowing vector shift "
   6722                        "intrinsic");
   6723 
   6724     default:
   6725       llvm_unreachable("unhandled vector shift");
   6726     }
   6727 
   6728     switch (IntNo) {
   6729     case Intrinsic::arm_neon_vshifts:
   6730     case Intrinsic::arm_neon_vshiftu:
   6731       // Opcode already set above.
   6732       break;
   6733     case Intrinsic::arm_neon_vshiftls:
   6734     case Intrinsic::arm_neon_vshiftlu:
   6735       if (Cnt == VT.getVectorElementType().getSizeInBits())
   6736         VShiftOpc = ARMISD::VSHLLi;
   6737       else
   6738         VShiftOpc = (IntNo == Intrinsic::arm_neon_vshiftls ?
   6739                      ARMISD::VSHLLs : ARMISD::VSHLLu);
   6740       break;
   6741     case Intrinsic::arm_neon_vshiftn:
   6742       VShiftOpc = ARMISD::VSHRN; break;
   6743     case Intrinsic::arm_neon_vrshifts:
   6744       VShiftOpc = ARMISD::VRSHRs; break;
   6745     case Intrinsic::arm_neon_vrshiftu:
   6746       VShiftOpc = ARMISD::VRSHRu; break;
   6747     case Intrinsic::arm_neon_vrshiftn:
   6748       VShiftOpc = ARMISD::VRSHRN; break;
   6749     case Intrinsic::arm_neon_vqshifts:
   6750       VShiftOpc = ARMISD::VQSHLs; break;
   6751     case Intrinsic::arm_neon_vqshiftu:
   6752       VShiftOpc = ARMISD::VQSHLu; break;
   6753     case Intrinsic::arm_neon_vqshiftsu:
   6754       VShiftOpc = ARMISD::VQSHLsu; break;
   6755     case Intrinsic::arm_neon_vqshiftns:
   6756       VShiftOpc = ARMISD::VQSHRNs; break;
   6757     case Intrinsic::arm_neon_vqshiftnu:
   6758       VShiftOpc = ARMISD::VQSHRNu; break;
   6759     case Intrinsic::arm_neon_vqshiftnsu:
   6760       VShiftOpc = ARMISD::VQSHRNsu; break;
   6761     case Intrinsic::arm_neon_vqrshiftns:
   6762       VShiftOpc = ARMISD::VQRSHRNs; break;
   6763     case Intrinsic::arm_neon_vqrshiftnu:
   6764       VShiftOpc = ARMISD::VQRSHRNu; break;
   6765     case Intrinsic::arm_neon_vqrshiftnsu:
   6766       VShiftOpc = ARMISD::VQRSHRNsu; break;
   6767     }
   6768 
   6769     return DAG.getNode(VShiftOpc, N->getDebugLoc(), N->getValueType(0),
   6770                        N->getOperand(1), DAG.getConstant(Cnt, MVT::i32));
   6771   }
   6772 
   6773   case Intrinsic::arm_neon_vshiftins: {
   6774     EVT VT = N->getOperand(1).getValueType();
   6775     int64_t Cnt;
   6776     unsigned VShiftOpc = 0;
   6777 
   6778     if (isVShiftLImm(N->getOperand(3), VT, false, Cnt))
   6779       VShiftOpc = ARMISD::VSLI;
   6780     else if (isVShiftRImm(N->getOperand(3), VT, false, true, Cnt))
   6781       VShiftOpc = ARMISD::VSRI;
   6782     else {
   6783       llvm_unreachable("invalid shift count for vsli/vsri intrinsic");
   6784     }
   6785 
   6786     return DAG.getNode(VShiftOpc, N->getDebugLoc(), N->getValueType(0),
   6787                        N->getOperand(1), N->getOperand(2),
   6788                        DAG.getConstant(Cnt, MVT::i32));
   6789   }
   6790 
   6791   case Intrinsic::arm_neon_vqrshifts:
   6792   case Intrinsic::arm_neon_vqrshiftu:
   6793     // No immediate versions of these to check for.
   6794     break;
   6795   }
   6796 
   6797   return SDValue();
   6798 }
   6799 
   6800 /// PerformShiftCombine - Checks for immediate versions of vector shifts and
   6801 /// lowers them.  As with the vector shift intrinsics, this is done during DAG
   6802 /// combining instead of DAG legalizing because the build_vectors for 64-bit
   6803 /// vector element shift counts are generally not legal, and it is hard to see
   6804 /// their values after they get legalized to loads from a constant pool.
   6805 static SDValue PerformShiftCombine(SDNode *N, SelectionDAG &DAG,
   6806                                    const ARMSubtarget *ST) {
   6807   EVT VT = N->getValueType(0);
   6808 
   6809   // Nothing to be done for scalar shifts.
   6810   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   6811   if (!VT.isVector() || !TLI.isTypeLegal(VT))
   6812     return SDValue();
   6813 
   6814   assert(ST->hasNEON() && "unexpected vector shift");
   6815   int64_t Cnt;
   6816 
   6817   switch (N->getOpcode()) {
   6818   default: llvm_unreachable("unexpected shift opcode");
   6819 
   6820   case ISD::SHL:
   6821     if (isVShiftLImm(N->getOperand(1), VT, false, Cnt))
   6822       return DAG.getNode(ARMISD::VSHL, N->getDebugLoc(), VT, N->getOperand(0),
   6823                          DAG.getConstant(Cnt, MVT::i32));
   6824     break;
   6825 
   6826   case ISD::SRA:
   6827   case ISD::SRL:
   6828     if (isVShiftRImm(N->getOperand(1), VT, false, false, Cnt)) {
   6829       unsigned VShiftOpc = (N->getOpcode() == ISD::SRA ?
   6830                             ARMISD::VSHRs : ARMISD::VSHRu);
   6831       return DAG.getNode(VShiftOpc, N->getDebugLoc(), VT, N->getOperand(0),
   6832                          DAG.getConstant(Cnt, MVT::i32));
   6833     }
   6834   }
   6835   return SDValue();
   6836 }
   6837 
   6838 /// PerformExtendCombine - Target-specific DAG combining for ISD::SIGN_EXTEND,
   6839 /// ISD::ZERO_EXTEND, and ISD::ANY_EXTEND.
   6840 static SDValue PerformExtendCombine(SDNode *N, SelectionDAG &DAG,
   6841                                     const ARMSubtarget *ST) {
   6842   SDValue N0 = N->getOperand(0);
   6843 
   6844   // Check for sign- and zero-extensions of vector extract operations of 8-
   6845   // and 16-bit vector elements.  NEON supports these directly.  They are
   6846   // handled during DAG combining because type legalization will promote them
   6847   // to 32-bit types and it is messy to recognize the operations after that.
