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: 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 bool enableCFIFixup(MachineFunction &MF) const override; 40 41 bool canUseAsPrologue(const MachineBasicBlock &MBB) const override; 42 43 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI, 44 Register &FrameReg) const override; 45 StackOffset getFrameIndexReferenceFromSP(const MachineFunction &MF, 46 int FI) const override; 47 StackOffset resolveFrameIndexReference(const MachineFunction &MF, int FI, 48 Register &FrameReg, bool PreferFP, 49 bool ForSimm) const; 50 StackOffset resolveFrameOffsetReference(const MachineFunction &MF, 51 int64_t ObjectOffset, bool isFixed, 52 bool isSVE, Register &FrameReg, 53 bool PreferFP, bool ForSimm) const; 54 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 55 MachineBasicBlock::iterator MI, 56 ArrayRef<CalleeSavedInfo> CSI, 57 const TargetRegisterInfo *TRI) const override; 58 59 bool 60 restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 61 MachineBasicBlock::iterator MI, 62 MutableArrayRef<CalleeSavedInfo> CSI, 63 const TargetRegisterInfo *TRI) const override; 64 65 /// Can this function use the red zone for local allocations. 66 bool canUseRedZone(const MachineFunction &MF) const; 67 68 bool hasReservedCallFrame(const MachineFunction &MF) const override; 69 70 bool assignCalleeSavedSpillSlots(MachineFunction &MF, 71 const TargetRegisterInfo *TRI, 72 std::vector<CalleeSavedInfo> &CSI, 73 unsigned &MinCSFrameIndex, 74 unsigned &MaxCSFrameIndex) const override; 75 76 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 77 RegScavenger *RS) const override; 78 79 /// Returns true if the target will correctly handle shrink wrapping. 80 bool enableShrinkWrapping(const MachineFunction &MF) const override { 81 return true; 82 } 83 84 bool enableStackSlotScavenging(const MachineFunction &MF) const override; 85 TargetStackID::Value getStackIDForScalableVectors() const override; 86 87 void processFunctionBeforeFrameFinalized(MachineFunction &MF, 88 RegScavenger *RS) const override; 89 90 void 91 processFunctionBeforeFrameIndicesReplaced(MachineFunction &MF, 92 RegScavenger *RS) const override; 93 94 unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override; 95 96 unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const; 97 98 StackOffset 99 getFrameIndexReferencePreferSP(const MachineFunction &MF, int FI, 100 Register &FrameReg, 101 bool IgnoreSPUpdates) const override; 102 StackOffset getNonLocalFrameIndexReference(const MachineFunction &MF, 103 int FI) const override; 104 int getSEHFrameIndexOffset(const MachineFunction &MF, int FI) const; 105 106 bool isSupportedStackID(TargetStackID::Value ID) const override { 107 switch (ID) { 108 default: 109 return false; 110 case TargetStackID::Default: 111 case TargetStackID::ScalableVector: 112 case TargetStackID::NoAlloc: 113 return true; 114 } 115 } 116 117 bool isStackIdSafeForLocalArea(unsigned StackId) const override { 118 // We don't support putting SVE objects into the pre-allocated local 119 // frame block at the moment. 120 return StackId != TargetStackID::ScalableVector; 121 } 122 123 void 124 orderFrameObjects(const MachineFunction &MF, 125 SmallVectorImpl<int> &ObjectsToAllocate) const override; 126 127 protected: 128 bool hasFPImpl(const MachineFunction &MF) const override; 129 130 private: 131 /// Returns true if a homogeneous prolog or epilog code can be emitted 132 /// for the size optimization. If so, HOM_Prolog/HOM_Epilog pseudo 133 /// instructions are emitted in place. When Exit block is given, this check is 134 /// for epilog. 135 bool homogeneousPrologEpilog(MachineFunction &MF, 136 MachineBasicBlock *Exit = nullptr) const; 137 138 /// Returns true if CSRs should be paired. 139 bool producePairRegisters(MachineFunction &MF) const; 140 141 bool shouldCombineCSRLocalStackBump(MachineFunction &MF, 142 uint64_t StackBumpBytes) const; 143 144 int64_t estimateSVEStackObjectOffsets(MachineFrameInfo &MF) const; 145 int64_t assignSVEStackObjectOffsets(MachineFrameInfo &MF, 146 int &MinCSFrameIndex, 147 int &MaxCSFrameIndex) const; 148 bool shouldCombineCSRLocalStackBumpInEpilogue(MachineBasicBlock &MBB, 149 uint64_t StackBumpBytes) const; 150 void emitCalleeSavedGPRLocations(MachineBasicBlock &MBB, 151 MachineBasicBlock::iterator MBBI) const; 152 void emitCalleeSavedSVELocations(MachineBasicBlock &MBB, 153 MachineBasicBlock::iterator MBBI) const; 154 void emitCalleeSavedGPRRestores(MachineBasicBlock &MBB, 155 MachineBasicBlock::iterator MBBI) const; 156 void emitCalleeSavedSVERestores(MachineBasicBlock &MBB, 157 MachineBasicBlock::iterator MBBI) const; 158 void allocateStackSpace(MachineBasicBlock &MBB, 159 MachineBasicBlock::iterator MBBI, 160 int64_t RealignmentPadding, StackOffset AllocSize, 161 bool NeedsWinCFI, bool *HasWinCFI, bool EmitCFI, 162 StackOffset InitialOffset, bool FollowupAllocs) const; 163 /// Make a determination whether a Hazard slot is used and create it if 164 /// needed. 165 void determineStackHazardSlot(MachineFunction &MF, 166 BitVector &SavedRegs) const; 167 168 /// Emit target zero call-used regs. 169 void emitZeroCallUsedRegs(BitVector RegsToZero, 170 MachineBasicBlock &MBB) const override; 171 172 /// Replace a StackProbe stub (if any) with the actual probe code inline 173 void inlineStackProbe(MachineFunction &MF, 174 MachineBasicBlock &PrologueMBB) const override; 175 176 void inlineStackProbeFixed(MachineBasicBlock::iterator MBBI, 177 Register ScratchReg, int64_t FrameSize, 178 StackOffset CFAOffset) const; 179 180 MachineBasicBlock::iterator 181 inlineStackProbeLoopExactMultiple(MachineBasicBlock::iterator MBBI, 182 int64_t NegProbeSize, 183 Register TargetReg) const; 184 185 void emitRemarks(const MachineFunction &MF, 186 MachineOptimizationRemarkEmitter *ORE) const override; 187 }; 188 189 } // End llvm namespace 190 191 #endif 192