From: Nuno Lopes <nunoplopes@sapo.pt>
Date: Tue, 8 Aug 2017 21:25:26 +0000 (+0000)
Subject: BasicAA: assert on another case where aliasGEP shouldn't get a PartialAlias response
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b95a570738179e6047bf05bdc1f923afb02f8996;p=llvm

BasicAA: assert on another case where aliasGEP shouldn't get a PartialAlias response

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310420 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 9bd4349835e..180e5f4a644 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -1238,13 +1238,15 @@ AliasResult BasicAAResult::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size,
     AliasResult R = aliasCheck(UnderlyingV1, MemoryLocation::UnknownSize,
                                AAMDNodes(), V2, MemoryLocation::UnknownSize,
                                V2AAInfo, nullptr, UnderlyingV2);
-    if (R != MustAlias)
+    if (R != MustAlias) {
       // If V2 may alias GEP base pointer, conservatively returns MayAlias.
       // If V2 is known not to alias GEP base pointer, then the two values
       // cannot alias per GEP semantics: "Any memory access must be done through
       // a pointer value associated with an address range of the memory access,
       // otherwise the behavior is undefined.".
+      assert(R == NoAlias || R == MayAlias);
       return R;
+    }
 
     // If the max search depth is reached the result is undefined
     if (GEP1MaxLookupReached)