From 04cb320c55698bbc38088575c304acbfa8c2c013 Mon Sep 17 00:00:00 2001
From: Doug Coleman <doug.coleman@gmail.com>
Date: Thu, 2 Jul 2009 11:33:15 -0500
Subject: [PATCH] simplify sub and sub-imm
---
.../cfg/value-numbering/simplify/simplify.factor | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/basis/compiler/cfg/value-numbering/simplify/simplify.factor b/basis/compiler/cfg/value-numbering/simplify/simplify.factor
index e70ba4b54b..b7526528e4 100644
--- a/basis/compiler/cfg/value-numbering/simplify/simplify.factor
+++ b/basis/compiler/cfg/value-numbering/simplify/simplify.factor
@@ -3,7 +3,7 @@
USING: kernel accessors combinators classes math layouts
compiler.cfg.instructions
compiler.cfg.value-numbering.graph
-compiler.cfg.value-numbering.expressions ;
+compiler.cfg.value-numbering.expressions locals ;
IN: compiler.cfg.value-numbering.simplify
! Return value of f means we didn't simplify.
@@ -42,6 +42,13 @@ M: unary-expr simplify*
[ 2drop f ]
} cond ; inline
+: simplify-sub ( expr -- vn/expr/f )
+ >binary-expr< {
+ { [ 2dup eq? ] [ 2drop T{ constant-expr f f 0 } ] }
+ { [ dup expr-zero? ] [ drop ] }
+ [ 2drop f ]
+ } cond ; inline
+
: useless-shift? ( in1 in2 -- ? )
over op>> \ ##shl-imm eq?
[ [ in2>> ] [ expr>vn ] bi* = ] [ 2drop f ] if ; inline
@@ -54,6 +61,8 @@ M: binary-expr simplify*
dup op>> {
{ \ ##add [ simplify-add ] }
{ \ ##add-imm [ simplify-add ] }
+ { \ ##sub [ simplify-sub ] }
+ { \ ##sub-imm [ simplify-sub ] }
{ \ ##shr-imm [ simplify-shift ] }
{ \ ##sar-imm [ simplify-shift ] }
[ 2drop f ]