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      1 //===-- ARMISelLowering.h - ARM DAG Lowering Interface ----------*- C++ -*-===//
      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 #ifndef LLVM_LIB_TARGET_ARM_ARMISELLOWERING_H
     16 #define LLVM_LIB_TARGET_ARM_ARMISELLOWERING_H
     17 
     18 #include "MCTargetDesc/ARMBaseInfo.h"
     19 #include "llvm/CodeGen/CallingConvLower.h"
     20 #include "llvm/CodeGen/SelectionDAG.h"
     21 #include "llvm/Target/TargetLowering.h"
     22 #include <vector>
     23 
     24 namespace llvm {
     25   class ARMConstantPoolValue;
     26   class ARMSubtarget;
     27 
     28   namespace ARMISD {
     29     // ARM Specific DAG Nodes
     30     enum NodeType : unsigned {
     31       // Start the numbering where the builtin ops and target ops leave off.
     32       FIRST_NUMBER = ISD::BUILTIN_OP_END,
     33 
     34       Wrapper,      // Wrapper - A wrapper node for TargetConstantPool,
     35                     // TargetExternalSymbol, and TargetGlobalAddress.
     36       WrapperPIC,   // WrapperPIC - A wrapper node for TargetGlobalAddress in
     37                     // PIC mode.
     38       WrapperJT,    // WrapperJT - A wrapper node for TargetJumpTable
     39 
     40       // Add pseudo op to model memcpy for struct byval.
     41       COPY_STRUCT_BYVAL,
     42 
     43       CALL,         // Function call.
     44       CALL_PRED,    // Function call that's predicable.
     45       CALL_NOLINK,  // Function call with branch not branch-and-link.
     46       tCALL,        // Thumb function call.
