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      1 //===-- X86Subtarget.h - Define Subtarget for the X86 ----------*- 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 X86 specific subclass of TargetSubtargetInfo.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_LIB_TARGET_X86_X86SUBTARGET_H
     15 #define LLVM_LIB_TARGET_X86_X86SUBTARGET_H
     16 
     17 #include "X86FrameLowering.h"
     18 #include "X86ISelLowering.h"
     19 #include "X86InstrInfo.h"
     20 #include "X86SelectionDAGInfo.h"
     21 #include "llvm/ADT/Triple.h"
     22 #include "llvm/IR/CallingConv.h"
     23 #include "llvm/Target/TargetSubtargetInfo.h"
     24 #include <string>
     25 
     26 #define GET_SUBTARGETINFO_HEADER
     27 #include "X86GenSubtargetInfo.inc"
     28 
     29 namespace llvm {
     30 class GlobalValue;
     31 class StringRef;
     32 class TargetMachine;
     33 
     34 /// The X86 backend supports a number of different styles of PIC.
     35 ///
     36 namespace PICStyles {
     37 enum Style {
     38   StubPIC,          // Used on i386-darwin in pic mode.
     39   GOT,              // Used on 32 bit elf on when in pic mode.
     40   RIPRel,           // Used on X86-64 when in pic mode.
     41   None              // Set when not in pic mode.
     42 };
     43 }
     44 
     45 class X86Subtarget final : public X86GenSubtargetInfo {
     46 
     47 protected:
     48   enum X86SSEEnum {
     49     NoSSE, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, AVX, AVX2, AVX512F
     50   };
     51 
     52   enum X863DNowEnum {
     53     NoThreeDNow, MMX, ThreeDNow, ThreeDNowA
     54   };
     55 
     56   enum X86ProcFamilyEnum {
     57     Others, IntelAtom, IntelSLM
     58   };
     59 
     60   /// X86 processor family: Intel Atom, and others
     61   X86ProcFamilyEnum X86ProcFamily;
     62 
     63   /// Which PIC style to use
     64   PICStyles::Style PICStyle;
     65 
     66   const TargetMachine &TM;
     67 
     68   /// SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, or none supported.
     69   X86SSEEnum X86SSELevel;
     70 
     71   /// MMX, 3DNow, 3DNow Athlon, or none supported.
     72   X863DNowEnum X863DNowLevel;
     73 
     74   /// True if the processor supports X87 instructions.
     75   bool HasX87;
     76 
     77   /// True if this processor has conditional move instructions
     78   /// (generally pentium pro+).
     79   bool HasCMov;
     80 
     81   /// True if the processor supports X86-64 instructions.
     82   bool HasX86_64;
     83 
     84   /// True if the processor supports POPCNT.
     85   bool HasPOPCNT;
     86 
     87   /// True if the processor supports SSE4A instructions.
     88   bool HasSSE4A;
     89 
     90   /// Target has AES instructions
     91   bool HasAES;
     92 
     93   /// Target has FXSAVE/FXRESTOR instructions
     94   bool HasFXSR;
     95 
     96   /// Target has XSAVE instructions
     97   bool HasXSAVE;
     98   /// Target has XSAVEOPT instructions
     99   bool HasXSAVEOPT;
    100   /// Target has XSAVEC instructions
    101   bool HasXSAVEC;
    102   /// Target has XSAVES instructions
    103   bool HasXSAVES;
    104 
    105   /// Target has carry-less multiplication
    106   bool HasPCLMUL;
    107 
    108   /// Target has 3-operand fused multiply-add
    109   bool HasFMA;
    110 
    111   /// Target has 4-operand fused multiply-add
    112   bool HasFMA4;
    113 
    114   /// Target has XOP instructions
    115   bool HasXOP;
    116 
    117   /// Target has TBM instructions.
    118   bool HasTBM;
    119 
    120   /// True if the processor has the MOVBE instruction.
    121   bool HasMOVBE;
    122 
    123   /// True if the processor has the RDRAND instruction.
    124   bool HasRDRAND;
    125 
    126   /// Processor has 16-bit floating point conversion instructions.
    127   bool HasF16C;
    128 
    129   /// Processor has FS/GS base insturctions.
