[Bug c/95715] __atomic_fetch_add accepts nonsense arguments

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95715

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-06-16
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
We also accept this, adding two void* pointer together:

void* i = 0;
void* p = 0;
void* r = __atomic_fetch_add(&i, &p, __ATOMIC_SEQ_CST);

The second argument should be ptrdiff_t.

Or adding a double* to an int*:

double* i = 0;
int* p = 0;
void* r = __atomic_fetch_add(&i, &p, __ATOMIC_SEQ_CST);