     47       BRCOND,       // Conditional branch.
     48       BR_JT,        // Jumptable branch.
     49       BR2_JT,       // Jumptable branch (2 level - jumptable entry is a jump).
     50       RET_FLAG,     // Return with a flag operand.
     51       INTRET_FLAG,  // Interrupt return with an LR-offset and a flag operand.
     52 
     53       PIC_ADD,      // Add with a PC operand and a PIC label.
     54 
     55       CMP,          // ARM compare instructions.
     56       CMN,          // ARM CMN instructions.
     57       CMPZ,         // ARM compare that sets only Z flag.
     58       CMPFP,        // ARM VFP compare instruction, sets FPSCR.
     59       CMPFPw0,      // ARM VFP compare against zero instruction, sets FPSCR.
     60       FMSTAT,       // ARM fmstat instruction.
     61 
     62       CMOV,         // ARM conditional move instructions.
     63 
     64       BCC_i64,
     65 
     66       SRL_FLAG,     // V,Flag = srl_flag X -> srl X, 1 + save carry out.
     67       SRA_FLAG,     // V,Flag = sra_flag X -> sra X, 1 + save carry out.
     68       RRX,          // V = RRX X, Flag     -> srl X, 1 + shift in carry flag.
     69 
     70       ADDC,         // Add with carry
     71       ADDE,         // Add using carry
     72       SUBC,         // Sub with carry
     73       SUBE,         // Sub using carry
     74 
     75       VMOVRRD,      // double to two gprs.
     76       VMOVDRR,      // Two gprs to double.
     77 
     78       EH_SJLJ_SETJMP,         // SjLj exception handling setjmp.
     79       EH_SJLJ_LONGJMP,        // SjLj exception handling longjmp.
     80       EH_SJLJ_SETUP_DISPATCH, // SjLj exception handling setup_dispatch.
     81 
     82       TC_RETURN,    // Tail call return pseudo.
     83 
     84       THREAD_POINTER,
     85 
     86       DYN_ALLOC,    // Dynamic allocation on the stack.
     87 
     88       MEMBARRIER_MCR, // Memory barrier (MCR)
     89 
     90       PRELOAD,      // Preload
     91 
     92       WIN__CHKSTK,  // Windows' __chkstk call to do stack probing.
     93       WIN__DBZCHK,  // Windows' divide by zero check
     94 
     95       VCEQ,         // Vector compare equal.
     96       VCEQZ,        // Vector compare equal to zero.
     97       VCGE,         // Vector compare greater than or equal.
     98       VCGEZ,        // Vector compare greater than or equal to zero.
     99       VCLEZ,        // Vector compare less than or equal to zero.
    100       VCGEU,        // Vector compare unsigned greater than or equal.
    101       VCGT,         // Vector compare greater than.
    102       VCGTZ,        // Vector compare greater than zero.
    103       VCLTZ,        // Vector compare less than zero.
    104       VCGTU,        // Vector compare unsigned greater than.
    105       VTST,         // Vector test bits.
    106 
    107       // Vector shift by immediate:
    108       VSHL,         // ...left
    109       VSHRs,        // ...right (signed)
    110       VSHRu,        // ...right (unsigned)
    111 
    112       // Vector rounding shift by immediate:
    113       VRSHRs,       // ...right (signed)
    114       VRSHRu,       // ...right (unsigned)
    115       VRSHRN,       // ...right narrow
    116 
    117       // Vector saturating shift by immediate:
    118       VQSHLs,       // ...left (signed)
    119       VQSHLu,       // ...left (unsigned)
    120       VQSHLsu,      // ...left (signed to unsigned)
    121       VQSHRNs,      // ...right narrow (signed)
    122       VQSHRNu,      // ...right narrow (unsigned)
    123       VQSHRNsu,     // ...right narrow (signed to unsigned)
    124 
    125       // Vector saturating rounding shift by immediate:
    126       VQRSHRNs,     // ...right narrow (signed)
    127       VQRSHRNu,     // ...right narrow (unsigned)
    128       VQRSHRNsu,    // ...right narrow (signed to unsigned)
    129 
    130       // Vector shift and insert:
    131       VSLI,         // ...left
    132       VSRI,         // ...right
    133 
    134       // Vector get lane (VMOV scalar to ARM core register)
    135       // (These are used for 8- and 16-bit element types only.)
    136       VGETLANEu,    // zero-extend vector extract element
    137       VGETLANEs,    // sign-extend vector extract element
    138 
    139       // Vector move immediate and move negated immediate:
    140       VMOVIMM,
    141       VMVNIMM,
    142 
    143       // Vector move f32 immediate:
    144       VMOVFPIMM,
    145 
    146       // Vector duplicate:
    147       VDUP,
    148       VDUPLANE,
    149 
    150       // Vector shuffles:
    151       VEXT,         // extract
    152       VREV64,       // reverse elements within 64-bit doublewords
    153       VREV32,       // reverse elements within 32-bit words
    154       VREV16,       // reverse elements within 16-bit halfwords
    155       VZIP,         // zip (interleave)
    156       VUZP,         // unzip (deinterleave)
    157       VTRN,         // transpose
    158       VTBL1,        // 1-register shuffle with mask
    159       VTBL2,        // 2-register shuffle with mask
    160 
    161       // Vector multiply long:
    162       VMULLs,       // ...signed
    163       VMULLu,       // ...unsigned
    164 
    165       UMLAL,        // 64bit Unsigned Accumulate Multiply
    166       SMLAL,        // 64bit Signed Accumulate Multiply
    167 
    168       // Operands of the standard BUILD_VECTOR node are not legalized, which
    169       // is fine if BUILD_VECTORs are always lowered to shuffles or other
    170       // operations, but for ARM some BUILD_VECTORs are legal as-is and their
    171       // operands need to be legalized.  Define an ARM-specific version of
    172       // BUILD_VECTOR for this purpose.
    173       BUILD_VECTOR,
    174 
    175       // Bit-field insert
    176       BFI,
    177 
    178       // Vector OR with immediate
    179       VORRIMM,
    180       // Vector AND with NOT of immediate
    181       VBICIMM,
    182 
    183       // Vector bitwise select
    184       VBSL,
    185 
    186       // Pseudo-instruction representing a memory copy using ldm/stm
    187       // instructions.
