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From: Sergey Fedorov <serge.fdrv@gmail.com>
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Date: Fri, 3 Jun 2016 19:45:05 +0300
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Subject: Re: [Qemu-devel] [RFC v1 05/12] atomic: introduce cmpxchg_bool
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To: =?UTF-8?Q?Alex_Benn=c3=a9e?= <alex.bennee@linaro.org>, mttcg@listserver.greensocs.com, fred.konrad@greensocs.com, a.rigo@virtualopensystems.com, cota@braap.org
Cc: qemu-devel@nongnu.org, mark.burton@greensocs.com, pbonzini@redhat.com, jan.kiszka@siemens.com, rth@twiddle.net, peter.maydell@linaro.org, claudio.fontana@huawei.com

On 15/04/16 17:23, Alex Bennée wrote:
> diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
> index 5dba7db..94e7110 100644
> --- a/include/qemu/atomic.h
> +++ b/include/qemu/atomic.h
> @@ -123,6 +123,16 @@
>      _old;                                                               \
>      })
>  
> +#define atomic_bool_cmpxchg(ptr, old, new)                              \
> +    ({                                                                  \
> +    typeof(*ptr) _old = (old), _new = (new);                            \
> +    bool r;                                                             \
> +    r = __atomic_compare_exchange(ptr, &_old, &_new, false,             \
> +                                  __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);  \
> +    r;                                                                  \
> +    })
> +
> +

Could be more simple:

#define atomic_bool_cmpxchg(ptr, old, new)                              \
    ({                                                                  \
    typeof(*ptr) _old = (old), _new = (new);                            \
    __atomic_compare_exchange(ptr, &_old, &_new, false,                 \
                              __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);      \
    })


Kind regards,
Sergey