Should atomic_xxx() functions reject not-_Atomic() arguments ?
Chris Hall
chris.hall@gmch.uk
Fri Feb 28 21:04:00 GMT 2020
On 28/02/2020 01:01, Jim Wilson wrote:
> On Thu, Feb 27, 2020 at 7:20 AM Chris Hall <gcc@gmch.uk> wrote:
>> Now, the Standard also tells us that _Atomic(uint64_t) and uint64_t may
>> have different sizes, representations and alignment. So I guess:
>> bar = atomic_fetch_add(&bar, 1) ;
>> should be an error ?
> __atomic_fetch_add accepts any integer or pointer type. So the fact
> that _Atomic(uint64_t) and uint64_t may be different types is not a
> problem, as long as they are still integer types. This works like an
> overloaded function in C++.
>
> https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/_005f_005fatomic-Builtins.html#g_t_005f_005fatomic-Builtins
Sure. But the Standard atomic_fetch_add() takes an _Atomic(xxx)* (as
the first parameter), and for the reasons given, I understand that
uint64_t* is not compatible with _Atomic(uint64_t)*.
Chris
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