1 //===- X86InstrInfo.h - X86 Instruction Information ------------*- C++ -*- ===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the X86 implementation of the TargetInstrInfo class.
12 //===----------------------------------------------------------------------===//
14 #ifndef X86INSTRUCTIONINFO_H
15 #define X86INSTRUCTIONINFO_H
17 #include "llvm/Target/TargetInstrInfo.h"
19 #include "X86RegisterInfo.h"
20 #include "llvm/ADT/DenseMap.h"
23 class X86RegisterInfo;
24 class X86TargetMachine;
27 // X86 specific condition code. These correspond to X86_*_COND in
28 // X86InstrInfo.td. They must be kept in synch.
47 // Artificial condition codes. These are used by AnalyzeBranch
48 // to indicate a block terminated with two conditional branches to
49 // the same location. This occurs in code using FCMP_OEQ or FCMP_UNE,
50 // which can't be represented on x86 with a single condition. These
51 // are never used in MachineInstrs.
58 // Turn condition code into conditional branch opcode.
59 unsigned GetCondBranchFromCond(CondCode CC);
61 /// GetOppositeBranchCondition - Return the inverse of the specified cond,
62 /// e.g. turning COND_E to COND_NE.
63 CondCode GetOppositeBranchCondition(X86::CondCode CC);
67 /// X86II - This namespace holds all of the target specific flags that
68 /// instruction info tracks.
71 /// Target Operand Flag enum.
73 //===------------------------------------------------------------------===//
74 // X86 Specific MachineOperand flags.
78 /// MO_GOT_ABSOLUTE_ADDRESS - On a symbol operand, this represents a
80 /// SYMBOL_LABEL + [. - PICBASELABEL]
81 MO_GOT_ABSOLUTE_ADDRESS,
83 /// MO_PIC_BASE_OFFSET - On a symbol operand this indicates that the
84 /// immediate should get the value of the symbol minus the PIC base label:
85 /// SYMBOL_LABEL - PICBASELABEL
88 /// MO_GOT - On a symbol operand this indicates that the immediate is the
89 /// offset to the GOT entry for the symbol name from the base of the GOT.
91 /// See the X86-64 ELF ABI supplement for more details.
95 /// MO_GOTOFF - On a symbol operand this indicates that the immediate is
96 /// the offset to the location of the symbol name from the base of the GOT.
98 /// See the X86-64 ELF ABI supplement for more details.
99 /// SYMBOL_LABEL @GOTOFF
102 /// MO_GOTPCREL - On a symbol operand this indicates that the immediate is
103 /// offset to the GOT entry for the symbol name from the current code
106 /// See the X86-64 ELF ABI supplement for more details.
107 /// SYMBOL_LABEL @GOTPCREL
110 /// MO_PLT - On a symbol operand this indicates that the immediate is
111 /// offset to the PLT entry of symbol name from the current code location.
113 /// See the X86-64 ELF ABI supplement for more details.
114 /// SYMBOL_LABEL @PLT
117 /// MO_TLSGD - On a symbol operand this indicates that the immediate is
120 /// See 'ELF Handling for Thread-Local Storage' for more details.
121 /// SYMBOL_LABEL @TLSGD
124 /// MO_GOTTPOFF - On a symbol operand this indicates that the immediate is
127 /// See 'ELF Handling for Thread-Local Storage' for more details.
128 /// SYMBOL_LABEL @GOTTPOFF
131 /// MO_INDNTPOFF - On a symbol operand this indicates that the immediate is
134 /// See 'ELF Handling for Thread-Local Storage' for more details.
135 /// SYMBOL_LABEL @INDNTPOFF
138 /// MO_TPOFF - On a symbol operand this indicates that the immediate is
141 /// See 'ELF Handling for Thread-Local Storage' for more details.
142 /// SYMBOL_LABEL @TPOFF
145 /// MO_NTPOFF - On a symbol operand this indicates that the immediate is
148 /// See 'ELF Handling for Thread-Local Storage' for more details.
