lib/Target/X86/X86InstrInfo.h

   1 //===-- X86InstrInfo.h - X86 Instruction Information ------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains the X86 implementation of the TargetInstrInfo class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_TARGET_X86_X86INSTRINFO_H
  14 #define LLVM_LIB_TARGET_X86_X86INSTRINFO_H
  15
  16 #include "MCTargetDesc/X86BaseInfo.h"
  17 #include "X86InstrFMA3Info.h"
  18 #include "X86RegisterInfo.h"
  19 #include "llvm/CodeGen/ISDOpcodes.h"
  20 #include "llvm/CodeGen/TargetInstrInfo.h"
  21 #include <vector>
  22
  23 #define GET_INSTRINFO_HEADER
  24 #include "X86GenInstrInfo.inc"
  25
  26 namespace llvm {
  27 class MachineInstrBuilder;
  28 class X86RegisterInfo;
  29 class X86Subtarget;
  30
  31 namespace X86 {
  32
  33 enum AsmComments {
  34   // For instr that was compressed from EVEX to VEX.
  35   AC_EVEX_2_VEX = MachineInstr::TAsmComments
  36 };
  37
  38 /// Return a pair of condition code for the given predicate and whether
  39 /// the instruction operands should be swaped to match the condition code.
  40 std::pair<CondCode, bool> getX86ConditionCode(CmpInst::Predicate Predicate);
  41
  42 /// Return a setcc opcode based on whether it has a memory operand.
  43 unsigned getSETOpc(bool HasMemoryOperand = false);
  44
  45 /// Return a cmov opcode for the given register size in bytes, and operand type.
  46 unsigned getCMovOpcode(unsigned RegBytes, bool HasMemoryOperand = false);
  47
  48 // Turn jCC instruction into condition code.
  49 CondCode getCondFromBranch(const MachineInstr &MI);
  50
  51 // Turn setCC instruction into condition code.
  52 CondCode getCondFromSETCC(const MachineInstr &MI);
  53
  54 // Turn CMov instruction into condition code.
  55 CondCode getCondFromCMov(const MachineInstr &MI);
  56
  57 /// GetOppositeBranchCondition - Return the inverse of the specified cond,
  58 /// e.g. turning COND_E to COND_NE.
  59 CondCode GetOppositeBranchCondition(CondCode CC);
  60
  61 /// Get the VPCMP immediate for the given condition.
  62 unsigned getVPCMPImmForCond(ISD::CondCode CC);
  63
  64 /// Get the VPCMP immediate if the opcodes are swapped.
  65 unsigned getSwappedVPCMPImm(unsigned Imm);
  66
  67 /// Get the VPCOM immediate if the opcodes are swapped.
  68 unsigned getSwappedVPCOMImm(unsigned Imm);
  69
  70 } // namespace X86
  71
  72 /// isGlobalStubReference - Return true if the specified TargetFlag operand is
  73 /// a reference to a stub for a global, not the global itself.
  74 inline static bool isGlobalStubReference(unsigned char TargetFlag) {
  75   switch (TargetFlag) {
  76   case X86II::MO_DLLIMPORT:               // dllimport stub.
  77   case X86II::MO_GOTPCREL:                // rip-relative GOT reference.
  78   case X86II::MO_GOT:                     // normal GOT reference.
  79   case X86II::MO_DARWIN_NONLAZY_PIC_BASE: // Normal $non_lazy_ptr ref.
  80   case X86II::MO_DARWIN_NONLAZY:          // Normal $non_lazy_ptr ref.
  81   case X86II::MO_COFFSTUB:                // COFF .refptr stub.
  82     return true;
  83   default:
  84     return false;
  85   }
  86 }
  87
  88 /// isGlobalRelativeToPICBase - Return true if the specified global value
  89 /// reference is relative to a 32-bit PIC base (X86ISD::GlobalBaseReg).  If this
  90 /// is true, the addressing mode has the PIC base register added in (e.g. EBX).
  91 inline static bool isGlobalRelativeToPICBase(unsigned char TargetFlag) {
  92   switch (TargetFlag) {
  93   case X86II::MO_GOTOFF:                  // isPICStyleGOT: local global.
  94   case X86II::MO_GOT:                     // isPICStyleGOT: other global.
  95   case X86II::MO_PIC_BASE_OFFSET:         // Darwin local global.
  96   case X86II::MO_DARWIN_NONLAZY_PIC_BASE: // Darwin/32 external global.
