garble/testdata/script/atomic.txtar

# amd64 can typically run 386 programs,
# which is handy to actually make this test useful.
# We assume that the same applies to arm64.
# Note that darwin is an exception compared to linux and windows,
# as darwin/386 and darwin/arm are not supported.
[amd64] [!darwin] env GOARCH=386
[arm64] [!darwin] env GOARCH=arm

exec garble build
exec ./main
cmp stderr main.stderr

[short] stop # no need to verify this with -short

go build
exec ./main
cmp stderr main.stderr
-- go.mod --
module test/main

go 1.21
-- main.go --
package main

import (
	"sync"
	"sync/atomic"
)

var unalignedUint64 struct {
	// If sync/atomic's support in the compiler is broken,
	// then u64 is not aligned to 64 bits on 32-bit platforms,
	// and that may cause a panic.
	_   bool
	u64 atomic.Uint64
}

func main() {
	var wg sync.WaitGroup
	for i := 0; i < 10; i++ {
		wg.Add(1)
		go func() {
			unalignedUint64.u64.Add(2)
			wg.Done()
		}()
	}
	wg.Wait()
	println(unalignedUint64.u64.Load())
}
-- main.stderr --
20