On Tue, Jan 16, 2018 at 2:57 PM, Schulz, Roland <roland.schulz@xxxxxxxxx> wrote: > > >> -----Original Message----- >> From: Matthias Kretz [mailto:m.kretz@xxxxxx] >> Sent: Monday, January 15, 2018 7:24 AM >> To: gcc-help@xxxxxxxxxxx >> Cc: Schulz, Roland <roland.schulz@xxxxxxxxx>; Victor Rodriguez >> <vm.rod25@xxxxxxxxx>; Mason <slash.tmp@xxxxxxx>; O Mahony, Billy >> <billy.o.mahony@xxxxxxxxx>; Evgeny Stupachenko <evstupac@xxxxxxxxx>; >> Jakub Jelinek <jakub@xxxxxxxxxx> >> Subject: Re: target_clones constexpr >> >> On Donnerstag, 11. Januar 2018 20:37:55 CET Schulz, Roland wrote: >> > I would like to do something like: [...] >> >> +1 >> >> > I would like to use width to do manual strip-mining or instantiate >> > SIMD C++ templates. The problem is that this doesn't compile because >> > __builtin_cpu_supports isn't constexpr. For every clone of foo, the >> > compiler knows the SIMD support at compile time. I'm looking for a >> > builtin which lets me query that in a constexpr way. >> >> AFAIK there is nothing (I'd be happy to be proven wrong). I also can't think of >> any hack that would produce the value as a constant expression. (I tried >> `using v64 [[gnu::vector_size(64)]] = float; alignof(v64)`, but its alignment is >> 64, independent of the register size it uses.) > > I filed it as feature request: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83875 > > Roland Thanks for filling a feature request, if approved I'm going to ask to assign it to me regards
