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authorDan Gohman <gohman@apple.com>2010-04-08 18:11:50 +0000
committerDan Gohman <gohman@apple.com>2010-04-08 18:11:50 +0000
commitb57b6f1575ec87b22dc793fe03539cae9df0e586 (patch)
treed44d7805422c7d31c9e45681edcf0b5c7ee1e8bc /lib
parent29e13e0c18de57209170d5cd2c3dd1311f5e2a40 (diff)
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Pointers to zero-sized objects don't point to overlapping objects.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100789 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r--lib/Analysis/BasicAliasAnalysis.cpp5
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 31a649d5cc..cfe7a1c0ca 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -655,6 +655,11 @@ BasicAliasAnalysis::aliasPHI(const PHINode *PN, unsigned PNSize,
AliasAnalysis::AliasResult
BasicAliasAnalysis::aliasCheck(const Value *V1, unsigned V1Size,
const Value *V2, unsigned V2Size) {
+ // If either of the memory references is empty, it doesn't matter what the
+ // pointer values are.
+ if (V1Size == 0 || V2Size == 0)
+ return NoAlias;
+
// Strip off any casts if they exist.
V1 = V1->stripPointerCasts();
V2 = V2->stripPointerCasts();