Assert on SSA errors in LiveVariables.
All uses of a virtual register must be dominated by its def.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152449 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index 9c3d255..48e1e4c 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -109,6 +109,7 @@
// Mark the variable known alive in this bb
VRInfo.AliveBlocks.set(BBNum);
+ assert(MBB != &MF->front() && "Can't find reaching def for virtreg");
WorkList.insert(WorkList.end(), MBB->pred_rbegin(), MBB->pred_rend());
}