149 /// SYMBOL_LABEL @NTPOFF
152 /// MO_DLLIMPORT - On a symbol operand "FOO", this indicates that the
153 /// reference is actually to the "__imp_FOO" symbol. This is used for
154 /// dllimport linkage on windows.
157 /// MO_DARWIN_STUB - On a symbol operand "FOO", this indicates that the
158 /// reference is actually to the "FOO$stub" symbol. This is used for calls
159 /// and jumps to external functions on Tiger and before.
162 /// MO_DARWIN_NONLAZY - On a symbol operand "FOO", this indicates that the
163 /// reference is actually to the "FOO$non_lazy_ptr" symbol, which is a
164 /// non-PIC-base-relative reference to a non-hidden dyld lazy pointer stub.
167 /// MO_DARWIN_NONLAZY_PIC_BASE - On a symbol operand "FOO", this indicates
168 /// that the reference is actually to "FOO$non_lazy_ptr - PICBASE", which is
169 /// a PIC-base-relative reference to a non-hidden dyld lazy pointer stub.
170 MO_DARWIN_NONLAZY_PIC_BASE,
172 /// MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE - On a symbol operand "FOO", this
173 /// indicates that the reference is actually to "FOO$non_lazy_ptr -PICBASE",
174 /// which is a PIC-base-relative reference to a hidden dyld lazy pointer
176 MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE
180 /// isGlobalStubReference - Return true if the specified TargetFlag operand is
181 /// a reference to a stub for a global, not the global itself.
182 inline static bool isGlobalStubReference(unsigned char TargetFlag) {
183 switch (TargetFlag) {
184 case X86II::MO_DLLIMPORT: // dllimport stub.
185 case X86II::MO_GOTPCREL: // rip-relative GOT reference.
186 case X86II::MO_GOT: // normal GOT reference.
187 case X86II::MO_DARWIN_NONLAZY_PIC_BASE: // Normal $non_lazy_ptr ref.
188 case X86II::MO_DARWIN_NONLAZY: // Normal $non_lazy_ptr ref.
189 case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: // Hidden $non_lazy_ptr ref.
196 /// isGlobalRelativeToPICBase - Return true if the specified global value
197 /// reference is relative to a 32-bit PIC base (X86ISD::GlobalBaseReg). If this
198 /// is true, the addressing mode has the PIC base register added in (e.g. EBX).
199 inline static bool isGlobalRelativeToPICBase(unsigned char TargetFlag) {
200 switch (TargetFlag) {
201 case X86II::MO_GOTOFF: // isPICStyleGOT: local global.
202 case X86II::MO_GOT: // isPICStyleGOT: other global.
203 case X86II::MO_PIC_BASE_OFFSET: // Darwin local global.
204 case X86II::MO_DARWIN_NONLAZY_PIC_BASE: // Darwin/32 external global.
205 case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: // Darwin/32 hidden global.
212 /// X86II - This namespace holds all of the target specific flags that
213 /// instruction info tracks.
217 //===------------------------------------------------------------------===//
218 // Instruction encodings. These are the standard/most common forms for X86
222 // PseudoFrm - This represents an instruction that is a pseudo instruction
223 // or one that has not been implemented yet. It is illegal to code generate
224 // it, but tolerated for intermediate implementation stages.
227 /// Raw - This form is for instructions that don't have any operands, so
228 /// they are just a fixed opcode value, like 'leave'.
231 /// AddRegFrm - This form is used for instructions like 'push r32' that have
232 /// their one register operand added to their opcode.
235 /// MRMDestReg - This form is used for instructions that use the Mod/RM byte
236 /// to specify a destination, which in this case is a register.
240 /// MRMDestMem - This form is used for instructions that use the Mod/RM byte
241 /// to specify a destination, which in this case is memory.
245 /// MRMSrcReg - This form is used for instructions that use the Mod/RM byte
246 /// to specify a source, which in this case is a register.
