llvm/lib/Target/ARM/ARMFrameLowering.h

   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/TargetFrameLowering.h"
  13 #include "llvm/Support/TypeSize.h"
  14
  15 namespace llvm {
  16
  17 class ARMSubtarget;
  18 class CalleeSavedInfo;
  19 class MachineFunction;
  20
  21 class ARMFrameLowering : public TargetFrameLowering {
  22 protected:
  23   const ARMSubtarget &STI;
  24
  25 public:
  26   explicit ARMFrameLowering(const ARMSubtarget &sti);
  27
  28   /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
  29   /// the function.
  30   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
  31   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
  32
  33   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
  34                                  MachineBasicBlock::iterator MI,
  35                                  ArrayRef<CalleeSavedInfo> CSI,
  36                                  const TargetRegisterInfo *TRI) const override;
  37
  38   bool
  39   restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
  40                               MachineBasicBlock::iterator MI,
  41                               MutableArrayRef<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   StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
  52                                      Register &FrameReg) const override;
  53   int ResolveFrameIndexReference(const MachineFunction &MF, int FI,
  54                                  Register &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
  67   bool isProfitableForNoCSROpt(const Function &F) const override {
  68     // The no-CSR optimisation is bad for code size on ARM, because we can save
  69     // many registers with a single PUSH/POP pair.
  70     return false;
  71   }
  72
  73   bool
  74   assignCalleeSavedSpillSlots(MachineFunction &MF,
  75                               const TargetRegisterInfo *TRI,
  76                               std::vector<CalleeSavedInfo> &CSI) const override;
  77
  78   const SpillSlot *
  79   getCalleeSavedSpillSlots(unsigned &NumEntries) const override;
  80
  81 private:
  82   void emitPushInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
  83                     ArrayRef<CalleeSavedInfo> CSI, unsigned StmOpc,
  84                     unsigned StrOpc, bool NoGap, bool (*Func)(unsigned, bool),
  85                     unsigned NumAlignedDPRCS2Regs, unsigned MIFlags = 0) const;
  86   void emitPopInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
  87                    MutableArrayRef<CalleeSavedInfo> CSI, unsigned LdmOpc,
  88                    unsigned LdrOpc, bool isVarArg, bool NoGap,
  89                    bool (*Func)(unsigned, bool),
  90                    unsigned NumAlignedDPRCS2Regs) const;
  91
  92   MachineBasicBlock::iterator
  93   eliminateCallFramePseudoInstr(MachineFunction &MF,
  94                                 MachineBasicBlock &MBB,
  95                                 MachineBasicBlock::iterator MI) const override;
  96 };
  97
  98 } // end namespace llvm
  99
 100 #endif // LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H