    130   bool HasFSGSBase;
    131 
    132   /// Processor has LZCNT instruction.
    133   bool HasLZCNT;
    134 
    135   /// Processor has BMI1 instructions.
    136   bool HasBMI;
    137 
    138   /// Processor has BMI2 instructions.
    139   bool HasBMI2;
    140 
    141   /// Processor has VBMI instructions.
    142   bool HasVBMI;
    143 
    144   /// Processor has Integer Fused Multiply Add
    145   bool HasIFMA;
    146 
    147   /// Processor has RTM instructions.
    148   bool HasRTM;
    149 
    150   /// Processor has HLE.
    151   bool HasHLE;
    152 
    153   /// Processor has ADX instructions.
    154   bool HasADX;
    155 
    156   /// Processor has SHA instructions.
    157   bool HasSHA;
    158 
    159   /// Processor has PRFCHW instructions.
    160   bool HasPRFCHW;
    161 
    162   /// Processor has RDSEED instructions.
    163   bool HasRDSEED;
    164 
    165   /// Processor has LAHF/SAHF instructions.
    166   bool HasLAHFSAHF;
    167 
    168   /// Processor has MONITORX/MWAITX instructions.
    169   bool HasMWAITX;
    170 
    171   /// Processor has Prefetch with intent to Write instruction
    172   bool HasPFPREFETCHWT1;
    173 
    174   /// True if BT (bit test) of memory instructions are slow.
    175   bool IsBTMemSlow;
    176 
    177   /// True if SHLD instructions are slow.
    178   bool IsSHLDSlow;
    179 
    180   /// True if unaligned memory accesses of 16-bytes are slow.
    181   bool IsUAMem16Slow;
    182 
    183   /// True if unaligned memory accesses of 32-bytes are slow.
    184   bool IsUAMem32Slow;
    185 
    186   /// True if SSE operations can have unaligned memory operands.
    187   /// This may require setting a configuration bit in the processor.
    188   bool HasSSEUnalignedMem;
    189 
    190   /// True if this processor has the CMPXCHG16B instruction;
    191   /// this is true for most x86-64 chips, but not the first AMD chips.
    192   bool HasCmpxchg16b;
    193 
    194   /// True if the LEA instruction should be used for adjusting
    195   /// the stack pointer. This is an optimization for Intel Atom processors.
    196   bool UseLeaForSP;
    197 
    198   /// True if there is no performance penalty to writing only the lower parts
    199   /// of a YMM register without clearing the upper part.
    200   bool HasFastPartialYMMWrite;
    201 
    202   /// True if 8-bit divisions are significantly faster than
    203   /// 32-bit divisions and should be used when possible.
    204   bool HasSlowDivide32;
    205 
    206   /// True if 16-bit divides are significantly faster than
    207   /// 64-bit divisions and should be used when possible.
    208   bool HasSlowDivide64;
    209 
    210   /// True if the short functions should be padded to prevent
    211   /// a stall when returning too early.
    212   bool PadShortFunctions;
    213 
    214   /// True if the Calls with memory reference should be converted
    215   /// to a register-based indirect call.
    216   bool CallRegIndirect;
    217 
    218   /// True if the LEA instruction inputs have to be ready at address generation
    219   /// (AG) time.
