1 //===- AArch64InstrInfo.h - AArch64 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 AArch64 implementation of the TargetInstrInfo class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_LIB_TARGET_AARCH64_AARCH64INSTRINFO_H
15 #define LLVM_LIB_TARGET_AARCH64_AARCH64INSTRINFO_H
18 #include "AArch64RegisterInfo.h"
19 #include "llvm/CodeGen/MachineCombinerPattern.h"
20 #include "llvm/CodeGen/TargetInstrInfo.h"
22 #define GET_INSTRINFO_HEADER
23 #include "AArch64GenInstrInfo.inc"
27 class AArch64Subtarget;
28 class AArch64TargetMachine;
30 static const MachineMemOperand::Flags MOSuppressPair =
31 MachineMemOperand::MOTargetFlag1;
32 static const MachineMemOperand::Flags MOStridedAccess =
33 MachineMemOperand::MOTargetFlag2;
35 #define FALKOR_STRIDED_ACCESS_MD "falkor.strided.access"
37 class AArch64InstrInfo final : public AArch64GenInstrInfo {
38 const AArch64RegisterInfo RI;
39 const AArch64Subtarget &Subtarget;
42 explicit AArch64InstrInfo(const AArch64Subtarget &STI);
44 /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info. As
45 /// such, whenever a client has an instance of instruction info, it should
46 /// always be able to get register info as well (through this method).
47 const AArch64RegisterInfo &getRegisterInfo() const { return RI; }
49 unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
51 bool isAsCheapAsAMove(const MachineInstr &MI) const override;
53 bool isCoalescableExtInstr(const MachineInstr &MI, unsigned &SrcReg,
54 unsigned &DstReg, unsigned &SubIdx) const override;
57 areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
58 AliasAnalysis *AA = nullptr) const override;
60 unsigned isLoadFromStackSlot(const MachineInstr &MI,
61 int &FrameIndex) const override;
62 unsigned isStoreToStackSlot(const MachineInstr &MI,
63 int &FrameIndex) const override;
65 /// Returns true if there is a shiftable register and that the shift value
67 bool hasShiftedReg(const MachineInstr &MI) const;
69 /// Returns true if there is an extendable register and that the extending
70 /// value is non-zero.
71 bool hasExtendedReg(const MachineInstr &MI) const;
73 /// \brief Does this instruction set its full destination register to zero?
74 bool isGPRZero(const MachineInstr &MI) const;
76 /// \brief Does this instruction rename a GPR without modifying bits?
77 bool isGPRCopy(const MachineInstr &MI) const;
79 /// \brief Does this instruction rename an FPR without modifying bits?
80 bool isFPRCopy(const MachineInstr &MI) const;
82 /// Return true if this is load/store scales or extends its register offset.
83 /// This refers to scaling a dynamic index as opposed to scaled immediates.
84 /// MI should be a memory op that allows scaled addressing.
85 bool isScaledAddr(const MachineInstr &MI) const;
87 /// Return true if pairing the given load or store is hinted to be
89 bool isLdStPairSuppressed(const MachineInstr &MI) const;
91 /// Return true if the given load or store is a strided memory access.
92 bool isStridedAccess(const MachineInstr &MI) const;
94 /// Return true if this is an unscaled load/store.
95 bool isUnscaledLdSt(unsigned Opc) const;
97 /// Return true if this is an unscaled load/store.
98 bool isUnscaledLdSt(MachineInstr &MI) const;
100 static bool isPairableLdStInst(const MachineInstr &MI) {
101 switch (MI.getOpcode()) {
104 // Scaled instructions.
105 case AArch64::STRSui:
106 case AArch64::STRDui:
107 case AArch64::STRQui:
108 case AArch64::STRXui:
109 case AArch64::STRWui:
110 case AArch64::LDRSui:
111 case AArch64::LDRDui:
112 case AArch64::LDRQui:
113 case AArch64::LDRXui:
114 case AArch64::LDRWui:
115 case AArch64::LDRSWui:
116 // Unscaled instructions.
117 case AArch64::STURSi:
118 case AArch64::STURDi:
119 case AArch64::STURQi:
120 case AArch64::STURWi:
121 case AArch64::STURXi:
122 case AArch64::LDURSi:
123 case AArch64::LDURDi:
124 case AArch64::LDURQi:
125 case AArch64::LDURWi:
126 case AArch64::LDURXi:
127 case AArch64::LDURSWi:
132 /// \brief Return the opcode that set flags when possible. The caller is
133 /// responsible for ensuring the opc has a flag setting equivalent.
