From 185f07621fc42c1da194ada0fe98439f07f78aa0 Mon Sep 17 00:00:00 2001
From: ths <ths@c046a42c-6fe2-441c-8c8c-71466251a162>
Date: Thu, 22 Nov 2007 15:10:21 +0000
Subject: [PATCH] Optimize the conventional move operation.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3720 c046a42c-6fe2-441c-8c8c-71466251a162
---
 target-mips/translate.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/target-mips/translate.c b/target-mips/translate.c
index b3ae2ccfea..55e6290f31 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -1240,6 +1240,12 @@ static void gen_arith (CPUState *env, DisasContext *ctx, uint32_t opc,
         return;
     }
     GEN_LOAD_REG_TN(T0, rs);
+    /* Specialcase the conventional move operation. */
+    if (rt == 0 && (opc == OPC_ADDU || opc == OPC_DADDU
+                    || opc == OPC_SUBU || opc == OPC_DSUBU)) {
+        GEN_STORE_TN_REG(rd, T0);
+        return;
+    }
     GEN_LOAD_REG_TN(T1, rt);
     switch (opc) {
     case OPC_ADD: