commit | b46e44a399045d0177dd063dc192168f0b5b3f55 | [log] [tgz] |
---|---|---|
author | Than McIntosh <thanm@google.com> | Tue Jan 10 10:21:16 2023 -0500 |
committer | Than McIntosh <thanm@google.com> | Mon Feb 06 20:53:29 2023 +0000 |
tree | 43aafa46b76ee6f8d1302475e4a331c83c6716ff | |
parent | 103f37497f2927eeb510789f63fe2a0319b6a49a [diff] |
cmd/compile: enable deadcode of unreferenced large global maps This patch changes the compiler's pkg init machinery to pick out large initialization assignments to global maps (e.g. var mymap = map[string]int{"foo":1, "bar":2, ... } and extract the map init code into a separate outlined function, which is then called from the main init function with a weak relocation: var mymap map[string]int // KEEP reloc -> map.init.0 func init() { map.init.0() // weak relocation } func map.init.0() { mymap = map[string]int{"foo":1, "bar":2} } The map init outlining is done selectively (only in the case where the RHS code exceeds a size limit of 20 IR nodes). In order to ensure that a given map.init.NNN function is included when its corresponding map is live, we add dummy R_KEEP relocation from the map variable to the map init function. This first patch includes the main compiler compiler changes, and with the weak relocation addition disabled. Subsequent patch includes the requred linker changes along with switching to the call to the outlined routine to a weak relocation. See the later linker change for associated compile time performance numbers. Updates #2559. Updates #36021. Updates #14840. Change-Id: I1fd6fd6397772be1ebd3eb397caf68ae9a3147e9 Reviewed-on: https://go-review.googlesource.com/c/go/+/461315 Run-TryBot: Than McIntosh <thanm@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
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 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.
Official binary distributions are available at https://go.dev/dl/.
After downloading a binary release, visit https://go.dev/doc/install for installation instructions.
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.
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.