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      1 //===-- PPCSubtarget.h - Define Subtarget for the PPC ----------*- 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 PowerPC specific subclass of TargetSubtargetInfo.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_LIB_TARGET_POWERPC_PPCSUBTARGET_H
     15 #define LLVM_LIB_TARGET_POWERPC_PPCSUBTARGET_H
     16 
     17 #include "PPCFrameLowering.h"
     18 #include "PPCISelLowering.h"
     19 #include "PPCInstrInfo.h"
     20 #include "llvm/ADT/Triple.h"
     21 #include "llvm/CodeGen/SelectionDAGTargetInfo.h"
     22 #include "llvm/CodeGen/TargetSubtargetInfo.h"
     23 #include "llvm/IR/DataLayout.h"
     24 #include "llvm/MC/MCInstrItineraries.h"
     25 #include <string>
     26 
     27 #define GET_SUBTARGETINFO_HEADER
     28 #include "PPCGenSubtargetInfo.inc"
     29 
     30 // GCC #defines PPC on Linux but we use it as our namespace name
     31 #undef PPC
     32 
     33 namespace llvm {
     34 class StringRef;
     35 
     36 namespace PPC {
     37   // -m directive values.
     38   enum {
     39     DIR_NONE,
     40     DIR_32,
     41     DIR_440,
     42     DIR_601,
     43     DIR_602,
     44     DIR_603,
     45     DIR_7400,
     46     DIR_750,
     47     DIR_970,
     48     DIR_A2,
     49     DIR_E500,
     50     DIR_E500mc,
     51     DIR_E5500,
     52     DIR_PWR3,
     53     DIR_PWR4,
     54     DIR_PWR5,
     55     DIR_PWR5X,
     56     DIR_PWR6,
     57     DIR_PWR6X,
     58     DIR_PWR7,
     59     DIR_PWR8,
     60     DIR_PWR9,
     61     DIR_64
     62   };
     63 }
     64 
     65 class GlobalValue;
     66 class TargetMachine;
     67 
     68 class PPCSubtarget : public PPCGenSubtargetInfo {
     69 public:
     70   enum POPCNTDKind {
     71     POPCNTD_Unavailable,
     72     POPCNTD_Slow,
     73     POPCNTD_Fast
     74   };
     75 
     76 protected:
     77   /// TargetTriple - What processor and OS we're targeting.
     78   Triple TargetTriple;
     79 
     80   /// stackAlignment - The minimum alignment known to hold of the stack frame on
     81   /// entry to the function and which must be maintained by every function.
     82   unsigned StackAlignment;
     83 
     84   /// Selected instruction itineraries (one entry per itinerary class.)
     85   InstrItineraryData InstrItins;
     86 
     87   /// Which cpu directive was used.
     88   unsigned DarwinDirective;
     89 
     90   /// Used by the ISel to turn in optimizations for POWER4-derived architectures
     91   bool HasMFOCRF;
     92   bool Has64BitSupport;
     93   bool Use64BitRegs;
     94   bool UseCRBits;
     95   bool HasHardFloat;
     96   bool IsPPC64;
     97   bool HasAltivec;
     98   bool HasFPU;
     99   bool HasSPE;
    100   bool HasQPX;
    101   bool HasVSX;
    102   bool HasP8Vector;
    103   bool HasP8Altivec;
    104   bool HasP8Crypto;
    105   bool HasP9Vector;
    106   bool HasP9Altivec;
    107   bool HasFCPSGN;
    108   bool HasFSQRT;
    109   bool HasFRE, HasFRES, HasFRSQRTE, HasFRSQRTES;
    110   bool HasRecipPrec;
    111   bool HasSTFIWX;
    112   bool HasLFIWAX;
    113   bool HasFPRND;
    114   bool HasFPCVT;
    115   bool HasISEL;
    116   bool HasBPERMD;
    117   bool HasExtDiv;
    118   bool HasCMPB;
    119   bool HasLDBRX;
    120   bool IsBookE;
    121   bool HasOnlyMSYNC;
    122   bool IsE500;
    123   bool IsPPC4xx;
    124   bool IsPPC6xx;
    125   bool FeatureMFTB;
    126   bool DeprecatedDST;
    127   bool HasLazyResolverStubs;
    128   bool IsLittleEndian;
    129   bool HasICBT;
    130   bool HasInvariantFunctionDescriptors;
    131   bool HasPartwordAtomics;
    132   bool HasDirectMove;
    133   bool HasHTM;
    134   bool HasFusion;
    135   bool HasFloat128;
    136   bool IsISA3_0;
    137   bool UseLongCalls;
    138   bool SecurePlt;
    139 
    140   POPCNTDKind HasPOPCNTD;
    141 
    142   /// When targeting QPX running a stock PPC64 Linux kernel where the stack
    143   /// alignment has not been changed, we need to keep the 16-byte alignment
    144   /// of the stack.