    220   bool LEAUsesAG;
    221 
    222   /// True if the LEA instruction with certain arguments is slow
    223   bool SlowLEA;
    224 
    225   /// True if INC and DEC instructions are slow when writing to flags
    226   bool SlowIncDec;
    227 
    228   /// Processor has AVX-512 PreFetch Instructions
    229   bool HasPFI;
    230 
    231   /// Processor has AVX-512 Exponential and Reciprocal Instructions
    232   bool HasERI;
    233 
    234   /// Processor has AVX-512 Conflict Detection Instructions
    235   bool HasCDI;
    236 
    237   /// Processor has AVX-512 Doubleword and Quadword instructions
    238   bool HasDQI;
    239 
    240   /// Processor has AVX-512 Byte and Word instructions
    241   bool HasBWI;
    242 
    243   /// Processor has AVX-512 Vector Length eXtenstions
    244   bool HasVLX;
    245 
    246   /// Processor has PKU extenstions
    247   bool HasPKU;
    248 
    249   /// Processor supports MPX - Memory Protection Extensions
    250   bool HasMPX;
    251 
    252   /// Processor supports Invalidate Process-Context Identifier
    253   bool HasInvPCId;
    254 
    255   /// Processor has VM Functions
    256   bool HasVMFUNC;
    257 
    258   /// Processor has Supervisor Mode Access Protection
    259   bool HasSMAP;
    260 
    261   /// Processor has Software Guard Extensions
    262   bool HasSGX;
    263 
    264   /// Processor supports Flush Cache Line instruction
    265   bool HasCLFLUSHOPT;
    266 
    267   /// Processor has Persistent Commit feature
    268   bool HasPCOMMIT;
    269 
    270   /// Processor supports Cache Line Write Back instruction
    271   bool HasCLWB;
    272 
    273   /// Use software floating point for code generation.
    274   bool UseSoftFloat;
    275 
    276   /// The minimum alignment known to hold of the stack frame on
    277   /// entry to the function and which must be maintained by every function.
    278   unsigned stackAlignment;
    279 
    280   /// Max. memset / memcpy size that is turned into rep/movs, rep/stos ops.
    281   ///
    282   unsigned MaxInlineSizeThreshold;
    283 
    284   /// What processor and OS we're targeting.
    285   Triple TargetTriple;
    286 
    287   /// Instruction itineraries for scheduling
    288   InstrItineraryData InstrItins;
    289 
    290 private:
    291 
    292   /// Override the stack alignment.
    293   unsigned StackAlignOverride;
    294 
    295   /// True if compiling for 64-bit, false for 16-bit or 32-bit.
    296   bool In64BitMode;
    297 
    298   /// True if compiling for 32-bit, false for 16-bit or 64-bit.
    299   bool In32BitMode;
    300 
    301   /// True if compiling for 16-bit, false for 32-bit or 64-bit.
    302   bool In16BitMode;
    303 
    304   X86SelectionDAGInfo TSInfo;
    305   // Ordering here is important. X86InstrInfo initializes X86RegisterInfo which
    306   // X86TargetLowering needs.
    307   X86InstrInfo InstrInfo;
    308   X86TargetLowering TLInfo;
    309   X86FrameLowering FrameLowering;
    310 
    311 public:
    312   /// This constructor initializes the data members to match that
    313   /// of the specified triple.
    314   ///
    315   X86Subtarget(const Triple &TT, StringRef CPU, StringRef FS,
    316                const X86TargetMachine &TM, unsigned StackAlignOverride);
    317 
    318   const X86TargetLowering *getTargetLowering() const override {
    319     return &TLInfo;
    320   }
    321   const X86InstrInfo *getInstrInfo() const override { return &InstrInfo; }
    322   const X86FrameLowering *getFrameLowering() const override {
    323     return &FrameLowering;
    324   }
    325   const X86SelectionDAGInfo *getSelectionDAGInfo() const override {
    326     return &TSInfo;
    327   }
    328   const X86RegisterInfo *getRegisterInfo() const override {
    329     return &getInstrInfo()->getRegisterInfo();
    330   }
    331 
    332   /// Returns the minimum alignment known to hold of the
    333   /// stack frame on entry to the function and which must be maintained by every
    334   /// function for this subtarget.
    335   unsigned getStackAlignment() const { return stackAlignment; }
    336 
    337   /// Returns the maximum memset / memcpy size
    338   /// that still makes it profitable to inline the call.
    339   unsigned getMaxInlineSizeThreshold() const { return MaxInlineSizeThreshold; }
    340 
    341   /// ParseSubtargetFeatures - Parses features string setting specified
    342   /// subtarget options.  Definition of function is auto generated by tblgen.
    343   void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
    344 
    345 private:
    346   /// Initialize the full set of dependencies so we can use an initializer
    347   /// list for X86Subtarget.
