From: Alina Sbirlea <asbirlea@google.com>
Date: Fri, 29 Mar 2019 22:55:59 +0000 (+0000)
Subject: [MemorySSA] Temporary fix assert when reaching 0 limit.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d266d2b04f83614042f16250d54e50e1359fb084;p=llvm

[MemorySSA] Temporary fix assert when reaching 0 limit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357327 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/MemorySSA.cpp b/lib/Analysis/MemorySSA.cpp
index 7a3f2db8831..a8100312f21 100644
--- a/lib/Analysis/MemorySSA.cpp
+++ b/lib/Analysis/MemorySSA.cpp
@@ -543,8 +543,11 @@ template <class AliasAnalysisType> class ClobberWalker {
   walkToPhiOrClobber(DefPath &Desc, const MemoryAccess *StopAt = nullptr,
                      const MemoryAccess *SkipStopAt = nullptr) const {
     assert(!isa<MemoryUse>(Desc.Last) && "Uses don't exist in my world");
-    assert(UpwardWalkLimit && *UpwardWalkLimit > 0 &&
-           "Need a positive walk limit");
+    assert(UpwardWalkLimit && "Need a valid walk limit");
+    // This will not do any alias() calls. It returns in the first iteration in
+    // the loop below.
+    if (*UpwardWalkLimit == 0)
+      (*UpwardWalkLimit)++;
 
     for (MemoryAccess *Current : def_chain(Desc.Last)) {
       Desc.Last = Current;