Re: [PATCH] x86: Enable Intel AVX512 VP2INTERSECT instruction

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Fri, May 31, 2019 at 4:45 AM Jan Beulich <JBeulich@suse.com> wrote:
>
> >>> On 31.05.19 at 09:05, <lili.cui@intel.com> wrote:
> > gas/
> >
> > 2019-05-27  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
> >           Lili Cui  <lili.cui@intel.com>
> >
> >       * config/tc-i386.c (cpu_arch): Add .avx512_vp2intersect.
> >       (cpu_noarch): Likewise.
>
> I think there's code missing here: Just like for 4FMAPS and 4VNNIW
> insns we warn when the programmer has specified a register not
> evenly divisible by 4 (see the ImplicitQuadGroup attribute), you want
> to warn here for an odd-numbered mask register. However, rather
> than taking the easy route by simply adding another boolean, please
> consider converting the existing one to an enum-like attribute, and
> simply add another enumerator for the case here. Or quite possibly
> a renamed boolean attribute could do - both cases can be easily
> distinguished by there being a %k register affected here, but
> %[xyz]mm ones there.

vp2intersectd %zmm1, %zmm2, %k0
vp2intersectd %zmm1, %zmm2, %k1

are well defined by

// dest_mask_reg_id is the register id specified in the instruction for destmask
dest_base ← dest_mask_reg_id & ~1

There is no requirement for even mask registers.

> > opcodes/
> >
> > 2019-05-27  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
> >           Lili Cui  <lili.cui@intel.com>
> >
> >       * i386-dis.c (enum): Add PREFIX_EVEX_0F3868, EVEX_W_0F3868_P_3.
> >       * i386-dis-evex.h (evex_table): Add AVX512_VP2INTERSECT
> >       instructions.
> >       * i386-gen.ci (cpu_flag_init): Add CPU_AVX512_VP2INTERSECT_FLAGS,
> >       CPU_ANY_AVX512_VP2INTERSECT_FLAGS.
> >       (cpu_flags): Add CpuAVX512_VP2INTERSECT.
> >       * i386-opc.h (enum): Add CpuAVX512_VP2INTERSECT.
> >       (i386_cpu_flags): Add cpuavx512_vp2intersect.
> >       * i386-opc.tbl: Add AVX512_VP2INTERSECT insns.
>
> May I ask that you omit the blank line between the two insns?
>

Lili,  please remove it.

Thanks.

-- 
H.J.