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Re: [PATCH x86_64][BZ #20139] Don't allow configure with not supporting AVX512 assembler w/o --disable-avx512.
- From: Andrew Senkevich <andrew dot n dot senkevich at gmail dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Florian Weimer <fweimer at redhat dot com>, Joseph Myers <joseph at codesourcery dot com>, libc-alpha <libc-alpha at sourceware dot org>
- Date: Tue, 28 Jun 2016 00:01:34 +0300
- Subject: Re: [PATCH x86_64][BZ #20139] Don't allow configure with not supporting AVX512 assembler w/o --disable-avx512.
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2016-06-27 22:07 GMT+03:00, H.J. Lu <hjl.tools@gmail.com>:
> 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.
--
WBR,
Andrew