mirror of
https://github.com/golang/go
synced 2024-11-05 16:06:10 -07:00
5029c3671d
type T struct {
s string
i int
}
Prior to this change, we generated this equality algorithm for T:
func eqT(p, q *T) bool {
return len(p.s) == len(q.s) &&
runtime.memequal(p.s.ptr, q.s.ptr, len(p.s)) &&
p.i == q.i
}
This change splits the two halves of the string equality,
so that we can do the cheap (length) half early and the expensive
(contents) half late. We now generate:
func eqT(p, q *T) bool {
return len(p.s) == len(q.s) &&
p.i == q.i &&
runtime.memequal(p.s.ptr, q.s.ptr, len(p.s))
}
The generated code for these functions tends to be a bit shorter. Examples:
runtime
.eq."".Frame 274 -> 272 (-0.73%)
.eq."".funcinl 249 -> 247 (-0.80%)
.eq."".modulehash 207 -> 205 (-0.97%)
Change-Id: I4efac9f7d410f0a11a94dcee2bf9c0b49b60e301
Reviewed-on: https://go-review.googlesource.com/c/go/+/230205
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
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| .. | ||
| archive | ||
| bufio | ||
| builtin | ||
| bytes | ||
| cmd | ||
| compress | ||
| container | ||
| context | ||
| crypto | ||
| database/sql | ||
| debug | ||
| encoding | ||
| errors | ||
| expvar | ||
| flag | ||
| fmt | ||
| go | ||
| hash | ||
| html | ||
| image | ||
| index/suffixarray | ||
| internal | ||
| io | ||
| log | ||
| math | ||
| mime | ||
| net | ||
| os | ||
| path | ||
| plugin | ||
| reflect | ||
| regexp | ||
| runtime | ||
| sort | ||
| strconv | ||
| strings | ||
| sync | ||
| syscall | ||
| testdata | ||
| testing | ||
| text | ||
| time | ||
| unicode | ||
| unsafe | ||
| vendor | ||
| all.bash | ||
| all.bat | ||
| all.rc | ||
| bootstrap.bash | ||
| buildall.bash | ||
| clean.bash | ||
| clean.bat | ||
| clean.rc | ||
| cmp.bash | ||
| go.mod | ||
| go.sum | ||
| iostest.bash | ||
| make.bash | ||
| make.bat | ||
| Make.dist | ||
| make.rc | ||
| race.bash | ||
| race.bat | ||
| README.vendor | ||
| run.bash | ||
| run.bat | ||
| run.rc | ||
Vendoring in std and cmd
========================
The Go command maintains copies of external packages needed by the
standard library in the src/vendor and src/cmd/vendor directories.
In GOPATH mode, imports of vendored packages are resolved to these
directories following normal vendor directory logic
(see golang.org/s/go15vendor).
In module mode, std and cmd are modules (defined in src/go.mod and
src/cmd/go.mod). When a package outside std or cmd is imported
by a package inside std or cmd, the import path is interpreted
as if it had a "vendor/" prefix. For example, within "crypto/tls",
an import of "golang.org/x/crypto/cryptobyte" resolves to
"vendor/golang.org/x/crypto/cryptobyte". When a package with the
same path is imported from a package outside std or cmd, it will
be resolved normally. Consequently, a binary may be built with two
copies of a package at different versions if the package is
imported normally and vendored by the standard library.
Vendored packages are internally renamed with a "vendor/" prefix
to preserve the invariant that all packages have distinct paths.
This is necessary to avoid compiler and linker conflicts. Adding
a "vendor/" prefix also maintains the invariant that standard
library packages begin with a dotless path element.
The module requirements of std and cmd do not influence version
selection in other modules. They are only considered when running
module commands like 'go get' and 'go mod vendor' from a directory
in GOROOT/src.
Maintaining vendor directories
==============================
Before updating vendor directories, ensure that module mode is enabled.
Make sure GO111MODULE=off is not set ('on' or 'auto' should work).
Requirements may be added, updated, and removed with 'go get'.
The vendor directory may be updated with 'go mod vendor'.
A typical sequence might be:
cd src
go get -d golang.org/x/net@latest
go mod tidy
go mod vendor
Use caution when passing '-u' to 'go get'. The '-u' flag updates
modules providing all transitively imported packages, not only
the module providing the target package.
Note that 'go mod vendor' only copies packages that are transitively
imported by packages in the current module. If a new package is needed,
it should be imported before running 'go mod vendor'.