Add testcase and fix for yet another case where we query the size an

abstract type.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18678 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 33 insertions, 9 deletions

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index a78c8abba2..c355f59ed0 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -456,7 +456,7 @@ CheckGEPInstructions(const Type* BasePtr1Ty, std::vector<Value*> &GEP1Ops,
   if (BasePtr1Ty != BasePtr2Ty)
     return MayAlias;
 
-  const Type *GEPPointerTy = BasePtr1Ty;
+  const PointerType *GEPPointerTy = cast<PointerType>(BasePtr1Ty);
 
   // Find the (possibly empty) initial sequence of equal values... which are not
   // necessarily constants.
@@ -657,14 +657,16 @@ CheckGEPInstructions(const Type* BasePtr1Ty, std::vector<Value*> &GEP1Ops,
     }
   }
   
-  int64_t Offset1 = getTargetData().getIndexedOffset(GEPPointerTy, GEP1Ops);
-  int64_t Offset2 = getTargetData().getIndexedOffset(GEPPointerTy, GEP2Ops);
-  assert(Offset1 < Offset2 &&"There is at least one different constant here!");
-
-  if ((uint64_t)(Offset2-Offset1) >= SizeMax) {
-    //std::cerr << "Determined that these two GEP's don't alias [" 
-    //          << SizeMax << " bytes]: \n" << *GEP1 << *GEP2;
-    return NoAlias;
+  if (GEPPointerTy->getElementType()->isSized()) {
+    int64_t Offset1 = getTargetData().getIndexedOffset(GEPPointerTy, GEP1Ops);
+    int64_t Offset2 = getTargetData().getIndexedOffset(GEPPointerTy, GEP2Ops);
+    assert(Offset1<Offset2 && "There is at least one different constant here!");
+
+    if ((uint64_t)(Offset2-Offset1) >= SizeMax) {
+      //std::cerr << "Determined that these two GEP's don't alias [" 
+      //          << SizeMax << " bytes]: \n" << *GEP1 << *GEP2;
+      return NoAlias;
+    }
   }
   return MayAlias;
 }
diff --git a/test/Analysis/BasicAA/2004-12-08-BasicAACrash2.ll b/test/Analysis/BasicAA/2004-12-08-BasicAACrash2.ll
new file mode 100644
index 0000000000..d856260bae
--- /dev/null
+++ b/test/Analysis/BasicAA/2004-12-08-BasicAACrash2.ll
@@ -0,0 +1,22 @@
+; RUN: llvm-as < %s | opt -dse
+
+"java/lang/Object" = type { %struct.llvm_java_object_base }
+	"java/lang/StringBuffer" = type { "java/lang/Object", int, { "java/lang/Object", uint, [0 x ushort] }*, bool }
+	%struct.llvm_java_object_base = type opaque
+
+implementation   ; Functions:
+
+void "java/lang/StringBuffer/ensureCapacity_unsynchronized(I)V"() {
+bc0:
+	%tmp = getelementptr "java/lang/StringBuffer"* null, int 0, uint 3		; <bool*> [#uses=1]
+	br bool false, label %bc16, label %bc7
+
+bc16:		; preds = %bc0
+	%tmp91 = getelementptr "java/lang/StringBuffer"* null, int 0, uint 2		; <{ "java/lang/Object", uint, [0 x ushort] }**> [#uses=1]
+	store { "java/lang/Object", uint, [0 x ushort] }* null, { "java/lang/Object", uint, [0 x ushort] }** %tmp91
+	store bool false, bool* %tmp
+	ret void
+
+bc7:		; preds = %bc0
+	ret void
+}