From 65e115098821925055d6e78312862bf2513f8996 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Wed, 2 Oct 2019 13:09:04 +0000
Subject: [PATCH] MemorySSA tryOptimizePhi - assert that we've found a
 DefChainEnd. NFCI.

Silences static analyzer null dereference warning.

llvm-svn: 373466
---
 llvm/lib/Analysis/MemorySSA.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/lib/Analysis/MemorySSA.cpp b/llvm/lib/Analysis/MemorySSA.cpp
index cc3bca1c2318..cfb8b7e7dcb5 100644
--- a/llvm/lib/Analysis/MemorySSA.cpp
+++ b/llvm/lib/Analysis/MemorySSA.cpp
@@ -873,6 +873,7 @@ template <class AliasAnalysisType> class ClobberWalker {
         if (!DefChainEnd)
           for (auto *MA : def_chain(const_cast<MemoryAccess *>(Target)))
             DefChainEnd = MA;
+        assert(DefChainEnd && "Failed to find dominating phi/liveOnEntry");
 
         // If any of the terminated paths don't dominate the phi we'll try to
         // optimize, we need to figure out what they are and quit.