From: Ivan Krasin <krasin@golang.org>
Date: Sat, 21 Jan 2012 17:18:15 +0000 (-0500)
Subject: compress/flate: fix a typo, improve compression rate by 3-4%.
X-Git-Tag: weekly.2012-01-27~121
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=4d3b9d97573082152894847f5040876f8febc70f;p=gostls13.git

compress/flate: fix a typo, improve compression rate by 3-4%.

R=rsc
CC=golang-dev
https://golang.org/cl/5556077
---

diff --git a/src/pkg/compress/flate/deflate.go b/src/pkg/compress/flate/deflate.go
index c61087672e..5f5100db83 100644
--- a/src/pkg/compress/flate/deflate.go
+++ b/src/pkg/compress/flate/deflate.go
@@ -112,7 +112,7 @@ func (d *compressor) fillDeflate(b []byte) int {
 			d.hashHead[i] = v
 		}
 		for i, h := range d.hashPrev {
-			v := -h - windowSize
+			v := h - windowSize
 			if v < -1 {
 				v = -1
 			}
diff --git a/src/pkg/compress/flate/deflate_test.go b/src/pkg/compress/flate/deflate_test.go
index 9cf93479a2..24881d31c0 100644
--- a/src/pkg/compress/flate/deflate_test.go
+++ b/src/pkg/compress/flate/deflate_test.go
@@ -291,7 +291,7 @@ var deflateInflateStringTests = []deflateInflateStringTest{
 	{
 		"../testdata/Mark.Twain-Tom.Sawyer.txt",
 		"Mark.Twain-Tom.Sawyer",
-		[...]int{416188, 191483, 185232, 179560, 175233, 171263, 169908, 169758, 169712, 169712},
+		[...]int{407330, 187598, 180361, 172974, 169160, 163476, 160936, 160506, 160295, 160295},
 	},
 }