250 /// MRMSrcMem - This form is used for instructions that use the Mod/RM byte
251 /// to specify a source, which in this case is memory.
255 /// MRM[0-7][rm] - These forms are used to represent instructions that use
256 /// a Mod/RM byte, and use the middle field to hold extended opcode
257 /// information. In the intel manual these are represented as /0, /1, ...
260 // First, instructions that operate on a register r/m operand...
261 MRM0r = 16, MRM1r = 17, MRM2r = 18, MRM3r = 19, // Format /0 /1 /2 /3
262 MRM4r = 20, MRM5r = 21, MRM6r = 22, MRM7r = 23, // Format /4 /5 /6 /7
264 // Next, instructions that operate on a memory r/m operand...
265 MRM0m = 24, MRM1m = 25, MRM2m = 26, MRM3m = 27, // Format /0 /1 /2 /3
266 MRM4m = 28, MRM5m = 29, MRM6m = 30, MRM7m = 31, // Format /4 /5 /6 /7
268 // MRMInitReg - This form is used for instructions whose source and
269 // destinations are the same register.
274 //===------------------------------------------------------------------===//
277 // OpSize - Set if this instruction requires an operand size prefix (0x66),
278 // which most often indicates that the instruction operates on 16 bit data
279 // instead of 32 bit data.
282 // AsSize - Set if this instruction requires an operand size prefix (0x67),
283 // which most often indicates that the instruction address 16 bit address
284 // instead of 32 bit address (or 32 bit address in 64 bit mode).
287 //===------------------------------------------------------------------===//
288 // Op0Mask - There are several prefix bytes that are used to form two byte
289 // opcodes. These are currently 0x0F, 0xF3, and 0xD8-0xDF. This mask is
290 // used to obtain the setting of this field. If no bits in this field is
291 // set, there is no prefix byte for obtaining a multibyte opcode.
294 Op0Mask = 0x1F << Op0Shift,
296 // TB - TwoByte - Set if this instruction has a two byte opcode, which
297 // starts with a 0x0F byte before the real opcode.
300 // REP - The 0xF3 prefix byte indicating repetition of the following
304 // D8-DF - These escape opcodes are used by the floating point unit. These
305 // values must remain sequential.
306 D8 = 3 << Op0Shift, D9 = 4 << Op0Shift,
307 DA = 5 << Op0Shift, DB = 6 << Op0Shift,
308 DC = 7 << Op0Shift, DD = 8 << Op0Shift,
309 DE = 9 << Op0Shift, DF = 10 << Op0Shift,
311 // XS, XD - These prefix codes are for single and double precision scalar
312 // floating point operations performed in the SSE registers.
313 XD = 11 << Op0Shift, XS = 12 << Op0Shift,
315 // T8, TA - Prefix after the 0x0F prefix.
316 T8 = 13 << Op0Shift, TA = 14 << Op0Shift,
318 // TF - Prefix before and after 0x0F
321 //===------------------------------------------------------------------===//
322 // REX_W - REX prefixes are instruction prefixes used in 64-bit mode.
323 // They are used to specify GPRs and SSE registers, 64-bit operand size,
324 // etc. We only cares about REX.W and REX.R bits and only the former is
325 // statically determined.
328 REX_W = 1 << REXShift,
330 //===------------------------------------------------------------------===//
331 // This three-bit field describes the size of an immediate operand. Zero is
332 // unused so that we can tell if we forgot to set a value.
334 ImmMask = 7 << ImmShift,
335 Imm8 = 1 << ImmShift,
336 Imm16 = 2 << ImmShift,
337 Imm32 = 3 << ImmShift,
338 Imm64 = 4 << ImmShift,
340 //===------------------------------------------------------------------===//
341 // FP Instruction Classification... Zero is non-fp instruction.
343 // FPTypeMask - Mask for all of the FP types...
345 FPTypeMask = 7 << FPTypeShift,
347 // NotFP - The default, set for instructions that do not use FP registers.
