1
0
mirror of https://github.com/golang/go synced 2024-11-17 02:54:45 -07:00
The Go programming language
Go to file
Than McIntosh e2ca417ee7 cmd/link: linker portion of dead map removal
This patch contains the linker changes needed to enable deadcoding of
large unreferenced map variables, in combination with a previous
compiler change. We add a new cleanup function that runs just after
deadcode that looks for relocations in "init" funcs that are weak, of
type R_CALL (and siblings), and are targeting an unreachable function.
If we find such a relocation, after checking to make sure it targets a
map.init.XXX helper, we redirect the relocation to a point to a no-op
routine ("mapinitnoop") in the runtime.

Compilebench results for this change:

			  │ out.base.txt │            out.wrap.txt            │
			  │    sec/op    │   sec/op     vs base               │
 Template                   218.6m ±  2%   221.1m ± 1%       ~ (p=0.129 n=39)
 Unicode                    180.5m ±  1%   178.9m ± 1%  -0.93% (p=0.006 n=39)
 GoTypes                     1.162 ±  1%    1.156 ± 1%       ~ (p=0.850 n=39)
 Compiler                   143.6m ±  1%   142.6m ± 1%       ~ (p=0.743 n=39)
 SSA                         8.698 ±  1%    8.719 ± 1%       ~ (p=0.145 n=39)
 Flate                      142.6m ±  1%   143.9m ± 3%       ~ (p=0.287 n=39)
 GoParser                   247.7m ±  1%   248.8m ± 1%       ~ (p=0.265 n=39)
 Reflect                    588.0m ±  1%   590.4m ± 1%       ~ (p=0.269 n=39)
 Tar                        198.5m ±  1%   201.3m ± 1%  +1.38% (p=0.005 n=39)
 XML                        259.1m ±  1%   260.0m ± 1%       ~ (p=0.376 n=39)
 LinkCompiler               746.8m ±  2%   747.8m ± 1%       ~ (p=0.706 n=39)
 ExternalLinkCompiler        1.906 ±  0%    1.902 ± 1%       ~ (p=0.207 n=40)
 LinkWithoutDebugCompiler   522.4m ± 21%   471.1m ± 1%  -9.81% (p=0.000 n=40)
 StdCmd                      21.32 ±  0%    21.39 ± 0%  +0.32% (p=0.035 n=40)
 geomean                    609.2m         606.0m       -0.53%

			  │ out.base.txt │            out.wrap.txt            │
			  │ user-sec/op  │ user-sec/op  vs base               │
 Template                    401.9m ± 3%   406.9m ± 2%       ~ (p=0.291 n=39)
 Unicode                     191.9m ± 6%   196.1m ± 3%       ~ (p=0.052 n=39)
 GoTypes                      3.967 ± 3%    4.056 ± 1%       ~ (p=0.099 n=39)
 Compiler                    171.1m ± 3%   173.4m ± 3%       ~ (p=0.415 n=39)
 SSA                          30.04 ± 4%    30.25 ± 4%       ~ (p=0.106 n=39)
 Flate                       246.3m ± 3%   248.9m ± 4%       ~ (p=0.499 n=39)
 GoParser                    518.7m ± 1%   520.6m ± 2%       ~ (p=0.531 n=39)
 Reflect                      1.670 ± 1%    1.656 ± 2%       ~ (p=0.137 n=39)
 Tar                         352.7m ± 2%   360.3m ± 2%       ~ (p=0.117 n=39)
 XML                         528.8m ± 2%   521.1m ± 2%       ~ (p=0.296 n=39)
 LinkCompiler                 1.128 ± 2%    1.140 ± 2%       ~ (p=0.324 n=39)
 ExternalLinkCompiler         2.165 ± 2%    2.147 ± 2%       ~ (p=0.537 n=40)
 LinkWithoutDebugCompiler    484.2m ± 4%   490.7m ± 3%       ~ (p=0.897 n=40)
 geomean                     818.5m        825.1m       +0.80%

	   │ out.base.txt │             out.wrap.txt              │
	   │  text-bytes  │  text-bytes   vs base                 │
 HelloSize   766.0Ki ± 0%   766.0Ki ± 0%       ~ (p=1.000 n=40) ¹
 CmdGoSize   10.02Mi ± 0%   10.02Mi ± 0%  -0.03% (n=40)
 geomean     2.738Mi        2.738Mi       -0.01%
 ¹ all samples are equal

	   │ out.base.txt │             out.wrap.txt              │
	   │  data-bytes  │  data-bytes   vs base                 │
 HelloSize   14.17Ki ± 0%   14.17Ki ± 0%       ~ (p=1.000 n=40) ¹
 CmdGoSize   308.3Ki ± 0%   298.5Ki ± 0%  -3.19% (n=40)
 geomean     66.10Ki        65.04Ki       -1.61%
 ¹ all samples are equal

	   │ out.base.txt │             out.wrap.txt              │
	   │  bss-bytes   │  bss-bytes    vs base                 │
 HelloSize   197.3Ki ± 0%   197.3Ki ± 0%       ~ (p=1.000 n=40) ¹
 CmdGoSize   228.2Ki ± 0%   228.1Ki ± 0%  -0.01% (n=40)
 geomean     212.2Ki        212.1Ki       -0.01%
 ¹ all samples are equal

	   │ out.base.txt │            out.wrap.txt             │
	   │  exe-bytes   │  exe-bytes    vs base               │
 HelloSize   1.192Mi ± 0%   1.192Mi ± 0%  +0.00% (p=0.000 n=40)
 CmdGoSize   14.85Mi ± 0%   14.83Mi ± 0%  -0.09% (n=40)
 geomean     4.207Mi        4.205Mi       -0.05%

Also tested for any linker changes by benchmarking relink of k8s
"kubelet"; no changes to speak of there.

Updates #2559.
Updates #36021.
Updates #14840.

Change-Id: I4cc5370b3f20679a1065aaaf87bdf2881e257631
Reviewed-on: https://go-review.googlesource.com/c/go/+/463395
Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
2023-02-06 20:56:47 +00:00
.github .github: suggest using private browsing in pkgsite template 2023-01-03 18:52:47 +00:00
api all: upgrade Unicode from 13.0.0 to 15.0.0 2023-02-06 04:29:53 +00:00
doc doc: move Go 1.20 release notes to x/website 2023-01-30 21:10:03 +00:00
lib/time time/tzdata: generate zip constant during cmd/dist 2023-01-17 22:30:53 +00:00
misc misc: increase node stack size 2023-02-02 15:35:28 +00:00
src cmd/link: linker portion of dead map removal 2023-02-06 20:56:47 +00:00
test cmd/compile: ensure first instruction in a function is not inlined 2023-02-06 20:39:54 +00:00
.gitattributes all: treat all files as binary, but check in .bat with CRLF 2020-06-08 15:31:43 +00:00
.gitignore time/tzdata: generate zip constant during cmd/dist 2023-01-17 22:30:53 +00:00
codereview.cfg codereview.cfg: add codereview.cfg for master branch 2021-02-19 18:44:53 +00:00
CONTRIBUTING.md
go.env cmd/go: introduce GOROOT/go.env and move proxy/sumdb config there 2023-01-17 23:10:39 +00:00
LICENSE
PATENTS
README.md README: update from CC-BY-3.0 to CC-BY-4.0 2022-11-02 20:14:56 +00:00
SECURITY.md SECURITY.md: replace golang.org with go.dev 2022-04-26 19:59:47 +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 4.0 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://go.dev/dl/.

After downloading a binary release, visit https://go.dev/doc/install for installation instructions.

Install From Source

If a binary distribution is not available for your combination of operating system and architecture, visit https://go.dev/doc/install/source for source installation instructions.

Contributing

Go is the work of thousands of contributors. We appreciate your help!

To contribute, please read the contribution guidelines at https://go.dev/doc/contribute.

Note that the Go project uses the issue tracker for bug reports and proposals only. See https://go.dev/wiki/Questions for a list of places to ask questions about the Go language.