baec148767
The existing implementation for Equal and similar functions in the bytes package operate on one byte at at time. This performs poorly on ppc64/ppc64le especially when the byte buffers are large. This change improves those functions by loading and comparing double words where possible. The common code has been moved to a function that can be shared by the other functions in this file which perform the same type of comparison. Further optimizations are done for the case where >= 32 bytes are being compared. The new function memeqbody is used by memeq_varlen, Equal, and eqstring. When running the bytes test with -test.bench=Equal benchmark old MB/s new MB/s speedup BenchmarkEqual1 164.83 129.49 0.79x BenchmarkEqual6 563.51 445.47 0.79x BenchmarkEqual9 656.15 1099.00 1.67x BenchmarkEqual15 591.93 1024.30 1.73x BenchmarkEqual16 613.25 1914.12 3.12x BenchmarkEqual20 682.37 1687.04 2.47x BenchmarkEqual32 807.96 3843.29 4.76x BenchmarkEqual4K 1076.25 23280.51 21.63x BenchmarkEqual4M 1079.30 13120.14 12.16x BenchmarkEqual64M 1073.28 10876.92 10.13x It was determined that the degradation in the smaller byte tests were due to unfavorable code alignment of the single byte loop. Fixes #14368 Change-Id: I0dd87382c28887c70f4fbe80877a8ba03c31d7cd Reviewed-on: https://go-review.googlesource.com/20249 Reviewed-by: Minux Ma <minux@golang.org> |
||
|---|---|---|
| .github | ||
| api | ||
| doc | ||
| lib/time | ||
| misc | ||
| src | ||
| test | ||
| .gitattributes | ||
| .gitignore | ||
| AUTHORS | ||
| CONTRIBUTING.md | ||
| CONTRIBUTORS | ||
| favicon.ico | ||
| LICENSE | ||
| PATENTS | ||
| README.md | ||
| robots.txt | ||
The Go Programming Language
Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
For documentation about how to install and use Go, visit https://golang.org/ or load doc/install-source.html in your web browser.
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.
Go is the work of hundreds of contributors. We appreciate your help!
To contribute, please read the contribution guidelines: https://golang.org/doc/contribute.html
Note that we do not accept pull requests and that we use the issue tracker for bug reports and proposals only. Please ask questions on https://forum.golangbridge.org or https://groups.google.com/forum/#!forum/golang-nuts.
Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.
--
Binary Distribution Notes
If you have just untarred a binary Go distribution, you need to set the environment variable $GOROOT to the full path of the go directory (the one containing this file). You can omit the variable if you unpack it into /usr/local/go, or if you rebuild from sources by running all.bash (see doc/install-source.html). You should also add the Go binary directory $GOROOT/bin to your shell's path.
For example, if you extracted the tar file into $HOME/go, you might put the following in your .profile:
export GOROOT=$HOME/go
export PATH=$PATH:$GOROOT/bin
See https://golang.org/doc/install or doc/install.html for more details.