348 NotFP = 0 << FPTypeShift,
350 // ZeroArgFP - 0 arg FP instruction which implicitly pushes ST(0), f.e. fld0
351 ZeroArgFP = 1 << FPTypeShift,
353 // OneArgFP - 1 arg FP instructions which implicitly read ST(0), such as fst
354 OneArgFP = 2 << FPTypeShift,
356 // OneArgFPRW - 1 arg FP instruction which implicitly read ST(0) and write a
357 // result back to ST(0). For example, fcos, fsqrt, etc.
359 OneArgFPRW = 3 << FPTypeShift,
361 // TwoArgFP - 2 arg FP instructions which implicitly read ST(0), and an
362 // explicit argument, storing the result to either ST(0) or the implicit
363 // argument. For example: fadd, fsub, fmul, etc...
364 TwoArgFP = 4 << FPTypeShift,
366 // CompareFP - 2 arg FP instructions which implicitly read ST(0) and an
367 // explicit argument, but have no destination. Example: fucom, fucomi, ...
368 CompareFP = 5 << FPTypeShift,
370 // CondMovFP - "2 operand" floating point conditional move instructions.
371 CondMovFP = 6 << FPTypeShift,
373 // SpecialFP - Special instruction forms. Dispatch by opcode explicitly.
374 SpecialFP = 7 << FPTypeShift,
378 LOCK = 1 << LOCKShift,
380 // Segment override prefixes. Currently we just need ability to address
381 // stuff in gs and fs segments.
383 SegOvrMask = 3 << SegOvrShift,
384 FS = 1 << SegOvrShift,
385 GS = 2 << SegOvrShift,
389 OpcodeMask = 0xFF << OpcodeShift
392 // getBaseOpcodeFor - This function returns the "base" X86 opcode for the
393 // specified machine instruction.
395 static inline unsigned char getBaseOpcodeFor(unsigned TSFlags) {
396 return TSFlags >> X86II::OpcodeShift;
399 /// getSizeOfImm - Decode the "size of immediate" field from the TSFlags field
400 /// of the specified instruction.
401 static inline unsigned getSizeOfImm(unsigned TSFlags) {
402 switch (TSFlags & X86II::ImmMask) {
403 default: assert(0 && "Unknown immediate size");
404 case X86II::Imm8: return 1;
405 case X86II::Imm16: return 2;
406 case X86II::Imm32: return 4;
407 case X86II::Imm64: return 8;
412 const int X86AddrNumOperands = 5;
414 inline static bool isScale(const MachineOperand &MO) {
416 (MO.getImm() == 1 || MO.getImm() == 2 ||
417 MO.getImm() == 4 || MO.getImm() == 8);
420 inline static bool isLeaMem(const MachineInstr *MI, unsigned Op) {
421 if (MI->getOperand(Op).isFI()) return true;
422 return Op+4 <= MI->getNumOperands() &&
423 MI->getOperand(Op ).isReg() && isScale(MI->getOperand(Op+1)) &&
424 MI->getOperand(Op+2).isReg() &&
425 (MI->getOperand(Op+3).isImm() ||
426 MI->getOperand(Op+3).isGlobal() ||
427 MI->getOperand(Op+3).isCPI() ||
428 MI->getOperand(Op+3).isJTI());
431 inline static bool isMem(const MachineInstr *MI, unsigned Op) {
432 if (MI->getOperand(Op).isFI()) return true;
433 return Op+5 <= MI->getNumOperands() &&
434 MI->getOperand(Op+4).isReg() &&
438 class X86InstrInfo : public TargetInstrInfoImpl {
439 X86TargetMachine &TM;
440 const X86RegisterInfo RI;
442 /// RegOp2MemOpTable2Addr, RegOp2MemOpTable0, RegOp2MemOpTable1,
443 /// RegOp2MemOpTable2 - Load / store folding opcode maps.
