Hi Prathamesh, > -----Original Message----- > From: Prathamesh Kulkarni <prathamesh.kulka...@linaro.org> > Sent: 29 June 2021 08:22 > To: gcc Patches <gcc-patches@gcc.gnu.org> > Cc: Kyrylo Tkachov <kyrylo.tkac...@arm.com> > Subject: Re: [ARM] PR66791: Replace calls to builtin in vmul_n (a, b) > intrinsics > with __a * __b > > On Mon, 21 Jun 2021 at 14:04, Prathamesh Kulkarni > <prathamesh.kulka...@linaro.org> wrote: > > > > On Mon, 14 Jun 2021 at 13:27, Prathamesh Kulkarni > > <prathamesh.kulka...@linaro.org> wrote: > > > > > > On Mon, 7 Jun 2021 at 12:45, Prathamesh Kulkarni > > > <prathamesh.kulka...@linaro.org> wrote: > > > > > > > > On Mon, 31 May 2021 at 16:01, Prathamesh Kulkarni > > > > <prathamesh.kulka...@linaro.org> wrote: > > > > > > > > > > On Mon, 31 May 2021 at 15:22, Prathamesh Kulkarni > > > > > <prathamesh.kulka...@linaro.org> wrote: > > > > > > > > > > > > On Wed, 26 May 2021 at 14:07, Marc Glisse <marc.gli...@inria.fr> > wrote: > > > > > > > > > > > > > > On Wed, 26 May 2021, Prathamesh Kulkarni via Gcc-patches > wrote: > > > > > > > > > > > > > > > The attached patch removes calls to builtins in vmul_n* (a, b) > with __a * __b. > > > > > > > > > > > > > > I am not familiar with neon, but are __a and __b unsigned here? > Otherwise, > > > > > > > is vmul_n already undefined in case of overflow? > > > > > > Hi Marc, > > > > > > Sorry for late reply, for vmul_n_s*, I think they are signed > > > > > > (int<width>x<width>_t). > > > > > Oops, I meant int<width>x<nelems>_t. > > > > > > I am not sure how should the intrinsic behave in case of signed > overflow, > > > > > > but I am assuming it's OK since vmul_s* intrinsics leave it > > > > > > undefined > too. > > > > > > Kyrill, is it OK to leave vmul_s* and vmul_n_s* undefined in case of > overflow ? > > > > The attached version fixes one fallout I missed earlier. > > > > Is this OK to commit ? > > > ping https://gcc.gnu.org/pipermail/gcc-patches/2021-June/572037.html > > ping * 2 https://gcc.gnu.org/pipermail/gcc-patches/2021- > June/572037.html > ping * 3 https://gcc.gnu.org/pipermail/gcc-patches/2021-June/572037.html
I'm a bit wary of leaving them undefined for signed overflow. I see that aarch64 leaves them too so maybe it's not such a big deal, but I'd like to consider that separately. Can you please split this into the unsigned and floating-point parts, followed by the signed intrinsics? The unsigned and FP parts are okay, lets' review the signed intrinsics separately. Thanks, Kyrill > > Thanks, > Prathamesh > > > > Thanks, > > Prathamesh > > > > > > Thanks, > > > Prathamesh > > > > > > > > Thanks, > > > > Prathamesh > > > > > > > > > > > > Thanks, > > > > > > Prathamesh > > > > > > > > > > > > > > -- > > > > > > > Marc Glisse
