Indvars: Don't recursively delete instruction during BB iteration.
This can invalidate the iterators leading to use after frees and crashes.
Fixes PR12536.
llvm-svn: 166291
diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index 78630b2..82eb746 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -551,15 +551,17 @@
PN->setIncomingValue(i, ExitVal);
- // If this instruction is dead now, delete it.
- RecursivelyDeleteTriviallyDeadInstructions(Inst, TLI);
+ // If this instruction is dead now, delete it. Don't do it now to avoid
+ // invalidating iterators.
+ if (isInstructionTriviallyDead(Inst, TLI))
+ DeadInsts.push_back(Inst);
if (NumPreds == 1) {
// Completely replace a single-pred PHI. This is safe, because the
// NewVal won't be variant in the loop, so we don't need an LCSSA phi
// node anymore.
PN->replaceAllUsesWith(ExitVal);
- RecursivelyDeleteTriviallyDeadInstructions(PN, TLI);
+ PN->eraseFromParent();
}
}
if (NumPreds != 1) {