445 DenseMap<unsigned*, std::pair<unsigned,unsigned> > RegOp2MemOpTable2Addr;
446 DenseMap<unsigned*, std::pair<unsigned,unsigned> > RegOp2MemOpTable0;
447 DenseMap<unsigned*, std::pair<unsigned,unsigned> > RegOp2MemOpTable1;
448 DenseMap<unsigned*, std::pair<unsigned,unsigned> > RegOp2MemOpTable2;
450 /// MemOp2RegOpTable - Load / store unfolding opcode map.
452 DenseMap<unsigned*, std::pair<unsigned, unsigned> > MemOp2RegOpTable;
455 explicit X86InstrInfo(X86TargetMachine &tm);
457 /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info. As
458 /// such, whenever a client has an instance of instruction info, it should
459 /// always be able to get register info as well (through this method).
461 virtual const X86RegisterInfo &getRegisterInfo() const { return RI; }
463 /// Return true if the instruction is a register to register move and return
464 /// the source and dest operands and their sub-register indices by reference.
465 virtual bool isMoveInstr(const MachineInstr &MI,
466 unsigned &SrcReg, unsigned &DstReg,
467 unsigned &SrcSubIdx, unsigned &DstSubIdx) const;
469 /// isCoalescableExtInstr - Return true if the instruction is a "coalescable"
470 /// extension instruction. That is, it's like a copy where it's legal for the
471 /// source to overlap the destination. e.g. X86::MOVSX64rr32. If this returns
472 /// true, then it's expected the pre-extension value is available as a subreg
473 /// of the result register. This also returns the sub-register index in
475 virtual bool isCoalescableExtInstr(const MachineInstr &MI,
476 unsigned &SrcReg, unsigned &DstReg,
477 unsigned &SubIdx) const;
479 unsigned isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const;
480 /// isLoadFromStackSlotPostFE - Check for post-frame ptr elimination
481 /// stack locations as well. This uses a heuristic so it isn't
482 /// reliable for correctness.
483 unsigned isLoadFromStackSlotPostFE(const MachineInstr *MI,
484 int &FrameIndex) const;
486 /// hasLoadFromStackSlot - If the specified machine instruction has
487 /// a load from a stack slot, return true along with the FrameIndex
488 /// of the loaded stack slot and the machine mem operand containing
489 /// the reference. If not, return false. Unlike
490 /// isLoadFromStackSlot, this returns true for any instructions that
491 /// loads from the stack. This is a hint only and may not catch all
493 bool hasLoadFromStackSlot(const MachineInstr *MI,
494 const MachineMemOperand *&MMO,
495 int &FrameIndex) const;
497 unsigned isStoreToStackSlot(const MachineInstr *MI, int &FrameIndex) const;
498 /// isStoreToStackSlotPostFE - Check for post-frame ptr elimination
499 /// stack locations as well. This uses a heuristic so it isn't
500 /// reliable for correctness.
501 unsigned isStoreToStackSlotPostFE(const MachineInstr *MI,
502 int &FrameIndex) const;
504 /// hasStoreToStackSlot - If the specified machine instruction has a
505 /// store to a stack slot, return true along with the FrameIndex of
506 /// the loaded stack slot and the machine mem operand containing the
507 /// reference. If not, return false. Unlike isStoreToStackSlot,
508 /// this returns true for any instructions that loads from the
509 /// stack. This is a hint only and may not catch all cases.
510 bool hasStoreToStackSlot(const MachineInstr *MI,
511 const MachineMemOperand *&MMO,
512 int &FrameIndex) const;
514 bool isReallyTriviallyReMaterializable(const MachineInstr *MI,
515 AliasAnalysis *AA) const;
516 void reMaterialize(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
517 unsigned DestReg, unsigned SubIdx,
518 const MachineInstr *Orig,
519 const TargetRegisterInfo *TRI) const;
521 /// convertToThreeAddress - This method must be implemented by targets that
522 /// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
523 /// may be able to convert a two-address instruction into a true
524 /// three-address instruction on demand. This allows the X86 target (for
525 /// example) to convert ADD and SHL instructions into LEA instructions if they
526 /// would require register copies due to two-addressness.
