From 2158e772ec0d23c9f656d4501985d4d9cc4750ed Mon Sep 17 00:00:00 2001
From: John Benediktsson <mrjbq7@gmail.com>
Date: Fri, 14 Sep 2012 08:43:29 -0700
Subject: [PATCH] math.order: speed up math comparisons using a math generic.

---
 core/math/order/order.factor | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/core/math/order/order.factor b/core/math/order/order.factor
index 499cf06e9a..702c54376b 100644
--- a/core/math/order/order.factor
+++ b/core/math/order/order.factor
@@ -1,6 +1,6 @@
 ! Copyright (C) 2008, 2010 Slava Pestov, Doug Coleman.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: kernel math ;
+USING: kernel kernel.private math ;
 IN: math.order
 
 SYMBOL: +lt+
@@ -15,7 +15,22 @@ GENERIC: <=> ( obj1 obj2 -- <=> )
 
 : >=< ( obj1 obj2 -- >=< ) <=> invert-comparison ; inline
 
-M: real <=> 2dup < [ 2drop +lt+ ] [ number= +eq+ +gt+ ? ] if ; inline
+<PRIVATE
+
+! defining a math generic for comparison forces a single math
+! promotion, and speeds up comparisons on numbers.
+: (number<=>) ( x y -- ? )
+    2dup < [ 2drop +lt+ ] [ number= +eq+ +gt+ ? ] if ; inline
+
+MATH: number<=> ( x y -- ? )
+M: fixnum number<=> { fixnum fixnum } declare (number<=>) ; inline
+M: bignum number<=> { bignum bignum } declare (number<=>) ; inline
+M: float number<=> { float float } declare (number<=>) ; inline
+M: real number<=> (number<=>) ; inline
+
+PRIVATE>
+
+M: real <=> number<=> ; inline
 
 GENERIC: before? ( obj1 obj2 -- ? )
 GENERIC: after? ( obj1 obj2 -- ? )