1 //==- HexagonFrameLowering.h - Define frame lowering for Hexagon -*- 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 #ifndef LLVM_LIB_TARGET_HEXAGON_HEXAGONFRAMELOWERING_H 10 #define LLVM_LIB_TARGET_HEXAGON_HEXAGONFRAMELOWERING_H 11 12 #include "Hexagon.h" 13 #include "HexagonBlockRanges.h" 14 #include "MCTargetDesc/HexagonMCTargetDesc.h" 15 #include "llvm/ADT/STLExtras.h" 16 #include "llvm/CodeGen/MachineBasicBlock.h" 17 #include "llvm/CodeGen/MachineFrameInfo.h" 18 #include "llvm/CodeGen/TargetFrameLowering.h" 19 #include <vector> 20 21 namespace llvm { 22 23 class BitVector; 24 class HexagonInstrInfo; 25 class HexagonRegisterInfo; 26 class MachineFunction; 27 class MachineInstr; 28 class MachineRegisterInfo; 29 class TargetRegisterClass; 30 31 class HexagonFrameLowering : public TargetFrameLowering { 32 public: 33 // First register which could possibly hold a variable argument. 34 int FirstVarArgSavedReg; HexagonFrameLowering()35 explicit HexagonFrameLowering() 36 : TargetFrameLowering(StackGrowsDown, Align(8), 0, Align(1), true) {} 37 38 // All of the prolog/epilog functionality, including saving and restoring 39 // callee-saved registers is handled in emitPrologue. This is to have the 40 // logic for shrink-wrapping in one place. 41 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const 42 override; emitEpilogue(MachineFunction & MF,MachineBasicBlock & MBB)43 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const 44 override {} 45 46 bool enableCalleeSaveSkip(const MachineFunction &MF) const override; 47 spillCalleeSavedRegisters(MachineBasicBlock & MBB,MachineBasicBlock::iterator MI,ArrayRef<CalleeSavedInfo> CSI,const TargetRegisterInfo * TRI)48 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 49 MachineBasicBlock::iterator MI, 50 ArrayRef<CalleeSavedInfo> CSI, 51 const TargetRegisterInfo *TRI) const override { 52 return true; 53 } 54 55 bool restoreCalleeSavedRegisters(MachineBasicBlock & MBB,MachineBasicBlock::iterator MI,MutableArrayRef<CalleeSavedInfo> CSI,const TargetRegisterInfo * TRI)56 restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 57 MachineBasicBlock::iterator MI, 58 MutableArrayRef<CalleeSavedInfo> CSI, 59 const TargetRegisterInfo *TRI) const override { 60 return true; 61 } 62 hasReservedCallFrame(const MachineFunction & MF)63 bool hasReservedCallFrame(const MachineFunction &MF) const override { 64 // We always reserve call frame as a part of the initial stack allocation. 65 return true; 66 } 67 canSimplifyCallFramePseudos(const MachineFunction & MF)68 bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override { 69 // Override this function to avoid calling hasFP before CSI is set 70 // (the default implementation calls hasFP). 71 return true; 72 } 73 74 MachineBasicBlock::iterator 75 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 76 MachineBasicBlock::iterator I) const override; 77 void processFunctionBeforeFrameFinalized(MachineFunction &MF, 78 RegScavenger *RS = nullptr) const override; 79 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 80 RegScavenger *RS) const override; 81 targetHandlesStackFrameRounding()82 bool targetHandlesStackFrameRounding() const override { 83 return true; 84 } 85 86 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI, 87 Register &FrameReg) const override; 88 bool hasFP(const MachineFunction &MF) const override; 89 getCalleeSavedSpillSlots(unsigned & NumEntries)90 const SpillSlot *getCalleeSavedSpillSlots(unsigned &NumEntries) 91 const override { 92 static const SpillSlot Offsets[] = { 93 { Hexagon::R17, -4 }, { Hexagon::R16, -8 }, { Hexagon::D8, -8 }, 94 { Hexagon::R19, -12 }, { Hexagon::R18, -16 }, { Hexagon::D9, -16 }, 95 { Hexagon::R21, -20 }, { Hexagon::R20, -24 }, { Hexagon::D10, -24 }, 96 { Hexagon::R23, -28 }, { Hexagon::R22, -32 }, { Hexagon::D11, -32 }, 97 { Hexagon::R25, -36 }, { Hexagon::R24, -40 }, { Hexagon::D12, -40 }, 98 { Hexagon::R27, -44 }, { Hexagon::R26, -48 }, { Hexagon::D13, -48 } 99 }; 100 NumEntries = array_lengthof(Offsets); 101 return Offsets; 102 } 103 104 bool assignCalleeSavedSpillSlots(MachineFunction &MF, 