> From: Kumar, Venkataramanan <[email protected]>
> Sent: Monday, July 6, 2026 1:19 AM
>
> > From: Haochen Jiang <[email protected]>
> > Sent: Thursday, July 2, 2026 12:19 PM
> >
> > + /* Get Advanced Features at level 0x1d (eax = 0x1d).
> > + ACE check must be put after AVX10 check to get AVX10 features.
> > + TODO: Change the condition after AVX10V1AUX is added. */ if
>
> As per the Specification
> To detect full ACE v1 support, software should verify:
> 1. (AVX10.1 and AVX10_V1_AUX) or AVX10.2
> 2. AVX10_V2_AUX
> 3. ACE
> 4. ACE_VSN >= 1
> 5. XCR0[20,18:17] = 0b111 (XSAVE state enabled for tile + BSR)
> 6. XCR0[7:5] = 0b111 (AVX-512 state)
> 7. CR4.OSXSAVE = 1
>
> Here the check says AVX10.2 is mandatory.
> Can u comment on that TODO: clearly saying version >= 2 to be replaced with
> ((version >= 1 && avx10v1ux_set) || (version >= 2)).
The comment now is exactly explaining the same issue as this condition?
>
> > + (version >= 2 && avx10v2aux_set && ace_set && max_cpuid_level >=
> 0x1d)
> > + {
> > + __cpuid_count (0x1d, 0, eax, ebx, ecx, edx);
> > + if (eax == 2)
> > + {
> > + __cpuid_count (0x1d, 2, eax, ebx, ecx, edx);
> > + version = eax & 0xff;
> > + switch (version)
> > + {
> > + case 1:
> > + set_feature (FEATURE_ACEV1);
> > + break;
> > + default:
>
> Can we error out instead of defaulting to FEATURE_ACEV1 ??
We should not error out this since this will lead to new HW running
on old GCCs error out since they will have newer versions and drop
to default.
> > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index
> > 2f927603f38..32595a934a8 100644
> > --- a/gcc/doc/invoke.texi
> > +++ b/gcc/doc/invoke.texi
> > @@ -1551,7 +1551,7 @@ See RS/6000 and PowerPC Options.
> > -mavxneconvert -mcmpccxadd -mamx-fp16 -mprefetchi -mraoint -
> mamx-
> > complex -mavxvnniint16 -msm3 -msha512 -msm4 -mapxf -musermsr -
> > mavx10.1 -mavx10.2 -mamx-avx512 -mmovrs -mamx-movrs --
> mavx512bmm -
> > mavx10v2aux
> > +-mavx512bmm -mavx10v2aux -macev1
> Only -macev1 is extra right?? .
Yes. As mentioned in an upcoming letter of the cover letter, the patch is and
must
based on AVX10V2AUX due to feature imply. That is why avx10v2aux is already
there.
Thx,
Haochen
