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Re: [PATCH] Don't write beyond destination in __mempcpy_avx512_no_vzeroupper (bug 23196)
- From: Andreas Schwab <schwab at suse dot de>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Andrew Senkevich <andrew dot n dot senkevich at gmail dot com>, GNU C Library <libc-alpha at sourceware dot org>
- Date: Tue, 22 May 2018 14:17:23 +0200
- Subject: Re: [PATCH] Don't write beyond destination in __mempcpy_avx512_no_vzeroupper (bug 23196)
- References: <mvm1se4romh.fsf@suse.de> <CAMe9rOq_Ba4Hah=Mj9QB1-SkUL1j_TzHjaPVnekiEU4HsacQBg@mail.gmail.com>
On Mai 22 2018, "H.J. Lu" <hjl.tools@gmail.com> wrote:
> The modified test does't fail on Skylake server with unchanged
> memmove-avx512-no-vzeroupper.S. Can you modify the test
> so that it fails with the original memmove-avx512-no-vzeroupper.S
> on Skylake server?
How to do that? I have tested it on a Xeon Phi (whateve that means)
where it failed without the fix.
> memmove-vec-unaligned-erms.S supports no vzeroupper:
>
> #ifndef VZEROUPPER
> # if VEC_SIZE > 16
> # define VZEROUPPER vzeroupper
> # else
> # define VZEROUPPER
> # endif
> #endif
>
> Should it be used instead?
I don't understand what that has to do with the bug in question.
Andreas.
--
Andreas Schwab, SUSE Labs, schwab@suse.de
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