1 //===- AArch64InstrInfo.h - AArch64 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 AArch64 implementation of the TargetInstrInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #ifndef LLVM_TARGET_AArch64INSTRINFO_H
15 #define LLVM_TARGET_AArch64INSTRINFO_H
16
17 #include "AArch64.h"
18 #include "AArch64RegisterInfo.h"
19 #include "llvm/Target/TargetInstrInfo.h"
20
21 #define GET_INSTRINFO_HEADER
22 #include "AArch64GenInstrInfo.inc"
23
24 namespace llvm {
25
26 class AArch64Subtarget;
27 class AArch64TargetMachine;
28
29 class AArch64InstrInfo : public AArch64GenInstrInfo {
30 // Reserve bits in the MachineMemOperand target hint flags, starting at 1.
31 // They will be shifted into MOTargetHintStart when accessed.
32 enum TargetMemOperandFlags {
33 MOSuppressPair = 1
34 };
35
36 const AArch64RegisterInfo RI;
37 const AArch64Subtarget &Subtarget;
38
39 public:
40 explicit AArch64InstrInfo(const AArch64Subtarget &STI);
41
42 /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info. As
43 /// such, whenever a client has an instance of instruction info, it should
44 /// always be able to get register info as well (through this method).
getRegisterInfo()45 const AArch64RegisterInfo &getRegisterInfo() const { return RI; }
46
47 unsigned GetInstSizeInBytes(const MachineInstr *MI) const;
48
49 bool isAsCheapAsAMove(const MachineInstr *MI) const override;
50
51 bool isCoalescableExtInstr(const MachineInstr &MI, unsigned &SrcReg,
52 unsigned &DstReg, unsigned &SubIdx) const override;
53
54 unsigned isLoadFromStackSlot(const MachineInstr *MI,
55 int &FrameIndex) const override;
56 unsigned isStoreToStackSlot(const MachineInstr *MI,
57 int &FrameIndex) const override;
58
59 /// Returns true if there is a shiftable register and that the shift value
60 /// is non-zero.
61 bool hasShiftedReg(const MachineInstr *MI) const;
62
63 /// Returns true if there is an extendable register and that the extending
64 /// value is non-zero.
65 bool hasExtendedReg(const MachineInstr *MI) const;
66
67 /// \brief Does this instruction set its full destination register to zero?
68 bool isGPRZero(const MachineInstr *MI) const;
69
70 /// \brief Does this instruction rename a GPR without modifying bits?
71 bool isGPRCopy(const MachineInstr *MI) const;
72
73 /// \brief Does this instruction rename an FPR without modifying bits?
74 bool isFPRCopy(const MachineInstr *MI) const;
75
76 /// Return true if this is load/store scales or extends its register offset.
77 /// This refers to scaling a dynamic index as opposed to scaled immediates.
78 /// MI should be a memory op that allows scaled addressing.
79 bool isScaledAddr(const MachineInstr *MI) const;
80
81 /// Return true if pairing the given load or store is hinted to be
82 /// unprofitable.
83 bool isLdStPairSuppressed(const MachineInstr *MI) const;
84
85 /// Hint that pairing the given load or store is unprofitable.
86 void suppressLdStPair(MachineInstr *MI) const;
87
88 bool getLdStBaseRegImmOfs(MachineInstr *LdSt, unsigned &BaseReg,
89 unsigned &Offset,
90 const TargetRegisterInfo *TRI) const override;
91
enableClusterLoads()92 bool enableClusterLoads() const override { return true; }
93
94 bool shouldClusterLoads(MachineInstr *FirstLdSt, MachineInstr *SecondLdSt,
95 unsigned NumLoads) const override;
96
97 bool shouldScheduleAdjacent(MachineInstr *First,
98 MachineInstr *Second) const override;
99
100 MachineInstr *emitFrameIndexDebugValue(MachineFunction &MF, int FrameIx,
101 uint64_t Offset, const MDNode *MDPtr,
102 DebugLoc DL) const;
103 void copyPhysRegTuple(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
104 DebugLoc DL, unsigned DestReg, unsigned SrcReg,
105 bool KillSrc, unsigned Opcode,
106 llvm::ArrayRef<unsigned> Indices) const;
107 void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
108 DebugLoc DL, unsigned DestReg, unsigned SrcReg,
109 bool KillSrc) const override;
110
111 void storeRegToStackSlot(MachineBasicBlock &MBB,
112 MachineBasicBlock::iterator MBBI, unsigned SrcReg,
113 bool isKill, int FrameIndex,
114 const TargetRegisterClass *RC,
115 const TargetRegisterInfo *TRI) const override;
116
117 void loadRegFromStackSlot(MachineBasicBlock &MBB,
118 MachineBasicBlock::iterator MBBI, unsigned DestReg,
119 int FrameIndex, const TargetRegisterClass *RC,
120 const TargetRegisterInfo *TRI) const override;
121
122 MachineInstr *
123 foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
124 const SmallVectorImpl<unsigned> &Ops,
125 int FrameIndex) const override;
126
127 bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
128 MachineBasicBlock *&FBB,
129 SmallVectorImpl<MachineOperand> &Cond,
130 bool AllowModify = false) const override;
131 unsigned RemoveBranch(MachineBasicBlock &MBB) const override;
132 unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
133 MachineBasicBlock *FBB,
134 const SmallVectorImpl<MachineOperand> &Cond,
135 DebugLoc DL) const override;
136 bool
137 ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
138 bool canInsertSelect(const MachineBasicBlock &,
139 const SmallVectorImpl<MachineOperand> &Cond, unsigned,
140 unsigned, int &, int &, int &) const override;
141 void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
142 DebugLoc DL, unsigned DstReg,
143 const SmallVectorImpl<MachineOperand> &Cond,
144 unsigned TrueReg, unsigned FalseReg) const override;
145 void getNoopForMachoTarget(MCInst &NopInst) const override;
146
147 /// analyzeCompare - For a comparison instruction, return the source registers
148 /// in SrcReg and SrcReg2, and the value it compares against in CmpValue.
