Probably not a good idea to convert a single vector load into a memcpy. We

don't do this now, but add a test case to prevent this from happening in the
future.
Additional test for rdar://9892684

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145879 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/ValueTracking.cpp

@@ -1370,6 +1370,8 @@ Value *llvm::isBytewiseValue(Value *V) {
     
     return Val;
   }
+
+  // FIXME: Vector types (e.g., <4 x i32> <i32 -1, i32 -1, i32 -1, i32 -1>).
   
   // Conceptually, we could handle things like:
   //   %a = zext i8 %X to i16