  97   case X86II::MO_TLVP:                    // ??? Pretty sure..
  98     return true;
  99   default:
 100     return false;
 101   }
 102 }
 103
 104 inline static bool isScale(const MachineOperand &MO) {
 105   return MO.isImm() && (MO.getImm() == 1 || MO.getImm() == 2 ||
 106                         MO.getImm() == 4 || MO.getImm() == 8);
 107 }
 108
 109 inline static bool isLeaMem(const MachineInstr &MI, unsigned Op) {
 110   if (MI.getOperand(Op).isFI())
 111     return true;
 112   return Op + X86::AddrSegmentReg <= MI.getNumOperands() &&
 113          MI.getOperand(Op + X86::AddrBaseReg).isReg() &&
 114          isScale(MI.getOperand(Op + X86::AddrScaleAmt)) &&
 115          MI.getOperand(Op + X86::AddrIndexReg).isReg() &&
 116          (MI.getOperand(Op + X86::AddrDisp).isImm() ||
 117           MI.getOperand(Op + X86::AddrDisp).isGlobal() ||
 118           MI.getOperand(Op + X86::AddrDisp).isCPI() ||
 119           MI.getOperand(Op + X86::AddrDisp).isJTI());
 120 }
 121
 122 inline static bool isMem(const MachineInstr &MI, unsigned Op) {
 123   if (MI.getOperand(Op).isFI())
 124     return true;
 125   return Op + X86::AddrNumOperands <= MI.getNumOperands() &&
 126          MI.getOperand(Op + X86::AddrSegmentReg).isReg() && isLeaMem(MI, Op);
 127 }
 128
 129 class X86InstrInfo final : public X86GenInstrInfo {
 130   X86Subtarget &Subtarget;
 131   const X86RegisterInfo RI;
 132
 133   virtual void anchor();
 134
 135   bool AnalyzeBranchImpl(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
 136                          MachineBasicBlock *&FBB,
 137                          SmallVectorImpl<MachineOperand> &Cond,
 138                          SmallVectorImpl<MachineInstr *> &CondBranches,
 139                          bool AllowModify) const;
 140
 141 public:
 142   explicit X86InstrInfo(X86Subtarget &STI);
 143
 144   /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
 145   /// such, whenever a client has an instance of instruction info, it should
 146   /// always be able to get register info as well (through this method).
 147   ///
 148   const X86RegisterInfo &getRegisterInfo() const { return RI; }
 149
 150   /// Returns the stack pointer adjustment that happens inside the frame
 151   /// setup..destroy sequence (e.g. by pushes, or inside the callee).
 152   int64_t getFrameAdjustment(const MachineInstr &I) const {
 153     assert(isFrameInstr(I));
 154     if (isFrameSetup(I))
 155       return I.getOperand(2).getImm();
 156     return I.getOperand(1).getImm();
 157   }
 158
 159   /// Sets the stack pointer adjustment made inside the frame made up by this
 160   /// instruction.
 161   void setFrameAdjustment(MachineInstr &I, int64_t V) const {
 162     assert(isFrameInstr(I));
 163     if (isFrameSetup(I))
 164       I.getOperand(2).setImm(V);
 165     else
 166       I.getOperand(1).setImm(V);
 167   }
 168
 169   /// getSPAdjust - This returns the stack pointer adjustment made by
 170   /// this instruction. For x86, we need to handle more complex call
 171   /// sequences involving PUSHes.
 172   int getSPAdjust(const MachineInstr &MI) const override;
 173
 174   /// isCoalescableExtInstr - Return true if the instruction is a "coalescable"
 175   /// extension instruction. That is, it's like a copy where it's legal for the
 176   /// source to overlap the destination. e.g. X86::MOVSX64rr32. If this returns
 177   /// true, then it's expected the pre-extension value is available as a subreg
 178   /// of the result register. This also returns the sub-register index in
 179   /// SubIdx.
 180   bool isCoalescableExtInstr(const MachineInstr &MI, unsigned &SrcReg,
 181                              unsigned &DstReg, unsigned &SubIdx) const override;
 182
 183   unsigned isLoadFromStackSlot(const MachineInstr &MI,
 184                                int &FrameIndex) const override;
 185   unsigned isLoadFromStackSlot(const MachineInstr &MI,
 186                                int &FrameIndex,
 187                                unsigned &MemBytes) const override;
 188   /// isLoadFromStackSlotPostFE - Check for post-frame ptr elimination
 189   /// stack locations as well.  This uses a heuristic so it isn't
 190   /// reliable for correctness.
