Fix crasher in GVN due to my recent capture tracking changes.

llvm-svn: 145047

llvm/lib/Analysis/CaptureTracking.cpp

@@ -53,6 +53,9 @@ namespace {
 /// counts as capturing it or not.
 bool llvm::PointerMayBeCaptured(const Value *V,
                                 bool ReturnCaptures, bool StoreCaptures) {
+  assert(!isa<GlobalValue>(V) &&
+         "It doesn't make sense to ask whether a global is captured.");
+
   // TODO: If StoreCaptures is not true, we could do Fancy analysis
   // to determine whether this store is not actually an escape point.
   // In that case, BasicAliasAnalysis should be updated as well to

llvm/lib/Analysis/MemoryDependenceAnalysis.cpp

@@ -375,7 +375,7 @@ MemoryDependenceAnalysis::getModRefInfo(const Instruction *Inst,
   // with a smarter AA in place, this test is just wasting compile time.
   if (!DT) return AliasAnalysis::ModRef;
   const Value *Object = GetUnderlyingObject(MemLoc.Ptr, TD);
-  if (!isIdentifiedObject(Object) || isa<GlobalVariable>(Object))
+  if (!isIdentifiedObject(Object) || isa<GlobalValue>(Object))
     return AliasAnalysis::ModRef;
   ImmutableCallSite CS(Inst);
   if (!CS.getInstruction()) return AliasAnalysis::ModRef;

llvm/test/Transforms/GVN/rle.ll

@@ -26,6 +26,15 @@ define i8 @crash0({i32, i32} %A, {i32, i32}* %P) {
   ret i8 %Y
 }
 
+;; No PR filed, crashed in CaptureTracker.
+declare void @helper()
+define void @crash1() {
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* undef, i8* undef, i64 undef, i32 1, i1 false) nounwind
+  %tmp = load i8* bitcast (void ()* @helper to i8*)
+  %x = icmp eq i8 %tmp, 15
+  ret void
+}
+
 
 ;;===----------------------------------------------------------------------===;;
 ;; Store -> Load  and  Load -> Load forwarding where src and dst are different