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/Support/TypeSize.h" 17 #include "llvm/CodeGen/TargetFrameLowering.h" 18 19 namespace llvm { 20 21 class AArch64FrameLowering : public TargetFrameLowering { 22 public: 23 explicit AArch64FrameLowering() 24 : TargetFrameLowering(StackGrowsDown, Align(16), 0, Align(16), 25 true /*StackRealignable*/) {} 26 27 void resetCFIToInitialState(MachineBasicBlock &MBB) const override; 28 29 MachineBasicBlock::iterator 30 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 31 MachineBasicBlock::iterator I) const override; 32 33 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into 34 /// the function. 35 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 36 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 37 38 bool canUseAsPrologue(const MachineBasicBlock &MBB) const override; 39 40 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI, 41 Register &FrameReg) const override; 42 StackOffset resolveFrameIndexReference(const MachineFunction &MF, int FI, 43 Register &FrameReg, bool PreferFP, 44 bool ForSimm) const; 45 StackOffset resolveFrameOffsetReference(const MachineFunction &MF, 46 int64_t ObjectOffset, bool isFixed, 47 bool isSVE, Register &FrameReg, 48 bool PreferFP, bool ForSimm) const; 49 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 50 MachineBasicBlock::iterator MI, 51 ArrayRef<CalleeSavedInfo> CSI, 52 const TargetRegisterInfo *TRI) const override; 53 54 bool 55 restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 56 MachineBasicBlock::iterator MI, 57 MutableArrayRef<CalleeSavedInfo> CSI, 58 const TargetRegisterInfo *TRI) const override; 59 60 /// Can this function use the red zone for local allocations. 61 bool canUseRedZone(const MachineFunction &MF) const; 62 63 bool hasFP(const MachineFunction &MF) const override; 64 bool hasReservedCallFrame(const MachineFunction &MF) const override; 65 66 bool assignCalleeSavedSpillSlots(MachineFunction &MF, 67 const TargetRegisterInfo *TRI, 68 std::vector<CalleeSavedInfo> &CSI, 69 unsigned &MinCSFrameIndex, 70 unsigned &MaxCSFrameIndex) const override; 71 72 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 73 RegScavenger *RS) const override; 74 75 /// Returns true if the target will correctly handle shrink wrapping. 76 bool enableShrinkWrapping(const MachineFunction &MF) const override { 77 return true; 78 } 79 80 bool enableStackSlotScavenging(const MachineFunction &MF) const override; 81 TargetStackID::Value getStackIDForScalableVectors() const override; 82 83 void processFunctionBeforeFrameFinalized(MachineFunction &MF, 84 RegScavenger *RS) const override; 85 86 void 87 processFunctionBeforeFrameIndicesReplaced(MachineFunction &MF, 88 RegScavenger *RS) const override; 89 90 unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override; 91 92 unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const; 93 94 StackOffset 95 getFrameIndexReferencePreferSP(const MachineFunction &MF, int FI, 96 Register &FrameReg, 97 bool IgnoreSPUpdates) const override; 98 StackOffset getNonLocalFrameIndexReference(const MachineFunction &MF, 99 int FI) const override; 100 int getSEHFrameIndexOffset(const MachineFunction &MF, int FI) const; 101 102 bool isSupportedStackID(TargetStackID::Value ID) const override { 103 switch (ID) { 104 default: 105 return false; 106 case TargetStackID::Default: 107 case TargetStackID::ScalableVector: 108 case TargetStackID::NoAlloc: 109 return true; 110 } 111 } 112 113 bool isStackIdSafeForLocalArea(unsigned StackId) const override { 114 // We don't support putting SVE objects into the pre-allocated local 115 // frame block at the moment. 116 return StackId != TargetStackID::ScalableVector; 117 } 118 119 void 120 orderFrameObjects(const MachineFunction &MF, 121 SmallVectorImpl<int> &ObjectsToAllocate) const override; 122 123 private: 124 /// Returns true if a homogeneous prolog or epilog code can be emitted 125 /// for the size optimization. If so, HOM_Prolog/HOM_Epilog pseudo 126 /// instructions are emitted in place. When Exit block is given, this check is 127 /// for epilog. 128 bool homogeneousPrologEpilog(MachineFunction &MF, 129 MachineBasicBlock *Exit = nullptr) const; 130 131 /// Returns true if CSRs should be paired. 132 bool producePairRegisters(MachineFunction &MF) const; 133 134 bool shouldCombineCSRLocalStackBump(MachineFunction &MF, 135 uint64_t StackBumpBytes) const; 136 137 int64_t estimateSVEStackObjectOffsets(MachineFrameInfo &MF) const; 138 int64_t assignSVEStackObjectOffsets(MachineFrameInfo &MF, 139 int &MinCSFrameIndex, 140 int &MaxCSFrameIndex) const; 141 bool shouldCombineCSRLocalStackBumpInEpilogue(MachineBasicBlock &MBB, 142 unsigned StackBumpBytes) const; 143 void emitCalleeSavedGPRLocations(MachineBasicBlock &MBB, 144 MachineBasicBlock::iterator MBBI) const; 145 void emitCalleeSavedSVELocations(MachineBasicBlock &MBB, 146 MachineBasicBlock::iterator MBBI) const; 147 void emitCalleeSavedGPRRestores(MachineBasicBlock &MBB, 148 MachineBasicBlock::iterator MBBI) const; 149 void emitCalleeSavedSVERestores(MachineBasicBlock &MBB, 150 MachineBasicBlock::iterator MBBI) const; 151 152 /// Emit target zero call-used regs. 153 void emitZeroCallUsedRegs(BitVector RegsToZero, 154 MachineBasicBlock &MBB) const override; 155 }; 156 157 } // End llvm namespace 158 159 #endif 160