    145   bool IsQPXStackUnaligned;
    146 
    147   const PPCTargetMachine &TM;
    148   PPCFrameLowering FrameLowering;
    149   PPCInstrInfo InstrInfo;
    150   PPCTargetLowering TLInfo;
    151   SelectionDAGTargetInfo TSInfo;
    152 
    153 public:
    154   /// This constructor initializes the data members to match that
    155   /// of the specified triple.
    156   ///
    157   PPCSubtarget(const Triple &TT, const std::string &CPU, const std::string &FS,
    158                const PPCTargetMachine &TM);
    159 
    160   /// ParseSubtargetFeatures - Parses features string setting specified
    161   /// subtarget options.  Definition of function is auto generated by tblgen.
    162   void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
    163 
    164   /// getStackAlignment - Returns the minimum alignment known to hold of the
    165   /// stack frame on entry to the function and which must be maintained by every
    166   /// function for this subtarget.
    167   unsigned getStackAlignment() const { return StackAlignment; }
    168 
    169   /// getDarwinDirective - Returns the -m directive specified for the cpu.
    170   ///
    171   unsigned getDarwinDirective() const { return DarwinDirective; }
    172 
    173   /// getInstrItins - Return the instruction itineraries based on subtarget
    174   /// selection.
    175   const InstrItineraryData *getInstrItineraryData() const override {
    176     return &InstrItins;
    177   }
    178 
    179   const PPCFrameLowering *getFrameLowering() const override {
    180     return &FrameLowering;
    181   }
    182   const PPCInstrInfo *getInstrInfo() const override { return &InstrInfo; }
    183   const PPCTargetLowering *getTargetLowering() const override {
    184     return &TLInfo;
    185   }
    186   const SelectionDAGTargetInfo *getSelectionDAGInfo() const override {
    187     return &TSInfo;
    188   }
    189   const PPCRegisterInfo *getRegisterInfo() const override {
    190     return &getInstrInfo()->getRegisterInfo();
    191   }
    192   const PPCTargetMachine &getTargetMachine() const { return TM; }
    193 
    194   /// initializeSubtargetDependencies - Initializes using a CPU and feature string
    195   /// so that we can use initializer lists for subtarget initialization.
    196   PPCSubtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS);
    197 
    198 private:
    199   void initializeEnvironment();
    200   void initSubtargetFeatures(StringRef CPU, StringRef FS);
    201 
    202 public:
    203   /// isPPC64 - Return true if we are generating code for 64-bit pointer mode.
    204   ///
    205   bool isPPC64() const;
    206 
    207   /// has64BitSupport - Return true if the selected CPU supports 64-bit
    208   /// instructions, regardless of whether we are in 32-bit or 64-bit mode.
    209   bool has64BitSupport() const { return Has64BitSupport; }
    210   // useSoftFloat - Return true if soft-float option is turned on.
    211   bool useSoftFloat() const { return !HasHardFloat; }
    212 
    213   /// use64BitRegs - Return true if in 64-bit mode or if we should use 64-bit
    214   /// registers in 32-bit mode when possible.  This can only true if
    215   /// has64BitSupport() returns true.
    216   bool use64BitRegs() const { return Use64BitRegs; }
    217 
    218   /// useCRBits - Return true if we should store and manipulate i1 values in
    219   /// the individual condition register bits.
    220   bool useCRBits() const { return UseCRBits; }
    221 
    222   /// hasLazyResolverStub - Return true if accesses to the specified global have
    223   /// to go through a dyld lazy resolution stub.  This means that an extra load
    224   /// is required to get the address of the global.
    225   bool hasLazyResolverStub(const GlobalValue *GV) const;
    226 
    227   // isLittleEndian - True if generating little-endian code
    228   bool isLittleEndian() const { return IsLittleEndian; }
    229 
    230   // Specific obvious features.