    188       MEMCPY,
    189 
    190       // Vector load N-element structure to all lanes:
    191       VLD2DUP = ISD::FIRST_TARGET_MEMORY_OPCODE,
    192       VLD3DUP,
    193       VLD4DUP,
    194 
    195       // NEON loads with post-increment base updates:
    196       VLD1_UPD,
    197       VLD2_UPD,
    198       VLD3_UPD,
    199       VLD4_UPD,
    200       VLD2LN_UPD,
    201       VLD3LN_UPD,
    202       VLD4LN_UPD,
    203       VLD2DUP_UPD,
    204       VLD3DUP_UPD,
    205       VLD4DUP_UPD,
    206 
    207       // NEON stores with post-increment base updates:
    208       VST1_UPD,
    209       VST2_UPD,
    210       VST3_UPD,
    211       VST4_UPD,
    212       VST2LN_UPD,
    213       VST3LN_UPD,
    214       VST4LN_UPD
    215     };
    216   }
    217 
    218   /// Define some predicates that are used for node matching.
    219   namespace ARM {
    220     bool isBitFieldInvertedMask(unsigned v);
    221   }
    222 
    223   //===--------------------------------------------------------------------===//
    224   //  ARMTargetLowering - ARM Implementation of the TargetLowering interface
    225 
    226   class ARMTargetLowering : public TargetLowering {
    227   public:
    228     explicit ARMTargetLowering(const TargetMachine &TM,
    229                                const ARMSubtarget &STI);
    230 
    231     unsigned getJumpTableEncoding() const override;
    232     bool useSoftFloat() const override;
    233 
    234     SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
    235 
    236     /// ReplaceNodeResults - Replace the results of node with an illegal result
    237     /// type with new values built out of custom code.
    238     ///
    239     void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
    240                             SelectionDAG &DAG) const override;
    241 
    242     const char *getTargetNodeName(unsigned Opcode) const override;
    243 
    244     bool isSelectSupported(SelectSupportKind Kind) const override {
    245       // ARM does not support scalar condition selects on vectors.
    246       return (Kind != ScalarCondVectorVal);
    247     }
    248 
    249     /// getSetCCResultType - Return the value type to use for ISD::SETCC.
    250     EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
    251                            EVT VT) const override;
    252 
    253     MachineBasicBlock *
    254       EmitInstrWithCustomInserter(MachineInstr *MI,
    255                                   MachineBasicBlock *MBB) const override;
    256 
    257     void AdjustInstrPostInstrSelection(MachineInstr *MI,
    258                                        SDNode *Node) const override;
    259 
    260     SDValue PerformCMOVCombine(SDNode *N, SelectionDAG &DAG) const;
    261     SDValue PerformCMOVToBFICombine(SDNode *N, SelectionDAG &DAG) const;
    262     SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
    263 
    264     bool isDesirableToTransformToIntegerOp(unsigned Opc, EVT VT) const override;
    265 
    266     /// allowsMisalignedMemoryAccesses - Returns true if the target allows
    267     /// unaligned memory accesses of the specified type. Returns whether it
    268     /// is "fast" by reference in the second argument.
    269     bool allowsMisalignedMemoryAccesses(EVT VT, unsigned AddrSpace,
    270                                         unsigned Align,
    271                                         bool *Fast) const override;
    272 
    273     EVT getOptimalMemOpType(uint64_t Size,
    274                             unsigned DstAlign, unsigned SrcAlign,
    275                             bool IsMemset, bool ZeroMemset,
    276                             bool MemcpyStrSrc,
    277                             MachineFunction &MF) const override;
    278 
    279     using TargetLowering::isZExtFree;
    280     bool isZExtFree(SDValue Val, EVT VT2) const override;
    281 
    282     bool isVectorLoadExtDesirable(SDValue ExtVal) const override;
    283 
    284     bool allowTruncateForTailCall(Type *Ty1, Type *Ty2) const override;
    285 
    286 
    287     /// isLegalAddressingMode - Return true if the addressing mode represented
    288     /// by AM is legal for this target, for a load/store of the specified type.
