From 15c2eb13f2af1f0e75bb7d961515e29bd7253962 Mon Sep 17 00:00:00 2001
From: Joel Dice <git@seibutsu.mailsnare.net>
Date: Sat, 17 May 2008 18:13:27 -0600
Subject: [PATCH] don't generate code for a move from a register to itself

---
 src/x86.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/x86.cpp b/src/x86.cpp
index 2e1cec2fc8..544e08a495 100644
--- a/src/x86.cpp
+++ b/src/x86.cpp
@@ -714,9 +714,11 @@ moveRR(Context* c, unsigned size, Assembler::Register* a,
 
     case 8:
     case 4:
-      rex(c);
-      c->code.append(0x89);
-      c->code.append(0xc0 | (a->low << 3) | b->low);
+      if (a->low != b->low) {
+        rex(c);
+        c->code.append(0x89);
+        c->code.append(0xc0 | (a->low << 3) | b->low);
+      }
       break;
     }
   }