Propagate "unread" across OpMoves. If the addr of this auto is only used
by an OpMove as its source arg, and the OpMove's target arg is the addr
of another auto. If the 2nd auto can be eliminated, this one can also be
eliminated.
This CL eliminates unnecessary memory copies and makes the frame smaller
in the following code snippet:
func contains(m map[string][16]int, k string) bool {
_, ok := m[k]
return ok
}
These are the benchmark results followed by the benchmark code:
goos: linux
goarch: amd64
cpu: Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
│ old.txt │ new.txt │
│ sec/op │ sec/op vs base │
Map1Access2Ok-8 9.582n ± 2% 9.226n ± 0% -3.72% (p=0.000 n=20)
Map2Access2Ok-8 13.79n ± 1% 10.24n ± 1% -25.77% (p=0.000 n=20)
Map3Access2Ok-8 68.68n ± 1% 12.65n ± 1% -81.58% (p=0.000 n=20)
package main_test
import "testing"
var (
m1 = map[int]int{}
m2 = map[int][16]int{}
m3 = map[int][256]int{}
)
func init() {
for i := range 1000 {
m1[i] = i
m2[i] = [16]int{15:i}
m3[i] = [256]int{255:i}
}
}
func BenchmarkMap1Access2Ok(b *testing.B) {
for i := range b.N {
_, ok := m1[i%1000]
if !ok {
b.Errorf("%d not found", i)
}
}
}
func BenchmarkMap2Access2Ok(b *testing.B) {
for i := range b.N {
_, ok := m2[i%1000]
if !ok {
b.Errorf("%d not found", i)
}
}
}
func BenchmarkMap3Access2Ok(b *testing.B) {
for i := range b.N {
_, ok := m3[i%1000]
if !ok {
b.Errorf("%d not found", i)
}
}
}
Fixes#75398
Change-Id: If75e9caaa50d460efc31a94565b9ba28c8158771
Reviewed-on: https://go-review.googlesource.com/c/go/+/702875
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
The test directory contains tests of the Go tool chain and runtime.
It includes black box tests, regression tests, and error output tests.
They are run as part of all.bash.
To run just these tests, execute:
../bin/go test cmd/internal/testdir
To run just tests from specified files in this directory, execute:
../bin/go test cmd/internal/testdir -run='Test/(file1.go|file2.go|...)'
Standard library tests should be written as regular Go tests in the appropriate package.
The tool chain and runtime also have regular Go tests in their packages.
The main reasons to add a new test to this directory are:
it is most naturally expressed using the test runner; or
it is also applicable to gccgo and other Go tool chains.
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