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Protect R31's frame offset from being used by callee-saved registers, when R31 

is the frame pointer.

llvm-svn: 35233
This commit is contained in:
Nicolas Geoffray 2007-03-21 16:44:14 +00:00
parent 0458c1db71
commit 4ea5217880
1 changed files with 20 additions and 0 deletions
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20
llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp
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@ -891,6 +891,26 @@ void PPCRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
unsigned LR = getRARegister();
FI->setUsesLR(MF.isPhysRegUsed(LR));
MF.changePhyRegUsed(LR, false);
// Save R31 if necessary
int FPSI = FI->getFramePointerSaveIndex();
bool IsPPC64 = Subtarget.isPPC64();
bool IsELF_ABI = Subtarget.isELF_ABI();
const MachineFrameInfo *MFI = MF.getFrameInfo();
// If the frame pointer save index hasn't been defined yet.
if (!FPSI && (NoFramePointerElim || MFI->hasVarSizedObjects())
&& IsELF_ABI) {
// Find out what the fix offset of the frame pointer save area.
int FPOffset = PPCFrameInfo::getFramePointerSaveOffset(IsPPC64,
!IsELF_ABI);
// Allocate the frame index for frame pointer save area.
FPSI = MF.getFrameInfo()->CreateFixedObject(IsPPC64? 8 : 4, FPOffset);
// Save the result.
FI->setFramePointerSaveIndex(FPSI);
}
}
void PPCRegisterInfo::emitPrologue(MachineFunction &MF) const {