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/Target/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: Is64Bit = false; return AArch64::ADDSWri;
140 case AArch64::ADDWrr: Is64Bit = false; return AArch64::ADDSWrr;
141 case AArch64::ADDWrs: Is64Bit = false; return AArch64::ADDSWrs;
142 case AArch64::ADDWrx: Is64Bit = false; return AArch64::ADDSWrx;
143 case AArch64::ANDWri: Is64Bit = false; return AArch64::ANDSWri;
144 case AArch64::ANDWrr: Is64Bit = false; return AArch64::ANDSWrr;
145 case AArch64::ANDWrs: Is64Bit = false; return AArch64::ANDSWrs;
146 case AArch64::BICWrr: Is64Bit = false; return AArch64::BICSWrr;
147 case AArch64::BICWrs: Is64Bit = false; return AArch64::BICSWrs;
148 case AArch64::SUBWri: Is64Bit = false; return AArch64::SUBSWri;
149 case AArch64::SUBWrr: Is64Bit = false; return AArch64::SUBSWrr;
150 case AArch64::SUBWrs: Is64Bit = false; return AArch64::SUBSWrs;
151 case AArch64::SUBWrx: Is64Bit = false; return AArch64::SUBSWrx;
153 case AArch64::ADDXri: Is64Bit = true; return AArch64::ADDSXri;
154 case AArch64::ADDXrr: Is64Bit = true; return AArch64::ADDSXrr;
155 case AArch64::ADDXrs: Is64Bit = true; return AArch64::ADDSXrs;
156 case AArch64::ADDXrx: Is64Bit = true; return AArch64::ADDSXrx;
157 case AArch64::ANDXri: Is64Bit = true; return AArch64::ANDSXri;
158 case AArch64::ANDXrr: Is64Bit = true; return AArch64::ANDSXrr;
159 case AArch64::ANDXrs: Is64Bit = true; return AArch64::ANDSXrs;
160 case AArch64::BICXrr: Is64Bit = true; return AArch64::BICSXrr;
161 case AArch64::BICXrs: Is64Bit = true; return AArch64::BICSXrs;
162 case AArch64::SUBXri: Is64Bit = true; return AArch64::SUBSXri;
163 case AArch64::SUBXrr: Is64Bit = true; return AArch64::SUBSXrr;
164 case AArch64::SUBXrs: Is64Bit = true; return AArch64::SUBSXrs;
165 case AArch64::SUBXrx: Is64Bit = true; return AArch64::SUBSXrx;
170 /// Return true if this is a load/store that can be potentially paired/merged.
171 bool isCandidateToMergeOrPair(MachineInstr &MI) const;
173 /// Hint that pairing the given load or store is unprofitable.
174 void suppressLdStPair(MachineInstr &MI) const;
176 bool getMemOpBaseRegImmOfs(MachineInstr &LdSt, unsigned &BaseReg,
178 const TargetRegisterInfo *TRI) const override;
180 bool getMemOpBaseRegImmOfsWidth(MachineInstr &LdSt, unsigned &BaseReg,
181 int64_t &Offset, unsigned &Width,
182 const TargetRegisterInfo *TRI) const;
184 /// Return the immediate offset of the base register in a load/store \p LdSt.
185 MachineOperand &getMemOpBaseRegImmOfsOffsetOperand(MachineInstr &LdSt) const;
187 /// \brief Returns true if opcode \p Opc is a memory operation. If it is, set
188 /// \p Scale, \p Width, \p MinOffset, and \p MaxOffset accordingly.
190 /// For unscaled instructions, \p Scale is set to 1.
191 bool getMemOpInfo(unsigned Opcode, unsigned &Scale, unsigned &Width,
192 int64_t &MinOffset, int64_t &MaxOffset) const;
194 bool shouldClusterMemOps(MachineInstr &FirstLdSt, MachineInstr &SecondLdSt,
195 unsigned NumLoads) const override;
197 MachineInstr *emitFrameIndexDebugValue(MachineFunction &MF, int FrameIx,
198 uint64_t Offset, const MDNode *Var,
200 const DebugLoc &DL) const;
201 void copyPhysRegTuple(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
202 const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
203 bool KillSrc, unsigned Opcode,
204 llvm::ArrayRef<unsigned> Indices) const;
205 void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
206 const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
207 bool KillSrc) const override;
209 void storeRegToStackSlot(MachineBasicBlock &MBB,
210 MachineBasicBlock::iterator MBBI, unsigned SrcReg,
211 bool isKill, int FrameIndex,
212 const TargetRegisterClass *RC,
213 const TargetRegisterInfo *TRI) const override;
215 void loadRegFromStackSlot(MachineBasicBlock &MBB,
216 MachineBasicBlock::iterator MBBI, unsigned DestReg,
217 int FrameIndex, const TargetRegisterClass *RC,
218 const TargetRegisterInfo *TRI) const override;
220 // This tells target independent code that it is okay to pass instructions
221 // with subreg operands to foldMemoryOperandImpl.
