b57ccdf992
Use a subslice of the pixel data to give the compiler hints for bounds checking. Only do this for image formats that require 4 or more slice reads/writes. See #27857 for discussion of small cap sizes. name old time/op new time/op delta At/rgba-8 18.8ns ± 2% 18.5ns ± 1% -1.49% (p=0.026 n=10+10) At/rgba64-8 22.2ns ± 2% 21.1ns ± 3% -4.51% (p=0.000 n=10+10) At/nrgba-8 18.8ns ± 2% 18.7ns ± 2% ~ (p=0.467 n=10+10) At/nrgba64-8 21.9ns ± 2% 21.0ns ± 2% -4.15% (p=0.000 n=10+9) At/alpha-8 14.3ns ± 1% 14.3ns ± 2% ~ (p=0.543 n=10+10) At/alpha16-8 6.43ns ± 1% 6.47ns ± 1% ~ (p=0.053 n=10+10) At/gray-8 14.4ns ± 2% 14.6ns ± 5% ~ (p=0.194 n=10+10) At/gray16-8 6.52ns ± 1% 6.55ns ± 2% ~ (p=0.610 n=10+10) At/paletted-8 4.17ns ± 1% 4.21ns ± 2% ~ (p=0.095 n=9+10) Set/rgba-8 39.2ns ± 2% 40.1ns ± 4% +2.45% (p=0.007 n=10+10) Set/rgba64-8 46.2ns ± 3% 43.3ns ± 3% -6.11% (p=0.000 n=10+10) Set/nrgba-8 39.2ns ± 1% 39.7ns ± 5% ~ (p=0.407 n=10+10) Set/nrgba64-8 45.6ns ± 3% 42.9ns ± 3% -5.83% (p=0.000 n=9+10) Set/alpha-8 35.0ns ± 3% 34.1ns ± 2% -2.43% (p=0.017 n=10+10) Set/alpha16-8 36.3ns ± 4% 35.8ns ± 5% ~ (p=0.254 n=10+10) Set/gray-8 19.8ns ± 1% 19.7ns ± 0% -0.69% (p=0.002 n=8+6) Set/gray16-8 36.0ns ± 1% 36.4ns ± 2% +1.08% (p=0.037 n=10+10) Set/paletted-8 39.1ns ± 0% 39.6ns ± 1% +1.30% (p=0.000 n=10+10) RGBAAt-8 3.72ns ± 1% 3.58ns ± 1% -3.76% (p=0.000 n=9+10) RGBASetRGBA-8 4.35ns ± 1% 3.70ns ± 1% -14.92% (p=0.000 n=10+10) RGBA64At-8 5.08ns ± 1% 3.69ns ± 1% -27.40% (p=0.000 n=9+9) RGBA64SetRGBA64-8 6.65ns ± 2% 3.63ns ± 0% -45.35% (p=0.000 n=10+9) NRGBAAt-8 3.72ns ± 1% 3.59ns ± 1% -3.55% (p=0.000 n=10+10) NRGBASetNRGBA-8 4.05ns ± 0% 3.71ns ± 1% -8.57% (p=0.000 n=9+10) NRGBA64At-8 4.99ns ± 1% 3.69ns ± 0% -26.07% (p=0.000 n=10+9) NRGBA64SetNRGBA64-8 6.66ns ± 1% 3.64ns ± 1% -45.40% (p=0.000 n=10+10) AlphaAt-8 1.44ns ± 1% 1.44ns ± 0% ~ (p=0.176 n=10+7) AlphaSetAlpha-8 1.60ns ± 2% 1.56ns ± 0% -2.62% (p=0.000 n=10+6) Alpha16At-8 2.87ns ± 1% 2.92ns ± 2% +1.67% (p=0.001 n=10+10) AlphaSetAlpha16-8 3.26ns ± 1% 3.35ns ± 1% +2.68% (p=0.012 n=8+3) Fixes #14884 Change-Id: Ia0383530596a550e1b1c7aafce5220e5e0935a53 Reviewed-on: https://go-review.googlesource.com/137495 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The Go Programming Language
Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
Gopher image by Renee French, licensed under Creative Commons 3.0 Attributions license.
Our canonical Git repository is located at https://go.googlesource.com/go. There is a mirror of the repository at https://github.com/golang/go.
Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.
Download and Install
Binary Distributions
Official binary distributions are available at https://golang.org/dl/.
After downloading a binary release, visit https://golang.org/doc/install or load doc/install.html in your web browser for installation instructions.
Install From Source
If a binary distribution is not available for your combination of operating system and architecture, visit https://golang.org/doc/install/source or load doc/install-source.html in your web browser for source installation instructions.
Contributing
Go is the work of thousands of contributors. We appreciate your help!
To contribute, please read the contribution guidelines: https://golang.org/doc/contribute.html
Note that the Go project uses the issue tracker for bug reports and proposals only. See https://golang.org/wiki/Questions for a list of places to ask questions about the Go language.