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      1 //===-- MipsSubtarget.h - Define Subtarget for the Mips ---------*- 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 declares the Mips specific subclass of TargetSubtargetInfo.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_LIB_TARGET_MIPS_MIPSSUBTARGET_H
     15 #define LLVM_LIB_TARGET_MIPS_MIPSSUBTARGET_H
     16 
     17 #include "MCTargetDesc/MipsABIInfo.h"
     18 #include "MipsFrameLowering.h"
     19 #include "MipsISelLowering.h"
     20 #include "MipsInstrInfo.h"
     21 #include "llvm/IR/DataLayout.h"
     22 #include "llvm/MC/MCInstrItineraries.h"
     23 #include "llvm/Support/ErrorHandling.h"
     24 #include "llvm/Target/TargetSelectionDAGInfo.h"
     25 #include "llvm/Target/TargetSubtargetInfo.h"
     26 #include <string>
     27 
     28 #define GET_SUBTARGETINFO_HEADER
     29 #include "MipsGenSubtargetInfo.inc"
     30 
     31 namespace llvm {
     32 class StringRef;
     33 
     34 class MipsTargetMachine;
     35 
     36 class MipsSubtarget : public MipsGenSubtargetInfo {
     37   virtual void anchor();
     38 
     39   enum MipsArchEnum {
     40     MipsDefault,
     41     Mips1, Mips2, Mips32, Mips32r2, Mips32r3, Mips32r5, Mips32r6, Mips32Max,
     42     Mips3, Mips4, Mips5, Mips64, Mips64r2, Mips64r3, Mips64r5, Mips64r6
     43   };
     44 
     45   enum class CPU { P5600 };
     46 
     47   // Mips architecture version
     48   MipsArchEnum MipsArchVersion;
     49 
     50   // Processor implementation (unused but required to exist by
     51   // tablegen-erated code).
     52   CPU ProcImpl;
     53 
     54   // IsLittle - The target is Little Endian
     55   bool IsLittle;
     56 
     57   // IsSoftFloat - The target does not support any floating point instructions.
     58   bool IsSoftFloat;
     59 
     60   // IsSingleFloat - The target only supports single precision float
     61   // point operations. This enable the target to use all 32 32-bit
     62   // floating point registers instead of only using even ones.
     63   bool IsSingleFloat;
     64 
     65   // IsFPXX - MIPS O32 modeless ABI.
     66   bool IsFPXX;
     67 
     68   // NoABICalls - Disable SVR4-style position-independent code.
     69   bool NoABICalls;
     70 
     71   // IsFP64bit - The target processor has 64-bit floating point registers.
     72   bool IsFP64bit;
     73 
     74   /// Are odd single-precision registers permitted?
     75   /// This corresponds to -modd-spreg and -mno-odd-spreg
     76   bool UseOddSPReg;
     77 
     78   // IsNan2008 - IEEE 754-2008 NaN encoding.
     79   bool IsNaN2008bit;
     80 
     81   // IsFP64bit - General-purpose registers are 64 bits wide
     82   bool IsGP64bit;
     83 
     84   // HasVFPU - Processor has a vector floating point unit.
     85   bool HasVFPU;
     86 
     87   // CPU supports cnMIPS (Cavium Networks Octeon CPU).
     88   bool HasCnMips;
     89 
     90   // isLinux - Target system is Linux. Is false we consider ELFOS for now.
     91   bool IsLinux;
     92 
     93   // UseSmallSection - Small section is used.
     94   bool UseSmallSection;
     95 
     96   /// Features related to the presence of specific instructions.
     97 
     98   // HasMips3_32 - The subset of MIPS-III instructions added to MIPS32
     99   bool HasMips3_32;
    100 
    101   // HasMips3_32r2 - The subset of MIPS-III instructions added to MIPS32r2
    102   bool HasMips3_32r2;
    103 
    104   // HasMips4_32 - Has the subset of MIPS-IV present in MIPS32
    105   bool HasMips4_32;
    106 
    107   // HasMips4_32r2 - Has the subset of MIPS-IV present in MIPS32r2
    108   bool HasMips4_32r2;
    109 
    110   // HasMips5_32r2 - Has the subset of MIPS-V present in MIPS32r2
    111   bool HasMips5_32r2;
    112 
    113   // InMips16 -- can process Mips16 instructions
    114   bool InMips16Mode;
    115 
    116   // Mips16 hard float
    117   bool InMips16HardFloat;
    118 
    119   // PreviousInMips16 -- the function we just processed was in Mips 16 Mode
    120   bool PreviousInMips16Mode;
    121 
    122   // InMicroMips -- can process MicroMips instructions
    123   bool InMicroMipsMode;
    124 
    125   // HasDSP, HasDSPR2, HasDSPR3 -- supports DSP ASE.
