Fix PR1575 and test/Transforms/CondProp/2007-08-01-InvalidRead.ll
llvm-svn: 40720
diff --git a/llvm/lib/Transforms/Scalar/CondPropagate.cpp b/llvm/lib/Transforms/Scalar/CondPropagate.cpp
index 80f6973..6fc27d4a 100644
--- a/llvm/lib/Transforms/Scalar/CondPropagate.cpp
+++ b/llvm/lib/Transforms/Scalar/CondPropagate.cpp
@@ -142,14 +142,15 @@
if (ConstantInt *CB = dyn_cast<ConstantInt>(PN->getIncomingValue(i-1))) {
// If we have a constant, forward the edge from its current to its
// ultimate destination.
- bool PHIGone = PN->getNumIncomingValues() == 2;
RevectorBlockTo(PN->getIncomingBlock(i-1),
BI->getSuccessor(CB->isZero()));
++NumBrThread;
- // If there were two predecessors before this simplification, the PHI node
- // will be deleted. Don't iterate through it the last time.
- if (PHIGone) return;
+ // If there were two predecessors before this simplification, or if the
+ // PHI node contained all the same value except for the one we just
+ // substituted, the PHI node may be deleted. Don't iterate through it the
+ // last time.
+ if (BI->getCondition() != PN) return;
}
}
@@ -177,16 +178,17 @@
if (ConstantInt *CI = dyn_cast<ConstantInt>(PN->getIncomingValue(i-1))) {
// If we have a constant, forward the edge from its current to its
// ultimate destination.
- bool PHIGone = PN->getNumIncomingValues() == 2;
unsigned DestCase = SI->findCaseValue(CI);
RevectorBlockTo(PN->getIncomingBlock(i-1),
SI->getSuccessor(DestCase));
++NumSwThread;
RemovedPreds = true;
- // If there were two predecessors before this simplification, the PHI node
- // will be deleted. Don't iterate through it the last time.
- if (PHIGone) return;
+ // If there were two predecessors before this simplification, or if the
+ // PHI node contained all the same value except for the one we just
+ // substituted, the PHI node may be deleted. Don't iterate through it the
+ // last time.
+ if (SI->getCondition() != PN) return;
}
}