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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 X86SUBTARGET_H
     15 #define X86SUBTARGET_H
     16 
     17 #include "llvm/ADT/Triple.h"
     18 #include "llvm/IR/CallingConv.h"
     19 #include "llvm/Target/TargetSubtargetInfo.h"
     20 #include <string>
     21 
     22 #define GET_SUBTARGETINFO_HEADER
     23 #include "X86GenSubtargetInfo.inc"
     24 
     25 namespace llvm {
     26 class GlobalValue;
     27 class StringRef;
     28 class TargetMachine;
     29 
     30 /// PICStyles - The X86 backend supports a number of different styles of PIC.
     31 ///
     32 namespace PICStyles {
     33 enum Style {
     34   StubPIC,          // Used on i386-darwin in -fPIC mode.
     35   StubDynamicNoPIC, // Used on i386-darwin in -mdynamic-no-pic mode.
     36   GOT,              // Used on many 32-bit unices in -fPIC mode.
     37   RIPRel,           // Used on X86-64 when not in -static mode.
     38   None              // Set when in -static mode (not PIC or DynamicNoPIC mode).
     39 };
     40 }
     41 
     42 class X86Subtarget : public X86GenSubtargetInfo {
     43 protected:
     44   enum X86SSEEnum {
     45     NoMMXSSE, MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, AVX, AVX2
     46   };
     47 
     48   enum X863DNowEnum {
     49     NoThreeDNow, ThreeDNow, ThreeDNowA
     50   };
     51 
     52   enum X86ProcFamilyEnum {
     53     Others, IntelAtom
     54   };
     55 
     56   /// X86ProcFamily - X86 processor family: Intel Atom, and others
     57   X86ProcFamilyEnum X86ProcFamily;
     58 
     59   /// PICStyle - Which PIC style to use
     60   ///
     61   PICStyles::Style PICStyle;
     62 
     63   /// X86SSELevel - MMX, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, or
     64   /// none supported.
     65   X86SSEEnum X86SSELevel;
     66 
     67   /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.
     68   ///
     69   X863DNowEnum X863DNowLevel;
     70 
     71   /// HasCMov - True if this processor has conditional move instructions
     72   /// (generally pentium pro+).
     73   bool HasCMov;
     74 
     75   /// HasX86_64 - True if the processor supports X86-64 instructions.
     76   ///
     77   bool HasX86_64;
     78 
     79   /// HasPOPCNT - True if the processor supports POPCNT.
     80   bool HasPOPCNT;
     81 
     82   /// HasSSE4A - True if the processor supports SSE4A instructions.
     83   bool HasSSE4A;
     84 
     85   /// HasAES - Target has AES instructions
     86   bool HasAES;
     87 
     88   /// HasPCLMUL - Target has carry-less multiplication
     89   bool HasPCLMUL;
     90 
     91   /// HasFMA - Target has 3-operand fused multiply-add
     92   bool HasFMA;
     93 
     94   /// HasFMA4 - Target has 4-operand fused multiply-add
     95   bool HasFMA4;
     96 
     97   /// HasXOP - Target has XOP instructions
     98   bool HasXOP;
     99 
    100   /// HasMOVBE - True if the processor has the MOVBE instruction.
    101   bool HasMOVBE;
    102 
    103   /// HasRDRAND - True if the processor has the RDRAND instruction.
    104   bool HasRDRAND;
    105 
    106   /// HasF16C - Processor has 16-bit floating point conversion instructions.
    107   bool HasF16C;
    108 
    109   /// HasFSGSBase - Processor has FS/GS base insturctions.
    110   bool HasFSGSBase;
    111 
    112   /// HasLZCNT - Processor has LZCNT instruction.
    113   bool HasLZCNT;
    114 
    115   /// HasBMI - Processor has BMI1 instructions.
    116   bool HasBMI;
    117 
    118   /// HasBMI2 - Processor has BMI2 instructions.
    119   bool HasBMI2;
    120 
    121   /// HasRTM - Processor has RTM instructions.
