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Handle register masks when searching for EFLAGS clobbers. 

Calls clobber the flags, but when using register masks there is no
EFLAGS<imp-def> operand.

llvm-svn: 150117
This commit is contained in:
Jakob Stoklund Olesen 2012-02-09 00:17:22 +00:00
parent 5d33291e8e
commit 4519fd0b21
1 changed files with 6 additions and 0 deletions
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6
llvm/lib/Target/X86/X86InstrInfo.cpp
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@ -1419,6 +1419,8 @@ static bool isSafeToClobberEFLAGS(MachineBasicBlock &MBB,
bool SeenDef = false; bool SeenDef = false;
for (unsigned j = 0, e = Iter->getNumOperands(); j != e; ++j) { for (unsigned j = 0, e = Iter->getNumOperands(); j != e; ++j) {
MachineOperand &MO = Iter->getOperand(j); MachineOperand &MO = Iter->getOperand(j);
if (MO.isRegMask() && MO.clobbersPhysReg(X86::EFLAGS))
SeenDef = true;
if (!MO.isReg()) if (!MO.isReg())
continue; continue;
if (MO.getReg() == X86::EFLAGS) { if (MO.getReg() == X86::EFLAGS) {
@ -1463,6 +1465,10 @@ static bool isSafeToClobberEFLAGS(MachineBasicBlock &MBB,
bool SawKill = false; bool SawKill = false;
for (unsigned j = 0, e = Iter->getNumOperands(); j != e; ++j) { for (unsigned j = 0, e = Iter->getNumOperands(); j != e; ++j) {
MachineOperand &MO = Iter->getOperand(j); MachineOperand &MO = Iter->getOperand(j);
// A register mask may clobber EFLAGS, but we should still look for a
// live EFLAGS def.
if (MO.isRegMask() && MO.clobbersPhysReg(X86::EFLAGS))
SawKill = true;
if (MO.isReg() && MO.getReg() == X86::EFLAGS) { if (MO.isReg() && MO.getReg() == X86::EFLAGS) {
if (MO.isDef()) return MO.isDead(); if (MO.isDef()) return MO.isDead();
if (MO.isKill()) SawKill = true; if (MO.isKill()) SawKill = true;