528 /// This method returns a null pointer if the transformation cannot be
529 /// performed, otherwise it returns the new instruction.
531 virtual MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
532 MachineBasicBlock::iterator &MBBI,
533 LiveVariables *LV) const;
535 /// commuteInstruction - We have a few instructions that must be hacked on to
538 virtual MachineInstr *commuteInstruction(MachineInstr *MI, bool NewMI) const;
541 virtual bool isUnpredicatedTerminator(const MachineInstr* MI) const;
542 virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
543 MachineBasicBlock *&FBB,
544 SmallVectorImpl<MachineOperand> &Cond,
545 bool AllowModify) const;
546 virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
547 virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
548 MachineBasicBlock *FBB,
549 const SmallVectorImpl<MachineOperand> &Cond) const;
550 virtual bool copyRegToReg(MachineBasicBlock &MBB,
551 MachineBasicBlock::iterator MI,
552 unsigned DestReg, unsigned SrcReg,
553 const TargetRegisterClass *DestRC,
554 const TargetRegisterClass *SrcRC) const;
555 virtual void storeRegToStackSlot(MachineBasicBlock &MBB,
556 MachineBasicBlock::iterator MI,
557 unsigned SrcReg, bool isKill, int FrameIndex,
558 const TargetRegisterClass *RC) const;
560 virtual void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
561 SmallVectorImpl<MachineOperand> &Addr,
562 const TargetRegisterClass *RC,
563 MachineInstr::mmo_iterator MMOBegin,
564 MachineInstr::mmo_iterator MMOEnd,
565 SmallVectorImpl<MachineInstr*> &NewMIs) const;
567 virtual void loadRegFromStackSlot(MachineBasicBlock &MBB,
568 MachineBasicBlock::iterator MI,
569 unsigned DestReg, int FrameIndex,
570 const TargetRegisterClass *RC) const;
572 virtual void loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
573 SmallVectorImpl<MachineOperand> &Addr,
574 const TargetRegisterClass *RC,
575 MachineInstr::mmo_iterator MMOBegin,
576 MachineInstr::mmo_iterator MMOEnd,
577 SmallVectorImpl<MachineInstr*> &NewMIs) const;
579 virtual bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
580 MachineBasicBlock::iterator MI,
581 const std::vector<CalleeSavedInfo> &CSI) const;
583 virtual bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
584 MachineBasicBlock::iterator MI,
585 const std::vector<CalleeSavedInfo> &CSI) const;
587 /// foldMemoryOperand - If this target supports it, fold a load or store of
588 /// the specified stack slot into the specified machine instruction for the
589 /// specified operand(s). If this is possible, the target should perform the
590 /// folding and return true, otherwise it should return false. If it folds
591 /// the instruction, it is likely that the MachineInstruction the iterator
592 /// references has been changed.
593 virtual MachineInstr* foldMemoryOperandImpl(MachineFunction &MF,
595 const SmallVectorImpl<unsigned> &Ops,
596 int FrameIndex) const;
598 /// foldMemoryOperand - Same as the previous version except it allows folding
599 /// of any load and store from / to any address, not just from a specific
601 virtual MachineInstr* foldMemoryOperandImpl(MachineFunction &MF,
603 const SmallVectorImpl<unsigned> &Ops,
604 MachineInstr* LoadMI) const;
606 /// canFoldMemoryOperand - Returns true if the specified load / store is
607 /// folding is possible.
608 virtual bool canFoldMemoryOperand(const MachineInstr*,
609 const SmallVectorImpl<unsigned> &) const;
611 /// unfoldMemoryOperand - Separate a single instruction which folded a load or
612 /// a store or a load and a store into two or more instruction. If this is
613 /// possible, returns true as well as the new instructions by reference.
