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      1 //===-- SystemZInstrInfo.h - SystemZ instruction information ----*- 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 contains the SystemZ implementation of the TargetInstrInfo class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZINSTRINFO_H
     15 #define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZINSTRINFO_H
     16 
     17 #include "SystemZ.h"
     18 #include "SystemZRegisterInfo.h"
     19 #include "llvm/Target/TargetInstrInfo.h"
     20 
     21 #define GET_INSTRINFO_HEADER
     22 #include "SystemZGenInstrInfo.inc"
     23 
     24 namespace llvm {
     25 
     26 class SystemZTargetMachine;
     27 
     28 namespace SystemZII {
     29 enum {
     30   // See comments in SystemZInstrFormats.td.
     31   SimpleBDXLoad          = (1 << 0),
     32   SimpleBDXStore         = (1 << 1),
     33   Has20BitOffset         = (1 << 2),
     34   HasIndex               = (1 << 3),
     35   Is128Bit               = (1 << 4),
     36   AccessSizeMask         = (31 << 5),
     37   AccessSizeShift        = 5,
     38   CCValuesMask           = (15 << 10),
     39   CCValuesShift          = 10,
     40   CompareZeroCCMaskMask  = (15 << 14),
     41   CompareZeroCCMaskShift = 14,
     42   CCMaskFirst            = (1 << 18),
     43   CCMaskLast             = (1 << 19),
     44   IsLogical              = (1 << 20)
     45 };
     46 static inline unsigned getAccessSize(unsigned int Flags) {
     47   return (Flags & AccessSizeMask) >> AccessSizeShift;
     48 }
     49 static inline unsigned getCCValues(unsigned int Flags) {
     50   return (Flags & CCValuesMask) >> CCValuesShift;
     51 }
     52 static inline unsigned getCompareZeroCCMask(unsigned int Flags) {
     53   return (Flags & CompareZeroCCMaskMask) >> CompareZeroCCMaskShift;
     54 }
     55 
     56 // SystemZ MachineOperand target flags.
     57 enum {
     58   // Masks out the bits for the access model.
     59   MO_SYMBOL_MODIFIER = (3 << 0),
     60 
     61   // @GOT (aka @GOTENT)
     62   MO_GOT = (1 << 0),
     63 
     64   // @INDNTPOFF
     65   MO_INDNTPOFF = (2 << 0)
     66 };
     67 // Classifies a branch.
     68 enum BranchType {
     69   // An instruction that branches on the current value of CC.
     70   BranchNormal,
     71 
     72   // An instruction that peforms a 32-bit signed comparison and branches
     73   // on the result.
     74   BranchC,
     75 
     76   // An instruction that peforms a 32-bit unsigned comparison and branches
     77   // on the result.
     78   BranchCL,
     79 
     80   // An instruction that peforms a 64-bit signed comparison and branches
     81   // on the result.
     82   BranchCG,
     83 
     84   // An instruction that peforms a 64-bit unsigned comparison and branches
     85   // on the result.
     86   BranchCLG,
     87 
     88   // An instruction that decrements a 32-bit register and branches if
     89   // the result is nonzero.
     90   BranchCT,
     91 
     92   // An instruction that decrements a 64-bit register and branches if
     93   // the result is nonzero.
     94   BranchCTG
     95 };
     96 // Information about a branch instruction.
     97 struct Branch {
     98   // The type of the branch.
     99   BranchType Type;
    100 
    101   // CCMASK_<N> is set if CC might be equal to N.
    102   unsigned CCValid;
    103 
    104   // CCMASK_<N> is set if the branch should be taken when CC == N.
    105   unsigned CCMask;
    106 
    107   // The target of the branch.
    108   const MachineOperand *Target;
    109 
    110   Branch(BranchType type, unsigned ccValid, unsigned ccMask,
    111          const MachineOperand *target)
    112     : Type(type), CCValid(ccValid), CCMask(ccMask), Target(target) {}
    113 };
    114 // Kinds of fused compares in compare-and-* instructions.  Together with type
    115 // of the converted compare, this identifies the compare-and-*
    116 // instruction.
    117 enum FusedCompareType {
    118   // Relative branch - CRJ etc.
    119   CompareAndBranch,
    120 
    121   // Indirect branch, used for return - CRBReturn etc.
    122   CompareAndReturn,
    123 
    124   // Indirect branch, used for sibcall - CRBCall etc.
    125   CompareAndSibcall,
    126 
    127   // Trap
    128   CompareAndTrap
    129 };
    130 } // end namespace SystemZII
    131 
    132 class SystemZSubtarget;
    133 class SystemZInstrInfo : public SystemZGenInstrInfo {
    134   const SystemZRegisterInfo RI;
    135   SystemZSubtarget &STI;
    136 
    137   void splitMove(MachineBasicBlock::iterator MI, unsigned NewOpcode) const;
    138   void splitAdjDynAlloc(MachineBasicBlock::iterator MI) const;
    139   void expandRIPseudo(MachineInstr &MI, unsigned LowOpcode, unsigned HighOpcode,
    140                       bool ConvertHigh) const;
    141   void expandRIEPseudo(MachineInstr &MI, unsigned LowOpcode,
    142                        unsigned LowOpcodeK, unsigned HighOpcode) const;
    143   void expandRXYPseudo(MachineInstr &MI, unsigned LowOpcode,
    144                        unsigned HighOpcode) const;
    145   void expandZExtPseudo(MachineInstr &MI, unsigned LowOpcode,
    146                         unsigned Size) const;
    147   void expandLoadStackGuard(MachineInstr *MI) const;
    148   void emitGRX32Move(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
    149                      const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
    150                      unsigned LowLowOpcode, unsigned Size, bool KillSrc) const;
    151   virtual void anchor();
    152 
    153 public:
    154   explicit SystemZInstrInfo(SystemZSubtarget &STI);
    155 
    156   // Override TargetInstrInfo.