    289     bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM,
    290                                Type *Ty, unsigned AS) const override;
    291     bool isLegalT2ScaledAddressingMode(const AddrMode &AM, EVT VT) const;
    292 
    293     /// isLegalICmpImmediate - Return true if the specified immediate is legal
    294     /// icmp immediate, that is the target has icmp instructions which can
    295     /// compare a register against the immediate without having to materialize
    296     /// the immediate into a register.
    297     bool isLegalICmpImmediate(int64_t Imm) const override;
    298 
    299     /// isLegalAddImmediate - Return true if the specified immediate is legal
    300     /// add immediate, that is the target has add instructions which can
    301     /// add a register and the immediate without having to materialize
    302     /// the immediate into a register.
    303     bool isLegalAddImmediate(int64_t Imm) const override;
    304 
    305     /// getPreIndexedAddressParts - returns true by value, base pointer and
    306     /// offset pointer and addressing mode by reference if the node's address
    307     /// can be legally represented as pre-indexed load / store address.
    308     bool getPreIndexedAddressParts(SDNode *N, SDValue &Base, SDValue &Offset,
    309                                    ISD::MemIndexedMode &AM,
    310                                    SelectionDAG &DAG) const override;
    311 
    312     /// getPostIndexedAddressParts - returns true by value, base pointer and
    313     /// offset pointer and addressing mode by reference if this node can be
    314     /// combined with a load / store to form a post-indexed load / store.
    315     bool getPostIndexedAddressParts(SDNode *N, SDNode *Op, SDValue &Base,
    316                                     SDValue &Offset, ISD::MemIndexedMode &AM,
    317                                     SelectionDAG &DAG) const override;
    318 
    319     void computeKnownBitsForTargetNode(const SDValue Op, APInt &KnownZero,
    320                                        APInt &KnownOne,
    321                                        const SelectionDAG &DAG,
    322                                        unsigned Depth) const override;
    323 
    324 
    325     bool ExpandInlineAsm(CallInst *CI) const override;
    326 
    327     ConstraintType getConstraintType(StringRef Constraint) const override;
    328 
    329     /// Examine constraint string and operand type and determine a weight value.
    330     /// The operand object must already have been set up with the operand type.
    331     ConstraintWeight getSingleConstraintMatchWeight(
    332       AsmOperandInfo &info, const char *constraint) const override;
    333 
    334     std::pair<unsigned, const TargetRegisterClass *>
    335     getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
    336                                  StringRef Constraint, MVT VT) const override;
    337 
    338     /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
    339     /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
    340     /// true it means one of the asm constraint of the inline asm instruction
    341     /// being processed is 'm'.
    342     void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
    343                                       std::vector<SDValue> &Ops,
    344                                       SelectionDAG &DAG) const override;
    345 
    346     unsigned
    347     getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
    348       if (ConstraintCode == "Q")
    349         return InlineAsm::Constraint_Q;
    350       else if (ConstraintCode == "o")
    351         return InlineAsm::Constraint_o;
    352       else if (ConstraintCode.size() == 2) {
    353         if (ConstraintCode[0] == 'U') {
    354           switch(ConstraintCode[1]) {
    355           default:
    356             break;
    357           case 'm':
    358             return InlineAsm::Constraint_Um;
    359           case 'n':
    360             return InlineAsm::Constraint_Un;
    361           case 'q':
    362             return InlineAsm::Constraint_Uq;
    363           case 's':
    364             return InlineAsm::Constraint_Us;
    365           case 't':
    366             return InlineAsm::Constraint_Ut;
    367           case 'v':
    368             return InlineAsm::Constraint_Uv;
    369           case 'y':
    370             return InlineAsm::Constraint_Uy;
    371           }
    372         }
    373       }
    374       return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
    375     }
    376 
    377     const ARMSubtarget* getSubtarget() const {
    378       return Subtarget;
    379     }
    380 
    381     /// getRegClassFor - Return the register class that should be used for the
    382     /// specified value type.
