On Wed, Aug 30, 2023 at 5:02 PM Andre Vieira (lists) <andre.simoesdiasvie...@arm.com> wrote: > > > > On 30/08/2023 14:01, Richard Biener wrote: > > On Wed, Aug 30, 2023 at 11:15 AM Andre Vieira (lists) via Gcc-patches > > <gcc-patches@gcc.gnu.org> wrote: > >> > >> This patch adds a machine_mode parameter to the TARGET_SIMD_CLONE_USABLE > >> hook to enable rejecting SVE modes when the target architecture does not > >> support SVE. > > > > How does the graph node of the SIMD clone lack this information? That is, > > it > > should have information on the types (and thus modes) for all formal > > arguments > > and return values already, no? At least the target would know how to > > instantiate > > it if it's not readily available at the point of use. > > > > Yes it does, but that's the modes the simd clone itself uses, it does > not know what vector_mode we are currently vectorizing for. Which is > exactly why we need the vinfo's vector_mode to make sure the simd clone > and its types are compatible with the vector mode. > > In practice, to make sure that a SVE simd clones are only used in loops > being vectorized for SVE modes. Having said that... I just realized that > the simdlen check already takes care of that currently... > > by simdlen check I mean the one that writes off simdclones that match: > if (!constant_multiple_p (vf, n->simdclone->simdlen, &num_calls) > > However, when using -msve-vector-bits this will become an issue, as the > VF will be constant and we will match NEON simdclones. This requires > some further attention though given that we now also reject the use of > SVE simdclones when using -msve-vector-bits, and I'm not entirely sure > we should...
Hmm, but vectorizable_simdclone should check for compatible types here and if they are compatible why should we reject them? Are -msve-vector-bits "SVE" modes different from "NEON" modes? I suppose not, because otherwise the type compatibility check would say incompatible. > I'm going on holidays for 2 weeks now though, so I'll have a look at > that scenario when I get back. Same with other feedback, didn't expect > feedback this quickly ;) Thank you!! > > Kind regards, > Andre >
