Try again to teach getFirstTerminator() about debug values.

Fix some callers to better deal with debug values.

llvm-svn: 123419
This commit is contained in:
Jakob Stoklund Olesen 2011-01-14 01:17:53 +00:00
parent 6de2a4d67c
commit 3d8deb13ee
2 changed files with 24 additions and 7 deletions

View File

@ -155,11 +155,22 @@ MachineBasicBlock::SkipPHIsAndLabels(MachineBasicBlock::iterator I) {
}
MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() {
iterator I = end();
while (I != begin() && (--I)->getDesc().isTerminator())
; /*noop */
if (I != end() && !I->getDesc().isTerminator()) ++I;
return I;
iterator B = begin(), I = end();
iterator Term = I;
while (I != B) {
--I;
// Ignore any debug values after the first terminator.
if (I->isDebugValue())
continue;
// Stop once we see a non-debug non-terminator.
if (!I->getDesc().isTerminator())
break;
// Earliest terminator so far.
Term = I;
}
// Return the first terminator, or end().
// Everything after Term is terminators and debug values.
return Term;
}
MachineBasicBlock::iterator MachineBasicBlock::getLastNonDebugInstr() {

View File

@ -339,6 +339,8 @@ void PHIElimination::LowerAtomicPHINode(
#ifndef NDEBUG
for (MachineBasicBlock::iterator TI = llvm::next(Term);
TI != opBlock.end(); ++TI) {
if (TI->isDebugValue())
continue;
assert(!TI->readsRegister(SrcReg) &&
"Terminator instructions cannot use virtual registers unless"
"they are the first terminator in a block!");
@ -347,9 +349,13 @@ void PHIElimination::LowerAtomicPHINode(
} else if (reusedIncoming || !IncomingReg) {
// We may have to rewind a bit if we didn't insert a copy this time.
KillInst = Term;
while (KillInst != opBlock.begin())
if ((--KillInst)->readsRegister(SrcReg))
while (KillInst != opBlock.begin()) {
--KillInst;
if (KillInst->isDebugValue())
continue;
if (KillInst->readsRegister(SrcReg))
break;
}
} else {
// We just inserted this copy.
KillInst = prior(InsertPos);