    122   bool HasRTM;
    123 
    124   /// HasADX - Processor has ADX instructions.
    125   bool HasADX;
    126 
    127   /// IsBTMemSlow - True if BT (bit test) of memory instructions are slow.
    128   bool IsBTMemSlow;
    129 
    130   /// IsUAMemFast - True if unaligned memory access is fast.
    131   bool IsUAMemFast;
    132 
    133   /// HasVectorUAMem - True if SIMD operations can have unaligned memory
    134   /// operands. This may require setting a feature bit in the processor.
    135   bool HasVectorUAMem;
    136 
    137   /// HasCmpxchg16b - True if this processor has the CMPXCHG16B instruction;
    138   /// this is true for most x86-64 chips, but not the first AMD chips.
    139   bool HasCmpxchg16b;
    140 
    141   /// UseLeaForSP - True if the LEA instruction should be used for adjusting
    142   /// the stack pointer. This is an optimization for Intel Atom processors.
    143   bool UseLeaForSP;
    144 
    145   /// HasSlowDivide - True if smaller divides are significantly faster than
    146   /// full divides and should be used when possible.
    147   bool HasSlowDivide;
    148 
    149   /// PostRAScheduler - True if using post-register-allocation scheduler.
    150   bool PostRAScheduler;
    151 
    152   /// PadShortFunctions - True if the short functions should be padded to prevent
    153   /// a stall when returning too early.
    154   bool PadShortFunctions;
    155 
    156   /// stackAlignment - The minimum alignment known to hold of the stack frame on
    157   /// entry to the function and which must be maintained by every function.
    158   unsigned stackAlignment;
    159 
    160   /// Max. memset / memcpy size that is turned into rep/movs, rep/stos ops.
    161   ///
    162   unsigned MaxInlineSizeThreshold;
    163 
    164   /// TargetTriple - What processor and OS we're targeting.
    165   Triple TargetTriple;
    166 
    167   /// Instruction itineraries for scheduling
    168   InstrItineraryData InstrItins;
    169 
    170 private:
    171   /// StackAlignOverride - Override the stack alignment.
    172   unsigned StackAlignOverride;
    173 
    174   /// In64BitMode - True if compiling for 64-bit, false for 32-bit.
    175   bool In64BitMode;
    176 
    177 public:
    178   /// This constructor initializes the data members to match that
    179   /// of the specified triple.
    180   ///
    181   X86Subtarget(const std::string &TT, const std::string &CPU,
    182                const std::string &FS,
    183                unsigned StackAlignOverride, bool is64Bit);
    184 
    185   /// getStackAlignment - Returns the minimum alignment known to hold of the
    186   /// stack frame on entry to the function and which must be maintained by every
    187   /// function for this subtarget.
    188   unsigned getStackAlignment() const { return stackAlignment; }
    189 
    190   /// getMaxInlineSizeThreshold - Returns the maximum memset / memcpy size
    191   /// that still makes it profitable to inline the call.
    192   unsigned getMaxInlineSizeThreshold() const { return MaxInlineSizeThreshold; }
    193 
    194   /// ParseSubtargetFeatures - Parses features string setting specified
    195   /// subtarget options.  Definition of function is auto generated by tblgen.
    196   void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
    197 
    198   /// AutoDetectSubtargetFeatures - Auto-detect CPU features using CPUID
    199   /// instruction.
    200   void AutoDetectSubtargetFeatures();
    201 
    202   /// \brief Reset the features for the X86 target.
    203   virtual void resetSubtargetFeatures(const MachineFunction *MF);
    204 private:
    205   void initializeEnvironment();
    206   void resetSubtargetFeatures(StringRef CPU, StringRef FS);
    207 public:
    208   /// Is this x86_64? (disregarding specific ABI / programming model)
    209   bool is64Bit() const {
    210     return In64BitMode;
    211   }
    212 
    213   /// Is this x86_64 with the ILP32 programming model (x32 ABI)?
