Re: [dpdk-dev] Build failures in 21.11-rc2

[David Marchand <david.marchand@redhat.com>]

On Tue, Nov 9, 2021 at 4:53 PM Lance Richardson
<lance.richardson@broadcom.com> wrote:
>
> 21.11-rc2 builds are failing on CentOS 8.4, apparently because
> the intrinsic _mm512_set_epi8() is not defined in the GCC
> headers (see example below).

Thanks for reporting Lance.
It rings a bell, think it was mentionned in the past.

>
> Perhaps code using _mm512_set_epi8() could be reworked to
> avoid that intrinsic, or maybe support could be detected at build
> configuration time and definitions for them could be provided in
> DPDK headers.
>
> Here is a GCC patch to add this intrinsic:
> https://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg188664.html
>
> BTW, GCC 10.2.1 (via "scl enable gcc-toolset-10") is able to build
> 21.11-rc2 successfully on CentOS 8.4.
>
>     Lance
>
> # gcc --version
> gcc (GCC) 8.4.1 20200928 (Red Hat 8.4.1-1)
> Copyright (C) 2018 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>
> In file included from ../lib/hash/rte_thash_gfni.h:16,
>                  from ../lib/hash/rte_thash.h:27,
>                  from ../lib/hash/rte_thash.c:7:
> ../lib/hash/rte_thash_x86_gfni.h: In function ‘__rte_thash_gfni’:
> ../lib/hash/rte_thash_x86_gfni.h:59:24: error: implicit declaration of
> function ‘_mm512_set_epi8’; did you mean ‘_mm512_set1_epi8’?
> [-Werror=implicit-function-declaration]
>   __m512i permute_idx = _mm512_set_epi8(7, 6, 5, 4, 7, 6, 5, 4,
>                         ^~~~~~~~~~~~~~~
>                         _mm512_set1_epi8
>

Vladimir, can you reimplement this part without relying on _mm512_set_epi8?
Thanks.



-- 
David Marchand