   6848   if (ST->hasNEON() && N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
   6849     SDValue Vec = N0.getOperand(0);
   6850     SDValue Lane = N0.getOperand(1);
   6851     EVT VT = N->getValueType(0);
   6852     EVT EltVT = N0.getValueType();
   6853     const TargetLowering &TLI = DAG.getTargetLoweringInfo();
   6854 
   6855     if (VT == MVT::i32 &&
   6856         (EltVT == MVT::i8 || EltVT == MVT::i16) &&
   6857         TLI.isTypeLegal(Vec.getValueType()) &&
   6858         isa<ConstantSDNode>(Lane)) {
   6859 
   6860       unsigned Opc = 0;
   6861       switch (N->getOpcode()) {
   6862       default: llvm_unreachable("unexpected opcode");
   6863       case ISD::SIGN_EXTEND:
   6864         Opc = ARMISD::VGETLANEs;
   6865         break;
   6866       case ISD::ZERO_EXTEND:
   6867       case ISD::ANY_EXTEND:
   6868         Opc = ARMISD::VGETLANEu;
   6869         break;
   6870       }
   6871       return DAG.getNode(Opc, N->getDebugLoc(), VT, Vec, Lane);
   6872     }
   6873   }
   6874 
   6875   return SDValue();
   6876 }
   6877 
   6878 /// PerformSELECT_CCCombine - Target-specific DAG combining for ISD::SELECT_CC
   6879 /// to match f32 max/min patterns to use NEON vmax/vmin instructions.
   6880 static SDValue PerformSELECT_CCCombine(SDNode *N, SelectionDAG &DAG,
   6881                                        const ARMSubtarget *ST) {
   6882   // If the target supports NEON, try to use vmax/vmin instructions for f32
   6883   // selects like "x < y ? x : y".  Unless the NoNaNsFPMath option is set,
   6884   // be careful about NaNs:  NEON's vmax/vmin return NaN if either operand is
   6885   // a NaN; only do the transformation when it matches that behavior.
   6886 
   6887   // For now only do this when using NEON for FP operations; if using VFP, it
   6888   // is not obvious that the benefit outweighs the cost of switching to the
   6889   // NEON pipeline.
   6890   if (!ST->hasNEON() || !ST->useNEONForSinglePrecisionFP() ||
   6891       N->getValueType(0) != MVT::f32)
   6892     return SDValue();
   6893 
   6894   SDValue CondLHS = N->getOperand(0);
   6895   SDValue CondRHS = N->getOperand(1);
   6896   SDValue LHS = N->getOperand(2);
   6897   SDValue RHS = N->getOperand(3);
   6898   ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
   6899 
   6900   unsigned Opcode = 0;
   6901   bool IsReversed;
   6902   if (DAG.isEqualTo(LHS, CondLHS) && DAG.isEqualTo(RHS, CondRHS)) {
   6903     IsReversed = false; // x CC y ? x : y
   6904   } else if (DAG.isEqualTo(LHS, CondRHS) && DAG.isEqualTo(RHS, CondLHS)) {
   6905     IsReversed = true ; // x CC y ? y : x
   6906   } else {
   6907     return SDValue();
   6908   }
   6909 
   6910   bool IsUnordered;
   6911   switch (CC) {
   6912   default: break;
   6913   case ISD::SETOLT:
   6914   case ISD::SETOLE:
   6915   case ISD::SETLT:
   6916   case ISD::SETLE:
   6917   case ISD::SETULT:
   6918   case ISD::SETULE:
   6919     // If LHS is NaN, an ordered comparison will be false and the result will
   6920     // be the RHS, but vmin(NaN, RHS) = NaN.  Avoid this by checking that LHS
   6921     // != NaN.  Likewise, for unordered comparisons, check for RHS != NaN.
   6922     IsUnordered = (CC == ISD::SETULT || CC == ISD::SETULE);
   6923     if (!DAG.isKnownNeverNaN(IsUnordered ? RHS : LHS))
   6924       break;
   6925     // For less-than-or-equal comparisons, "+0 <= -0" will be true but vmin
   6926     // will return -0, so vmin can only be used for unsafe math or if one of
   6927     // the operands is known to be nonzero.
   6928     if ((CC == ISD::SETLE || CC == ISD::SETOLE || CC == ISD::SETULE) &&
   6929         !UnsafeFPMath &&
   6930         !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
   6931       break;
   6932     Opcode = IsReversed ? ARMISD::FMAX : ARMISD::FMIN;
   6933     break;
   6934 
   6935   case ISD::SETOGT:
   6936   case ISD::SETOGE:
   6937   case ISD::SETGT:
   6938   case ISD::SETGE:
   6939   case ISD::SETUGT:
   6940   case ISD::SETUGE:
   6941     // If LHS is NaN, an ordered comparison will be false and the result will
   6942     // be the RHS, but vmax(NaN, RHS) = NaN.  Avoid this by checking that LHS
   6943     // != NaN.  Likewise, for unordered comparisons, check for RHS != NaN.
   6944     IsUnordered = (CC == ISD::SETUGT || CC == ISD::SETUGE);
   6945     if (!DAG.isKnownNeverNaN(IsUnordered ? RHS : LHS))
   6946       break;
   6947     // For greater-than-or-equal comparisons, "-0 >= +0" will be true but vmax
   6948     // will return +0, so vmax can only be used for unsafe math or if one of
   6949     // the operands is known to be nonzero.
   6950     if ((CC == ISD::SETGE || CC == ISD::SETOGE || CC == ISD::SETUGE) &&
   6951         !UnsafeFPMath &&
   6952         !(DAG.isKnownNeverZero(LHS) || DAG.isKnownNeverZero(RHS)))
   6953       break;
   6954     Opcode = IsReversed ? ARMISD::FMIN : ARMISD::FMAX;
   6955     break;
   6956   }
   6957 
   6958   if (!Opcode)
   6959     return SDValue();
   6960   return DAG.getNode(Opcode, N->getDebugLoc(), N->getValueType(0), LHS, RHS);
   6961 }
   6962 
   6963 /// PerformCMOVCombine - Target-specific DAG combining for ARMISD::CMOV.
   6964 SDValue
   6965 ARMTargetLowering::PerformCMOVCombine(SDNode *N, SelectionDAG &DAG) const {
   6966   SDValue Cmp = N->getOperand(4);
   6967   if (Cmp.getOpcode() != ARMISD::CMPZ)
   6968     // Only looking at EQ and NE cases.
   6969     return SDValue();
   6970 
   6971   EVT VT = N->getValueType(0);
   6972   DebugLoc dl = N->getDebugLoc();
   6973   SDValue LHS = Cmp.getOperand(0);
   6974   SDValue RHS = Cmp.getOperand(1);
   6975   SDValue FalseVal = N->getOperand(0);
   6976   SDValue TrueVal = N->getOperand(1);
   6977   SDValue ARMcc = N->getOperand(2);
   6978   ARMCC::CondCodes CC = (ARMCC::CondCodes)cast<ConstantSDNode>(ARMcc)->getZExtValue();
   6979 
   6980   // Simplify
   6981   //   mov     r1, r0
   6982   //   cmp     r1, x
   6983   //   mov     r0, y
   6984   //   moveq   r0, x
   6985   // to
   6986   //   cmp     r0, x
   6987   //   movne   r0, y
   6988   //
   6989   //   mov     r1, r0
   6990   //   cmp     r1, x
   6991   //   mov     r0, x
   6992   //   movne   r0, y
   6993   // to
   6994   //   cmp     r0, x
   6995   //   movne   r0, y
   6996   /// FIXME: Turn this into a target neutral optimization?
