On Mon, Jun 23, 2025 at 10:51:21AM -0400, Tom Lane wrote:
> This has broken the build completely on my RHEL8 x86_64 box,
> with gcc 8.5.0:
>
> $ ./configure ...
> $ make -s
> pg_crc32c_sse42.c: In function 'pg_comp_crc32c_avx512':
> pg_crc32c_sse42.c:126:25: warning: implicit declaration of function '_mm512_zextsi128_si512'; did you mean
'_mm512_castsi128_si512'?[-Wimplicit-function-declaration]
> x0 = _mm512_xor_si512(_mm512_zextsi128_si512(_mm_cvtsi32_si128(crc0)), x0);
> ^~~~~~~~~~~~~~~~~~~~~~
> _mm512_castsi128_si512
It looks like thse weren't added until GCC 10 [0].
> I see similar symptoms on buildfarm animal conchuela, which
> is DragonFly BSD of some vintage or other. Not sure why
> more animals aren't complaining. Anyway, it seems that the
> configure probe to see if this facility is available had
> better be adjusted to match the new code.
Unfortunately, this will probably require more than replacing
_mm512_castsi512_si128 with _mm512_zextsi512_si128 because the latter
doesn't exist.
[0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83250
--
nathan
