This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH] X86-64: Add _dl_runtime_resolve_avx[512]_opt [BZ #20508]
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Florian Weimer <fweimer at redhat dot com>
- Cc: Richard Henderson <rth at twiddle dot net>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Tue, 4 Oct 2016 13:59:41 -0700
- Subject: Re: [PATCH] X86-64: Add _dl_runtime_resolve_avx[512]_opt [BZ #20508]
- Authentication-results: sourceware.org; auth=none
- References: <CAMe9rOojpuFz1jTbMpNcqZK1KVDqaWozNuEuS3E67dvD3Rh=hw@mail.gmail.com> <c6e21847-bc95-3c75-ed54-798c62194072@redhat.com> <CAMe9rOp=bvrk0MBF8SrP4JqLHembRdeyfGNqNkcVWvoEs3R=tA@mail.gmail.com> <CAMe9rOo7MmGNPKct=AzzbtR564yH1P96tUcLD7pFv7GtxF3-Ng@mail.gmail.com> <48eeea78-99e8-f255-bd26-b6d28929b4f0@twiddle.net> <CAMe9rOqXhVLVbT90JBfkJnCLzZBrkUHtkO4Ddfk9HPH7jiyEzw@mail.gmail.com> <CAMe9rOoDp7XYwLdDetFNghAdDo_zj-4342LKV4i0zCH36aBWtw@mail.gmail.com> <CAMe9rOo+_TQABBp0eC4nQcJ5ENLrZAOSvtAjo17E6H0ezDpWvg@mail.gmail.com> <CAMe9rOqoATTPzXqjtqenV0h+hMtMYcr+W-ZL3Bi4jFJWYBCUpg@mail.gmail.com> <76f9e5c1-d1de-04d1-49f5-30673bf3060b@redhat.com> <CAMe9rOq8yu+b0-N6UR3vb843NApZ+ZjBwAw5GsERHpvuCrVjrw@mail.gmail.com> <14cc7a47-1a39-6285-d4b5-dab2769c092b@redhat.com> <CAMe9rOrqmLmHLhHL7pDSvR=8=dUUGP07zY5A3DiOubtpvR25WQ@mail.gmail.com> <ea7fe73f-b8cb-6049-d4c4-918d724bd883@redhat.com> <CAMe9rOqxqffhZAb1Sj-qxg_1oU0J=0v7rvhoXVbjbJrrthHucg@mail.gmail.com> <10a9fba6-9c5b-a7ed-3150-a9101c00c07f@redhat.com>
On Tue, Oct 4, 2016 at 12:20 PM, Florian Weimer <fweimer@redhat.com> wrote:
> On 10/04/2016 06:08 PM, H.J. Lu wrote:
>>>>>>
>>>>>> Good question. This is also needed:
>>>>>>
>>>>>> commit f43cb35c9b3c35addc6dc0f1427caf51786ca1d2
>>>>>> Author: H.J. Lu <hjl.tools@gmail.com>
>>>>>> Date: Fri Jul 1 05:54:43 2016 -0700
>>>>>>
>>>>>> Require binutils 2.24 to build x86-64 glibc [BZ #20139]
>>>
>>>
>>>
>>>>> That's not really backportable, I'm afraid. Our users don't expect we
>>>>> break
>>>>> builds in this way.
>>>>>
>>>>
>>>> Who are those users?
>>>
>>>
>>>
>>> We don't know, really. But moving forward the baseline binutils
>>> requirement
>>> in a stable release really contradicts what a stable release is about.
>
>
>> Do our users expect a broken glibc binary of a stable release on AVX512
>> machine?
>
>
> Either switch to the XSAVE approach, or encode the relevant opcodes using
> .byte.
>
> We used the latter in Red Hat Enterprise Linux 6, and I'm attaching our
> patch in case it is helpful.
>
This patch was for a very different code base. _dl_runtime_resolve
has been rewritten in glibc 2.23.
--
H.J.