    157   unsigned isLoadFromStackSlot(const MachineInstr &MI,
    158                                int &FrameIndex) const override;
    159   unsigned isStoreToStackSlot(const MachineInstr &MI,
    160                               int &FrameIndex) const override;
    161   bool isStackSlotCopy(const MachineInstr &MI, int &DestFrameIndex,
    162                        int &SrcFrameIndex) const override;
    163   bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
    164                      MachineBasicBlock *&FBB,
    165                      SmallVectorImpl<MachineOperand> &Cond,
    166                      bool AllowModify) const override;
    167   unsigned RemoveBranch(MachineBasicBlock &MBB) const override;
    168   unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
    169                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
    170                         const DebugLoc &DL) const override;
    171   bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
    172                       unsigned &SrcReg2, int &Mask, int &Value) const override;
    173   bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
    174                             unsigned SrcReg2, int Mask, int Value,
    175                             const MachineRegisterInfo *MRI) const override;
    176   bool isPredicable(MachineInstr &MI) const override;
    177   bool isProfitableToIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
    178                            unsigned ExtraPredCycles,
    179                            BranchProbability Probability) const override;
    180   bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
    181                            unsigned NumCyclesT, unsigned ExtraPredCyclesT,
    182                            MachineBasicBlock &FMBB,
    183                            unsigned NumCyclesF, unsigned ExtraPredCyclesF,
    184                            BranchProbability Probability) const override;
    185   bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
    186                             BranchProbability Probability) const override;
    187   bool PredicateInstruction(MachineInstr &MI,
    188                             ArrayRef<MachineOperand> Pred) const override;
    189   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
    190                    const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
    191                    bool KillSrc) const override;
    192   void storeRegToStackSlot(MachineBasicBlock &MBB,
    193                            MachineBasicBlock::iterator MBBI,
    194                            unsigned SrcReg, bool isKill, int FrameIndex,
    195                            const TargetRegisterClass *RC,
    196                            const TargetRegisterInfo *TRI) const override;
    197   void loadRegFromStackSlot(MachineBasicBlock &MBB,
    198                             MachineBasicBlock::iterator MBBI,
    199                             unsigned DestReg, int FrameIdx,
    200                             const TargetRegisterClass *RC,
    201                             const TargetRegisterInfo *TRI) const override;
    202   MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
    203                                       MachineInstr &MI,
    204                                       LiveVariables *LV) const override;
    205   MachineInstr *
    206   foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
    207                         ArrayRef<unsigned> Ops,
    208                         MachineBasicBlock::iterator InsertPt, int FrameIndex,
    209                         LiveIntervals *LIS = nullptr) const override;
    210   MachineInstr *foldMemoryOperandImpl(
    211       MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
    212       MachineBasicBlock::iterator InsertPt, MachineInstr &LoadMI,
    213       LiveIntervals *LIS = nullptr) const override;
    214   bool expandPostRAPseudo(MachineInstr &MBBI) const override;
    215   bool ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const
    216     override;
    217 
    218   // Return the SystemZRegisterInfo, which this class owns.
    219   const SystemZRegisterInfo &getRegisterInfo() const { return RI; }
    220 
    221   // Return the size in bytes of MI.
    222   uint64_t getInstSizeInBytes(const MachineInstr &MI) const;
    223 
    224   // Return true if MI is a conditional or unconditional branch.
    225   // When returning true, set Cond to the mask of condition-code
    226   // values on which the instruction will branch, and set Target
    227   // to the operand that contains the branch target.  This target
    228   // can be a register or a basic block.
    229   SystemZII::Branch getBranchInfo(const MachineInstr &MI) const;
    230 
    231   // Get the load and store opcodes for a given register class.
    232   void getLoadStoreOpcodes(const TargetRegisterClass *RC,
    233                            unsigned &LoadOpcode, unsigned &StoreOpcode) const;
    234 
    235   // Opcode is the opcode of an instruction that has an address operand,
    236   // and the caller wants to perform that instruction's operation on an
    237   // address that has displacement Offset.  Return the opcode of a suitable
    238   // instruction (which might be Opcode itself) or 0 if no such instruction
    239   // exists.
    240   unsigned getOpcodeForOffset(unsigned Opcode, int64_t Offset) const;
    241 
    242   // If Opcode is a load instruction that has a LOAD AND TEST form,
    243   // return the opcode for the testing form, otherwise return 0.
    244   unsigned getLoadAndTest(unsigned Opcode) const;
    245 
    246   // Return true if ROTATE AND ... SELECTED BITS can be used to select bits
    247   // Mask of the R2 operand, given that only the low BitSize bits of Mask are
    248   // significant.  Set Start and End to the I3 and I4 operands if so.
    249   bool isRxSBGMask(uint64_t Mask, unsigned BitSize,
    250                    unsigned &Start, unsigned &End) const;
    251 
    252   // If Opcode is a COMPARE opcode for which an associated fused COMPARE AND *
    253   // operation exists, return the opcode for the latter, otherwise return 0.
    254   // MI, if nonnull, is the compare instruction.
    255   unsigned getFusedCompare(unsigned Opcode,
    256                            SystemZII::FusedCompareType Type,
    257                            const MachineInstr *MI = nullptr) const;
    258 
    259   // Emit code before MBBI in MI to move immediate value Value into
    260   // physical register Reg.
    261   void loadImmediate(MachineBasicBlock &MBB,
    262                      MachineBasicBlock::iterator MBBI,
    263                      unsigned Reg, uint64_t Value) const;
    264 };
    265 } // end namespace llvm
    266 
    267 #endif
    268