   6997   SDValue Res;
   6998   if (CC == ARMCC::NE && FalseVal == RHS) {
   6999     Res = DAG.getNode(ARMISD::CMOV, dl, VT, LHS, TrueVal, ARMcc,
   7000                       N->getOperand(3), Cmp);
   7001   } else if (CC == ARMCC::EQ && TrueVal == RHS) {
   7002     SDValue ARMcc;
   7003     SDValue NewCmp = getARMCmp(LHS, RHS, ISD::SETNE, ARMcc, DAG, dl);
   7004     Res = DAG.getNode(ARMISD::CMOV, dl, VT, LHS, FalseVal, ARMcc,
   7005                       N->getOperand(3), NewCmp);
   7006   }
   7007 
   7008   if (Res.getNode()) {
   7009     APInt KnownZero, KnownOne;
   7010     APInt Mask = APInt::getAllOnesValue(VT.getScalarType().getSizeInBits());
   7011     DAG.ComputeMaskedBits(SDValue(N,0), Mask, KnownZero, KnownOne);
   7012     // Capture demanded bits information that would be otherwise lost.
   7013     if (KnownZero == 0xfffffffe)
   7014       Res = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Res,
   7015                         DAG.getValueType(MVT::i1));
   7016     else if (KnownZero == 0xffffff00)
   7017       Res = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Res,
   7018                         DAG.getValueType(MVT::i8));
   7019     else if (KnownZero == 0xffff0000)
   7020       Res = DAG.getNode(ISD::AssertZext, dl, MVT::i32, Res,
   7021                         DAG.getValueType(MVT::i16));
   7022   }
   7023 
   7024   return Res;
   7025 }
   7026 
   7027 SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N,
   7028                                              DAGCombinerInfo &DCI) const {
   7029   switch (N->getOpcode()) {
   7030   default: break;
   7031   case ISD::ADD:        return PerformADDCombine(N, DCI, Subtarget);
   7032   case ISD::SUB:        return PerformSUBCombine(N, DCI);
   7033   case ISD::MUL:        return PerformMULCombine(N, DCI, Subtarget);
   7034   case ISD::OR:         return PerformORCombine(N, DCI, Subtarget);
   7035   case ISD::AND:        return PerformANDCombine(N, DCI);
   7036   case ARMISD::BFI:     return PerformBFICombine(N, DCI);
   7037   case ARMISD::VMOVRRD: return PerformVMOVRRDCombine(N, DCI);
   7038   case ARMISD::VMOVDRR: return PerformVMOVDRRCombine(N, DCI.DAG);
   7039   case ISD::STORE:      return PerformSTORECombine(N, DCI);
   7040   case ISD::BUILD_VECTOR: return PerformBUILD_VECTORCombine(N, DCI);
   7041   case ISD::INSERT_VECTOR_ELT: return PerformInsertEltCombine(N, DCI);
   7042   case ISD::VECTOR_SHUFFLE: return PerformVECTOR_SHUFFLECombine(N, DCI.DAG);
   7043   case ARMISD::VDUPLANE: return PerformVDUPLANECombine(N, DCI);
   7044   case ISD::FP_TO_SINT:
   7045   case ISD::FP_TO_UINT: return PerformVCVTCombine(N, DCI, Subtarget);
   7046   case ISD::FDIV:       return PerformVDIVCombine(N, DCI, Subtarget);
   7047   case ISD::INTRINSIC_WO_CHAIN: return PerformIntrinsicCombine(N, DCI.DAG);
   7048   case ISD::SHL:
   7049   case ISD::SRA:
   7050   case ISD::SRL:        return PerformShiftCombine(N, DCI.DAG, Subtarget);
   7051   case ISD::SIGN_EXTEND:
   7052   case ISD::ZERO_EXTEND:
   7053   case ISD::ANY_EXTEND: return PerformExtendCombine(N, DCI.DAG, Subtarget);
   7054   case ISD::SELECT_CC:  return PerformSELECT_CCCombine(N, DCI.DAG, Subtarget);
   7055   case ARMISD::CMOV: return PerformCMOVCombine(N, DCI.DAG);
   7056   case ARMISD::VLD2DUP:
   7057   case ARMISD::VLD3DUP:
   7058   case ARMISD::VLD4DUP:
   7059     return CombineBaseUpdate(N, DCI);
   7060   case ISD::INTRINSIC_VOID:
   7061   case ISD::INTRINSIC_W_CHAIN:
   7062     switch (cast<ConstantSDNode>(N->getOperand(1))->getZExtValue()) {
   7063     case Intrinsic::arm_neon_vld1:
   7064     case Intrinsic::arm_neon_vld2:
   7065     case Intrinsic::arm_neon_vld3:
   7066     case Intrinsic::arm_neon_vld4:
   7067     case Intrinsic::arm_neon_vld2lane:
   7068     case Intrinsic::arm_neon_vld3lane:
   7069     case Intrinsic::arm_neon_vld4lane:
   7070     case Intrinsic::arm_neon_vst1:
   7071     case Intrinsic::arm_neon_vst2:
   7072     case Intrinsic::arm_neon_vst3:
   7073     case Intrinsic::arm_neon_vst4:
   7074     case Intrinsic::arm_neon_vst2lane:
   7075     case Intrinsic::arm_neon_vst3lane:
   7076     case Intrinsic::arm_neon_vst4lane:
   7077       return CombineBaseUpdate(N, DCI);
   7078     default: break;
   7079     }
   7080     break;
   7081   }
   7082   return SDValue();
   7083 }
   7084 
   7085 bool ARMTargetLowering::isDesirableToTransformToIntegerOp(unsigned Opc,
   7086                                                           EVT VT) const {
   7087   return (VT == MVT::f32) && (Opc == ISD::LOAD || Opc == ISD::STORE);
   7088 }
   7089 
   7090 bool ARMTargetLowering::allowsUnalignedMemoryAccesses(EVT VT) const {
   7091   if (!Subtarget->allowsUnalignedMem())
   7092     return false;
   7093 
   7094   switch (VT.getSimpleVT().SimpleTy) {
   7095   default:
   7096     return false;
   7097   case MVT::i8:
   7098   case MVT::i16:
   7099   case MVT::i32:
   7100     return true;
   7101   // FIXME: VLD1 etc with standard alignment is legal.
   7102   }
   7103 }
   7104 
   7105 static bool isLegalT1AddressImmediate(int64_t V, EVT VT) {
   7106   if (V < 0)
   7107     return false;
   7108 
   7109   unsigned Scale = 1;
   7110   switch (VT.getSimpleVT().SimpleTy) {
   7111   default: return false;
   7112   case MVT::i1:
   7113   case MVT::i8:
   7114     // Scale == 1;
   7115     break;
   7116   case MVT::i16:
   7117     // Scale == 2;
   7118     Scale = 2;
   7119     break;
   7120   case MVT::i32:
   7121     // Scale == 4;
   7122     Scale = 4;
   7123     break;
   7124   }
   7125 
   7126   if ((V & (Scale - 1)) != 0)
   7127     return false;
   7128   V /= Scale;
   7129   return V == (V & ((1LL << 5) - 1));
   7130 }
   7131 
   7132 static bool isLegalT2AddressImmediate(int64_t V, EVT VT,
   7133                                       const ARMSubtarget *Subtarget) {
   7134   bool isNeg = false;
   7135   if (V < 0) {
   7136     isNeg = true;
   7137     V = - V;
   7138   }
   7139 
   7140   switch (VT.getSimpleVT().SimpleTy) {
   7141   default: return false;
   7142   case MVT::i1:
   7143   case MVT::i8:
   7144   case MVT::i16:
   7145   case MVT::i32:
   7146     // + imm12 or - imm8
   7147     if (isNeg)
   7148       return V == (V & ((1LL << 8) - 1));
   7149     return V == (V & ((1LL << 12) - 1));
   7150   case MVT::f32:
   7151   case MVT::f64:
   7152     // Same as ARM mode. FIXME: NEON?
