1 //===- ARMTargetFrameLowering.h - Define frame lowering for ARM -*- 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_ARM_ARMFRAMELOWERING_H 10 #define LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H 11 12 #include "llvm/CodeGen/MachineBasicBlock.h" 13 #include "llvm/CodeGen/TargetFrameLowering.h" 14 #include <vector> 15 16 namespace llvm { 17 18 class ARMSubtarget; 19 class CalleeSavedInfo; 20 class MachineFunction; 21 22 class ARMFrameLowering : public TargetFrameLowering { 23 protected: 24 const ARMSubtarget &STI; 25 26 public: 27 explicit ARMFrameLowering(const ARMSubtarget &sti); 28 29 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into 30 /// the function. 31 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 32 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override; 33 34 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 35 MachineBasicBlock::iterator MI, 36 const std::vector<CalleeSavedInfo> &CSI, 37 const TargetRegisterInfo *TRI) const override; 38 39 bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 40 MachineBasicBlock::iterator MI, 41 std::vector<CalleeSavedInfo> &CSI, 42 const TargetRegisterInfo *TRI) const override; 43 44 bool keepFramePointer(const MachineFunction &MF) const override; 45 46 bool enableCalleeSaveSkip(const MachineFunction &MF) const override; 47 48 bool hasFP(const MachineFunction &MF) const override; 49 bool hasReservedCallFrame(const MachineFunction &MF) const override; 50 bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override; 51 int getFrameIndexReference(const MachineFunction &MF, int FI, 52 unsigned &FrameReg) const override; 53 int ResolveFrameIndexReference(const MachineFunction &MF, int FI, 54 unsigned &FrameReg, int SPAdj) const; 55 56 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 57 RegScavenger *RS) const override; 58 59 void adjustForSegmentedStacks(MachineFunction &MF, 60 MachineBasicBlock &MBB) const override; 61 62 /// Returns true if the target will correctly handle shrink wrapping. 63 bool enableShrinkWrapping(const MachineFunction &MF) const override { 64 return true; 65 } 66 bool isProfitableForNoCSROpt(const Function &F) const override { 67 // The no-CSR optimisation is bad for code size on ARM, because we can save 68 // many registers with a single PUSH/POP pair. 69 return false; 70 } 71 72 private: 73 void emitPushInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, 74 const std::vector<CalleeSavedInfo> &CSI, unsigned StmOpc, 75 unsigned StrOpc, bool NoGap, 76 bool(*Func)(unsigned, bool), unsigned NumAlignedDPRCS2Regs, 77 unsigned MIFlags = 0) const; 78 void emitPopInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, 79 std::vector<CalleeSavedInfo> &CSI, unsigned LdmOpc, 80 unsigned LdrOpc, bool isVarArg, bool NoGap, 81 bool(*Func)(unsigned, bool), 82 unsigned NumAlignedDPRCS2Regs) const; 83 84 MachineBasicBlock::iterator 85 eliminateCallFramePseudoInstr(MachineFunction &MF, 86 MachineBasicBlock &MBB, 87 MachineBasicBlock::iterator MI) const override; 88 }; 89 90 } // end namespace llvm 91 92 #endif // LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H 93