a1550d3ca3
This changes the code generated for variable length shift counts to use isel instead of instructions that set and read the carry flag. This reduces the generated code for shifts like this by 1 instruction and avoids the use of instructions to set and read the carry flag. This sequence can be found in strconv with these results on power9: Atof64Decimal 71.6ns ± 0% 68.3ns ± 0% -4.61% Atof64Float 95.3ns ± 0% 90.9ns ± 0% -4.62% Atof64FloatExp 153ns ± 0% 149ns ± 0% -2.61% Atof64Big 234ns ± 0% 232ns ± 0% -0.85% Atof64RandomBits 348ns ± 0% 369ns ± 0% +6.03% Atof64RandomFloats 262ns ± 0% 262ns ± 0% ~ Atof32Decimal 72.0ns ± 0% 68.2ns ± 0% -5.28% Atof32Float 92.1ns ± 0% 87.1ns ± 0% -5.43% Atof32FloatExp 159ns ± 0% 158ns ± 0% -0.63% Atof32Random 194ns ± 0% 191ns ± 0% -1.55% Some tests in codegen/shift.go are enabled to verify the expected instructions are generated. Change-Id: I968715d10ada405a8c46132bf19b8ed9b85796d1 Reviewed-on: https://go-review.googlesource.com/c/go/+/227337 Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> |
||
|---|---|---|
| .github | ||
| api | ||
| doc | ||
| lib/time | ||
| misc | ||
| src | ||
| test | ||
| .gitattributes | ||
| .gitignore | ||
| AUTHORS | ||
| CONTRIBUTING.md | ||
| CONTRIBUTORS | ||
| favicon.ico | ||
| LICENSE | ||
| PATENTS | ||
| README.md | ||
| robots.txt | ||
| SECURITY.md | ||
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.