[Bug c/105495] `__atomic_compare_exchange` prevents tail-call optimization

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105495

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-05-05
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
The issue is that we pass the 2nd argument by reference which causes a stack
slot to be allocated for 'c':

  c.b = x_2(D);
  __atomic_compare_exchange_4 (p_4(D), &c, 2, 1, 0, 0);