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