InstSimplify: canonicalize is idempotent

llvm-svn: 312685
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 94d7181..ad3f9c3 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4268,6 +4268,7 @@
   case Intrinsic::rint:
   case Intrinsic::nearbyint:
   case Intrinsic::round:
+  case Intrinsic::canonicalize:
     return true;
   }
 }