222 bool isSubregFoldable() const override { return true; }
224 using TargetInstrInfo::foldMemoryOperandImpl;
226 foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
227 ArrayRef<unsigned> Ops,
228 MachineBasicBlock::iterator InsertPt, int FrameIndex,
229 LiveIntervals *LIS = nullptr) const override;
231 /// \returns true if a branch from an instruction with opcode \p BranchOpc
232 /// bytes is capable of jumping to a position \p BrOffset bytes away.
233 bool isBranchOffsetInRange(unsigned BranchOpc,
234 int64_t BrOffset) const override;
236 MachineBasicBlock *getBranchDestBlock(const MachineInstr &MI) const override;
238 bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
239 MachineBasicBlock *&FBB,
240 SmallVectorImpl<MachineOperand> &Cond,
241 bool AllowModify = false) const override;
242 unsigned removeBranch(MachineBasicBlock &MBB,
243 int *BytesRemoved = nullptr) const override;
244 unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
245 MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
247 int *BytesAdded = nullptr) const override;
249 reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
250 bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
251 unsigned, unsigned, int &, int &, int &) const override;
252 void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
253 const DebugLoc &DL, unsigned DstReg,
254 ArrayRef<MachineOperand> Cond, unsigned TrueReg,
255 unsigned FalseReg) const override;
256 void getNoop(MCInst &NopInst) const override;
258 /// analyzeCompare - For a comparison instruction, return the source registers
259 /// in SrcReg and SrcReg2, and the value it compares against in CmpValue.
260 /// Return true if the comparison instruction can be analyzed.
261 bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
262 unsigned &SrcReg2, int &CmpMask,
263 int &CmpValue) const override;
264 /// optimizeCompareInstr - Convert the instruction supplying the argument to
265 /// the comparison into one that sets the zero bit in the flags register.
266 bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
267 unsigned SrcReg2, int CmpMask, int CmpValue,
268 const MachineRegisterInfo *MRI) const override;
269 bool optimizeCondBranch(MachineInstr &MI) const override;
271 /// Return true when a code sequence can improve throughput. It
272 /// should be called only for instructions in loops.
273 /// \param Pattern - combiner pattern
274 bool isThroughputPattern(MachineCombinerPattern Pattern) const override;
275 /// Return true when there is potentially a faster code sequence
276 /// for an instruction chain ending in ``Root``. All potential patterns are
277 /// listed in the ``Patterns`` array.
278 bool getMachineCombinerPatterns(MachineInstr &Root,
279 SmallVectorImpl<MachineCombinerPattern> &Patterns)
281 /// Return true when Inst is associative and commutative so that it can be
283 bool isAssociativeAndCommutative(const MachineInstr &Inst) const override;
284 /// When getMachineCombinerPatterns() finds patterns, this function generates
285 /// the instructions that could replace the original code sequence
286 void genAlternativeCodeSequence(
287 MachineInstr &Root, MachineCombinerPattern Pattern,
288 SmallVectorImpl<MachineInstr *> &InsInstrs,
289 SmallVectorImpl<MachineInstr *> &DelInstrs,
290 DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;
291 /// AArch64 supports MachineCombiner.