149 /// Return true if the comparison instruction can be analyzed.
150 bool analyzeCompare(const MachineInstr *MI, unsigned &SrcReg,
151 unsigned &SrcReg2, int &CmpMask,
152 int &CmpValue) const override;
153 /// optimizeCompareInstr - Convert the instruction supplying the argument to
154 /// the comparison into one that sets the zero bit in the flags register.
155 bool optimizeCompareInstr(MachineInstr *CmpInstr, unsigned SrcReg,
156 unsigned SrcReg2, int CmpMask, int CmpValue,
157 const MachineRegisterInfo *MRI) const override;
158
159 private:
160 void instantiateCondBranch(MachineBasicBlock &MBB, DebugLoc DL,
161 MachineBasicBlock *TBB,
162 const SmallVectorImpl<MachineOperand> &Cond) const;
163 };
164
165 /// emitFrameOffset - Emit instructions as needed to set DestReg to SrcReg
166 /// plus Offset. This is intended to be used from within the prolog/epilog
167 /// insertion (PEI) pass, where a virtual scratch register may be allocated
168 /// if necessary, to be replaced by the scavenger at the end of PEI.
169 void emitFrameOffset(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
170 DebugLoc DL, unsigned DestReg, unsigned SrcReg, int Offset,
171 const TargetInstrInfo *TII,
172 MachineInstr::MIFlag = MachineInstr::NoFlags,
173 bool SetNZCV = false);
174
175 /// rewriteAArch64FrameIndex - Rewrite MI to access 'Offset' bytes from the
176 /// FP. Return false if the offset could not be handled directly in MI, and
177 /// return the left-over portion by reference.
178 bool rewriteAArch64FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
179 unsigned FrameReg, int &Offset,
180 const AArch64InstrInfo *TII);
181
182 /// \brief Use to report the frame offset status in isAArch64FrameOffsetLegal.
183 enum AArch64FrameOffsetStatus {
184 AArch64FrameOffsetCannotUpdate = 0x0, ///< Offset cannot apply.
185 AArch64FrameOffsetIsLegal = 0x1, ///< Offset is legal.
186 AArch64FrameOffsetCanUpdate = 0x2 ///< Offset can apply, at least partly.
187 };
188
189 /// \brief Check if the @p Offset is a valid frame offset for @p MI.
190 /// The returned value reports the validity of the frame offset for @p MI.
191 /// It uses the values defined by AArch64FrameOffsetStatus for that.
192 /// If result == AArch64FrameOffsetCannotUpdate, @p MI cannot be updated to
193 /// use an offset.eq
194 /// If result & AArch64FrameOffsetIsLegal, @p Offset can completely be
195 /// rewriten in @p MI.
196 /// If result & AArch64FrameOffsetCanUpdate, @p Offset contains the
197 /// amount that is off the limit of the legal offset.
198 /// If set, @p OutUseUnscaledOp will contain the whether @p MI should be
199 /// turned into an unscaled operator, which opcode is in @p OutUnscaledOp.
200 /// If set, @p EmittableOffset contains the amount that can be set in @p MI
201 /// (possibly with @p OutUnscaledOp if OutUseUnscaledOp is true) and that
202 /// is a legal offset.
203 int isAArch64FrameOffsetLegal(const MachineInstr &MI, int &Offset,
204 bool *OutUseUnscaledOp = nullptr,
205 unsigned *OutUnscaledOp = nullptr,
206 int *EmittableOffset = nullptr);
207
isUncondBranchOpcode(int Opc)208 static inline bool isUncondBranchOpcode(int Opc) { return Opc == AArch64::B; }
209
isCondBranchOpcode(int Opc)210 static inline bool isCondBranchOpcode(int Opc) {
211 switch (Opc) {
212 case AArch64::Bcc:
213 case AArch64::CBZW:
214 case AArch64::CBZX:
215 case AArch64::CBNZW:
216 case AArch64::CBNZX:
217 case AArch64::TBZW:
218 case AArch64::TBZX:
219 case AArch64::TBNZW:
220 case AArch64::TBNZX:
221 return true;
222 default:
223 return false;
224 }
225 }
226
isIndirectBranchOpcode(int Opc)227 static inline bool isIndirectBranchOpcode(int Opc) { return Opc == AArch64::BR; }
228
229 } // end namespace llvm
230
231 #endif
232