From 4e4be608840d50f152d4f1643c5f06f2b7899a12 Mon Sep 17 00:00:00 2001
From: Joe Groff <arcata@gmail.com>
Date: Sat, 10 Oct 2009 13:13:53 -0500
Subject: [PATCH] use TEST reg, reg to compare integer equality with zero

---
 basis/cpu/x86/x86.factor | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/basis/cpu/x86/x86.factor b/basis/cpu/x86/x86.factor
index a163ba6482..8612acdcff 100644
--- a/basis/cpu/x86/x86.factor
+++ b/basis/cpu/x86/x86.factor
@@ -432,8 +432,13 @@ M: x86 %epilogue ( n -- ) cell - incr-stack-reg ;
     temp 0 MOV \ t rc-absolute-cell rel-immediate
     dst temp word execute ; inline
 
+: (%compare) ( src1 src2 cc -- )
+    2over [ { cc= cc/= } member? ] [ register? ] [ 0 = ] tri* and and
+    [ drop dup TEST ]
+    [ CMP ] if ;
+
 M:: x86 %compare ( dst src1 src2 cc temp -- )
-    src1 src2 CMP
+    src1 src2 cc (%compare)
     cc order-cc {
         { cc<  [ dst temp \ CMOVL %boolean ] }
         { cc<= [ dst temp \ CMOVLE %boolean ] }
@@ -447,7 +452,7 @@ M: x86 %compare-imm ( dst src1 src2 cc temp -- )
     %compare ;
 
 M:: x86 %compare-branch ( label src1 src2 cc -- )
-    src1 src2 CMP
+    src1 src2 cc (%compare)
     cc order-cc {
         { cc<  [ label JL ] }
         { cc<= [ label JLE ] }