[TRE] Add assertion for folding trivial return block
llvm-svn: 305637
diff --git a/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp b/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
index 93c4b57..365566c 100644
--- a/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/TailRecursionElimination.cpp
@@ -677,6 +677,10 @@
const TargetTransformInfo *TTI) {
bool Change = false;
+ // Make sure this block is a trivial return block.
+ assert(BB->getFirstNonPHIOrDbg() == Ret &&
+ "Trying to fold non-trivial return block");
+
// If the return block contains nothing but the return and PHI's,
// there might be an opportunity to duplicate the return in its
// predecessors and perform TRE there. Look for predecessors that end