    383     const TargetRegisterClass *getRegClassFor(MVT VT) const override;
    384 
    385     /// Returns true if a cast between SrcAS and DestAS is a noop.
    386     bool isNoopAddrSpaceCast(unsigned SrcAS, unsigned DestAS) const override {
    387       // Addrspacecasts are always noops.
    388       return true;
    389     }
    390 
    391     bool shouldAlignPointerArgs(CallInst *CI, unsigned &MinSize,
    392                                 unsigned &PrefAlign) const override;
    393 
    394     /// createFastISel - This method returns a target specific FastISel object,
    395     /// or null if the target does not support "fast" ISel.
    396     FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
    397                              const TargetLibraryInfo *libInfo) const override;
    398 
    399     Sched::Preference getSchedulingPreference(SDNode *N) const override;
    400 
    401     bool
    402     isShuffleMaskLegal(const SmallVectorImpl<int> &M, EVT VT) const override;
    403     bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
    404 
    405     /// isFPImmLegal - Returns true if the target can instruction select the
    406     /// specified FP immediate natively. If false, the legalizer will
    407     /// materialize the FP immediate as a load from a constant pool.
    408     bool isFPImmLegal(const APFloat &Imm, EVT VT) const override;
    409 
    410     bool getTgtMemIntrinsic(IntrinsicInfo &Info,
    411                             const CallInst &I,
    412                             unsigned Intrinsic) const override;
    413 
    414     /// \brief Returns true if it is beneficial to convert a load of a constant
    415     /// to just the constant itself.
    416     bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
    417                                            Type *Ty) const override;
    418 
    419     /// \brief Returns true if an argument of type Ty needs to be passed in a
    420     /// contiguous block of registers in calling convention CallConv.
    421     bool functionArgumentNeedsConsecutiveRegisters(
    422         Type *Ty, CallingConv::ID CallConv, bool isVarArg) const override;
    423 
    424     /// If a physical register, this returns the register that receives the
    425     /// exception address on entry to an EH pad.
    426     unsigned
    427     getExceptionPointerRegister(const Constant *PersonalityFn) const override;
    428 
    429     /// If a physical register, this returns the register that receives the
    430     /// exception typeid on entry to a landing pad.
    431     unsigned
    432     getExceptionSelectorRegister(const Constant *PersonalityFn) const override;
    433 
    434     Instruction *makeDMB(IRBuilder<> &Builder, ARM_MB::MemBOpt Domain) const;
    435     Value *emitLoadLinked(IRBuilder<> &Builder, Value *Addr,
    436                           AtomicOrdering Ord) const override;
    437     Value *emitStoreConditional(IRBuilder<> &Builder, Value *Val,
    438                                 Value *Addr, AtomicOrdering Ord) const override;
    439 
    440     void emitAtomicCmpXchgNoStoreLLBalance(IRBuilder<> &Builder) const override;
    441 
    442     Instruction* emitLeadingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
    443                           bool IsStore, bool IsLoad) const override;
    444     Instruction* emitTrailingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
    445                            bool IsStore, bool IsLoad) const override;
    446 
    447     unsigned getMaxSupportedInterleaveFactor() const override { return 4; }
    448 
    449     bool lowerInterleavedLoad(LoadInst *LI,
    450                               ArrayRef<ShuffleVectorInst *> Shuffles,
    451                               ArrayRef<unsigned> Indices,
    452                               unsigned Factor) const override;
    453     bool lowerInterleavedStore(StoreInst *SI, ShuffleVectorInst *SVI,
    454                                unsigned Factor) const override;
    455 
    456     TargetLoweringBase::AtomicExpansionKind
    457     shouldExpandAtomicLoadInIR(LoadInst *LI) const override;
    458     bool shouldExpandAtomicStoreInIR(StoreInst *SI) const override;
    459     TargetLoweringBase::AtomicExpansionKind
    460     shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const override;
    461     bool shouldExpandAtomicCmpXchgInIR(AtomicCmpXchgInst *AI) const override;
    462 
    463     bool useLoadStackGuardNode() const override;
    464 
    465     bool canCombineStoreAndExtract(Type *VectorTy, Value *Idx,
    466                                    unsigned &Cost) const override;
    467 
    468     bool isCheapToSpeculateCttz() const override;
    469     bool isCheapToSpeculateCtlz() const override;
    470 
    471   protected:
    472     std::pair<const TargetRegisterClass *, uint8_t>
    473     findRepresentativeClass(const TargetRegisterInfo *TRI,
    474                             MVT VT) const override;
    475 
    476   private:
    477     /// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
    478     /// make the right decision when generating code for different targets.
