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

[Andrew Senkevich]

2016-06-27 23:59 GMT+03:00 H.J. Lu <hjl.tools@gmail.com>:
> 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?

Yes, binutils 2.24 is enough for that.


--
WBR,
Andrew