1
0
mirror of https://github.com/golang/go synced 2024-11-23 19:50:06 -07:00
The Go programming language
Go to file
Michael Munday 6e876f1985 cmd/compile: clean up and optimize s390x multiplication rules
Some of the existing optimizations aren't triggered because they
are handled by the generic rules so this CL removes them. Also
some constraints were copied without much thought from the amd64
rules and they don't make sense on s390x, so we remove those
constraints.

Finally, add a 'multiply by the sum of two powers of two'
optimization. This makes sense on s390x as shifts are low latency
and can also sometimes be optimized further (especially if we add
support for RISBG instructions).

name                   old time/op  new time/op  delta
IntMulByConst/3-8      1.70ns ±11%  1.10ns ± 5%  -35.26%  (p=0.000 n=10+10)
IntMulByConst/5-8      1.64ns ± 7%  1.10ns ± 4%  -32.94%  (p=0.000 n=10+9)
IntMulByConst/12-8     1.65ns ± 6%  1.20ns ± 4%  -27.16%  (p=0.000 n=10+9)
IntMulByConst/120-8    1.66ns ± 4%  1.22ns ±13%  -26.43%  (p=0.000 n=10+10)
IntMulByConst/-120-8   1.65ns ± 7%  1.19ns ± 4%  -28.06%  (p=0.000 n=9+10)
IntMulByConst/65537-8  0.86ns ± 9%  1.12ns ±12%  +30.41%  (p=0.000 n=10+10)
IntMulByConst/65538-8  1.65ns ± 5%  1.23ns ± 5%  -25.11%  (p=0.000 n=10+10)

Change-Id: Ib196e6bff1e97febfd266134d0a2b2a62897989f
Reviewed-on: https://go-review.googlesource.com/c/go/+/248937
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-08-18 15:39:44 +00:00
.github .github: add link to questions in ISSUE_TEMPLATE 2020-01-06 17:05:31 +00:00
api go/printer: remove exported StdFormat flag 2020-07-17 02:15:01 +00:00
doc all: replace Replace(..., -1) with ReplaceAll(...) 2020-08-17 04:07:23 +00:00
lib/time lib/time, time/tzdata: update tz data to 2020a 2020-04-30 08:07:39 +00:00
misc cmd/cgo: fix mangling of enum and union types 2020-07-31 16:35:33 +00:00
src cmd/compile: clean up and optimize s390x multiplication rules 2020-08-18 15:39:44 +00:00
test cmd/compile: clean up and optimize s390x multiplication rules 2020-08-18 15:39:44 +00:00
.gitattributes all: treat all files as binary, but check in .bat with CRLF 2020-06-08 15:31:43 +00:00
.gitignore
AUTHORS A+C: add Kush Patel (corporate CLA for Hootsuite Inc) 2020-07-08 00:10:44 +00:00
CONTRIBUTING.md all: restore changes from faulty merge/revert 2018-02-12 20:13:59 +00:00
CONTRIBUTORS CONTRIBUTORS: update for the Go 1.15 release 2020-08-10 21:51:48 +00:00
favicon.ico
LICENSE
PATENTS
README.md README: linkify some paths 2018-06-06 18:07:01 +00:00
robots.txt
SECURITY.md SECURITY.md: update go versions 2019-09-26 15:34:57 +00:00

The Go Programming Language

Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.

Gopher image 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.