   7153     if (!Subtarget->hasVFP2())
   7154       return false;
   7155     if ((V & 3) != 0)
   7156       return false;
   7157     V >>= 2;
   7158     return V == (V & ((1LL << 8) - 1));
   7159   }
   7160 }
   7161 
   7162 /// isLegalAddressImmediate - Return true if the integer value can be used
   7163 /// as the offset of the target addressing mode for load / store of the
   7164 /// given type.
   7165 static bool isLegalAddressImmediate(int64_t V, EVT VT,
   7166                                     const ARMSubtarget *Subtarget) {
   7167   if (V == 0)
   7168     return true;
   7169 
   7170   if (!VT.isSimple())
   7171     return false;
   7172 
   7173   if (Subtarget->isThumb1Only())
   7174     return isLegalT1AddressImmediate(V, VT);
   7175   else if (Subtarget->isThumb2())
   7176     return isLegalT2AddressImmediate(V, VT, Subtarget);
   7177 
   7178   // ARM mode.
   7179   if (V < 0)
   7180     V = - V;
   7181   switch (VT.getSimpleVT().SimpleTy) {
   7182   default: return false;
   7183   case MVT::i1:
   7184   case MVT::i8:
   7185   case MVT::i32:
   7186     // +- imm12
   7187     return V == (V & ((1LL << 12) - 1));
   7188   case MVT::i16:
   7189     // +- imm8
   7190     return V == (V & ((1LL << 8) - 1));
   7191   case MVT::f32:
   7192   case MVT::f64:
   7193     if (!Subtarget->hasVFP2()) // FIXME: NEON?
   7194       return false;
   7195     if ((V & 3) != 0)
   7196       return false;
   7197     V >>= 2;
   7198     return V == (V & ((1LL << 8) - 1));
   7199   }
   7200 }
   7201 
   7202 bool ARMTargetLowering::isLegalT2ScaledAddressingMode(const AddrMode &AM,
   7203                                                       EVT VT) const {
   7204   int Scale = AM.Scale;
   7205   if (Scale < 0)
   7206     return false;
   7207 
   7208   switch (VT.getSimpleVT().SimpleTy) {
   7209   default: return false;
   7210   case MVT::i1:
   7211   case MVT::i8:
   7212   case MVT::i16:
   7213   case MVT::i32:
   7214     if (Scale == 1)
   7215       return true;
   7216     // r + r << imm
   7217     Scale = Scale & ~1;
   7218     return Scale == 2 || Scale == 4 || Scale == 8;
   7219   case MVT::i64:
   7220     // r + r
   7221     if (((unsigned)AM.HasBaseReg + Scale) <= 2)
   7222       return true;
   7223     return false;
   7224   case MVT::isVoid:
   7225     // Note, we allow "void" uses (basically, uses that aren't loads or
   7226     // stores), because arm allows folding a scale into many arithmetic
   7227     // operations.  This should be made more precise and revisited later.
   7228 
   7229     // Allow r << imm, but the imm has to be a multiple of two.
   7230     if (Scale & 1) return false;
   7231     return isPowerOf2_32(Scale);
   7232   }
   7233 }
   7234 
   7235 /// isLegalAddressingMode - Return true if the addressing mode represented
   7236 /// by AM is legal for this target, for a load/store of the specified type.
   7237 bool ARMTargetLowering::isLegalAddressingMode(const AddrMode &AM,
   7238                                               Type *Ty) const {
   7239   EVT VT = getValueType(Ty, true);
   7240   if (!isLegalAddressImmediate(AM.BaseOffs, VT, Subtarget))
   7241     return false;
   7242 
   7243   // Can never fold addr of global into load/store.
   7244   if (AM.BaseGV)
   7245     return false;
   7246 
   7247   switch (AM.Scale) {
   7248   case 0:  // no scale reg, must be "r+i" or "r", or "i".
   7249     break;
   7250   case 1:
   7251     if (Subtarget->isThumb1Only())
   7252       return false;
   7253     // FALL THROUGH.
   7254   default:
   7255     // ARM doesn't support any R+R*scale+imm addr modes.
   7256     if (AM.BaseOffs)
   7257       return false;
   7258 
   7259     if (!VT.isSimple())
   7260       return false;
   7261 
   7262     if (Subtarget->isThumb2())
   7263       return isLegalT2ScaledAddressingMode(AM, VT);
   7264 
   7265     int Scale = AM.Scale;
   7266     switch (VT.getSimpleVT().SimpleTy) {
   7267     default: return false;
   7268     case MVT::i1:
   7269     case MVT::i8:
   7270     case MVT::i32:
   7271       if (Scale < 0) Scale = -Scale;
   7272       if (Scale == 1)
   7273         return true;
   7274       // r + r << imm
   7275       return isPowerOf2_32(Scale & ~1);
   7276     case MVT::i16:
   7277     case MVT::i64:
   7278       // r + r
   7279       if (((unsigned)AM.HasBaseReg + Scale) <= 2)
   7280         return true;
   7281       return false;
   7282 
   7283     case MVT::isVoid:
   7284       // Note, we allow "void" uses (basically, uses that aren't loads or
   7285       // stores), because arm allows folding a scale into many arithmetic
   7286       // operations.  This should be made more precise and revisited later.
   7287 
   7288       // Allow r << imm, but the imm has to be a multiple of two.
   7289       if (Scale & 1) return false;
   7290       return isPowerOf2_32(Scale);
   7291     }
   7292     break;
   7293   }
   7294   return true;
   7295 }
   7296 
   7297 /// isLegalICmpImmediate - Return true if the specified immediate is legal
   7298 /// icmp immediate, that is the target has icmp instructions which can compare
   7299 /// a register against the immediate without having to materialize the
   7300 /// immediate into a register.
   7301 bool ARMTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
   7302   if (!Subtarget->isThumb())
   7303     return ARM_AM::getSOImmVal(Imm) != -1;
   7304   if (Subtarget->isThumb2())
   7305     return ARM_AM::getT2SOImmVal(Imm) != -1;
   7306   return Imm >= 0 && Imm <= 255;
   7307 }
   7308 
   7309 /// isLegalAddImmediate - Return true if the specified immediate is legal
   7310 /// add immediate, that is the target has add instructions which can add
   7311 /// a register with the immediate without having to materialize the
   7312 /// immediate into a register.