    214   bool isTarget64BitILP32() const {
    215     return In64BitMode && (TargetTriple.getEnvironment() == Triple::GNUX32);
    216   }
    217 
    218   /// Is this x86_64 with the LP64 programming model (standard AMD64, no x32)?
    219   bool isTarget64BitLP64() const {
    220     return In64BitMode && (TargetTriple.getEnvironment() != Triple::GNUX32);
    221   }
    222 
    223   PICStyles::Style getPICStyle() const { return PICStyle; }
    224   void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
    225 
    226   bool hasCMov() const { return HasCMov; }
    227   bool hasMMX() const { return X86SSELevel >= MMX; }
    228   bool hasSSE1() const { return X86SSELevel >= SSE1; }
    229   bool hasSSE2() const { return X86SSELevel >= SSE2; }
    230   bool hasSSE3() const { return X86SSELevel >= SSE3; }
    231   bool hasSSSE3() const { return X86SSELevel >= SSSE3; }
    232   bool hasSSE41() const { return X86SSELevel >= SSE41; }
    233   bool hasSSE42() const { return X86SSELevel >= SSE42; }
    234   bool hasAVX() const { return X86SSELevel >= AVX; }
    235   bool hasAVX2() const { return X86SSELevel >= AVX2; }
    236   bool hasFp256() const { return hasAVX(); }
    237   bool hasInt256() const { return hasAVX2(); }
    238   bool hasSSE4A() const { return HasSSE4A; }
    239   bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
    240   bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
    241   bool hasPOPCNT() const { return HasPOPCNT; }
    242   bool hasAES() const { return HasAES; }
    243   bool hasPCLMUL() const { return HasPCLMUL; }
    244   bool hasFMA() const { return HasFMA; }
    245   // FIXME: Favor FMA when both are enabled. Is this the right thing to do?
    246   bool hasFMA4() const { return HasFMA4 && !HasFMA; }
    247   bool hasXOP() const { return HasXOP; }
    248   bool hasMOVBE() const { return HasMOVBE; }
    249   bool hasRDRAND() const { return HasRDRAND; }
    250   bool hasF16C() const { return HasF16C; }
    251   bool hasFSGSBase() const { return HasFSGSBase; }
    252   bool hasLZCNT() const { return HasLZCNT; }
    253   bool hasBMI() const { return HasBMI; }
    254   bool hasBMI2() const { return HasBMI2; }
    255   bool hasRTM() const { return HasRTM; }
    256   bool hasADX() const { return HasADX; }
    257   bool isBTMemSlow() const { return IsBTMemSlow; }
    258   bool isUnalignedMemAccessFast() const { return IsUAMemFast; }
    259   bool hasVectorUAMem() const { return HasVectorUAMem; }
    260   bool hasCmpxchg16b() const { return HasCmpxchg16b; }
    261   bool useLeaForSP() const { return UseLeaForSP; }
    262   bool hasSlowDivide() const { return HasSlowDivide; }
    263   bool padShortFunctions() const { return PadShortFunctions; }
    264 
    265   bool isAtom() const { return X86ProcFamily == IntelAtom; }
    266 
    267   const Triple &getTargetTriple() const { return TargetTriple; }
    268 
    269   bool isTargetDarwin() const { return TargetTriple.isOSDarwin(); }
    270   bool isTargetFreeBSD() const {
    271     return TargetTriple.getOS() == Triple::FreeBSD;
    272   }
    273   bool isTargetSolaris() const {
    274     return TargetTriple.getOS() == Triple::Solaris;
    275   }
    276   bool isTargetELF() const {
    277     return (TargetTriple.getEnvironment() == Triple::ELF ||
    278             TargetTriple.isOSBinFormatELF());
    279   }
    280   bool isTargetLinux() const { return TargetTriple.getOS() == Triple::Linux; }
    281   bool isTargetNaCl() const {
    282     return TargetTriple.getOS() == Triple::NaCl;
    283   }
    284   bool isTargetNaCl32() const { return isTargetNaCl() && !is64Bit(); }
    285   bool isTargetNaCl64() const { return isTargetNaCl() && is64Bit(); }
    286   bool isTargetWindows() const { return TargetTriple.getOS() == Triple::Win32; }
    287   bool isTargetMingw() const { return TargetTriple.getOS() == Triple::MinGW32; }
    288   bool isTargetCygwin() const { return TargetTriple.getOS() == Triple::Cygwin; }
    289   bool isTargetCygMing() const { return TargetTriple.isOSCygMing(); }
    290   bool isTargetCOFF() const {
    291     return (TargetTriple.getEnvironment() != Triple::ELF &&
    292             TargetTriple.isOSBinFormatCOFF());
    293   }
    294   bool isTargetEnvMacho() const { return TargetTriple.isEnvironmentMachO(); }
    295 
    296   bool isTargetWin64() const {
    297     // FIXME: x86_64-cygwin has not been released yet.