 191   unsigned isLoadFromStackSlotPostFE(const MachineInstr &MI,
 192                                      int &FrameIndex) const override;
 193
 194   unsigned isStoreToStackSlot(const MachineInstr &MI,
 195                               int &FrameIndex) const override;
 196   unsigned isStoreToStackSlot(const MachineInstr &MI,
 197                               int &FrameIndex,
 198                               unsigned &MemBytes) const override;
 199   /// isStoreToStackSlotPostFE - Check for post-frame ptr elimination
 200   /// stack locations as well.  This uses a heuristic so it isn't
 201   /// reliable for correctness.
 202   unsigned isStoreToStackSlotPostFE(const MachineInstr &MI,
 203                                     int &FrameIndex) const override;
 204
 205   bool isReallyTriviallyReMaterializable(const MachineInstr &MI,
 206                                          AliasAnalysis *AA) const override;
 207   void reMaterialize(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
 208                      unsigned DestReg, unsigned SubIdx,
 209                      const MachineInstr &Orig,
 210                      const TargetRegisterInfo &TRI) const override;
 211
 212   /// Given an operand within a MachineInstr, insert preceding code to put it
 213   /// into the right format for a particular kind of LEA instruction. This may
 214   /// involve using an appropriate super-register instead (with an implicit use
 215   /// of the original) or creating a new virtual register and inserting COPY
 216   /// instructions to get the data into the right class.
 217   ///
 218   /// Reference parameters are set to indicate how caller should add this
 219   /// operand to the LEA instruction.
 220   bool classifyLEAReg(MachineInstr &MI, const MachineOperand &Src,
 221                       unsigned LEAOpcode, bool AllowSP, Register &NewSrc,
 222                       bool &isKill, MachineOperand &ImplicitOp,
 223                       LiveVariables *LV) const;
 224
 225   /// convertToThreeAddress - This method must be implemented by targets that
 226   /// set the M_CONVERTIBLE_TO_3_ADDR flag.  When this flag is set, the target
 227   /// may be able to convert a two-address instruction into a true
 228   /// three-address instruction on demand.  This allows the X86 target (for
 229   /// example) to convert ADD and SHL instructions into LEA instructions if they
 230   /// would require register copies due to two-addressness.
 231   ///
 232   /// This method returns a null pointer if the transformation cannot be
 233   /// performed, otherwise it returns the new instruction.
 234   ///
 235   MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
 236                                       MachineInstr &MI,
 237                                       LiveVariables *LV) const override;
 238
 239   /// Returns true iff the routine could find two commutable operands in the
 240   /// given machine instruction.
 241   /// The 'SrcOpIdx1' and 'SrcOpIdx2' are INPUT and OUTPUT arguments. Their
 242   /// input values can be re-defined in this method only if the input values
 243   /// are not pre-defined, which is designated by the special value
 244   /// 'CommuteAnyOperandIndex' assigned to it.
 245   /// If both of indices are pre-defined and refer to some operands, then the
 246   /// method simply returns true if the corresponding operands are commutable
 247   /// and returns false otherwise.
 248   ///
 249   /// For example, calling this method this way:
 250   ///     unsigned Op1 = 1, Op2 = CommuteAnyOperandIndex;
 251   ///     findCommutedOpIndices(MI, Op1, Op2);
 252   /// can be interpreted as a query asking to find an operand that would be
 253   /// commutable with the operand#1.
 254   bool findCommutedOpIndices(MachineInstr &MI, unsigned &SrcOpIdx1,
 255                              unsigned &SrcOpIdx2) const override;
 256
 257   /// Returns an adjusted FMA opcode that must be used in FMA instruction that
 258   /// performs the same computations as the given \p MI but which has the
 259   /// operands \p SrcOpIdx1 and \p SrcOpIdx2 commuted.
 260   /// It may return 0 if it is unsafe to commute the operands.
 261   /// Note that a machine instruction (instead of its opcode) is passed as the
 262   /// first parameter to make it possible to analyze the instruction's uses and
 263   /// commute the first operand of FMA even when it seems unsafe when you look
 264   /// at the opcode. For example, it is Ok to commute the first operand of
 265   /// VFMADD*SD_Int, if ONLY the lowest 64-bit element of the result is used.
