code review 6619056: image/jpeg: add DCT tests, do a small optimization (com...

image/jpeg: add DCT tests, do a small optimization (common sub-expression
elimination) in idct.go.

benchmark                   old ns/op    new ns/op    delta
BenchmarkIDCT                    5649         5610   -0.69%
BenchmarkDecodeRGBOpaque      2948607      2941051   -0.26%

The "type block" declaration moved so that idct.go is compilable
as a stand-alone file: "go tool 6g -S idct.go" works.

[nigeltao, 2012-10-06 07:12:41]

Hello r@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[r, 2012-10-06 11:51:35]

LGTM

[nigeltao, 2012-10-06 23:21:23]

*** Submitted as http://code.google.com/p/go/source/detail?r=b32301e11025 ***

image/jpeg: add DCT tests, do a small optimization (common sub-expression
elimination) in idct.go.

benchmark                   old ns/op    new ns/op    delta
BenchmarkIDCT                    5649         5610   -0.69%
BenchmarkDecodeRGBOpaque      2948607      2941051   -0.26%

The "type block" declaration moved so that idct.go is compilable
as a stand-alone file: "go tool 6g -S idct.go" works.

R=r
CC=golang-dev
http://codereview.appspot.com/6619056