   7313 bool ARMTargetLowering::isLegalAddImmediate(int64_t Imm) const {
   7314   return ARM_AM::getSOImmVal(Imm) != -1;
   7315 }
   7316 
   7317 static bool getARMIndexedAddressParts(SDNode *Ptr, EVT VT,
   7318                                       bool isSEXTLoad, SDValue &Base,
   7319                                       SDValue &Offset, bool &isInc,
   7320                                       SelectionDAG &DAG) {
   7321   if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
   7322     return false;
   7323 
   7324   if (VT == MVT::i16 || ((VT == MVT::i8 || VT == MVT::i1) && isSEXTLoad)) {
   7325     // AddressingMode 3
   7326     Base = Ptr->getOperand(0);
   7327     if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
   7328       int RHSC = (int)RHS->getZExtValue();
   7329       if (RHSC < 0 && RHSC > -256) {
   7330         assert(Ptr->getOpcode() == ISD::ADD);
   7331         isInc = false;
   7332         Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
   7333         return true;
   7334       }
   7335     }
   7336     isInc = (Ptr->getOpcode() == ISD::ADD);
   7337     Offset = Ptr->getOperand(1);
   7338     return true;
   7339   } else if (VT == MVT::i32 || VT == MVT::i8 || VT == MVT::i1) {
   7340     // AddressingMode 2
   7341     if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
   7342       int RHSC = (int)RHS->getZExtValue();
   7343       if (RHSC < 0 && RHSC > -0x1000) {
   7344         assert(Ptr->getOpcode() == ISD::ADD);
   7345         isInc = false;
   7346         Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
   7347         Base = Ptr->getOperand(0);
   7348         return true;
   7349       }
   7350     }
   7351 
   7352     if (Ptr->getOpcode() == ISD::ADD) {
   7353       isInc = true;
   7354       ARM_AM::ShiftOpc ShOpcVal= ARM_AM::getShiftOpcForNode(Ptr->getOperand(0));
   7355       if (ShOpcVal != ARM_AM::no_shift) {
   7356         Base = Ptr->getOperand(1);
   7357         Offset = Ptr->getOperand(0);
   7358       } else {
   7359         Base = Ptr->getOperand(0);
   7360         Offset = Ptr->getOperand(1);
   7361       }
   7362       return true;
   7363     }
   7364 
   7365     isInc = (Ptr->getOpcode() == ISD::ADD);
   7366     Base = Ptr->getOperand(0);
   7367     Offset = Ptr->getOperand(1);
   7368     return true;
   7369   }
   7370 
   7371   // FIXME: Use VLDM / VSTM to emulate indexed FP load / store.
   7372   return false;
   7373 }
   7374 
   7375 static bool getT2IndexedAddressParts(SDNode *Ptr, EVT VT,
   7376                                      bool isSEXTLoad, SDValue &Base,
   7377                                      SDValue &Offset, bool &isInc,
   7378                                      SelectionDAG &DAG) {
   7379   if (Ptr->getOpcode() != ISD::ADD && Ptr->getOpcode() != ISD::SUB)
   7380     return false;
   7381 
   7382   Base = Ptr->getOperand(0);
   7383   if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Ptr->getOperand(1))) {
   7384     int RHSC = (int)RHS->getZExtValue();
   7385     if (RHSC < 0 && RHSC > -0x100) { // 8 bits.
   7386       assert(Ptr->getOpcode() == ISD::ADD);
   7387       isInc = false;
   7388       Offset = DAG.getConstant(-RHSC, RHS->getValueType(0));
   7389       return true;
   7390     } else if (RHSC > 0 && RHSC < 0x100) { // 8 bit, no zero.
   7391       isInc = Ptr->getOpcode() == ISD::ADD;
   7392       Offset = DAG.getConstant(RHSC, RHS->getValueType(0));
   7393       return true;
   7394     }
   7395   }
   7396 
   7397   return false;
   7398 }
   7399 
   7400 /// getPreIndexedAddressParts - returns true by value, base pointer and
   7401 /// offset pointer and addressing mode by reference if the node's address
   7402 /// can be legally represented as pre-indexed load / store address.
   7403 bool
   7404 ARMTargetLowering::getPreIndexedAddressParts(SDNode *N, SDValue &Base,
   7405                                              SDValue &Offset,
   7406                                              ISD::MemIndexedMode &AM,
   7407                                              SelectionDAG &DAG) const {
   7408   if (Subtarget->isThumb1Only())
   7409     return false;
   7410 
   7411   EVT VT;
   7412   SDValue Ptr;
   7413   bool isSEXTLoad = false;
   7414   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
   7415     Ptr = LD->getBasePtr();
   7416     VT  = LD->getMemoryVT();
   7417     isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
   7418   } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
   7419     Ptr = ST->getBasePtr();
   7420     VT  = ST->getMemoryVT();
   7421   } else
   7422     return false;
   7423 
   7424   bool isInc;
   7425   bool isLegal = false;
   7426   if (Subtarget->isThumb2())
   7427     isLegal = getT2IndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
   7428                                        Offset, isInc, DAG);
   7429   else
   7430     isLegal = getARMIndexedAddressParts(Ptr.getNode(), VT, isSEXTLoad, Base,
   7431                                         Offset, isInc, DAG);
   7432   if (!isLegal)
   7433     return false;
   7434 
   7435   AM = isInc ? ISD::PRE_INC : ISD::PRE_DEC;
   7436   return true;
   7437 }
   7438 
   7439 /// getPostIndexedAddressParts - returns true by value, base pointer and
   7440 /// offset pointer and addressing mode by reference if this node can be
   7441 /// combined with a load / store to form a post-indexed load / store.
   7442 bool ARMTargetLowering::getPostIndexedAddressParts(SDNode *N, SDNode *Op,
   7443                                                    SDValue &Base,
   7444                                                    SDValue &Offset,
   7445                                                    ISD::MemIndexedMode &AM,
   7446                                                    SelectionDAG &DAG) const {
   7447   if (Subtarget->isThumb1Only())
   7448     return false;
   7449 
   7450   EVT VT;
   7451   SDValue Ptr;
   7452   bool isSEXTLoad = false;
   7453   if (LoadSDNode *LD = dyn_cast<LoadSDNode>(N)) {
   7454     VT  = LD->getMemoryVT();
   7455     Ptr = LD->getBasePtr();
   7456     isSEXTLoad = LD->getExtensionType() == ISD::SEXTLOAD;
   7457   } else if (StoreSDNode *ST = dyn_cast<StoreSDNode>(N)) {
   7458     VT  = ST->getMemoryVT();
   7459     Ptr = ST->getBasePtr();
   7460   } else
   7461     return false;
   7462 
   7463   bool isInc;
   7464   bool isLegal = false;
   7465   if (Subtarget->isThumb2())
   7466     isLegal = getT2IndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
   7467                                        isInc, DAG);
   7468   else
   7469     isLegal = getARMIndexedAddressParts(Op, VT, isSEXTLoad, Base, Offset,
   7470                                         isInc, DAG);
   7471   if (!isLegal)
   7472     return false;
   7473 
   7474   if (Ptr != Base) {
   7475     // Swap base ptr and offset to catch more post-index load / store when
   7476     // it's legal. In Thumb2 mode, offset must be an immediate.
   7477     if (Ptr == Offset && Op->getOpcode() == ISD::ADD &&
   7478         !Subtarget->isThumb2())
   7479       std::swap(Base, Offset);
   7480 
   7481     // Post-indexed load / store update the base pointer.
