Merge branch 'upstream' into merge-2012_09_10

Conflicts:
	lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
	lib/Support/DynamicLibrary.cpp
	lib/Support/LockFileManager.cpp

Change-Id: I91e94c3a7a76e19c688307c5a480a640a3bd2b7e

1 files changed, 11 insertions, 3 deletions

diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index 059e574..5736c35 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -148,7 +148,7 @@ AliasAnalysis::ModRefResult GetLocation(const Instruction *Inst,
     return AliasAnalysis::ModRef;
   }
 
-  if (const CallInst *CI = isFreeCall(Inst)) {
+  if (const CallInst *CI = isFreeCall(Inst, AA->getTargetLibraryInfo())) {
     // calls to free() deallocate the entire structure
     Loc = AliasAnalysis::Location(CI->getArgOperand(0));
     return AliasAnalysis::Mod;
@@ -479,12 +479,20 @@ getPointerDependencyFrom(const AliasAnalysis::Location &MemLoc, bool isLoad,
     // a subsequent bitcast of the malloc call result.  There can be stores to
     // the malloced memory between the malloc call and its bitcast uses, and we
     // need to continue scanning until the malloc call.
-    if (isa<AllocaInst>(Inst) || isNoAliasFn(Inst)) {
+    const TargetLibraryInfo *TLI = AA->getTargetLibraryInfo();
+    if (isa<AllocaInst>(Inst) || isNoAliasFn(Inst, TLI)) {
       const Value *AccessPtr = GetUnderlyingObject(MemLoc.Ptr, TD);
       
       if (AccessPtr == Inst || AA->isMustAlias(Inst, AccessPtr))
         return MemDepResult::getDef(Inst);
-      continue;
+      // Be conservative if the accessed pointer may alias the allocation.
+      if (AA->alias(Inst, AccessPtr) != AliasAnalysis::NoAlias)
+        return MemDepResult::getClobber(Inst);
+      // If the allocation is not aliased and does not read memory (like
+      // strdup), it is safe to ignore.
+      if (isa<AllocaInst>(Inst) ||
+          isMallocLikeFn(Inst, TLI) || isCallocLikeFn(Inst, TLI))
+        continue;
     }
 
     // See if this instruction (e.g. a call or vaarg) mod/ref's the pointer.