[MemorySSA] Verify Phi incoming blocks are block predecessors.

Summary: Make the MemorySSA verify also check that all Phi incoming blocks are block predecessors.

Reviewers: george.burgess.iv

Subscribers: sanjoy, jlebar, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D48333

llvm-svn: 335174

1 files changed, 5 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/MemorySSA.cpp b/llvm/lib/Analysis/MemorySSA.cpp
index dda42274fdc..1a0103dd363 100644
--- a/llvm/lib/Analysis/MemorySSA.cpp
+++ b/llvm/lib/Analysis/MemorySSA.cpp
@@ -1746,8 +1746,12 @@ void MemorySSA::verifyDefUses(Function &F) const {
       assert(Phi->getNumOperands() == static_cast<unsigned>(std::distance(
                                           pred_begin(&B), pred_end(&B))) &&
              "Incomplete MemoryPhi Node");
-      for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I)
+      for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I) {
         verifyUseInDefs(Phi->getIncomingValue(I), Phi);
+        assert(find(predecessors(&B), Phi->getIncomingBlock(I)) !=
+                   pred_end(&B) &&
+               "Incoming phi block not a block predecessor");
+      }
     }
 
     for (Instruction &I : B) {