diff --git a/test/Regression/Transforms/InstCombine/cast-set.ll b/test/Regression/Transforms/InstCombine/cast-set.ll
index c890a07be42..e9312ad5d9a 100644
--- a/test/Regression/Transforms/InstCombine/cast-set.ll
+++ b/test/Regression/Transforms/InstCombine/cast-set.ll
@@ -1,3 +1,8 @@
+; I'm not really sure if instcombine should do things like these.  LevelRaise 
+; already sufficiently takes care of these cases, but level raise is really
+; slow.  Might it be better to make there be an instcombine prepass before
+; level raise that takes care of the obvious stuff?
+
 ; RUN: if as < %s | opt -instcombine | dis | grep cast
 ; RUN: then exit 1
 ; RUN: else exit 0