https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94359
Iain Sandoe <iains at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2020-03-27
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
--- Comment #1 from Iain Sandoe <iains at gcc dot gnu.org> ---
There are two cases here.
1) When the optimisation level is < 2 (where GCC does not normally tail-call).
- in that case, the specific call [ which is in the tail position, and AFAIU
should be tail-callable ] is marked as TAIL_CALL, MUST_TAIL_CALL (hence the
complaint error: cannot tail-call: target is not able to optimize the call into
a sibling call, I suppose).
2) for O >= 2 where GCC would normally tail call anyway
- for this, the coroutine code does not mark the cll specially, so for these
cases it indicates that the tail-call is not being made in "normal"
circumstance.
the function signature is
void actor (void *)
and the codgen should be emitting an indirect call, followed by a void return
(the indirect call is expanding __builtin_coro_resume() [expansion happens very
early in the ME].