105 const TargetRegisterInfo *TRI, std::vector<CalleeSavedInfo> &CSI) 106 const override; 107 108 bool needsAligna(const MachineFunction &MF) const; 109 const MachineInstr *getAlignaInstr(const MachineFunction &MF) const; 110 111 void insertCFIInstructions(MachineFunction &MF) const; 112 113 private: 114 using CSIVect = std::vector<CalleeSavedInfo>; 115 116 void expandAlloca(MachineInstr *AI, const HexagonInstrInfo &TII, 117 unsigned SP, unsigned CF) const; 118 void insertPrologueInBlock(MachineBasicBlock &MBB, bool PrologueStubs) const; 119 void insertEpilogueInBlock(MachineBasicBlock &MBB) const; 120 void insertAllocframe(MachineBasicBlock &MBB, 121 MachineBasicBlock::iterator InsertPt, unsigned NumBytes) const; 122 bool insertCSRSpillsInBlock(MachineBasicBlock &MBB, const CSIVect &CSI, 123 const HexagonRegisterInfo &HRI, bool &PrologueStubs) const; 124 bool insertCSRRestoresInBlock(MachineBasicBlock &MBB, const CSIVect &CSI, 125 const HexagonRegisterInfo &HRI) const; 126 void updateEntryPaths(MachineFunction &MF, MachineBasicBlock &SaveB) const; 127 bool updateExitPaths(MachineBasicBlock &MBB, MachineBasicBlock &RestoreB, 128 BitVector &DoneT, BitVector &DoneF, BitVector &Path) const; 129 void insertCFIInstructionsAt(MachineBasicBlock &MBB, 130 MachineBasicBlock::iterator At) const; 131 132 void adjustForCalleeSavedRegsSpillCall(MachineFunction &MF) const; 133 134 bool expandCopy(MachineBasicBlock &B, MachineBasicBlock::iterator It, 135 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 136 SmallVectorImpl<unsigned> &NewRegs) const; 137 bool expandStoreInt(MachineBasicBlock &B, MachineBasicBlock::iterator It, 138 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 139 SmallVectorImpl<unsigned> &NewRegs) const; 140 bool expandLoadInt(MachineBasicBlock &B, MachineBasicBlock::iterator It, 141 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 142 SmallVectorImpl<unsigned> &NewRegs) const; 143 bool expandStoreVecPred(MachineBasicBlock &B, MachineBasicBlock::iterator It, 144 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 145 SmallVectorImpl<unsigned> &NewRegs) const; 146 bool expandLoadVecPred(MachineBasicBlock &B, MachineBasicBlock::iterator It, 147 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 148 SmallVectorImpl<unsigned> &NewRegs) const; 149 bool expandStoreVec2(MachineBasicBlock &B, MachineBasicBlock::iterator It, 150 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 151 SmallVectorImpl<unsigned> &NewRegs) const; 152 bool expandLoadVec2(MachineBasicBlock &B, MachineBasicBlock::iterator It, 153 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 154 SmallVectorImpl<unsigned> &NewRegs) const; 155 bool expandStoreVec(MachineBasicBlock &B, MachineBasicBlock::iterator It, 156 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 157 SmallVectorImpl<unsigned> &NewRegs) const; 158 bool expandLoadVec(MachineBasicBlock &B, MachineBasicBlock::iterator It, 159 MachineRegisterInfo &MRI, const HexagonInstrInfo &HII, 160 SmallVectorImpl<unsigned> &NewRegs) const; 161 bool expandSpillMacros(MachineFunction &MF, 162 SmallVectorImpl<unsigned> &NewRegs) const; 163 164 unsigned findPhysReg(MachineFunction &MF, HexagonBlockRanges::IndexRange &FIR, 165 HexagonBlockRanges::InstrIndexMap &IndexMap, 166 HexagonBlockRanges::RegToRangeMap &DeadMap, 167 const TargetRegisterClass *RC) const; 168 void optimizeSpillSlots(MachineFunction &MF, 169 SmallVectorImpl<unsigned> &VRegs) const; 170 171 void findShrunkPrologEpilog(MachineFunction &MF, MachineBasicBlock *&PrologB, 172 MachineBasicBlock *&EpilogB) const; 173 174 void addCalleeSaveRegistersAsImpOperand(MachineInstr *MI, const CSIVect &CSI, 175 bool IsDef, bool IsKill) const; 176 bool shouldInlineCSR(const MachineFunction &MF, const CSIVect &CSI) const; 177 bool useSpillFunction(const MachineFunction &MF, const CSIVect &CSI) const; 178 bool useRestoreFunction(const MachineFunction &MF, const CSIVect &CSI) const; 179 bool mayOverflowFrameOffset(MachineFunction &MF) const; 180 }; 181 182 } // end namespace llvm 183 184 #endif // LLVM_LIB_TARGET_HEXAGON_HEXAGONFRAMELOWERING_H 185