    126   bool HasDSP, HasDSPR2, HasDSPR3;
    127 
    128   // Allow mixed Mips16 and Mips32 in one source file
    129   bool AllowMixed16_32;
    130 
    131   // Optimize for space by compiling all functions as Mips 16 unless
    132   // it needs floating point. Functions needing floating point are
    133   // compiled as Mips32
    134   bool Os16;
    135 
    136   // HasMSA -- supports MSA ASE.
    137   bool HasMSA;
    138 
    139   // UseTCCInDIV -- Enables the use of trapping in the assembler.
    140   bool UseTCCInDIV;
    141 
    142   // HasEVA -- supports EVA ASE.
    143   bool HasEVA;
    144 
    145   InstrItineraryData InstrItins;
    146 
    147   // We can override the determination of whether we are in mips16 mode
    148   // as from the command line
    149   enum {NoOverride, Mips16Override, NoMips16Override} OverrideMode;
    150 
    151   const MipsTargetMachine &TM;
    152 
    153   Triple TargetTriple;
    154 
    155   const TargetSelectionDAGInfo TSInfo;
    156   std::unique_ptr<const MipsInstrInfo> InstrInfo;
    157   std::unique_ptr<const MipsFrameLowering> FrameLowering;
    158   std::unique_ptr<const MipsTargetLowering> TLInfo;
    159 
    160 public:
    161   /// This overrides the PostRAScheduler bit in the SchedModel for each CPU.
    162   bool enablePostRAScheduler() const override;
    163   void getCriticalPathRCs(RegClassVector &CriticalPathRCs) const override;
    164   CodeGenOpt::Level getOptLevelToEnablePostRAScheduler() const override;
    165 
    166   /// Only O32 and EABI supported right now.
    167   bool isABI_EABI() const;
    168   bool isABI_N64() const;
    169   bool isABI_N32() const;
    170   bool isABI_O32() const;
    171   const MipsABIInfo &getABI() const;
    172   bool isABI_FPXX() const { return isABI_O32() && IsFPXX; }
    173 
    174   /// This constructor initializes the data members to match that
    175   /// of the specified triple.
    176   MipsSubtarget(const Triple &TT, const std::string &CPU, const std::string &FS,
    177                 bool little, const MipsTargetMachine &TM);
    178 
    179   /// ParseSubtargetFeatures - Parses features string setting specified
    180   /// subtarget options.  Definition of function is auto generated by tblgen.
    181   void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
    182 
    183   bool hasMips1() const { return MipsArchVersion >= Mips1; }
    184   bool hasMips2() const { return MipsArchVersion >= Mips2; }
    185   bool hasMips3() const { return MipsArchVersion >= Mips3; }
    186   bool hasMips4() const { return MipsArchVersion >= Mips4; }
    187   bool hasMips5() const { return MipsArchVersion >= Mips5; }
    188   bool hasMips4_32() const { return HasMips4_32; }
    189   bool hasMips4_32r2() const { return HasMips4_32r2; }
    190   bool hasMips32() const {
    191     return (MipsArchVersion >= Mips32 && MipsArchVersion < Mips32Max) ||
    192            hasMips64();
    193   }
    194   bool hasMips32r2() const {
    195     return (MipsArchVersion >= Mips32r2 && MipsArchVersion < Mips32Max) ||
    196            hasMips64r2();
    197   }
    198   bool hasMips32r3() const {
    199     return (MipsArchVersion >= Mips32r3 && MipsArchVersion < Mips32Max) ||
    200            hasMips64r2();
    201   }
    202   bool hasMips32r5() const {
    203     return (MipsArchVersion >= Mips32r5 && MipsArchVersion < Mips32Max) ||
    204            hasMips64r5();
    205   }
    206   bool hasMips32r6() const {
    207     return (MipsArchVersion >= Mips32r6 && MipsArchVersion < Mips32Max) ||
    208            hasMips64r6();
    209   }
    210   bool hasMips64() const { return MipsArchVersion >= Mips64; }
    211   bool hasMips64r2() const { return MipsArchVersion >= Mips64r2; }
    212   bool hasMips64r3() const { return MipsArchVersion >= Mips64r3; }
    213   bool hasMips64r5() const { return MipsArchVersion >= Mips64r5; }
    214   bool hasMips64r6() const { return MipsArchVersion >= Mips64r6; }
    215 
    216   bool hasCnMips() const { return HasCnMips; }
    217 
    218   bool isLittle() const { return IsLittle; }
    219   bool isABICalls() const { return !NoABICalls; }
    220   bool isFPXX() const { return IsFPXX; }
    221   bool isFP64bit() const { return IsFP64bit; }
    222   bool useOddSPReg() const { return UseOddSPReg; }
    223   bool noOddSPReg() const { return !UseOddSPReg; }
    224   bool isNaN2008() const { return IsNaN2008bit; }
    225   bool isGP64bit() const { return IsGP64bit; }
    226   bool isGP32bit() const { return !IsGP64bit; }
    227   unsigned getGPRSizeInBytes() const { return isGP64bit() ? 8 : 4; }
    228   bool isSingleFloat() const { return IsSingleFloat; }
    229   bool hasVFPU() const { return HasVFPU; }
    230   bool inMips16Mode() const { return InMips16Mode; }
    231   bool inMips16ModeDefault() const {
    232     return InMips16Mode;
    233   }
    234   // Hard float for mips16 means essentially to compile as soft float
    235   // but to use a runtime library for soft float that is written with
    236   // native mips32 floating point instructions (those runtime routines
    237   // run in mips32 hard float mode).
