mirror of
https://github.com/golang/go
synced 2024-11-26 23:11:24 -07:00
ae10914e67
The atomic add instructions modify the condition code and so need to be marked as clobbering flags. Fixes #24449. Change-Id: Ic69c8d775fbdbfb2a56c5e0cfca7a49c0d7f6897 Reviewed-on: https://go-review.googlesource.com/101455 Run-TryBot: Michael Munday <mike.munday@ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
63 lines
1.2 KiB
Go
63 lines
1.2 KiB
Go
// run
|
|
|
|
// Copyright 2018 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 main
|
|
|
|
import (
|
|
"sync/atomic"
|
|
)
|
|
|
|
var cnt32 int32
|
|
|
|
//go:noinline
|
|
func test32(a, b []int) bool {
|
|
// Try to generate flag value, issue atomic
|
|
// adds and then re-use the flag value to see if
|
|
// the atomic add has clobbered them.
|
|
atomic.AddInt32(&cnt32, 1)
|
|
if len(a) == len(b) {
|
|
atomic.AddInt32(&cnt32, 2)
|
|
}
|
|
atomic.AddInt32(&cnt32, 4)
|
|
if len(a) >= len(b) {
|
|
atomic.AddInt32(&cnt32, 8)
|
|
}
|
|
if len(a) <= len(b) {
|
|
atomic.AddInt32(&cnt32, 16)
|
|
}
|
|
return atomic.LoadInt32(&cnt32) == 31
|
|
}
|
|
|
|
var cnt64 int64
|
|
|
|
//go:noinline
|
|
func test64(a, b []int) bool {
|
|
// Try to generate flag value, issue atomic
|
|
// adds and then re-use the flag value to see if
|
|
// the atomic add has clobbered them.
|
|
atomic.AddInt64(&cnt64, 1)
|
|
if len(a) == len(b) {
|
|
atomic.AddInt64(&cnt64, 2)
|
|
}
|
|
atomic.AddInt64(&cnt64, 4)
|
|
if len(a) >= len(b) {
|
|
atomic.AddInt64(&cnt64, 8)
|
|
}
|
|
if len(a) <= len(b) {
|
|
atomic.AddInt64(&cnt64, 16)
|
|
}
|
|
return atomic.LoadInt64(&cnt64) == 31
|
|
}
|
|
|
|
func main() {
|
|
if !test32([]int{}, []int{}) {
|
|
panic("test32")
|
|
}
|
|
if !test64([]int{}, []int{}) {
|
|
panic("test64")
|
|
}
|
|
}
|