    348   X86Subtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS);
    349   void initializeEnvironment();
    350   void initSubtargetFeatures(StringRef CPU, StringRef FS);
    351 public:
    352   /// Is this x86_64? (disregarding specific ABI / programming model)
    353   bool is64Bit() const {
    354     return In64BitMode;
    355   }
    356 
    357   bool is32Bit() const {
    358     return In32BitMode;
    359   }
    360 
    361   bool is16Bit() const {
    362     return In16BitMode;
    363   }
    364 
    365   /// Is this x86_64 with the ILP32 programming model (x32 ABI)?
    366   bool isTarget64BitILP32() const {
    367     return In64BitMode && (TargetTriple.getEnvironment() == Triple::GNUX32 ||
    368                            TargetTriple.isOSNaCl());
    369   }
    370 
    371   /// Is this x86_64 with the LP64 programming model (standard AMD64, no x32)?
    372   bool isTarget64BitLP64() const {
    373     return In64BitMode && (TargetTriple.getEnvironment() != Triple::GNUX32 &&
    374                            !TargetTriple.isOSNaCl());
    375   }
    376 
    377   PICStyles::Style getPICStyle() const { return PICStyle; }
    378   void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
    379 
    380   bool hasX87() const { return HasX87; }
    381   bool hasCMov() const { return HasCMov; }
    382   bool hasSSE1() const { return X86SSELevel >= SSE1; }
    383   bool hasSSE2() const { return X86SSELevel >= SSE2; }
    384   bool hasSSE3() const { return X86SSELevel >= SSE3; }
    385   bool hasSSSE3() const { return X86SSELevel >= SSSE3; }
    386   bool hasSSE41() const { return X86SSELevel >= SSE41; }
    387   bool hasSSE42() const { return X86SSELevel >= SSE42; }
    388   bool hasAVX() const { return X86SSELevel >= AVX; }
    389   bool hasAVX2() const { return X86SSELevel >= AVX2; }
    390   bool hasAVX512() const { return X86SSELevel >= AVX512F; }
    391   bool hasFp256() const { return hasAVX(); }
    392   bool hasInt256() const { return hasAVX2(); }
    393   bool hasSSE4A() const { return HasSSE4A; }
    394   bool hasMMX() const { return X863DNowLevel >= MMX; }
    395   bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
    396   bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
    397   bool hasPOPCNT() const { return HasPOPCNT; }
    398   bool hasAES() const { return HasAES; }
    399   bool hasFXSR() const { return HasFXSR; }
    400   bool hasXSAVE() const { return HasXSAVE; }
    401   bool hasXSAVEOPT() const { return HasXSAVEOPT; }
    402   bool hasXSAVEC() const { return HasXSAVEC; }
    403   bool hasXSAVES() const { return HasXSAVES; }
    404   bool hasPCLMUL() const { return HasPCLMUL; }
    405   // Prefer FMA4 to FMA - its better for commutation/memory folding and
    406   // has equal or better performance on all supported targets.
    407   bool hasFMA() const { return HasFMA && !HasFMA4; }
    408   bool hasFMA4() const { return HasFMA4; }
    409   bool hasAnyFMA() const { return hasFMA() || hasFMA4() || hasAVX512(); }
    410   bool hasXOP() const { return HasXOP; }
    411   bool hasTBM() const { return HasTBM; }
    412   bool hasMOVBE() const { return HasMOVBE; }
    413   bool hasRDRAND() const { return HasRDRAND; }
    414   bool hasF16C() const { return HasF16C; }
    415   bool hasFSGSBase() const { return HasFSGSBase; }
    416   bool hasLZCNT() const { return HasLZCNT; }
    417   bool hasBMI() const { return HasBMI; }
    418   bool hasBMI2() const { return HasBMI2; }
    419   bool hasVBMI() const { return HasVBMI; }
    420   bool hasIFMA() const { return HasIFMA; }
    421   bool hasRTM() const { return HasRTM; }
    422   bool hasHLE() const { return HasHLE; }
    423   bool hasADX() const { return HasADX; }
    424   bool hasSHA() const { return HasSHA; }
    425   bool hasPRFCHW() const { return HasPRFCHW; }
    426   bool hasRDSEED() const { return HasRDSEED; }
    427   bool hasLAHFSAHF() const { return HasLAHFSAHF; }
    428   bool hasMWAITX() const { return HasMWAITX; }