   7482     if (Ptr != Base)
   7483       return false;
   7484   }
   7485 
   7486   AM = isInc ? ISD::POST_INC : ISD::POST_DEC;
   7487   return true;
   7488 }
   7489 
   7490 void ARMTargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
   7491                                                        const APInt &Mask,
   7492                                                        APInt &KnownZero,
   7493                                                        APInt &KnownOne,
   7494                                                        const SelectionDAG &DAG,
   7495                                                        unsigned Depth) const {
   7496   KnownZero = KnownOne = APInt(Mask.getBitWidth(), 0);
   7497   switch (Op.getOpcode()) {
   7498   default: break;
   7499   case ARMISD::CMOV: {
   7500     // Bits are known zero/one if known on the LHS and RHS.
   7501     DAG.ComputeMaskedBits(Op.getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
   7502     if (KnownZero == 0 && KnownOne == 0) return;
   7503 
   7504     APInt KnownZeroRHS, KnownOneRHS;
   7505     DAG.ComputeMaskedBits(Op.getOperand(1), Mask,
   7506                           KnownZeroRHS, KnownOneRHS, Depth+1);
   7507     KnownZero &= KnownZeroRHS;
   7508     KnownOne  &= KnownOneRHS;
   7509     return;
   7510   }
   7511   }
   7512 }
   7513 
   7514 //===----------------------------------------------------------------------===//
   7515 //                           ARM Inline Assembly Support
   7516 //===----------------------------------------------------------------------===//
   7517 
   7518 bool ARMTargetLowering::ExpandInlineAsm(CallInst *CI) const {
   7519   // Looking for "rev" which is V6+.
   7520   if (!Subtarget->hasV6Ops())
   7521     return false;
   7522 
   7523   InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
   7524   std::string AsmStr = IA->getAsmString();
   7525   SmallVector<StringRef, 4> AsmPieces;
   7526   SplitString(AsmStr, AsmPieces, ";\n");
   7527 
   7528   switch (AsmPieces.size()) {
   7529   default: return false;
   7530   case 1:
   7531     AsmStr = AsmPieces[0];
   7532     AsmPieces.clear();
   7533     SplitString(AsmStr, AsmPieces, " \t,");
   7534 
   7535     // rev $0, $1
   7536     if (AsmPieces.size() == 3 &&
   7537         AsmPieces[0] == "rev" && AsmPieces[1] == "$0" && AsmPieces[2] == "$1" &&
   7538         IA->getConstraintString().compare(0, 4, "=l,l") == 0) {
   7539       IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
   7540       if (Ty && Ty->getBitWidth() == 32)
   7541         return IntrinsicLowering::LowerToByteSwap(CI);
   7542     }
   7543     break;
   7544   }
   7545 
   7546   return false;
   7547 }
   7548 
   7549 /// getConstraintType - Given a constraint letter, return the type of
   7550 /// constraint it is for this target.
   7551 ARMTargetLowering::ConstraintType
   7552 ARMTargetLowering::getConstraintType(const std::string &Constraint) const {
   7553   if (Constraint.size() == 1) {
   7554     switch (Constraint[0]) {
   7555     default:  break;
   7556     case 'l': return C_RegisterClass;
   7557     case 'w': return C_RegisterClass;
   7558     case 'h': return C_RegisterClass;
   7559     case 'x': return C_RegisterClass;
   7560     case 't': return C_RegisterClass;
   7561     case 'j': return C_Other; // Constant for movw.
   7562     }
   7563   } else if (Constraint.size() == 2) {
   7564     switch (Constraint[0]) {
   7565     default: break;
   7566     // All 'U+' constraints are addresses.
   7567     case 'U': return C_Memory;
   7568     }
   7569   }
   7570   return TargetLowering::getConstraintType(Constraint);
   7571 }
   7572 
   7573 /// Examine constraint type and operand type and determine a weight value.
   7574 /// This object must already have been set up with the operand type
   7575 /// and the current alternative constraint selected.
   7576 TargetLowering::ConstraintWeight
   7577 ARMTargetLowering::getSingleConstraintMatchWeight(
   7578     AsmOperandInfo &info, const char *constraint) const {
   7579   ConstraintWeight weight = CW_Invalid;
   7580   Value *CallOperandVal = info.CallOperandVal;
   7581     // If we don't have a value, we can't do a match,
   7582     // but allow it at the lowest weight.
   7583   if (CallOperandVal == NULL)
   7584     return CW_Default;
   7585   Type *type = CallOperandVal->getType();
   7586   // Look at the constraint type.
   7587   switch (*constraint) {
   7588   default:
   7589     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
   7590     break;
   7591   case 'l':
   7592     if (type->isIntegerTy()) {
   7593       if (Subtarget->isThumb())
   7594         weight = CW_SpecificReg;
   7595       else
   7596         weight = CW_Register;
   7597     }
   7598     break;
   7599   case 'w':
   7600     if (type->isFloatingPointTy())
   7601       weight = CW_Register;
   7602     break;
   7603   }
   7604   return weight;
   7605 }
   7606 
   7607 typedef std::pair<unsigned, const TargetRegisterClass*> RCPair;
   7608 RCPair
   7609 ARMTargetLowering::getRegForInlineAsmConstraint(const std::string &Constraint,
   7610                                                 EVT VT) const {
   7611   if (Constraint.size() == 1) {
   7612     // GCC ARM Constraint Letters
   7613     switch (Constraint[0]) {
   7614     case 'l': // Low regs or general regs.
   7615       if (Subtarget->isThumb())
   7616         return RCPair(0U, ARM::tGPRRegisterClass);
   7617       else
   7618         return RCPair(0U, ARM::GPRRegisterClass);
   7619     case 'h': // High regs or no regs.
   7620       if (Subtarget->isThumb())
   7621 	return RCPair(0U, ARM::hGPRRegisterClass);
   7622       break;
   7623     case 'r':
   7624       return RCPair(0U, ARM::GPRRegisterClass);
   7625     case 'w':
   7626       if (VT == MVT::f32)
   7627         return RCPair(0U, ARM::SPRRegisterClass);
   7628       if (VT.getSizeInBits() == 64)
   7629         return RCPair(0U, ARM::DPRRegisterClass);
   7630       if (VT.getSizeInBits() == 128)
   7631         return RCPair(0U, ARM::QPRRegisterClass);
   7632       break;
   7633     case 'x':
   7634       if (VT == MVT::f32)
   7635 	return RCPair(0U, ARM::SPR_8RegisterClass);
   7636       if (VT.getSizeInBits() == 64)
   7637 	return RCPair(0U, ARM::DPR_8RegisterClass);
   7638       if (VT.getSizeInBits() == 128)
   7639 	return RCPair(0U, ARM::QPR_8RegisterClass);
   7640       break;
   7641     case 't':
   7642       if (VT == MVT::f32)
   7643 	return RCPair(0U, ARM::SPRRegisterClass);
   7644       break;
   7645     }
   7646   }
   7647   if (StringRef("{cc}").equals_lower(Constraint))
   7648     return std::make_pair(unsigned(ARM::CPSR), ARM::CCRRegisterClass);
   7649 
   7650   return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
   7651 }
   7652 
   7653 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
   7654 /// vector.  If it is invalid, don't add anything to Ops.
