Files
clang-p2996/llvm/lib/Target/ARM/ARMFrameLowering.h
Florian Hahn b1a5ee1feb [ARM] Check all terms in emitPopInst when clearing Restored for LR. (#75527)
emitPopInst checks a single function exit MBB. If other paths also exit
the function and any of there terminators uses LR implicitly, it is not
save to clear the Restored bit.

Check all terminators for the function before clearing Restored.

This fixes a mis-compile in outlined-fn-may-clobber-lr-in-caller.ll
where the machine-outliner previously introduced BLs that clobbered LR
which in turn is used by the tail call return.

Alternative to #73553
2023-12-20 16:56:15 +01:00

105 lines
4.2 KiB
C++

//===- ARMTargetFrameLowering.h - Define frame lowering for ARM -*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
#define LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/Support/TypeSize.h"
namespace llvm {
class ARMSubtarget;
class CalleeSavedInfo;
class MachineFunction;
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,
ArrayRef<CalleeSavedInfo> CSI,
const TargetRegisterInfo *TRI) const override;
bool
restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
MutableArrayRef<CalleeSavedInfo> CSI,
const TargetRegisterInfo *TRI) const override;
bool keepFramePointer(const MachineFunction &MF) const override;
bool enableCalleeSaveSkip(const MachineFunction &MF) const override;
bool hasFP(const MachineFunction &MF) const override;
bool isFPReserved(const MachineFunction &MF) const;
bool hasReservedCallFrame(const MachineFunction &MF) const override;
bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override;
StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
Register &FrameReg) const override;
int ResolveFrameIndexReference(const MachineFunction &MF, int FI,
Register &FrameReg, int SPAdj) const;
void getCalleeSaves(const MachineFunction &MF,
BitVector &SavedRegs) const override;
void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
RegScavenger *RS) const override;
void processFunctionBeforeFrameFinalized(
MachineFunction &MF, RegScavenger *RS = nullptr) 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;
bool isProfitableForNoCSROpt(const Function &F) const override {
// The no-CSR optimisation is bad for code size on ARM, because we can save
// many registers with a single PUSH/POP pair.
return false;
}
bool
assignCalleeSavedSpillSlots(MachineFunction &MF,
const TargetRegisterInfo *TRI,
std::vector<CalleeSavedInfo> &CSI) const override;
const SpillSlot *
getCalleeSavedSpillSlots(unsigned &NumEntries) const override;
private:
void emitPushInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
ArrayRef<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,
MutableArrayRef<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 namespace llvm
#endif // LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H