From 0b89d6d5f9f8c788f4391d8a0499f10aed624371 Mon Sep 17 00:00:00 2001
From: ko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 27 Aug 2012 09:22:21 +0000
Subject: [PATCH] * include/ruby/ruby.h (rb_float_value): optimize it.   This
 technique was pointed by shinichiro.hamaji  
 <http://shinh.skr.jp/m/?date=20120825#p02>.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36832 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog           |    6 ++++++
 include/ruby/ruby.h |   10 +++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 3905b32..b8b2267 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -733,10 +733,7 @@ struct RFloat {
 rb_float_value(VALUE v)
 {
     if (FLONUM_P(v)) {
-	if (v == (VALUE)0x8000000000000002) {
-	    return 0.0;
-	}
-	else {
+	if (v != (VALUE)0x8000000000000002) { /* LIKELY */
 	    union {
 		double d;
 		VALUE v;
@@ -746,9 +743,12 @@ struct RFloat {
 	    /* e: xx1... -> 011... */
 	    /*    xx0... -> 100... */
 	    /*      ^b63           */
-	    t.v = RUBY_BIT_ROTR(((b63 ^ 1) << 1) | b63 | (v & ~0x03), 3);
+	    t.v = RUBY_BIT_ROTR(2 - b63 | (v & ~0x03), 3);
 	    return t.d;
 	}
+	else {
+	    return 0.0;
+	}
     }
     else {
 	return ((struct RFloat *)v)->float_value;
-- 
1.7.10