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 30 emitCalleeSavedFrameMoves(MachineBasicBlock &MBB, 31 MachineBasicBlock::iterator MBBI) const override; 32 33 MachineBasicBlock::iterator 34 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 35 MachineBasicBlock::iterator I) const override; 36 37 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into 38 /// the function. 39 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 40 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 41 42 bool canUseAsPrologue(const MachineBasicBlock &MBB) const override; 43 44 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI, 45 Register &FrameReg) const override; 46 StackOffset resolveFrameIndexReference(const MachineFunction &MF, int FI, 47 Register &FrameReg, bool PreferFP, 48 bool ForSimm) const; 49 StackOffset resolveFrameOffsetReference(const MachineFunction &MF, 50 int64_t ObjectOffset, bool isFixed, 51 bool isSVE, Register &FrameReg, 52 bool PreferFP, bool ForSimm) const; 53 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 54 MachineBasicBlock::iterator MI, 55 ArrayRef<CalleeSavedInfo> CSI, 56 const TargetRegisterInfo *TRI) const override; 57 58 bool 59 restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 60 MachineBasicBlock::iterator MI, 61 MutableArrayRef<CalleeSavedInfo> CSI, 62 const TargetRegisterInfo *TRI) const override; 63 64 /// Can this function use the red zone for local allocations. 65 bool canUseRedZone(const MachineFunction &MF) const; 66 67 bool hasFP(const MachineFunction &MF) const override; 68 bool hasReservedCallFrame(const MachineFunction &MF) const override; 69 70 bool 71 assignCalleeSavedSpillSlots(MachineFunction &MF, 72 const TargetRegisterInfo *TRI, 73 std::vector<CalleeSavedInfo> &CSI) 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 bool shouldCombineCSRLocalStackBump(MachineFunction &MF, 128 uint64_t StackBumpBytes) const; 129 130 int64_t estimateSVEStackObjectOffsets(MachineFrameInfo &MF) const; 131 int64_t assignSVEStackObjectOffsets(MachineFrameInfo &MF, 132 int &MinCSFrameIndex, 133 int &MaxCSFrameIndex) const; 134 MCCFIInstruction 135 createDefCFAExpressionFromSP(const TargetRegisterInfo &TRI, 136 const StackOffset &OffsetFromSP) const; 137 MCCFIInstruction createCfaOffset(const TargetRegisterInfo &MRI, unsigned DwarfReg, 138 const StackOffset &OffsetFromDefCFA) const; 139 bool shouldCombineCSRLocalStackBumpInEpilogue(MachineBasicBlock &MBB, 140 unsigned StackBumpBytes) const; 141 }; 142 143 } // End llvm namespace 144 145 #endif 146