    429   bool isBTMemSlow() const { return IsBTMemSlow; }
    430   bool isSHLDSlow() const { return IsSHLDSlow; }
    431   bool isUnalignedMem16Slow() const { return IsUAMem16Slow; }
    432   bool isUnalignedMem32Slow() const { return IsUAMem32Slow; }
    433   bool hasSSEUnalignedMem() const { return HasSSEUnalignedMem; }
    434   bool hasCmpxchg16b() const { return HasCmpxchg16b; }
    435   bool useLeaForSP() const { return UseLeaForSP; }
    436   bool hasFastPartialYMMWrite() const { return HasFastPartialYMMWrite; }
    437   bool hasSlowDivide32() const { return HasSlowDivide32; }
    438   bool hasSlowDivide64() const { return HasSlowDivide64; }
    439   bool padShortFunctions() const { return PadShortFunctions; }
    440   bool callRegIndirect() const { return CallRegIndirect; }
    441   bool LEAusesAG() const { return LEAUsesAG; }
    442   bool slowLEA() const { return SlowLEA; }
    443   bool slowIncDec() const { return SlowIncDec; }
    444   bool hasCDI() const { return HasCDI; }
    445   bool hasPFI() const { return HasPFI; }
    446   bool hasERI() const { return HasERI; }
    447   bool hasDQI() const { return HasDQI; }
    448   bool hasBWI() const { return HasBWI; }
    449   bool hasVLX() const { return HasVLX; }
    450   bool hasPKU() const { return HasPKU; }
    451   bool hasMPX() const { return HasMPX; }
    452 
    453   bool isAtom() const { return X86ProcFamily == IntelAtom; }
    454   bool isSLM() const { return X86ProcFamily == IntelSLM; }
    455   bool useSoftFloat() const { return UseSoftFloat; }
    456 
    457   /// Use mfence if we have SSE2 or we're on x86-64 (even if we asked for
    458   /// no-sse2). There isn't any reason to disable it if the target processor
    459   /// supports it.
    460   bool hasMFence() const { return hasSSE2() || is64Bit(); }
    461 
    462   const Triple &getTargetTriple() const { return TargetTriple; }
    463 
    464   bool isTargetDarwin() const { return TargetTriple.isOSDarwin(); }
    465   bool isTargetFreeBSD() const { return TargetTriple.isOSFreeBSD(); }
    466   bool isTargetDragonFly() const { return TargetTriple.isOSDragonFly(); }
    467   bool isTargetSolaris() const { return TargetTriple.isOSSolaris(); }
    468   bool isTargetPS4() const { return TargetTriple.isPS4(); }
    469 
    470   bool isTargetELF() const { return TargetTriple.isOSBinFormatELF(); }
    471   bool isTargetCOFF() const { return TargetTriple.isOSBinFormatCOFF(); }
    472   bool isTargetMachO() const { return TargetTriple.isOSBinFormatMachO(); }
    473 
    474   bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
    475   bool isTargetKFreeBSD() const { return TargetTriple.isOSKFreeBSD(); }
    476   bool isTargetGlibc() const { return TargetTriple.isOSGlibc(); }
    477   bool isTargetAndroid() const { return TargetTriple.isAndroid(); }
    478   bool isTargetNaCl() const { return TargetTriple.isOSNaCl(); }
    479   bool isTargetNaCl32() const { return isTargetNaCl() && !is64Bit(); }
    480   bool isTargetNaCl64() const { return isTargetNaCl() && is64Bit(); }
    481   bool isTargetMCU() const { return TargetTriple.isOSIAMCU(); }
    482 
    483   bool isTargetWindowsMSVC() const {
    484     return TargetTriple.isWindowsMSVCEnvironment();
    485   }
    486 
    487   bool isTargetKnownWindowsMSVC() const {
    488     return TargetTriple.isKnownWindowsMSVCEnvironment();
    489   }
    490 
    491   bool isTargetWindowsCoreCLR() const {
    492     return TargetTriple.isWindowsCoreCLREnvironment();
    493   }
    494 
    495   bool isTargetWindowsCygwin() const {
    496     return TargetTriple.isWindowsCygwinEnvironment();
    497   }
    498 
    499   bool isTargetWindowsGNU() const {
    500     return TargetTriple.isWindowsGNUEnvironment();
    501   }
    502 
    503   bool isTargetWindowsItanium() const {
    504     return TargetTriple.isWindowsItaniumEnvironment();
    505   }
    506 
    507   bool isTargetCygMing() const { return TargetTriple.isOSCygMing(); }
    508 
