From 3a01feb9ba0e676b8065b96c4cca82e65f18f0e4 Mon Sep 17 00:00:00 2001
From: Josh Berdine <jjb@fb.com>
Date: Tue, 19 Mar 2019 09:26:39 -0700
Subject: [PATCH] [sledge] Strengthen simplification of Convert exps

Summary: Omit casts when source and destination types are equal.

Reviewed By: mbouaziz

Differential Revision: D14495814

fbshipit-source-id: 21bcfb6ab
---
 sledge/src/llair/exp.ml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sledge/src/llair/exp.ml b/sledge/src/llair/exp.ml
index da2b44f39..5078944d8 100644
--- a/sledge/src/llair/exp.ml
+++ b/sledge/src/llair/exp.ml
@@ -654,6 +654,7 @@ let float data = Float {data} |> check invariant
 
 let simp_convert signed (dst : Typ.t) src arg =
   match (dst, arg) with
+  | _ when Typ.equal dst src -> arg
   | Integer {bits= m}, Integer {data; typ= Integer {bits= n}} ->
       integer (Z.clamp ~signed (min m n) data) dst
   | _ -> App {op= Convert {signed; dst; src}; arg}