    298     return In64BitMode && TargetTriple.isOSWindows();
    299   }
    300 
    301   bool isTargetWin32() const {
    302     // FIXME: Cygwin is included for isTargetWin64 -- should it be included
    303     // here too?
    304     return !In64BitMode && (isTargetMingw() || isTargetWindows());
    305   }
    306 
    307   bool isPICStyleSet() const { return PICStyle != PICStyles::None; }
    308   bool isPICStyleGOT() const { return PICStyle == PICStyles::GOT; }
    309   bool isPICStyleRIPRel() const { return PICStyle == PICStyles::RIPRel; }
    310 
    311   bool isPICStyleStubPIC() const {
    312     return PICStyle == PICStyles::StubPIC;
    313   }
    314 
    315   bool isPICStyleStubNoDynamic() const {
    316     return PICStyle == PICStyles::StubDynamicNoPIC;
    317   }
    318   bool isPICStyleStubAny() const {
    319     return PICStyle == PICStyles::StubDynamicNoPIC ||
    320            PICStyle == PICStyles::StubPIC; }
    321 
    322   /// ClassifyGlobalReference - Classify a global variable reference for the
    323   /// current subtarget according to how we should reference it in a non-pcrel
    324   /// context.
    325   unsigned char ClassifyGlobalReference(const GlobalValue *GV,
    326                                         const TargetMachine &TM)const;
    327 
    328   /// ClassifyBlockAddressReference - Classify a blockaddress reference for the
    329   /// current subtarget according to how we should reference it in a non-pcrel
    330   /// context.
    331   unsigned char ClassifyBlockAddressReference() const;
    332 
    333   /// IsLegalToCallImmediateAddr - Return true if the subtarget allows calls
    334   /// to immediate address.
    335   bool IsLegalToCallImmediateAddr(const TargetMachine &TM) const;
    336 
    337   /// This function returns the name of a function which has an interface
    338   /// like the non-standard bzero function, if such a function exists on
    339   /// the current subtarget and it is considered prefereable over
    340   /// memset with zero passed as the second argument. Otherwise it
    341   /// returns null.
    342   const char *getBZeroEntry() const;
    343 
    344   /// This function returns true if the target has sincos() routine in its
    345   /// compiler runtime or math libraries.
    346   bool hasSinCos() const;
    347 
    348   /// enablePostRAScheduler - run for Atom optimization.
    349   bool enablePostRAScheduler(CodeGenOpt::Level OptLevel,
    350                              TargetSubtargetInfo::AntiDepBreakMode& Mode,
    351                              RegClassVector& CriticalPathRCs) const;
    352 
    353   bool postRAScheduler() const { return PostRAScheduler; }
    354 
    355   /// getInstrItins = Return the instruction itineraries based on the
    356   /// subtarget selection.
    357   const InstrItineraryData &getInstrItineraryData() const { return InstrItins; }
    358 };
    359 
    360 } // End llvm namespace
    361 
    362 #endif
    363