Remove dead PPC LR spilling code

The LR register is unconditionally reserved, and its spilling and restoration
is handled by the prologue/epilogue code. As a result, it is never explicitly
spilled by the register allocator.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177823 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Hal Finkel 2013-03-23 17:14:27 +00:00
parent 7cdba152bb
commit 7257fda1b3

View File

@ -443,37 +443,15 @@ PPCInstrInfo::StoreRegToStackSlot(MachineFunction &MF,
bool &NonRI) const{
DebugLoc DL;
if (PPC::GPRCRegClass.hasSubClassEq(RC)) {
if (SrcReg != PPC::LR) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STW))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
} else {
// FIXME: this spills LR immediately to memory in one step. To do this,
// we use R11, which we know cannot be used in the prolog/epilog. This is
// a hack.
NewMIs.push_back(BuildMI(MF, DL, get(PPC::MFLR), PPC::R11));
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STW))
.addReg(PPC::R11,
getKillRegState(isKill)),
FrameIdx));
}
} else if (PPC::G8RCRegClass.hasSubClassEq(RC)) {
if (SrcReg != PPC::LR8) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STD))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
} else {
// FIXME: this spills LR immediately to memory in one step. To do this,
// we use X11, which we know cannot be used in the prolog/epilog. This is
// a hack.
NewMIs.push_back(BuildMI(MF, DL, get(PPC::MFLR8), PPC::X11));
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STD))
.addReg(PPC::X11,
getKillRegState(isKill)),
FrameIdx));
}
} else if (PPC::F8RCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STFD))
.addReg(SrcReg,