134 static unsigned convertToFlagSettingOpc(unsigned Opc, bool &Is64Bit) {
137 llvm_unreachable("Opcode has no flag setting equivalent!");
139 case AArch64::ADDWri:
141 return AArch64::ADDSWri;
142 case AArch64::ADDWrr:
144 return AArch64::ADDSWrr;
145 case AArch64::ADDWrs:
147 return AArch64::ADDSWrs;
148 case AArch64::ADDWrx:
150 return AArch64::ADDSWrx;
151 case AArch64::ANDWri:
153 return AArch64::ANDSWri;
154 case AArch64::ANDWrr:
156 return AArch64::ANDSWrr;
157 case AArch64::ANDWrs:
159 return AArch64::ANDSWrs;
160 case AArch64::BICWrr:
162 return AArch64::BICSWrr;
163 case AArch64::BICWrs:
165 return AArch64::BICSWrs;
166 case AArch64::SUBWri:
168 return AArch64::SUBSWri;
169 case AArch64::SUBWrr:
171 return AArch64::SUBSWrr;
172 case AArch64::SUBWrs:
174 return AArch64::SUBSWrs;
175 case AArch64::SUBWrx:
177 return AArch64::SUBSWrx;
179 case AArch64::ADDXri:
181 return AArch64::ADDSXri;
182 case AArch64::ADDXrr:
184 return AArch64::ADDSXrr;
185 case AArch64::ADDXrs:
187 return AArch64::ADDSXrs;
188 case AArch64::ADDXrx:
190 return AArch64::ADDSXrx;
191 case AArch64::ANDXri:
193 return AArch64::ANDSXri;
194 case AArch64::ANDXrr:
196 return AArch64::ANDSXrr;
197 case AArch64::ANDXrs:
199 return AArch64::ANDSXrs;
200 case AArch64::BICXrr:
202 return AArch64::BICSXrr;
203 case AArch64::BICXrs:
205 return AArch64::BICSXrs;
206 case AArch64::SUBXri:
208 return AArch64::SUBSXri;
209 case AArch64::SUBXrr:
211 return AArch64::SUBSXrr;
212 case AArch64::SUBXrs:
214 return AArch64::SUBSXrs;
215 case AArch64::SUBXrx:
217 return AArch64::SUBSXrx;
221 /// Return true if this is a load/store that can be potentially paired/merged.
222 bool isCandidateToMergeOrPair(MachineInstr &MI) const;
224 /// Hint that pairing the given load or store is unprofitable.
225 void suppressLdStPair(MachineInstr &MI) const;
227 bool getMemOpBaseRegImmOfs(MachineInstr &LdSt, unsigned &BaseReg,
229 const TargetRegisterInfo *TRI) const override;
231 bool getMemOpBaseRegImmOfsWidth(MachineInstr &LdSt, unsigned &BaseReg,
232 int64_t &Offset, unsigned &Width,
233 const TargetRegisterInfo *TRI) const;
235 /// Return the immediate offset of the base register in a load/store \p LdSt.
236 MachineOperand &getMemOpBaseRegImmOfsOffsetOperand(MachineInstr &LdSt) const;
238 /// \brief Returns true if opcode \p Opc is a memory operation. If it is, set
239 /// \p Scale, \p Width, \p MinOffset, and \p MaxOffset accordingly.
241 /// For unscaled instructions, \p Scale is set to 1.
242 bool getMemOpInfo(unsigned Opcode, unsigned &Scale, unsigned &Width,
243 int64_t &MinOffset, int64_t &MaxOffset) const;
245 bool shouldClusterMemOps(MachineInstr &FirstLdSt, unsigned BaseReg1,
246 MachineInstr &SecondLdSt, unsigned BaseReg2,
247 unsigned NumLoads) const override;
249 void copyPhysRegTuple(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
250 const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
251 bool KillSrc, unsigned Opcode,
252 llvm::ArrayRef<unsigned> Indices) const;
253 void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
254 const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
255 bool KillSrc) const override;
257 void storeRegToStackSlot(MachineBasicBlock &MBB,
258 MachineBasicBlock::iterator MBBI, unsigned SrcReg,
259 bool isKill, int FrameIndex,
260 const TargetRegisterClass *RC,
261 const TargetRegisterInfo *TRI) const override;
263 void loadRegFromStackSlot(MachineBasicBlock &MBB,
264 MachineBasicBlock::iterator MBBI, unsigned DestReg,
265 int FrameIndex, const TargetRegisterClass *RC,
266 const TargetRegisterInfo *TRI) const override;
268 // This tells target independent code that it is okay to pass instructions
269 // with subreg operands to foldMemoryOperandImpl.