    479     const ARMSubtarget *Subtarget;
    480 
    481     const TargetRegisterInfo *RegInfo;
    482 
    483     const InstrItineraryData *Itins;
    484 
    485     /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
    486     ///
    487     unsigned ARMPCLabelIndex;
    488 
    489     void addTypeForNEON(MVT VT, MVT PromotedLdStVT, MVT PromotedBitwiseVT);
    490     void addDRTypeForNEON(MVT VT);
    491     void addQRTypeForNEON(MVT VT);
    492     std::pair<SDValue, SDValue> getARMXALUOOp(SDValue Op, SelectionDAG &DAG, SDValue &ARMcc) const;
    493 
    494     typedef SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPassVector;
    495     void PassF64ArgInRegs(SDLoc dl, SelectionDAG &DAG,
    496                           SDValue Chain, SDValue &Arg,
    497                           RegsToPassVector &RegsToPass,
    498                           CCValAssign &VA, CCValAssign &NextVA,
    499                           SDValue &StackPtr,
    500                           SmallVectorImpl<SDValue> &MemOpChains,
    501                           ISD::ArgFlagsTy Flags) const;
    502     SDValue GetF64FormalArgument(CCValAssign &VA, CCValAssign &NextVA,
    503                                  SDValue &Root, SelectionDAG &DAG,
    504                                  SDLoc dl) const;
    505 
    506     CallingConv::ID getEffectiveCallingConv(CallingConv::ID CC,
    507                                             bool isVarArg) const;
    508     CCAssignFn *CCAssignFnForNode(CallingConv::ID CC, bool Return,
    509                                   bool isVarArg) const;
    510     SDValue LowerMemOpCallTo(SDValue Chain, SDValue StackPtr, SDValue Arg,
    511                              SDLoc dl, SelectionDAG &DAG,
    512                              const CCValAssign &VA,
    513                              ISD::ArgFlagsTy Flags) const;
    514     SDValue LowerEH_SJLJ_SETJMP(SDValue Op, SelectionDAG &DAG) const;
    515     SDValue LowerEH_SJLJ_LONGJMP(SDValue Op, SelectionDAG &DAG) const;
    516     SDValue LowerEH_SJLJ_SETUP_DISPATCH(SDValue Op, SelectionDAG &DAG) const;
    517     SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG,
    518                                     const ARMSubtarget *Subtarget) const;
    519     SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
    520     SDValue LowerGlobalAddressDarwin(SDValue Op, SelectionDAG &DAG) const;
    521     SDValue LowerGlobalAddressELF(SDValue Op, SelectionDAG &DAG) const;
    522     SDValue LowerGlobalAddressWindows(SDValue Op, SelectionDAG &DAG) const;
    523     SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
    524     SDValue LowerToTLSGeneralDynamicModel(GlobalAddressSDNode *GA,
    525                                             SelectionDAG &DAG) const;
    526     SDValue LowerToTLSExecModels(GlobalAddressSDNode *GA,
    527                                  SelectionDAG &DAG,
    528                                  TLSModel::Model model) const;
    529     SDValue LowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
    530     SDValue LowerXALUO(SDValue Op, SelectionDAG &DAG) const;
    531     SDValue LowerSELECT(SDValue Op, SelectionDAG &DAG) const;
    532     SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
    533     SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG) const;
    534     SDValue LowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
    535     SDValue LowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
    536     SDValue LowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
    537     SDValue LowerShiftRightParts(SDValue Op, SelectionDAG &DAG) const;
    538     SDValue LowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
    539     SDValue LowerFLT_ROUNDS_(SDValue Op, SelectionDAG &DAG) const;
    540     SDValue LowerConstantFP(SDValue Op, SelectionDAG &DAG,
