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 getCalleeSaves(const MachineFunction &MF, 57 BitVector &SavedRegs) const override; 58 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, 59 RegScavenger *RS) const override; 60 61 void adjustForSegmentedStacks(MachineFunction &MF, 62 MachineBasicBlock &MBB) const override; 63 64 /// Returns true if the target will correctly handle shrink wrapping. 65 bool enableShrinkWrapping(const MachineFunction &MF) const override { 66 return true; 67 } 68 bool isProfitableForNoCSROpt(const Function &F) const override { 69 // The no-CSR optimisation is bad for code size on ARM, because we can save 70 // many registers with a single PUSH/POP pair. 71 return false; 72 } 73 74 private: 75 void emitPushInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, 76 const std::vector<CalleeSavedInfo> &CSI, unsigned StmOpc, 77 unsigned StrOpc, bool NoGap, 78 bool(*Func)(unsigned, bool), unsigned NumAlignedDPRCS2Regs, 79 unsigned MIFlags = 0) const; 80 void emitPopInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, 81 std::vector<CalleeSavedInfo> &CSI, unsigned LdmOpc, 82 unsigned LdrOpc, bool isVarArg, bool NoGap, 83 bool(*Func)(unsigned, bool), 84 unsigned NumAlignedDPRCS2Regs) const; 85 86 MachineBasicBlock::iterator 87 eliminateCallFramePseudoInstr(MachineFunction &MF, 88 MachineBasicBlock &MBB, 89 MachineBasicBlock::iterator MI) const override; 90 }; 91 92 } // end namespace llvm 93 94 #endif // LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H 95