   7655 void ARMTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
   7656                                                      std::string &Constraint,
   7657                                                      std::vector<SDValue>&Ops,
   7658                                                      SelectionDAG &DAG) const {
   7659   SDValue Result(0, 0);
   7660 
   7661   // Currently only support length 1 constraints.
   7662   if (Constraint.length() != 1) return;
   7663 
   7664   char ConstraintLetter = Constraint[0];
   7665   switch (ConstraintLetter) {
   7666   default: break;
   7667   case 'j':
   7668   case 'I': case 'J': case 'K': case 'L':
   7669   case 'M': case 'N': case 'O':
   7670     ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
   7671     if (!C)
   7672       return;
   7673 
   7674     int64_t CVal64 = C->getSExtValue();
   7675     int CVal = (int) CVal64;
   7676     // None of these constraints allow values larger than 32 bits.  Check
   7677     // that the value fits in an int.
   7678     if (CVal != CVal64)
   7679       return;
   7680 
   7681     switch (ConstraintLetter) {
   7682       case 'j':
   7683 	// Constant suitable for movw, must be between 0 and
   7684 	// 65535.
   7685 	if (Subtarget->hasV6T2Ops())
   7686 	  if (CVal >= 0 && CVal <= 65535)
   7687 	    break;
   7688 	return;
   7689       case 'I':
   7690         if (Subtarget->isThumb1Only()) {
   7691           // This must be a constant between 0 and 255, for ADD
   7692           // immediates.
   7693           if (CVal >= 0 && CVal <= 255)
   7694             break;
   7695         } else if (Subtarget->isThumb2()) {
   7696           // A constant that can be used as an immediate value in a
   7697           // data-processing instruction.
   7698           if (ARM_AM::getT2SOImmVal(CVal) != -1)
   7699             break;
   7700         } else {
   7701           // A constant that can be used as an immediate value in a
   7702           // data-processing instruction.
   7703           if (ARM_AM::getSOImmVal(CVal) != -1)
   7704             break;
   7705         }
   7706         return;
   7707 
   7708       case 'J':
   7709         if (Subtarget->isThumb()) {  // FIXME thumb2
   7710           // This must be a constant between -255 and -1, for negated ADD
   7711           // immediates. This can be used in GCC with an "n" modifier that
   7712           // prints the negated value, for use with SUB instructions. It is
   7713           // not useful otherwise but is implemented for compatibility.
   7714           if (CVal >= -255 && CVal <= -1)
   7715             break;
   7716         } else {
   7717           // This must be a constant between -4095 and 4095. It is not clear
   7718           // what this constraint is intended for. Implemented for
   7719           // compatibility with GCC.
   7720           if (CVal >= -4095 && CVal <= 4095)
   7721             break;
   7722         }
   7723         return;
   7724 
   7725       case 'K':
   7726         if (Subtarget->isThumb1Only()) {
   7727           // A 32-bit value where only one byte has a nonzero value. Exclude
   7728           // zero to match GCC. This constraint is used by GCC internally for
   7729           // constants that can be loaded with a move/shift combination.
   7730           // It is not useful otherwise but is implemented for compatibility.
   7731           if (CVal != 0 && ARM_AM::isThumbImmShiftedVal(CVal))
   7732             break;
   7733         } else if (Subtarget->isThumb2()) {
   7734           // A constant whose bitwise inverse can be used as an immediate
   7735           // value in a data-processing instruction. This can be used in GCC
   7736           // with a "B" modifier that prints the inverted value, for use with
   7737           // BIC and MVN instructions. It is not useful otherwise but is
   7738           // implemented for compatibility.
   7739           if (ARM_AM::getT2SOImmVal(~CVal) != -1)
   7740             break;
   7741         } else {
   7742           // A constant whose bitwise inverse can be used as an immediate
   7743           // value in a data-processing instruction. This can be used in GCC
   7744           // with a "B" modifier that prints the inverted value, for use with
   7745           // BIC and MVN instructions. It is not useful otherwise but is
   7746           // implemented for compatibility.
   7747           if (ARM_AM::getSOImmVal(~CVal) != -1)
   7748             break;
   7749         }
   7750         return;
   7751 
   7752       case 'L':
   7753         if (Subtarget->isThumb1Only()) {
   7754           // This must be a constant between -7 and 7,
   7755           // for 3-operand ADD/SUB immediate instructions.
   7756           if (CVal >= -7 && CVal < 7)
   7757             break;
   7758         } else if (Subtarget->isThumb2()) {
   7759           // A constant whose negation can be used as an immediate value in a
   7760           // data-processing instruction. This can be used in GCC with an "n"
   7761           // modifier that prints the negated value, for use with SUB
   7762           // instructions. It is not useful otherwise but is implemented for
   7763           // compatibility.
   7764           if (ARM_AM::getT2SOImmVal(-CVal) != -1)
   7765             break;
   7766         } else {
   7767           // A constant whose negation can be used as an immediate value in a
   7768           // data-processing instruction. This can be used in GCC with an "n"
   7769           // modifier that prints the negated value, for use with SUB
   7770           // instructions. It is not useful otherwise but is implemented for
   7771           // compatibility.
   7772           if (ARM_AM::getSOImmVal(-CVal) != -1)
   7773             break;
   7774         }
   7775         return;
   7776 
   7777       case 'M':
   7778         if (Subtarget->isThumb()) { // FIXME thumb2
   7779           // This must be a multiple of 4 between 0 and 1020, for
   7780           // ADD sp + immediate.
   7781           if ((CVal >= 0 && CVal <= 1020) && ((CVal & 3) == 0))
   7782             break;
   7783         } else {
   7784           // A power of two or a constant between 0 and 32.  This is used in
   7785           // GCC for the shift amount on shifted register operands, but it is
   7786           // useful in general for any shift amounts.
   7787           if ((CVal >= 0 && CVal <= 32) || ((CVal & (CVal - 1)) == 0))
   7788             break;
   7789         }
   7790         return;
   7791 
   7792       case 'N':
   7793         if (Subtarget->isThumb()) {  // FIXME thumb2
   7794           // This must be a constant between 0 and 31, for shift amounts.
   7795           if (CVal >= 0 && CVal <= 31)
   7796             break;
   7797         }
   7798         return;
   7799 
   7800       case 'O':
   7801         if (Subtarget->isThumb()) {  // FIXME thumb2
   7802           // This must be a multiple of 4 between -508 and 508, for
   7803           // ADD/SUB sp = sp + immediate.
   7804           if ((CVal >= -508 && CVal <= 508) && ((CVal & 3) == 0))
   7805             break;
   7806         }
   7807         return;
   7808     }
   7809     Result = DAG.getTargetConstant(CVal, Op.getValueType());
   7810     break;
   7811   }
   7812 
   7813   if (Result.getNode()) {
   7814     Ops.push_back(Result);
   7815     return;
   7816   }
   7817   return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
   7818 }
   7819 
   7820 bool
   7821 ARMTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
   7822   // The ARM target isn't yet aware of offsets.
   7823   return false;
   7824 }
   7825 
   7826 int ARM::getVFPf32Imm(const APFloat &FPImm) {
   7827   APInt Imm = FPImm.bitcastToAPInt();
   7828   uint32_t Sign = Imm.lshr(31).getZExtValue() & 1;
   7829   int32_t Exp = (Imm.lshr(23).getSExtValue() & 0xff) - 127;  // -126 to 127
   7830   int64_t Mantissa = Imm.getZExtValue() & 0x7fffff;  // 23 bits
   7831 
   7832   // We can handle 4 bits of mantissa.