    541                             const ARMSubtarget *ST) const;
    542     SDValue LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG,
    543                               const ARMSubtarget *ST) const;
    544     SDValue LowerFSINCOS(SDValue Op, SelectionDAG &DAG) const;
    545     SDValue LowerDivRem(SDValue Op, SelectionDAG &DAG) const;
    546     SDValue LowerDIV_Windows(SDValue Op, SelectionDAG &DAG, bool Signed) const;
    547     void ExpandDIV_Windows(SDValue Op, SelectionDAG &DAG, bool Signed,
    548                            SmallVectorImpl<SDValue> &Results) const;
    549     SDValue LowerWindowsDIVLibCall(SDValue Op, SelectionDAG &DAG, bool Signed,
    550                                    SDValue &Chain) const;
    551     SDValue LowerREM(SDNode *N, SelectionDAG &DAG) const;
    552     SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) const;
    553     SDValue LowerFP_ROUND(SDValue Op, SelectionDAG &DAG) const;
    554     SDValue LowerFP_EXTEND(SDValue Op, SelectionDAG &DAG) const;
    555     SDValue LowerFP_TO_INT(SDValue Op, SelectionDAG &DAG) const;
    556     SDValue LowerINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
    557 
    558     unsigned getRegisterByName(const char* RegName, EVT VT,
    559                                SelectionDAG &DAG) const override;
    560 
    561     /// isFMAFasterThanFMulAndFAdd - Return true if an FMA operation is faster
    562     /// than a pair of fmul and fadd instructions. fmuladd intrinsics will be
    563     /// expanded to FMAs when this method returns true, otherwise fmuladd is
    564     /// expanded to fmul + fadd.
    565     ///
    566     /// ARM supports both fused and unfused multiply-add operations; we already
    567     /// lower a pair of fmul and fadd to the latter so it's not clear that there
    568     /// would be a gain or that the gain would be worthwhile enough to risk
    569     /// correctness bugs.
    570     bool isFMAFasterThanFMulAndFAdd(EVT VT) const override { return false; }
    571 
    572     SDValue ReconstructShuffle(SDValue Op, SelectionDAG &DAG) const;
    573 
    574     SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
    575                             CallingConv::ID CallConv, bool isVarArg,
    576                             const SmallVectorImpl<ISD::InputArg> &Ins,
    577                             SDLoc dl, SelectionDAG &DAG,
    578                             SmallVectorImpl<SDValue> &InVals,
    579                             bool isThisReturn, SDValue ThisVal) const;
    580 
    581     SDValue
    582       LowerFormalArguments(SDValue Chain,
    583                            CallingConv::ID CallConv, bool isVarArg,
    584                            const SmallVectorImpl<ISD::InputArg> &Ins,
    585                            SDLoc dl, SelectionDAG &DAG,
    586                            SmallVectorImpl<SDValue> &InVals) const override;
    587 
    588     int StoreByValRegs(CCState &CCInfo, SelectionDAG &DAG,
    589                        SDLoc dl, SDValue &Chain,
    590                        const Value *OrigArg,
    591                        unsigned InRegsParamRecordIdx,
    592                        int ArgOffset,
    593                        unsigned ArgSize) const;
    594 
    595     void VarArgStyleRegisters(CCState &CCInfo, SelectionDAG &DAG,
    596                               SDLoc dl, SDValue &Chain,
    597                               unsigned ArgOffset,
    598                               unsigned TotalArgRegsSaveSize,
    599                               bool ForceMutable = false) const;
    600 
    601     SDValue
    602       LowerCall(TargetLowering::CallLoweringInfo &CLI,
    603                 SmallVectorImpl<SDValue> &InVals) const override;
    604 
    605     /// HandleByVal - Target-specific cleanup for ByVal support.
