[tsan] disable load widening in ThreadSanitizer mode
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175034 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index 5cb0016..9a1edc7 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -283,6 +283,12 @@
const DataLayout &TD) {
// We can only extend simple integer loads.
if (!isa<IntegerType>(LI->getType()) || !LI->isSimple()) return 0;
+
+ // Load widening is hostile to ThreadSanitizer: it may cause false positives
+ // or make the reports more cryptic (access sizes are wrong).
+ if (LI->getParent()->getParent()->getAttributes().
+ hasAttribute(AttributeSet::FunctionIndex, Attribute::ThreadSafety))
+ return 0;
// Get the base of this load.
int64_t LIOffs = 0;