llvm/lib/Target/ARM/ARMFrameLowering.h
Hans Wennborg f864a32c13 Change eliminateCallFramePseudoInstr() to return an iterator
This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.

It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.

Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.

Differential Revision: http://reviews.llvm.org/D18627

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265036 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-31 18:33:38 +00:00

86 lines
3.4 KiB
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//==-- ARMTargetFrameLowering.h - Define frame lowering for ARM --*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
#define LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
#include "llvm/Target/TargetFrameLowering.h"
namespace llvm {
class ARMSubtarget;
class ARMFrameLowering : public TargetFrameLowering {
protected:
const ARMSubtarget &STI;
public:
explicit ARMFrameLowering(const ARMSubtarget &sti);
/// emitProlog/emitEpilog - These methods insert prolog and epilog code into
/// the function.
void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool noFramePointerElim(const MachineFunction &MF) const override;
bool hasFP(const MachineFunction &MF) const override;
bool hasReservedCallFrame(const MachineFunction &MF) const override;
bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override;
int getFrameIndexReference(const MachineFunction &MF, int FI,
unsigned &FrameReg) const override;
int ResolveFrameIndexReference(const MachineFunction &MF, int FI,
unsigned &FrameReg, int SPAdj) const;
void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
RegScavenger *RS) const override;
void adjustForSegmentedStacks(MachineFunction &MF,
MachineBasicBlock &MBB) const override;
/// Returns true if the target will correctly handle shrink wrapping.
bool enableShrinkWrapping(const MachineFunction &MF) const override {
return true;
}
private:
void emitPushInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI, unsigned StmOpc,
unsigned StrOpc, bool NoGap,
bool(*Func)(unsigned, bool), unsigned NumAlignedDPRCS2Regs,
unsigned MIFlags = 0) const;
void emitPopInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI, unsigned LdmOpc,
unsigned LdrOpc, bool isVarArg, bool NoGap,
bool(*Func)(unsigned, bool),
unsigned NumAlignedDPRCS2Regs) const;
MachineBasicBlock::iterator
eliminateCallFramePseudoInstr(MachineFunction &MF,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const override;
};
} // End llvm namespace
#endif