class CalleeSavedInfo {
unsigned Reg;
int FrameIdx;
+ /// Flag indicating whether the register is actually restored in the epilog.
+ /// In most cases, if a register is saved, it is also restored. There are
+ /// some situations, though, when this is not the case. For example, the
+ /// LR register on ARM is usually saved, but on exit from the function its
+ /// saved value may be loaded directly into PC. Since liveness tracking of
+ /// physical registers treats callee-saved registers are live outside of
+ /// the function, LR would be treated as live-on-exit, even though in these
+ /// scenarios it is not. This flag is added to indicate that the saved
+ /// register described by this object is not restored in the epilog.
+ /// The long-term solution is to model the liveness of callee-saved registers
+ /// by implicit uses on the return instructions, however, the required
+ /// changes in the ARM backend would be quite extensive.
+ bool Restored;
public:
explicit CalleeSavedInfo(unsigned R, int FI = 0)
- : Reg(R), FrameIdx(FI) {}
+ : Reg(R), FrameIdx(FI), Restored(true) {}
// Accessors.
unsigned getReg() const { return Reg; }
int getFrameIdx() const { return FrameIdx; }
void setFrameIdx(int FI) { FrameIdx = FI; }
+ bool isRestored() const { return Restored; }
+ void setRestored(bool R) { Restored = R; }
};
/// The MachineFrameInfo class represents an abstract stack frame until
const std::vector<CalleeSavedInfo> &getCalleeSavedInfo() const {
return CSInfo;
}
+ /// \copydoc getCalleeSavedInfo()
+ std::vector<CalleeSavedInfo> &getCalleeSavedInfo() { return CSInfo; }
/// Used by prolog/epilog inserter to set the function's callee saved
/// information.
/// restoreCalleeSavedRegisters - Issues instruction(s) to restore all callee
/// saved registers and returns true if it isn't possible / profitable to do
/// so by issuing a series of load instructions via loadRegToStackSlot().
+ /// If it returns true, and any of the registers in CSI is not restored,
+ /// it sets the corresponding Restored flag in CSI to false.
/// Returns false otherwise.
virtual bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
return false;
}
const MachineFrameInfo &MFI = MF.getFrameInfo();
if (MFI.isCalleeSavedInfoValid()) {
for (const CalleeSavedInfo &Info : MFI.getCalleeSavedInfo())
- addReg(Info.getReg());
+ if (Info.isRestored())
+ addReg(Info.getReg());
}
}
}
/// Insert restore code for the callee-saved registers used in the function.
static void insertCSRRestores(MachineBasicBlock &RestoreBlock,
- ArrayRef<CalleeSavedInfo> CSI) {
+ std::vector<CalleeSavedInfo> &CSI) {
MachineFunction &Fn = *RestoreBlock.getParent();
const TargetInstrInfo &TII = *Fn.getSubtarget().getInstrInfo();
const TargetFrameLowering *TFI = Fn.getSubtarget().getFrameLowering();
if (!F->hasFnAttribute(Attribute::Naked)) {
MFI.setCalleeSavedInfoValid(true);
- ArrayRef<CalleeSavedInfo> CSI = MFI.getCalleeSavedInfo();
+ std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo();
if (!CSI.empty()) {
for (MachineBasicBlock *SaveBlock : SaveBlocks) {
insertCSRSaves(*SaveBlock, CSI);
bool AArch64FrameLowering::restoreCalleeSavedRegisters(
MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
MachineFunction &MF = *MBB.getParent();
const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
/// \brief Can this function use the red zone for local allocations.
void ARMFrameLowering::emitPopInst(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
unsigned LdmOpc, unsigned LdrOpc,
bool isVarArg, bool NoGap,
bool(*Func)(unsigned, bool),
.add(predOps(ARMCC::AL));
for (unsigned i = 0, e = Regs.size(); i < e; ++i)
MIB.addReg(Regs[i], getDefRegState(true));
- if (DeleteRet && MI != MBB.end()) {
- MIB.copyImplicitOps(*MI);
- MI->eraseFromParent();
+ if (DeleteRet) {
+ if (MI != MBB.end()) {
+ MIB.copyImplicitOps(*MI);
+ MI->eraseFromParent();
+ }
+ // If LR is not restored, mark it in CSI.
+ for (CalleeSavedInfo &I : CSI) {
+ if (I.getReg() != ARM::LR)
+ continue;
+ I.setRestored(false);
+ break;
+ }
}
MI = MIB;
} else if (Regs.size() == 1) {
bool ARMFrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
if (CSI.empty())
return false;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool noFramePointerElim(const MachineFunction &MF) const override;
bool(*Func)(unsigned, bool), unsigned NumAlignedDPRCS2Regs,
unsigned MIFlags = 0) const;
void emitPopInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI, unsigned LdmOpc,
+ std::vector<CalleeSavedInfo> &CSI, unsigned LdmOpc,
unsigned LdrOpc, bool isVarArg, bool NoGap,
bool(*Func)(unsigned, bool),
unsigned NumAlignedDPRCS2Regs) const;
bool Thumb1FrameLowering::
restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
if (CSI.empty())
return false;
const TargetRegisterInfo *TRI) const override;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool hasReservedCallFrame(const MachineFunction &MF) const override;
bool AVRFrameLowering::restoreCalleeSavedRegisters(
MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
if (CSI.empty()) {
return false;
bool
restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool hasReservedCallFrame(const MachineFunction &MF) const override;
bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override;
}
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator MI, const std::vector<CalleeSavedInfo> &CSI,
+ MachineBasicBlock::iterator MI, std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override {
return true;
}
bool
MSP430FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
if (CSI.empty())
return false;
const TargetRegisterInfo *TRI) const override;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool hasFP(const MachineFunction &MF) const override;
bool Mips16FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
//
// Registers RA,S0,S1 are the callee saved registers and they will be restored
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool hasReservedCallFrame(const MachineFunction &MF) const override;
bool
PPCFrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
// Currently, this function only handles SVR4 32- and 64-bit ABIs.
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
/// targetHandlesStackFrameRounding - Returns true if the target is
bool SystemZFrameLowering::
restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
if (CSI.empty())
return false;
const TargetRegisterInfo *TRI) const override;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBII,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const
override;
void processFunctionBeforeFrameFinalized(MachineFunction &MF,
bool X86FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
if (CSI.empty())
return false;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
bool hasFP(const MachineFunction &MF) const override;
bool XCoreFrameLowering::
restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const{
MachineFunction *MF = MBB.getParent();
const TargetInstrInfo &TII = *MF->getSubtarget().getInstrInfo();
const TargetRegisterInfo *TRI) const override;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
+ std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const override;
MachineBasicBlock::iterator