    509   bool isOSWindows() const { return TargetTriple.isOSWindows(); }
    510 
    511   bool isTargetWin64() const {
    512     return In64BitMode && TargetTriple.isOSWindows();
    513   }
    514 
    515   bool isTargetWin32() const {
    516     return !In64BitMode && (isTargetCygMing() || isTargetKnownWindowsMSVC());
    517   }
    518 
    519   bool isPICStyleGOT() const { return PICStyle == PICStyles::GOT; }
    520   bool isPICStyleRIPRel() const { return PICStyle == PICStyles::RIPRel; }
    521 
    522   bool isPICStyleStubPIC() const {
    523     return PICStyle == PICStyles::StubPIC;
    524   }
    525 
    526   bool isPositionIndependent() const { return TM.isPositionIndependent(); }
    527 
    528   bool isCallingConvWin64(CallingConv::ID CC) const {
    529     switch (CC) {
    530     // On Win64, all these conventions just use the default convention.
    531     case CallingConv::C:
    532     case CallingConv::Fast:
    533     case CallingConv::X86_FastCall:
    534     case CallingConv::X86_StdCall:
    535     case CallingConv::X86_ThisCall:
    536     case CallingConv::X86_VectorCall:
    537     case CallingConv::Intel_OCL_BI:
    538       return isTargetWin64();
    539     // This convention allows using the Win64 convention on other targets.
    540     case CallingConv::X86_64_Win64:
    541       return true;
    542     // This convention allows using the SysV convention on Windows targets.
    543     case CallingConv::X86_64_SysV:
    544       return false;
    545     // Otherwise, who knows what this is.
    546     default:
    547       return false;
    548     }
    549   }
    550 
    551   /// Classify a global variable reference for the current subtarget according
    552   /// to how we should reference it in a non-pcrel context.
    553   unsigned char classifyLocalReference(const GlobalValue *GV) const;
    554 
    555   unsigned char classifyGlobalReference(const GlobalValue *GV,
    556                                         const Module &M) const;
    557   unsigned char classifyGlobalReference(const GlobalValue *GV) const;
    558 
    559   /// Classify a global function reference for the current subtarget.
    560   unsigned char classifyGlobalFunctionReference(const GlobalValue *GV,
    561                                                 const Module &M) const;
    562   unsigned char classifyGlobalFunctionReference(const GlobalValue *GV) const;
    563 
    564   /// Classify a blockaddress reference for the current subtarget according to
    565   /// how we should reference it in a non-pcrel context.
    566   unsigned char classifyBlockAddressReference() const;
    567 
    568   /// Return true if the subtarget allows calls to immediate address.
    569   bool isLegalToCallImmediateAddr() const;
    570 
    571   /// This function returns the name of a function which has an interface
    572   /// like the non-standard bzero function, if such a function exists on
    573   /// the current subtarget and it is considered prefereable over
    574   /// memset with zero passed as the second argument. Otherwise it
    575   /// returns null.
    576   const char *getBZeroEntry() const;
    577 
    578   /// This function returns true if the target has sincos() routine in its
    579   /// compiler runtime or math libraries.
    580   bool hasSinCos() const;
    581 
    582   /// Enable the MachineScheduler pass for all X86 subtargets.
    583   bool enableMachineScheduler() const override { return true; }
    584 
    585   bool enableEarlyIfConversion() const override;
    586 
    587   /// Return the instruction itineraries based on the subtarget selection.
    588   const InstrItineraryData *getInstrItineraryData() const override {
    589     return &InstrItins;
    590   }
    591 
    592   AntiDepBreakMode getAntiDepBreakMode() const override {
    593     return TargetSubtargetInfo::ANTIDEP_CRITICAL;
    594   }
    595 };
    596 
    597 } // End llvm namespace
    598 
    599 #endif
    600