On Fri, Jul 31, 2020 at 4:35 AM Richard Henderson <
richard.hender...@linaro.org> wrote:
> On 7/22/20 2:16 AM, frank.ch...@sifive.com wrote:
> > + static gen_helper_gvec_3_ptr * const fns[6][4] = {
> > + {
> > + NULL, gen_helper_vzext_vf2_h,
> > + gen_helper_vzext_vf2_w, gen_helper_vzext_vf2_d
> > + },
> > + {
> > + NULL, NULL,
> > + gen_helper_vzext_vf4_w, gen_helper_vzext_vf4_d,
> > + },
> > + {
> > + NULL, NULL,
> > + NULL, gen_helper_vzext_vf8_d
> > + },
> > + {
> > + NULL, gen_helper_vsext_vf2_h,
> > + gen_helper_vsext_vf2_w, gen_helper_vsext_vf2_d
> > + },
> > + {
> > + NULL, NULL,
> > + gen_helper_vsext_vf4_w, gen_helper_vsext_vf4_d,
> > + },
> > + {
> > + NULL, NULL,
> > + NULL, gen_helper_vsext_vf8_d
> > + }
> > + };
>
> I don't understand why there aren't more functions in this table. As far
> as I
> can see, the only NULLs should be at [*][0].
>
>
> r~
>
As source EEW has to be 1/2, 1/4, 1/8 of SEW and the source EEW must be
a supported width (Section 12.3).
Shouldn't it impossible to have the cases, e.g.
vzext.vf4 with SEW = 16, i.e. EEW = SEW / 4 = 4 bits
vzext.vf8 with SEW = 16, i.e. EEW = SEW / 8 = 2 bits
vzext.vf8 with SEW = 32, i.e. EEW = SEW / 8 = 4 bits
Frank Chang