 266   ///
 267   /// The returned FMA opcode may differ from the opcode in the given \p MI.
 268   /// For example, commuting the operands #1 and #3 in the following FMA
 269   ///     FMA213 #1, #2, #3
 270   /// results into instruction with adjusted opcode:
 271   ///     FMA231 #3, #2, #1
 272   unsigned
 273   getFMA3OpcodeToCommuteOperands(const MachineInstr &MI, unsigned SrcOpIdx1,
 274                                  unsigned SrcOpIdx2,
 275                                  const X86InstrFMA3Group &FMA3Group) const;
 276
 277   // Branch analysis.
 278   bool isUnpredicatedTerminator(const MachineInstr &MI) const override;
 279   bool isUnconditionalTailCall(const MachineInstr &MI) const override;
 280   bool canMakeTailCallConditional(SmallVectorImpl<MachineOperand> &Cond,
 281                                   const MachineInstr &TailCall) const override;
 282   void replaceBranchWithTailCall(MachineBasicBlock &MBB,
 283                                  SmallVectorImpl<MachineOperand> &Cond,
 284                                  const MachineInstr &TailCall) const override;
 285
 286   bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
 287                      MachineBasicBlock *&FBB,
 288                      SmallVectorImpl<MachineOperand> &Cond,
 289                      bool AllowModify) const override;
 290
 291   bool getMemOperandWithOffset(const MachineInstr &LdSt,
 292                                const MachineOperand *&BaseOp,
 293                                int64_t &Offset,
 294                                const TargetRegisterInfo *TRI) const override;
 295   bool analyzeBranchPredicate(MachineBasicBlock &MBB,
 296                               TargetInstrInfo::MachineBranchPredicate &MBP,
 297                               bool AllowModify = false) const override;
 298
 299   unsigned removeBranch(MachineBasicBlock &MBB,
 300                         int *BytesRemoved = nullptr) const override;
 301   unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
 302                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
 303                         const DebugLoc &DL,
 304                         int *BytesAdded = nullptr) const override;
 305   bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
 306                        unsigned, unsigned, int &, int &, int &) const override;
 307   void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
 308                     const DebugLoc &DL, unsigned DstReg,
 309                     ArrayRef<MachineOperand> Cond, unsigned TrueReg,
 310                     unsigned FalseReg) const override;
 311   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
 312                    const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
 313                    bool KillSrc) const override;
 314   void storeRegToStackSlot(MachineBasicBlock &MBB,
 315                            MachineBasicBlock::iterator MI, unsigned SrcReg,
 316                            bool isKill, int FrameIndex,
 317                            const TargetRegisterClass *RC,
 318                            const TargetRegisterInfo *TRI) const override;
 319
 320   void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
 321                       SmallVectorImpl<MachineOperand> &Addr,
 322                       const TargetRegisterClass *RC,
 323                       ArrayRef<MachineMemOperand *> MMOs,
 324                       SmallVectorImpl<MachineInstr *> &NewMIs) const;
 325
 326   void loadRegFromStackSlot(MachineBasicBlock &MBB,
 327                             MachineBasicBlock::iterator MI, unsigned DestReg,
 328                             int FrameIndex, const TargetRegisterClass *RC,
 329                             const TargetRegisterInfo *TRI) const override;
 330
 331   void loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
 332                        SmallVectorImpl<MachineOperand> &Addr,
 333                        const TargetRegisterClass *RC,
 334                        ArrayRef<MachineMemOperand *> MMOs,
 335                        SmallVectorImpl<MachineInstr *> &NewMIs) const;
 336
 337   bool expandPostRAPseudo(MachineInstr &MI) const override;
 338
 339   /// Check whether the target can fold a load that feeds a subreg operand
 340   /// (or a subreg operand that feeds a store).
 341   bool isSubregFoldable() const override { return true; }
 342
 343   /// foldMemoryOperand - If this target supports it, fold a load or store of
 344   /// the specified stack slot into the specified machine instruction for the
 345   /// specified operand(s).  If this is possible, the target should perform the
 346   /// folding and return true, otherwise it should return false.  If it folds
 347   /// the instruction, it is likely that the MachineInstruction the iterator
 348   /// references has been changed.