270 bool isSubregFoldable() const override { return true; }
272 using TargetInstrInfo::foldMemoryOperandImpl;
274 foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
275 ArrayRef<unsigned> Ops,
276 MachineBasicBlock::iterator InsertPt, int FrameIndex,
277 LiveIntervals *LIS = nullptr) const override;
279 /// \returns true if a branch from an instruction with opcode \p BranchOpc
280 /// bytes is capable of jumping to a position \p BrOffset bytes away.
281 bool isBranchOffsetInRange(unsigned BranchOpc,
282 int64_t BrOffset) const override;
284 MachineBasicBlock *getBranchDestBlock(const MachineInstr &MI) const override;
286 bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
287 MachineBasicBlock *&FBB,
288 SmallVectorImpl<MachineOperand> &Cond,
289 bool AllowModify = false) const override;
290 unsigned removeBranch(MachineBasicBlock &MBB,
291 int *BytesRemoved = nullptr) const override;
292 unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
293 MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
295 int *BytesAdded = nullptr) const override;
297 reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
298 bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
299 unsigned, unsigned, int &, int &, int &) const override;
300 void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
301 const DebugLoc &DL, unsigned DstReg,
302 ArrayRef<MachineOperand> Cond, unsigned TrueReg,
303 unsigned FalseReg) const override;
304 void getNoop(MCInst &NopInst) const override;
306 /// analyzeCompare - For a comparison instruction, return the source registers
307 /// in SrcReg and SrcReg2, and the value it compares against in CmpValue.
308 /// Return true if the comparison instruction can be analyzed.
309 bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
310 unsigned &SrcReg2, int &CmpMask,
311 int &CmpValue) const override;
312 /// optimizeCompareInstr - Convert the instruction supplying the argument to
313 /// the comparison into one that sets the zero bit in the flags register.
314 bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
315 unsigned SrcReg2, int CmpMask, int CmpValue,
316 const MachineRegisterInfo *MRI) const override;
317 bool optimizeCondBranch(MachineInstr &MI) const override;
319 /// Return true when a code sequence can improve throughput. It
320 /// should be called only for instructions in loops.
321 /// \param Pattern - combiner pattern
322 bool isThroughputPattern(MachineCombinerPattern Pattern) const override;
323 /// Return true when there is potentially a faster code sequence
324 /// for an instruction chain ending in ``Root``. All potential patterns are
325 /// listed in the ``Patterns`` array.
326 bool getMachineCombinerPatterns(
328 SmallVectorImpl<MachineCombinerPattern> &Patterns) const override;
329 /// Return true when Inst is associative and commutative so that it can be
331 bool isAssociativeAndCommutative(const MachineInstr &Inst) const override;
332 /// When getMachineCombinerPatterns() finds patterns, this function generates
333 /// the instructions that could replace the original code sequence
334 void genAlternativeCodeSequence(
335 MachineInstr &Root, MachineCombinerPattern Pattern,
336 SmallVectorImpl<MachineInstr *> &InsInstrs,
337 SmallVectorImpl<MachineInstr *> &DelInstrs,
338 DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;
339 /// AArch64 supports MachineCombiner.
340 bool useMachineCombiner() const override;
342 bool expandPostRAPseudo(MachineInstr &MI) const override;
344 std::pair<unsigned, unsigned>
345 decomposeMachineOperandsTargetFlags(unsigned TF) const override;
346 ArrayRef<std::pair<unsigned, const char *>>
347 getSerializableDirectMachineOperandTargetFlags() const override;
348 ArrayRef<std::pair<unsigned, const char *>>
349 getSerializableBitmaskMachineOperandTargetFlags() const override;
350 ArrayRef<std::pair<MachineMemOperand::Flags, const char *>>
351 getSerializableMachineMemOperandTargetFlags() const override;
354 canOutlineWithoutLRSave(MachineBasicBlock::iterator &CallInsertionPt) const;
355 bool isFunctionSafeToOutlineFrom(MachineFunction &MF,
356 bool OutlineFromLinkOnceODRs) const override;
357 MachineOutlinerInfo getOutlininingCandidateInfo(
359 std::pair<MachineBasicBlock::iterator, MachineBasicBlock::iterator>>
360 &RepeatedSequenceLocs) const override;
361 AArch64GenInstrInfo::MachineOutlinerInstrType
362 getOutliningType(MachineInstr &MI) const override;
363 void insertOutlinerEpilogue(MachineBasicBlock &MBB, MachineFunction &MF,
364 const MachineOutlinerInfo &MInfo) const override;
365 void insertOutlinerPrologue(MachineBasicBlock &MBB, MachineFunction &MF,
366 const MachineOutlinerInfo &MInfo) const override;
367 MachineBasicBlock::iterator
368 insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
369 MachineBasicBlock::iterator &It, MachineFunction &MF,
370 const MachineOutlinerInfo &MInfo) const override;
371 /// Returns true if the instruction has a shift left that can be executed
372 /// more efficiently.