614 virtual bool unfoldMemoryOperand(MachineFunction &MF, MachineInstr *MI,
615 unsigned Reg, bool UnfoldLoad, bool UnfoldStore,
616 SmallVectorImpl<MachineInstr*> &NewMIs) const;
618 virtual bool unfoldMemoryOperand(SelectionDAG &DAG, SDNode *N,
619 SmallVectorImpl<SDNode*> &NewNodes) const;
621 /// getOpcodeAfterMemoryUnfold - Returns the opcode of the would be new
622 /// instruction after load / store are unfolded from an instruction of the
623 /// specified opcode. It returns zero if the specified unfolding is not
624 /// possible. If LoadRegIndex is non-null, it is filled in with the operand
625 /// index of the operand which will hold the register holding the loaded
627 virtual unsigned getOpcodeAfterMemoryUnfold(unsigned Opc,
628 bool UnfoldLoad, bool UnfoldStore,
629 unsigned *LoadRegIndex = 0) const;
631 /// areLoadsFromSameBasePtr - This is used by the pre-regalloc scheduler
632 /// to determine if two loads are loading from the same base address. It
633 /// should only return true if the base pointers are the same and the
634 /// only differences between the two addresses are the offset. It also returns
635 /// the offsets by reference.
636 virtual bool areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2,
637 int64_t &Offset1, int64_t &Offset2) const;
639 /// shouldScheduleLoadsNear - This is a used by the pre-regalloc scheduler to
640 /// determine (in conjuction with areLoadsFromSameBasePtr) if two loads should
641 /// be scheduled togther. On some targets if two loads are loading from
642 /// addresses in the same cache line, it's better if they are scheduled
643 /// together. This function takes two integers that represent the load offsets
644 /// from the common base address. It returns true if it decides it's desirable
645 /// to schedule the two loads together. "NumLoads" is the number of loads that
646 /// have already been scheduled after Load1.
647 virtual bool shouldScheduleLoadsNear(SDNode *Load1, SDNode *Load2,
648 int64_t Offset1, int64_t Offset2,
649 unsigned NumLoads) const;
652 bool ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const;
654 /// isSafeToMoveRegClassDefs - Return true if it's safe to move a machine
655 /// instruction that defines the specified register class.
656 bool isSafeToMoveRegClassDefs(const TargetRegisterClass *RC) const;
658 static bool isX86_64NonExtLowByteReg(unsigned reg) {
659 return (reg == X86::SPL || reg == X86::BPL ||
660 reg == X86::SIL || reg == X86::DIL);
663 static bool isX86_64ExtendedReg(const MachineOperand &MO) {
664 if (!MO.isReg()) return false;
665 return isX86_64ExtendedReg(MO.getReg());
667 static unsigned determineREX(const MachineInstr &MI);
669 /// isX86_64ExtendedReg - Is the MachineOperand a x86-64 extended (r8 or
670 /// higher) register? e.g. r8, xmm8, xmm13, etc.
671 static bool isX86_64ExtendedReg(unsigned RegNo);
673 /// GetInstSize - Returns the size of the specified MachineInstr.
675 virtual unsigned GetInstSizeInBytes(const MachineInstr *MI) const;
677 /// getGlobalBaseReg - Return a virtual register initialized with the
678 /// the global base register value. Output instructions required to
679 /// initialize the register in the function entry block, if necessary.
681 unsigned getGlobalBaseReg(MachineFunction *MF) const;
684 MachineInstr * convertToThreeAddressWithLEA(unsigned MIOpc,
685 MachineFunction::iterator &MFI,
686 MachineBasicBlock::iterator &MBBI,
687 LiveVariables *LV) const;
689 MachineInstr* foldMemoryOperandImpl(MachineFunction &MF,
692 const SmallVectorImpl<MachineOperand> &MOs,
693 unsigned Size, unsigned Alignment) const;
695 /// isFrameOperand - Return true and the FrameIndex if the specified
696 /// operand and follow operands form a reference to the stack frame.
697 bool isFrameOperand(const MachineInstr *MI, unsigned int Op,
698 int &FrameIndex) const;
701 } // End llvm namespace