[PATCH x86_64][BZ #20139] Don't allow configure with not supporting AVX512 assembler w/o --disable-avx512.

[H.J. Lu]

On Mon, Jun 27, 2016 at 1:49 PM, Andrew Senkevich
<andrew.n.senkevich@gmail.com> wrote:
> 27 Июн 2016 г. 22:07 пользователь "H.J. Lu" <hjl.tools@gmail.com> написал:
>>
>> On Mon, Jun 27, 2016 at 12:04 PM, Florian Weimer <fweimer@redhat.com>
>> wrote:
>> > On 06/27/2016 08:36 PM, Andrew Senkevich wrote:
>> >>
>> >> 2016-06-27 20:53 GMT+03:00 Joseph Myers <joseph@codesourcery.com>:
>> >>>
>> >>> On Mon, 27 Jun 2016, Andrew Senkevich wrote:
>> >>>
>> >>>> Hi,
>> >>>>
>> >>>> this patch adds new configure option --enable-avx512 and defaults it
>> >>>> for
>> >>>> x86_64.
>> >>>>
>> >>>> To fix BZ #20139 we need don't let to configure with not supporting
>> >>>> AVX512 assembler w/o --disable-avx512.
>> >>>
>> >>>
>> >>> What assembler version is required to support AVX512, and when was
>> >>> that
>> >>> version released?  It might be better to increase the minimum binutils
>> >>> version for building glibc (generally, or for x86_64).
>> >>
>> >>
>> >> May be it will be the best way.  Needed version is 2.25 and it was
>> >> released at Mon, 5 Jan 2015.
>> >
>> >
>> > It's a fairly recent version.
>> >
>>
>> Binutils 2.24 released in Dec., 2013 supports AVX512.
>
> Yes, but not all required.  There were some with ZMM registers supported
> from 2.25.  According configure check defining HAVE_AVX512_ASM_SUPPORT was
> changed for that reason.

Will binutils 2.24 able to save/restore ZMM registers?


-- 
H.J.