373 bool isExynosShiftLeftFast(const MachineInstr &MI) const;
374 /// Returns true if the instruction has a shift by immediate that can be
375 /// executed in one cycle less.
376 bool isFalkorShiftExtFast(const MachineInstr &MI) const;
379 /// \brief Sets the offsets on outlined instructions in \p MBB which use SP
380 /// so that they will be valid post-outlining.
382 /// \param MBB A \p MachineBasicBlock in an outlined function.
383 void fixupPostOutline(MachineBasicBlock &MBB) const;
385 void instantiateCondBranch(MachineBasicBlock &MBB, const DebugLoc &DL,
386 MachineBasicBlock *TBB,
387 ArrayRef<MachineOperand> Cond) const;
388 bool substituteCmpToZero(MachineInstr &CmpInstr, unsigned SrcReg,
389 const MachineRegisterInfo *MRI) const;
392 /// emitFrameOffset - Emit instructions as needed to set DestReg to SrcReg
393 /// plus Offset. This is intended to be used from within the prolog/epilog
394 /// insertion (PEI) pass, where a virtual scratch register may be allocated
395 /// if necessary, to be replaced by the scavenger at the end of PEI.
396 void emitFrameOffset(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
397 const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
398 int Offset, const TargetInstrInfo *TII,
399 MachineInstr::MIFlag = MachineInstr::NoFlags,
400 bool SetNZCV = false);
402 /// rewriteAArch64FrameIndex - Rewrite MI to access 'Offset' bytes from the
403 /// FP. Return false if the offset could not be handled directly in MI, and
404 /// return the left-over portion by reference.
405 bool rewriteAArch64FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
406 unsigned FrameReg, int &Offset,
407 const AArch64InstrInfo *TII);
409 /// \brief Use to report the frame offset status in isAArch64FrameOffsetLegal.
410 enum AArch64FrameOffsetStatus {
411 AArch64FrameOffsetCannotUpdate = 0x0, ///< Offset cannot apply.
412 AArch64FrameOffsetIsLegal = 0x1, ///< Offset is legal.
413 AArch64FrameOffsetCanUpdate = 0x2 ///< Offset can apply, at least partly.
416 /// \brief Check if the @p Offset is a valid frame offset for @p MI.
417 /// The returned value reports the validity of the frame offset for @p MI.
418 /// It uses the values defined by AArch64FrameOffsetStatus for that.
419 /// If result == AArch64FrameOffsetCannotUpdate, @p MI cannot be updated to
421 /// If result & AArch64FrameOffsetIsLegal, @p Offset can completely be
422 /// rewritten in @p MI.
423 /// If result & AArch64FrameOffsetCanUpdate, @p Offset contains the
424 /// amount that is off the limit of the legal offset.
425 /// If set, @p OutUseUnscaledOp will contain the whether @p MI should be
426 /// turned into an unscaled operator, which opcode is in @p OutUnscaledOp.
427 /// If set, @p EmittableOffset contains the amount that can be set in @p MI
428 /// (possibly with @p OutUnscaledOp if OutUseUnscaledOp is true) and that
429 /// is a legal offset.
430 int isAArch64FrameOffsetLegal(const MachineInstr &MI, int &Offset,
431 bool *OutUseUnscaledOp = nullptr,
432 unsigned *OutUnscaledOp = nullptr,
433 int *EmittableOffset = nullptr);
435 static inline bool isUncondBranchOpcode(int Opc) { return Opc == AArch64::B; }
437 static inline bool isCondBranchOpcode(int Opc) {
454 static inline bool isIndirectBranchOpcode(int Opc) {
455 return Opc == AArch64::BR;
458 } // end namespace llvm