llvm/lib/Target/SystemZ/SystemZFrameLowering.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

65 lines
2.7 KiB
C++

//===-- SystemZFrameLowering.h - Frame lowering for SystemZ -----*- 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_SYSTEMZ_SYSTEMZFRAMELOWERING_H
#define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZFRAMELOWERING_H
#include "llvm/ADT/IndexedMap.h"
#include "llvm/Target/TargetFrameLowering.h"
namespace llvm {
class SystemZTargetMachine;
class SystemZSubtarget;
class SystemZFrameLowering : public TargetFrameLowering {
IndexedMap<unsigned> RegSpillOffsets;
public:
SystemZFrameLowering();
// Override TargetFrameLowering.
bool isFPCloseToIncomingSP() const override { return false; }
const SpillSlot *getCalleeSavedSpillSlots(unsigned &NumEntries) const
override;
void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
RegScavenger *RS) const override;
bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBII,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const
override;
void processFunctionBeforeFrameFinalized(MachineFunction &MF,
RegScavenger *RS) const override;
void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
bool hasFP(const MachineFunction &MF) const override;
int getFrameIndexReference(const MachineFunction &MF, int FI,
unsigned &FrameReg) const override;
bool hasReservedCallFrame(const MachineFunction &MF) const override;
MachineBasicBlock::iterator
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const override;
// Return the number of bytes in the callee-allocated part of the frame.
uint64_t getAllocatedStackSize(const MachineFunction &MF) const;
// Return the byte offset from the incoming stack pointer of Reg's
// ABI-defined save slot. Return 0 if no slot is defined for Reg.
unsigned getRegSpillOffset(unsigned Reg) const {
return RegSpillOffsets[Reg];
}
};
} // end namespace llvm
#endif