   7833   // mantissa = (16+UInt(e:f:g:h))/16.
   7834   if (Mantissa & 0x7ffff)
   7835     return -1;
   7836   Mantissa >>= 19;
   7837   if ((Mantissa & 0xf) != Mantissa)
   7838     return -1;
   7839 
   7840   // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
   7841   if (Exp < -3 || Exp > 4)
   7842     return -1;
   7843   Exp = ((Exp+3) & 0x7) ^ 4;
   7844 
   7845   return ((int)Sign << 7) | (Exp << 4) | Mantissa;
   7846 }
   7847 
   7848 int ARM::getVFPf64Imm(const APFloat &FPImm) {
   7849   APInt Imm = FPImm.bitcastToAPInt();
   7850   uint64_t Sign = Imm.lshr(63).getZExtValue() & 1;
   7851   int64_t Exp = (Imm.lshr(52).getSExtValue() & 0x7ff) - 1023;   // -1022 to 1023
   7852   uint64_t Mantissa = Imm.getZExtValue() & 0xfffffffffffffLL;
   7853 
   7854   // We can handle 4 bits of mantissa.
   7855   // mantissa = (16+UInt(e:f:g:h))/16.
   7856   if (Mantissa & 0xffffffffffffLL)
   7857     return -1;
   7858   Mantissa >>= 48;
   7859   if ((Mantissa & 0xf) != Mantissa)
   7860     return -1;
   7861 
   7862   // We can handle 3 bits of exponent: exp == UInt(NOT(b):c:d)-3
   7863   if (Exp < -3 || Exp > 4)
   7864     return -1;
   7865   Exp = ((Exp+3) & 0x7) ^ 4;
   7866 
   7867   return ((int)Sign << 7) | (Exp << 4) | Mantissa;
   7868 }
   7869 
   7870 bool ARM::isBitFieldInvertedMask(unsigned v) {
   7871   if (v == 0xffffffff)
   7872     return 0;
   7873   // there can be 1's on either or both "outsides", all the "inside"
   7874   // bits must be 0's
   7875   unsigned int lsb = 0, msb = 31;
   7876   while (v & (1 << msb)) --msb;
   7877   while (v & (1 << lsb)) ++lsb;
   7878   for (unsigned int i = lsb; i <= msb; ++i) {
   7879     if (v & (1 << i))
   7880       return 0;
   7881   }
   7882   return 1;
   7883 }
   7884 
   7885 /// isFPImmLegal - Returns true if the target can instruction select the
   7886 /// specified FP immediate natively. If false, the legalizer will
   7887 /// materialize the FP immediate as a load from a constant pool.
   7888 bool ARMTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
   7889   if (!Subtarget->hasVFP3())
   7890     return false;
   7891   if (VT == MVT::f32)
   7892     return ARM::getVFPf32Imm(Imm) != -1;
   7893   if (VT == MVT::f64)
   7894     return ARM::getVFPf64Imm(Imm) != -1;
   7895   return false;
   7896 }
   7897 
   7898 /// getTgtMemIntrinsic - Represent NEON load and store intrinsics as
   7899 /// MemIntrinsicNodes.  The associated MachineMemOperands record the alignment
   7900 /// specified in the intrinsic calls.
   7901 bool ARMTargetLowering::getTgtMemIntrinsic(IntrinsicInfo &Info,
   7902                                            const CallInst &I,
   7903                                            unsigned Intrinsic) const {
   7904   switch (Intrinsic) {
   7905   case Intrinsic::arm_neon_vld1:
   7906   case Intrinsic::arm_neon_vld2:
   7907   case Intrinsic::arm_neon_vld3:
   7908   case Intrinsic::arm_neon_vld4:
   7909   case Intrinsic::arm_neon_vld2lane:
   7910   case Intrinsic::arm_neon_vld3lane:
   7911   case Intrinsic::arm_neon_vld4lane: {
   7912     Info.opc = ISD::INTRINSIC_W_CHAIN;
   7913     // Conservatively set memVT to the entire set of vectors loaded.
   7914     uint64_t NumElts = getTargetData()->getTypeAllocSize(I.getType()) / 8;
   7915     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
   7916     Info.ptrVal = I.getArgOperand(0);
   7917     Info.offset = 0;
   7918     Value *AlignArg = I.getArgOperand(I.getNumArgOperands() - 1);
   7919     Info.align = cast<ConstantInt>(AlignArg)->getZExtValue();
   7920     Info.vol = false; // volatile loads with NEON intrinsics not supported
   7921     Info.readMem = true;
   7922     Info.writeMem = false;
   7923     return true;
   7924   }
   7925   case Intrinsic::arm_neon_vst1:
   7926   case Intrinsic::arm_neon_vst2:
   7927   case Intrinsic::arm_neon_vst3:
   7928   case Intrinsic::arm_neon_vst4:
   7929   case Intrinsic::arm_neon_vst2lane:
   7930   case Intrinsic::arm_neon_vst3lane:
   7931   case Intrinsic::arm_neon_vst4lane: {
   7932     Info.opc = ISD::INTRINSIC_VOID;
   7933     // Conservatively set memVT to the entire set of vectors stored.
   7934     unsigned NumElts = 0;
   7935     for (unsigned ArgI = 1, ArgE = I.getNumArgOperands(); ArgI < ArgE; ++ArgI) {
   7936       Type *ArgTy = I.getArgOperand(ArgI)->getType();
   7937       if (!ArgTy->isVectorTy())
   7938         break;
   7939       NumElts += getTargetData()->getTypeAllocSize(ArgTy) / 8;
   7940     }
   7941     Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
   7942     Info.ptrVal = I.getArgOperand(0);
   7943     Info.offset = 0;
   7944     Value *AlignArg = I.getArgOperand(I.getNumArgOperands() - 1);
   7945     Info.align = cast<ConstantInt>(AlignArg)->getZExtValue();
   7946     Info.vol = false; // volatile stores with NEON intrinsics not supported
   7947     Info.readMem = false;
   7948     Info.writeMem = true;
   7949     return true;
   7950   }
   7951   case Intrinsic::arm_strexd: {
   7952     Info.opc = ISD::INTRINSIC_W_CHAIN;
   7953     Info.memVT = MVT::i64;
   7954     Info.ptrVal = I.getArgOperand(2);
   7955     Info.offset = 0;
   7956     Info.align = 8;
   7957     Info.vol = true;
   7958     Info.readMem = false;
   7959     Info.writeMem = true;
   7960     return true;
   7961   }
   7962   case Intrinsic::arm_ldrexd: {
   7963     Info.opc = ISD::INTRINSIC_W_CHAIN;
   7964     Info.memVT = MVT::i64;
   7965     Info.ptrVal = I.getArgOperand(0);
   7966     Info.offset = 0;
   7967     Info.align = 8;
   7968     Info.vol = true;
   7969     Info.readMem = true;
   7970     Info.writeMem = false;
   7971     return true;
   7972   }
   7973   default:
   7974     break;
   7975   }
   7976 
   7977   return false;
   7978 }
   7979