File size: 1,455 Bytes
fc11197 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 | // Copyright 2025 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package test
import (
"sync/atomic"
"testing"
)
func locals() {
var x int64
var y int32
var z int16
var w int8
sink64 = &x
sink32 = &y
sink16 = &z
sink8 = &w
}
//go:noinline
func args(x int64, y int32, z int16, w int8) {
sink64 = &x
sink32 = &y
sink16 = &z
sink8 = &w
}
//go:noinline
func half(x int64, y int16) {
var z int32
var w int8
sink64 = &x
sink16 = &y
sink32 = &z
sink8 = &w
}
//go:noinline
func closure() func() {
var x int64
var y int32
var z int16
var w int8
_, _, _, _ = x, y, z, w
return func() {
x = 1
y = 2
z = 3
w = 4
}
}
//go:noinline
func atomicFn() {
var x int32
var y int64
var z int16
var w int8
sink32 = &x
sink64 = &y
sink16 = &z
sink8 = &w
atomic.StoreInt64(&y, 7)
}
var sink64 *int64
var sink32 *int32
var sink16 *int16
var sink8 *int8
func TestLocalAllocations(t *testing.T) {
type test struct {
name string
f func()
want int
}
for _, tst := range []test{
{"locals", locals, 1},
{"args", func() { args(1, 2, 3, 4) }, 1},
{"half", func() { half(1, 2) }, 1},
{"closure", func() { _ = closure() }, 2},
{"atomic", atomicFn, 1},
} {
allocs := testing.AllocsPerRun(100, tst.f)
if allocs != float64(tst.want) {
t.Errorf("test %s uses %v allocs, want %d", tst.name, allocs, tst.want)
}
}
}
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