 349   MachineInstr *
 350   foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
 351                         ArrayRef<unsigned> Ops,
 352                         MachineBasicBlock::iterator InsertPt, int FrameIndex,
 353                         LiveIntervals *LIS = nullptr,
 354                         VirtRegMap *VRM = nullptr) const override;
 355
 356   /// foldMemoryOperand - Same as the previous version except it allows folding
 357   /// of any load and store from / to any address, not just from a specific
 358   /// stack slot.
 359   MachineInstr *foldMemoryOperandImpl(
 360       MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
 361       MachineBasicBlock::iterator InsertPt, MachineInstr &LoadMI,
 362       LiveIntervals *LIS = nullptr) const override;
 363
 364   /// unfoldMemoryOperand - Separate a single instruction which folded a load or
 365   /// a store or a load and a store into two or more instruction. If this is
 366   /// possible, returns true as well as the new instructions by reference.
 367   bool
 368   unfoldMemoryOperand(MachineFunction &MF, MachineInstr &MI, unsigned Reg,
 369                       bool UnfoldLoad, bool UnfoldStore,
 370                       SmallVectorImpl<MachineInstr *> &NewMIs) const override;
 371
 372   bool unfoldMemoryOperand(SelectionDAG &DAG, SDNode *N,
 373                            SmallVectorImpl<SDNode *> &NewNodes) const override;
 374
 375   /// getOpcodeAfterMemoryUnfold - Returns the opcode of the would be new
 376   /// instruction after load / store are unfolded from an instruction of the
 377   /// specified opcode. It returns zero if the specified unfolding is not
 378   /// possible. If LoadRegIndex is non-null, it is filled in with the operand
 379   /// index of the operand which will hold the register holding the loaded
 380   /// value.
 381   unsigned
 382   getOpcodeAfterMemoryUnfold(unsigned Opc, bool UnfoldLoad, bool UnfoldStore,
 383                              unsigned *LoadRegIndex = nullptr) const override;
 384
 385   /// areLoadsFromSameBasePtr - This is used by the pre-regalloc scheduler
 386   /// to determine if two loads are loading from the same base address. It
 387   /// should only return true if the base pointers are the same and the
 388   /// only differences between the two addresses are the offset. It also returns
 389   /// the offsets by reference.
 390   bool areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2, int64_t &Offset1,
 391                                int64_t &Offset2) const override;
 392
 393   /// shouldScheduleLoadsNear - This is a used by the pre-regalloc scheduler to
 394   /// determine (in conjunction with areLoadsFromSameBasePtr) if two loads
 395   /// should be scheduled togther. On some targets if two loads are loading from
 396   /// addresses in the same cache line, it's better if they are scheduled
 397   /// together. This function takes two integers that represent the load offsets
 398   /// from the common base address. It returns true if it decides it's desirable
 399   /// to schedule the two loads together. "NumLoads" is the number of loads that
 400   /// have already been scheduled after Load1.
 401   bool shouldScheduleLoadsNear(SDNode *Load1, SDNode *Load2, int64_t Offset1,
 402                                int64_t Offset2,
 403                                unsigned NumLoads) const override;
 404
 405   void getNoop(MCInst &NopInst) const override;
 406
 407   bool
 408   reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
 409
 410   /// isSafeToMoveRegClassDefs - Return true if it's safe to move a machine
 411   /// instruction that defines the specified register class.
 412   bool isSafeToMoveRegClassDefs(const TargetRegisterClass *RC) const override;
 413
 414   /// isSafeToClobberEFLAGS - Return true if it's safe insert an instruction tha
 415   /// would clobber the EFLAGS condition register. Note the result may be
 416   /// conservative. If it cannot definitely determine the safety after visiting
 417   /// a few instructions in each direction it assumes it's not safe.
 418   bool isSafeToClobberEFLAGS(MachineBasicBlock &MBB,
 419                              MachineBasicBlock::iterator I) const {
 420     return MBB.computeRegisterLiveness(&RI, X86::EFLAGS, I, 4) ==
 421            MachineBasicBlock::LQR_Dead;
 422   }
 423
 424   /// True if MI has a condition code def, e.g. EFLAGS, that is
 425   /// not marked dead.
 426   bool hasLiveCondCodeDef(MachineInstr &MI) const;
 427
 428   /// getGlobalBaseReg - Return a virtual register initialized with the
 429   /// the global base register value. Output instructions required to
 430   /// initialize the register in the function entry block, if necessary.