    606     void HandleByVal(CCState *, unsigned &, unsigned) const override;
    607 
    608     /// IsEligibleForTailCallOptimization - Check whether the call is eligible
    609     /// for tail call optimization. Targets which want to do tail call
    610     /// optimization should implement this function.
    611     bool IsEligibleForTailCallOptimization(SDValue Callee,
    612                                            CallingConv::ID CalleeCC,
    613                                            bool isVarArg,
    614                                            bool isCalleeStructRet,
    615                                            bool isCallerStructRet,
    616                                     const SmallVectorImpl<ISD::OutputArg> &Outs,
    617                                     const SmallVectorImpl<SDValue> &OutVals,
    618                                     const SmallVectorImpl<ISD::InputArg> &Ins,
    619                                            SelectionDAG& DAG) const;
    620 
    621     bool CanLowerReturn(CallingConv::ID CallConv,
    622                         MachineFunction &MF, bool isVarArg,
    623                         const SmallVectorImpl<ISD::OutputArg> &Outs,
    624                         LLVMContext &Context) const override;
    625 
    626     SDValue
    627       LowerReturn(SDValue Chain,
    628                   CallingConv::ID CallConv, bool isVarArg,
    629                   const SmallVectorImpl<ISD::OutputArg> &Outs,
    630                   const SmallVectorImpl<SDValue> &OutVals,
    631                   SDLoc dl, SelectionDAG &DAG) const override;
    632 
    633     bool isUsedByReturnOnly(SDNode *N, SDValue &Chain) const override;
    634 
    635     bool mayBeEmittedAsTailCall(CallInst *CI) const override;
    636 
    637     SDValue getCMOV(SDLoc dl, EVT VT, SDValue FalseVal, SDValue TrueVal,
    638                     SDValue ARMcc, SDValue CCR, SDValue Cmp,
    639                     SelectionDAG &DAG) const;
    640     SDValue getARMCmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
    641                       SDValue &ARMcc, SelectionDAG &DAG, SDLoc dl) const;
    642     SDValue getVFPCmp(SDValue LHS, SDValue RHS,
    643                       SelectionDAG &DAG, SDLoc dl) const;
    644     SDValue duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const;
    645 
    646     SDValue OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const;
    647 
    648     void SetupEntryBlockForSjLj(MachineInstr *MI,
    649                                 MachineBasicBlock *MBB,
    650                                 MachineBasicBlock *DispatchBB, int FI) const;
    651 
    652     void EmitSjLjDispatchBlock(MachineInstr *MI, MachineBasicBlock *MBB) const;
    653 
    654     bool RemapAddSubWithFlags(MachineInstr *MI, MachineBasicBlock *BB) const;
    655 
    656     MachineBasicBlock *EmitStructByval(MachineInstr *MI,
    657                                        MachineBasicBlock *MBB) const;
    658 
    659     MachineBasicBlock *EmitLowered__chkstk(MachineInstr *MI,
    660                                            MachineBasicBlock *MBB) const;
    661     MachineBasicBlock *EmitLowered__dbzchk(MachineInstr *MI,
    662                                            MachineBasicBlock *MBB) const;
    663   };
    664 
    665   enum NEONModImmType {
    666     VMOVModImm,
    667     VMVNModImm,
    668     OtherModImm
    669   };
    670 
    671   namespace ARM {
    672     FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
    673                              const TargetLibraryInfo *libInfo);
    674   }
    675 }
    676 
    677 #endif  // ARMISELLOWERING_H
    678