1 //==-- AArch64FrameLowering.h - TargetFrameLowering for AArch64 --*- 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 // 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_LIB_TARGET_AARCH64_AARCH64FRAMELOWERING_H 14 #define LLVM_LIB_TARGET_AARCH64_AARCH64FRAMELOWERING_H 15 16 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h" 17 #include "llvm/CodeGen/TargetFrameLowering.h" 18 #include "llvm/Support/TypeSize.h" 19 20 namespace llvm { 21 22 class AArch64FrameLowering : public TargetFrameLowering { 23 public: AArch64FrameLowering()24 explicit AArch64FrameLowering() 25 : TargetFrameLowering(StackGrowsDown, Align(16), 0, Align(16), 26 true /*StackRealignable*/) {} 27 28 void resetCFIToInitialState(MachineBasicBlock &MBB) const override; 29 30 MachineBasicBlock::iterator 31 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 32 MachineBasicBlock::iterator I) const override; 33 34 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into 35 /// the function. 36 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 37 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 38 39 /// Harden the entire function with pac-ret. 40 /// 41 /// If pac-ret+leaf is requested, we want to harden as much code as possible. 42 /// This function inserts pac-ret hardening at the points where prologue and 43 /// epilogue are traditionally inserted, ignoring possible shrink-wrapping 44 /// optimization. 45 void emitPacRetPlusLeafHardening(MachineFunction &MF) const; 46 47 bool enableCFIFixup(const MachineFunction &MF) const override; 48 49 bool enableFullCFIFixup(const MachineFunction &MF) const override; 50 51 bool canUseAsPrologue(const MachineBasicBlock &MBB) const override; 52 53 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI, 54 Register &FrameReg) const override; 55 StackOffset getFrameIndexReferenceFromSP(const MachineFunction &MF, 56 int FI) const override; 57 StackOffset resolveFrameIndexReference(const MachineFunction &MF, int FI, 58 Register &FrameReg, bool PreferFP, 59 bool ForSimm) const; 60 StackOffset resolveFrameOffsetReference(const MachineFunction &MF, 61 int64_t ObjectOffset, bool isFixed, 62 bool isSVE, Register &FrameReg, 63 bool PreferFP, bool ForSimm) const; 64 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 65 MachineBasicBlock::iterator MI, 66 ArrayRef<CalleeSavedInfo> CSI, 67 const TargetRegisterInfo *TRI) const override; 68 69 bool 70 restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 71 MachineBasicBlock::iterator MI, 72 MutableArrayRef<CalleeSavedInfo> CSI, 73 const TargetRegisterInfo *TRI) const override; 74 75 /// Can this function use the red zone for local allocations. 76 bool canUseRedZone(const MachineFunction &MF) const; 77 78 bool hasReservedCallFrame(const MachineFunction &MF) const override; 79 80 bool assignCalleeSavedSpillSlots(MachineFunction &MF, 81 const TargetRegisterInfo *TRI, 82 std::vector<CalleeSavedInfo> &CSI, 83 unsigned &MinCSFrameIndex, 84 unsigned &MaxCSFrameIndex) const override; 85 86 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 87 RegScavenger *RS) const override; 88 89 /// Returns true if the target will correctly handle shrink wrapping. enableShrinkWrapping(const MachineFunction & MF)90 bool enableShrinkWrapping(const MachineFunction &MF) const override { 91 return true; 92 } 93 94 bool enableStackSlotScavenging(const MachineFunction &MF) const override; 95 TargetStackID::Value getStackIDForScalableVectors() const override; 96 97 void processFunctionBeforeFrameFinalized(MachineFunction &MF, 98 RegScavenger *RS) const override; 99 100 void 101 processFunctionBeforeFrameIndicesReplaced(MachineFunction &MF, 102 RegScavenger *RS) const override; 103 104 unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override; 105 106 unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const; 107 108 StackOffset 109 getFrameIndexReferencePreferSP(const MachineFunction &MF, int FI, 110 Register &FrameReg, 111 bool IgnoreSPUpdates) const override; 112 StackOffset getNonLocalFrameIndexReference(const MachineFunction &MF, 113 int FI) const override; 114 int getSEHFrameIndexOffset(const MachineFunction &MF, int FI) const; 115 isSupportedStackID(TargetStackID::Value ID)116 bool isSupportedStackID(TargetStackID::Value ID) const override { 117 switch (ID) { 118 default: 119 return false; 120 case TargetStackID::Default: 121 case TargetStackID::ScalableVector: 122 case TargetStackID::NoAlloc: 123 return true; 124 } 125 } 126 isStackIdSafeForLocalArea(unsigned StackId)127 bool isStackIdSafeForLocalArea(unsigned StackId) const override { 128 // We don't support putting SVE objects into the pre-allocated local 129 // frame block at the moment. 130 return StackId != TargetStackID::ScalableVector; 131 } 132 133 void 134 orderFrameObjects(const MachineFunction &MF, 135 SmallVectorImpl<int> &ObjectsToAllocate) const override; 136 137 bool isFPReserved(const MachineFunction &MF) const; 138 139 protected: 140 bool hasFPImpl(const MachineFunction &MF) const override; 141 142 private: 143 /// Returns true if a homogeneous prolog or epilog code can be emitted 144 /// for the size optimization. If so, HOM_Prolog/HOM_Epilog pseudo 145 /// instructions are emitted in place. When Exit block is given, this check is 146 /// for epilog. 147 bool homogeneousPrologEpilog(MachineFunction &MF, 148 MachineBasicBlock *Exit = nullptr) const; 149 150 /// Returns true if CSRs should be paired. 151 bool producePairRegisters(MachineFunction &MF) const; 152 153 bool shouldCombineCSRLocalStackBump(MachineFunction &MF, 154 uint64_t StackBumpBytes) const; 155 156 int64_t estimateSVEStackObjectOffsets(MachineFrameInfo &MF) const; 157 int64_t assignSVEStackObjectOffsets(MachineFrameInfo &MF, 158 int &MinCSFrameIndex, 159 int &MaxCSFrameIndex) const; 160 bool shouldCombineCSRLocalStackBumpInEpilogue(MachineBasicBlock &MBB, 161 uint64_t StackBumpBytes) const; 162 void emitCalleeSavedGPRLocations(MachineBasicBlock &MBB, 163 MachineBasicBlock::iterator MBBI) const; 164 void emitCalleeSavedSVELocations(MachineBasicBlock &MBB, 165 MachineBasicBlock::iterator MBBI) const; 166 void emitCalleeSavedGPRRestores(MachineBasicBlock &MBB, 167 MachineBasicBlock::iterator MBBI) const; 168 void emitCalleeSavedSVERestores(MachineBasicBlock &MBB, 169 MachineBasicBlock::iterator MBBI) const; 170 void allocateStackSpace(MachineBasicBlock &MBB, 171 MachineBasicBlock::iterator MBBI, 172 int64_t RealignmentPadding, StackOffset AllocSize, 173 bool NeedsWinCFI, bool *HasWinCFI, bool EmitCFI, 174 StackOffset InitialOffset, bool FollowupAllocs) const; 175 /// Make a determination whether a Hazard slot is used and create it if 176 /// needed. 177 void determineStackHazardSlot(MachineFunction &MF, 178 BitVector &SavedRegs) const; 179 180 /// Emit target zero call-used regs. 181 void emitZeroCallUsedRegs(BitVector RegsToZero, 182 MachineBasicBlock &MBB) const override; 183 184 /// Replace a StackProbe stub (if any) with the actual probe code inline 185 void inlineStackProbe(MachineFunction &MF, 186 MachineBasicBlock &PrologueMBB) const override; 187 188 void inlineStackProbeFixed(MachineBasicBlock::iterator MBBI, 189 Register ScratchReg, int64_t FrameSize, 190 StackOffset CFAOffset) const; 191 192 MachineBasicBlock::iterator 193 inlineStackProbeLoopExactMultiple(MachineBasicBlock::iterator MBBI, 194 int64_t NegProbeSize, 195 Register TargetReg) const; 196 197 void emitRemarks(const MachineFunction &MF, 198 MachineOptimizationRemarkEmitter *ORE) const override; 199 }; 200 201 } // End llvm namespace 202 203 #endif 204