 431   ///
 432   unsigned getGlobalBaseReg(MachineFunction *MF) const;
 433
 434   std::pair<uint16_t, uint16_t>
 435   getExecutionDomain(const MachineInstr &MI) const override;
 436
 437   uint16_t getExecutionDomainCustom(const MachineInstr &MI) const;
 438
 439   void setExecutionDomain(MachineInstr &MI, unsigned Domain) const override;
 440
 441   bool setExecutionDomainCustom(MachineInstr &MI, unsigned Domain) const;
 442
 443   unsigned
 444   getPartialRegUpdateClearance(const MachineInstr &MI, unsigned OpNum,
 445                                const TargetRegisterInfo *TRI) const override;
 446   unsigned getUndefRegClearance(const MachineInstr &MI, unsigned &OpNum,
 447                                 const TargetRegisterInfo *TRI) const override;
 448   void breakPartialRegDependency(MachineInstr &MI, unsigned OpNum,
 449                                  const TargetRegisterInfo *TRI) const override;
 450
 451   MachineInstr *foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
 452                                       unsigned OpNum,
 453                                       ArrayRef<MachineOperand> MOs,
 454                                       MachineBasicBlock::iterator InsertPt,
 455                                       unsigned Size, unsigned Alignment,
 456                                       bool AllowCommute) const;
 457
 458   bool isHighLatencyDef(int opc) const override;
 459
 460   bool hasHighOperandLatency(const TargetSchedModel &SchedModel,
 461                              const MachineRegisterInfo *MRI,
 462                              const MachineInstr &DefMI, unsigned DefIdx,
 463                              const MachineInstr &UseMI,
 464                              unsigned UseIdx) const override;
 465
 466   bool useMachineCombiner() const override { return true; }
 467
 468   bool isAssociativeAndCommutative(const MachineInstr &Inst) const override;
 469
 470   bool hasReassociableOperands(const MachineInstr &Inst,
 471                                const MachineBasicBlock *MBB) const override;
 472
 473   void setSpecialOperandAttr(MachineInstr &OldMI1, MachineInstr &OldMI2,
 474                              MachineInstr &NewMI1,
 475                              MachineInstr &NewMI2) const override;
 476
 477   /// analyzeCompare - For a comparison instruction, return the source registers
 478   /// in SrcReg and SrcReg2 if having two register operands, and the value it
 479   /// compares against in CmpValue. Return true if the comparison instruction
 480   /// can be analyzed.
 481   bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
 482                       unsigned &SrcReg2, int &CmpMask,
 483                       int &CmpValue) const override;
 484
 485   /// optimizeCompareInstr - Check if there exists an earlier instruction that
 486   /// operates on the same source operands and sets flags in the same way as
 487   /// Compare; remove Compare if possible.
 488   bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
 489                             unsigned SrcReg2, int CmpMask, int CmpValue,
 490                             const MachineRegisterInfo *MRI) const override;
 491
 492   /// optimizeLoadInstr - Try to remove the load by folding it to a register
 493   /// operand at the use. We fold the load instructions if and only if the
 494   /// def and use are in the same BB. We only look at one load and see
 495   /// whether it can be folded into MI. FoldAsLoadDefReg is the virtual register
 496   /// defined by the load we are trying to fold. DefMI returns the machine
 497   /// instruction that defines FoldAsLoadDefReg, and the function returns
 498   /// the machine instruction generated due to folding.
 499   MachineInstr *optimizeLoadInstr(MachineInstr &MI,
 500                                   const MachineRegisterInfo *MRI,
 501                                   unsigned &FoldAsLoadDefReg,
 502                                   MachineInstr *&DefMI) const override;
 503
 504   std::pair<unsigned, unsigned>
 505   decomposeMachineOperandsTargetFlags(unsigned TF) const override;
 506
 507   ArrayRef<std::pair<unsigned, const char *>>
 508   getSerializableDirectMachineOperandTargetFlags() const override;
 509
 510   virtual outliner::OutlinedFunction getOutliningCandidateInfo(
 511       std::vector<outliner::Candidate> &RepeatedSequenceLocs) const override;
 512
 513   bool isFunctionSafeToOutlineFrom(MachineFunction &MF,
 514                                    bool OutlineFromLinkOnceODRs) const override;
 515
 516   outliner::InstrType
 517   getOutliningType(MachineBasicBlock::iterator &MIT, unsigned Flags) const override;
 518
 519   void buildOutlinedFrame(MachineBasicBlock &MBB, MachineFunction &MF,
 520                           const outliner::OutlinedFunction &OF) const override;
 521
 522   MachineBasicBlock::iterator
 523   insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
 524                      MachineBasicBlock::iterator &It, MachineFunction &MF,
 525                      const outliner::Candidate &C) const override;
 526
 527 #define GET_INSTRINFO_HELPER_DECLS
 528 #include "X86GenInstrInfo.inc"
 529
 530   static bool hasLockPrefix(const MachineInstr &MI) {
 531     return MI.getDesc().TSFlags & X86II::LOCK;
 532   }
 533
 534   Optional<ParamLoadedValue>
 535   describeLoadedValue(const MachineInstr &MI) const override;
 536
 537 protected:
 538   /// Commutes the operands in the given instruction by changing the operands
 539   /// order and/or changing the instruction's opcode and/or the immediate value
 540   /// operand.