    238   bool inMips16HardFloat() const {
    239     return inMips16Mode() && InMips16HardFloat;
    240   }
    241   bool inMicroMipsMode() const { return InMicroMipsMode; }
    242   bool inMicroMips32r6Mode() const { return InMicroMipsMode && hasMips32r6(); }
    243   bool inMicroMips64r6Mode() const { return InMicroMipsMode && hasMips64r6(); }
    244   bool hasDSP() const { return HasDSP; }
    245   bool hasDSPR2() const { return HasDSPR2; }
    246   bool hasDSPR3() const { return HasDSPR3; }
    247   bool hasMSA() const { return HasMSA; }
    248   bool hasEVA() const { return HasEVA; }
    249   bool useSmallSection() const { return UseSmallSection; }
    250 
    251   bool hasStandardEncoding() const { return !inMips16Mode(); }
    252 
    253   bool useSoftFloat() const { return IsSoftFloat; }
    254 
    255   bool enableLongBranchPass() const {
    256     return hasStandardEncoding() || allowMixed16_32();
    257   }
    258 
    259   /// Features related to the presence of specific instructions.
    260   bool hasExtractInsert() const { return !inMips16Mode() && hasMips32r2(); }
    261   bool hasMTHC1() const { return hasMips32r2(); }
    262 
    263   bool allowMixed16_32() const { return inMips16ModeDefault() |
    264                                         AllowMixed16_32; }
    265 
    266   bool os16() const { return Os16; }
    267 
    268   bool isTargetNaCl() const { return TargetTriple.isOSNaCl(); }
    269 
    270   // for now constant islands are on for the whole compilation unit but we only
    271   // really use them if in addition we are in mips16 mode
    272   static bool useConstantIslands();
    273 
    274   unsigned stackAlignment() const { return hasMips64() ? 16 : 8; }
    275 
    276   // Grab relocation model
    277   Reloc::Model getRelocationModel() const;
    278 
    279   MipsSubtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS,
    280                                                  const TargetMachine &TM);
    281 
    282   /// Does the system support unaligned memory access.
    283   ///
    284   /// MIPS32r6/MIPS64r6 require full unaligned access support but does not
    285   /// specify which component of the system provides it. Hardware, software, and
    286   /// hybrid implementations are all valid.
    287   bool systemSupportsUnalignedAccess() const { return hasMips32r6(); }
    288 
    289   // Set helper classes
    290   void setHelperClassesMips16();
    291   void setHelperClassesMipsSE();
    292 
    293   const TargetSelectionDAGInfo *getSelectionDAGInfo() const override {
    294     return &TSInfo;
    295   }
    296   const MipsInstrInfo *getInstrInfo() const override { return InstrInfo.get(); }
    297   const TargetFrameLowering *getFrameLowering() const override {
    298     return FrameLowering.get();
    299   }
    300   const MipsRegisterInfo *getRegisterInfo() const override {
    301     return &InstrInfo->getRegisterInfo();
    302   }
    303   const MipsTargetLowering *getTargetLowering() const override {
    304     return TLInfo.get();
    305   }
    306   const InstrItineraryData *getInstrItineraryData() const override {
    307     return &InstrItins;
    308   }
    309 };
    310 } // End llvm namespace
    311 
    312 #endif
    313