    231   bool hasFCPSGN() const { return HasFCPSGN; }
    232   bool hasFSQRT() const { return HasFSQRT; }
    233   bool hasFRE() const { return HasFRE; }
    234   bool hasFRES() const { return HasFRES; }
    235   bool hasFRSQRTE() const { return HasFRSQRTE; }
    236   bool hasFRSQRTES() const { return HasFRSQRTES; }
    237   bool hasRecipPrec() const { return HasRecipPrec; }
    238   bool hasSTFIWX() const { return HasSTFIWX; }
    239   bool hasLFIWAX() const { return HasLFIWAX; }
    240   bool hasFPRND() const { return HasFPRND; }
    241   bool hasFPCVT() const { return HasFPCVT; }
    242   bool hasAltivec() const { return HasAltivec; }
    243   bool hasSPE() const { return HasSPE; }
    244   bool hasFPU() const { return HasFPU; }
    245   bool hasQPX() const { return HasQPX; }
    246   bool hasVSX() const { return HasVSX; }
    247   bool hasP8Vector() const { return HasP8Vector; }
    248   bool hasP8Altivec() const { return HasP8Altivec; }
    249   bool hasP8Crypto() const { return HasP8Crypto; }
    250   bool hasP9Vector() const { return HasP9Vector; }
    251   bool hasP9Altivec() const { return HasP9Altivec; }
    252   bool hasMFOCRF() const { return HasMFOCRF; }
    253   bool hasISEL() const { return HasISEL; }
    254   bool hasBPERMD() const { return HasBPERMD; }
    255   bool hasExtDiv() const { return HasExtDiv; }
    256   bool hasCMPB() const { return HasCMPB; }
    257   bool hasLDBRX() const { return HasLDBRX; }
    258   bool isBookE() const { return IsBookE; }
    259   bool hasOnlyMSYNC() const { return HasOnlyMSYNC; }
    260   bool isPPC4xx() const { return IsPPC4xx; }
    261   bool isPPC6xx() const { return IsPPC6xx; }
    262   bool isSecurePlt() const {return SecurePlt; }
    263   bool isE500() const { return IsE500; }
    264   bool isFeatureMFTB() const { return FeatureMFTB; }
    265   bool isDeprecatedDST() const { return DeprecatedDST; }
    266   bool hasICBT() const { return HasICBT; }
    267   bool hasInvariantFunctionDescriptors() const {
    268     return HasInvariantFunctionDescriptors;
    269   }
    270   bool hasPartwordAtomics() const { return HasPartwordAtomics; }
    271   bool hasDirectMove() const { return HasDirectMove; }
    272 
    273   bool isQPXStackUnaligned() const { return IsQPXStackUnaligned; }
    274   unsigned getPlatformStackAlignment() const {
    275     if ((hasQPX() || isBGQ()) && !isQPXStackUnaligned())
    276       return 32;
    277 
    278     return 16;
    279   }
    280 
    281   // DarwinABI has a 224-byte red zone. PPC32 SVR4ABI(Non-DarwinABI) has no
    282   // red zone and PPC64 SVR4ABI has a 288-byte red zone.
    283   unsigned  getRedZoneSize() const {
    284     return isDarwinABI() ? 224 : (isPPC64() ? 288 : 0);
    285   }
    286 
    287   bool hasHTM() const { return HasHTM; }
    288   bool hasFusion() const { return HasFusion; }
    289   bool hasFloat128() const { return HasFloat128; }
    290   bool isISA3_0() const { return IsISA3_0; }
    291   bool useLongCalls() const { return UseLongCalls; }
    292   bool needsSwapsForVSXMemOps() const {
    293     return hasVSX() && isLittleEndian() && !hasP9Vector();
    294   }
    295 
    296   POPCNTDKind hasPOPCNTD() const { return HasPOPCNTD; }
    297 
    298   const Triple &getTargetTriple() const { return TargetTriple; }
    299 
    300   /// isDarwin - True if this is any darwin platform.
    301   bool isDarwin() const { return TargetTriple.isMacOSX(); }
    302   /// isBGQ - True if this is a BG/Q platform.
    303   bool isBGQ() const { return TargetTriple.getVendor() == Triple::BGQ; }
    304 
    305   bool isTargetELF() const { return TargetTriple.isOSBinFormatELF(); }
    306   bool isTargetMachO() const { return TargetTriple.isOSBinFormatMachO(); }
    307   bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
    308 
    309   bool isDarwinABI() const { return isTargetMachO() || isDarwin(); }
    310   bool isSVR4ABI() const { return !isDarwinABI(); }
    311   bool isELFv2ABI() const;
    312 
    313   /// Originally, this function return hasISEL(). Now we always enable it,
    314   /// but may expand the ISEL instruction later.
    315   bool enableEarlyIfConversion() const override { return true; }
    316 
    317   // Scheduling customization.
    318   bool enableMachineScheduler() const override;
    319   // This overrides the PostRAScheduler bit in the SchedModel for each CPU.
    320   bool enablePostRAScheduler() const override;
    321   AntiDepBreakMode getAntiDepBreakMode() const override;
    322   void getCriticalPathRCs(RegClassVector &CriticalPathRCs) const override;
    323 
    324   void overrideSchedPolicy(MachineSchedPolicy &Policy,
    325                            unsigned NumRegionInstrs) const override;
    326   bool useAA() const override;
    327 
    328   bool enableSubRegLiveness() const override;
    329 
    330   /// classifyGlobalReference - Classify a global variable reference for the
    331   /// current subtarget accourding to how we should reference it.
    332   unsigned char classifyGlobalReference(const GlobalValue *GV) const;
    333 
    334   bool isXRaySupported() const override { return IsPPC64 && IsLittleEndian; }
    335 };
    336 } // End llvm namespace
    337 
    338 #endif
    339