 541   ///
 542   /// The arguments 'CommuteOpIdx1' and 'CommuteOpIdx2' specify the operands
 543   /// to be commuted.
 544   ///
 545   /// Do not call this method for a non-commutable instruction or
 546   /// non-commutable operands.
 547   /// Even though the instruction is commutable, the method may still
 548   /// fail to commute the operands, null pointer is returned in such cases.
 549   MachineInstr *commuteInstructionImpl(MachineInstr &MI, bool NewMI,
 550                                        unsigned CommuteOpIdx1,
 551                                        unsigned CommuteOpIdx2) const override;
 552
 553   /// If the specific machine instruction is a instruction that moves/copies
 554   /// value from one register to another register return true along with
 555   /// @Source machine operand and @Destination machine operand.
 556   bool isCopyInstrImpl(const MachineInstr &MI, const MachineOperand *&Source,
 557                        const MachineOperand *&Destination) const override;
 558
 559 private:
 560   /// This is a helper for convertToThreeAddress for 8 and 16-bit instructions.
 561   /// We use 32-bit LEA to form 3-address code by promoting to a 32-bit
 562   /// super-register and then truncating back down to a 8/16-bit sub-register.
 563   MachineInstr *convertToThreeAddressWithLEA(unsigned MIOpc,
 564                                              MachineFunction::iterator &MFI,
 565                                              MachineInstr &MI,
 566                                              LiveVariables *LV,
 567                                              bool Is8BitOp) const;
 568
 569   /// Handles memory folding for special case instructions, for instance those
 570   /// requiring custom manipulation of the address.
 571   MachineInstr *foldMemoryOperandCustom(MachineFunction &MF, MachineInstr &MI,
 572                                         unsigned OpNum,
 573                                         ArrayRef<MachineOperand> MOs,
 574                                         MachineBasicBlock::iterator InsertPt,
 575                                         unsigned Size, unsigned Align) const;
 576
 577   /// isFrameOperand - Return true and the FrameIndex if the specified
 578   /// operand and follow operands form a reference to the stack frame.
 579   bool isFrameOperand(const MachineInstr &MI, unsigned int Op,
 580                       int &FrameIndex) const;
 581
 582   /// Returns true iff the routine could find two commutable operands in the
 583   /// given machine instruction with 3 vector inputs.
 584   /// The 'SrcOpIdx1' and 'SrcOpIdx2' are INPUT and OUTPUT arguments. Their
 585   /// input values can be re-defined in this method only if the input values
 586   /// are not pre-defined, which is designated by the special value
 587   /// 'CommuteAnyOperandIndex' assigned to it.
 588   /// If both of indices are pre-defined and refer to some operands, then the
 589   /// method simply returns true if the corresponding operands are commutable
 590   /// and returns false otherwise.
 591   ///
 592   /// For example, calling this method this way:
 593   ///     unsigned Op1 = 1, Op2 = CommuteAnyOperandIndex;
 594   ///     findThreeSrcCommutedOpIndices(MI, Op1, Op2);
 595   /// can be interpreted as a query asking to find an operand that would be
 596   /// commutable with the operand#1.
 597   ///
 598   /// If IsIntrinsic is set, operand 1 will be ignored for commuting.
 599   bool findThreeSrcCommutedOpIndices(const MachineInstr &MI,
 600                                      unsigned &SrcOpIdx1,
 601                                      unsigned &SrcOpIdx2,
 602                                      bool IsIntrinsic = false) const;
 603 };
 604
 605 } // namespace llvm
 606
 607 #endif