On Tue, Mar 16, 2021 at 11:19 AM Jakub Jelinek <ja...@redhat.com> wrote: > > On Tue, Mar 16, 2021 at 11:16:54AM +0100, Richard Biener wrote: > > > Not varargs semantics, but unprototyped function semantics, i.e. the same > > > as for > > > int foo (); > > > Which means callers can pass anything, but it is not ..., i.e. callee > > > can't > > > use va_start/va_end/va_arg and the ... calling conventions are not in > > > place > > > (e.g. the passing of arguments in two places on some targets, or the > > > extra %rax on x86_64 etc.). > > > > Right, so for the caller side looking at DECL_ARGUMENTS is wrong as well > > then, the actual argument list is what matters for the used ABI. > > > > Anyway, I suppose the hook may just give up for calls to unprototyped > > functions? > > It can't. We can punt at trying to optimize them that way in the > vectorizer, that is purely an optimization, but on the function definition, > it is an ABI thing and perhaps some caller in some other TU could have correct > prototype and call clones that don't exist.
I suppose we could simply reject OMP simd on K&R style definitions, OTOH they seem to be supported even in C18 ... > Jakub >