292 bool useMachineCombiner() const override;
294 bool expandPostRAPseudo(MachineInstr &MI) const override;
296 std::pair<unsigned, unsigned>
297 decomposeMachineOperandsTargetFlags(unsigned TF) const override;
298 ArrayRef<std::pair<unsigned, const char *>>
299 getSerializableDirectMachineOperandTargetFlags() const override;
300 ArrayRef<std::pair<unsigned, const char *>>
301 getSerializableBitmaskMachineOperandTargetFlags() const override;
302 ArrayRef<std::pair<MachineMemOperand::Flags, const char *>>
303 getSerializableMachineMemOperandTargetFlags() const override;
305 bool isFunctionSafeToOutlineFrom(MachineFunction &MF) const override;
306 unsigned getOutliningBenefit(size_t SequenceSize, size_t Occurrences,
307 bool CanBeTailCall) const override;
308 AArch64GenInstrInfo::MachineOutlinerInstrType
309 getOutliningType(MachineInstr &MI) const override;
310 void insertOutlinerEpilogue(MachineBasicBlock &MBB,
312 bool IsTailCall) const override;
313 void insertOutlinerPrologue(MachineBasicBlock &MBB,
315 bool isTailCall) const override;
316 MachineBasicBlock::iterator
317 insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
318 MachineBasicBlock::iterator &It,
320 bool IsTailCall) const override;
321 /// Returns true if the instruction has a shift by immediate that can be
322 /// executed in one cycle less.
323 bool isFalkorShiftExtFast(const MachineInstr &MI) const;
326 /// \brief Sets the offsets on outlined instructions in \p MBB which use SP
327 /// so that they will be valid post-outlining.
329 /// \param MBB A \p MachineBasicBlock in an outlined function.
330 void fixupPostOutline(MachineBasicBlock &MBB) const;
332 void instantiateCondBranch(MachineBasicBlock &MBB, const DebugLoc &DL,
333 MachineBasicBlock *TBB,
334 ArrayRef<MachineOperand> Cond) const;
335 bool substituteCmpToZero(MachineInstr &CmpInstr, unsigned SrcReg,
336 const MachineRegisterInfo *MRI) const;
339 /// emitFrameOffset - Emit instructions as needed to set DestReg to SrcReg
340 /// plus Offset. This is intended to be used from within the prolog/epilog
341 /// insertion (PEI) pass, where a virtual scratch register may be allocated
342 /// if necessary, to be replaced by the scavenger at the end of PEI.
343 void emitFrameOffset(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
344 const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
345 int Offset, const TargetInstrInfo *TII,
346 MachineInstr::MIFlag = MachineInstr::NoFlags,
347 bool SetNZCV = false);
349 /// rewriteAArch64FrameIndex - Rewrite MI to access 'Offset' bytes from the
350 /// FP. Return false if the offset could not be handled directly in MI, and
351 /// return the left-over portion by reference.
352 bool rewriteAArch64FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
353 unsigned FrameReg, int &Offset,
354 const AArch64InstrInfo *TII);
356 /// \brief Use to report the frame offset status in isAArch64FrameOffsetLegal.
357 enum AArch64FrameOffsetStatus {
358 AArch64FrameOffsetCannotUpdate = 0x0, ///< Offset cannot apply.
359 AArch64FrameOffsetIsLegal = 0x1, ///< Offset is legal.
360 AArch64FrameOffsetCanUpdate = 0x2 ///< Offset can apply, at least partly.
363 /// \brief Check if the @p Offset is a valid frame offset for @p MI.
364 /// The returned value reports the validity of the frame offset for @p MI.
365 /// It uses the values defined by AArch64FrameOffsetStatus for that.
366 /// If result == AArch64FrameOffsetCannotUpdate, @p MI cannot be updated to
368 /// If result & AArch64FrameOffsetIsLegal, @p Offset can completely be
369 /// rewritten in @p MI.
370 /// If result & AArch64FrameOffsetCanUpdate, @p Offset contains the
371 /// amount that is off the limit of the legal offset.
372 /// If set, @p OutUseUnscaledOp will contain the whether @p MI should be
373 /// turned into an unscaled operator, which opcode is in @p OutUnscaledOp.
374 /// If set, @p EmittableOffset contains the amount that can be set in @p MI
375 /// (possibly with @p OutUnscaledOp if OutUseUnscaledOp is true) and that
376 /// is a legal offset.
377 int isAArch64FrameOffsetLegal(const MachineInstr &MI, int &Offset,
378 bool *OutUseUnscaledOp = nullptr,
379 unsigned *OutUnscaledOp = nullptr,
380 int *EmittableOffset = nullptr);
382 static inline bool isUncondBranchOpcode(int Opc) { return Opc == AArch64::B; }
384 static inline bool isCondBranchOpcode(int Opc) {
401 static inline bool isIndirectBranchOpcode(int Opc) { return Opc == AArch64::BR; }
403 } // end namespace llvm