From: John Naylor <john.naylor@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Check for __cpuidex and __get_cpuid_count separately
Date: Thu, 02 Apr 2026 12:46:16 +0000
Message-ID: <E1w8HR9-002boq-0q@gemulon.postgresql.org> (raw)
Check for __cpuidex and __get_cpuid_count separately
Previously we would only check for the availability of __cpuidex if
the related __get_cpuid_count was not available on a platform.
Future commits will need to access hypervisor information about
the TSC frequency of x86 CPUs. For that case __cpuidex is the only
viable option for accessing a high leaf (e.g. 0x40000000), since
__get_cpuid_count does not allow that.
__cpuidex is defined in cpuid.h for gcc/clang, but in intrin.h
for MSVC, so adjust tests to suite. We also need to cast the array
of unsigned ints to signed, since gcc (with -Wall) and clang emit
warnings otherwise.
Author: Lukas Fittl <lukas@fittl.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: John Naylor <john.naylor@postgresql.org>
Discussion: https://postgr.es/m/CAP53PkyooCeR8YV0BUD_xC7oTZESHz8OdA=tP7pBRHFVQ9xtKg@mail.gmail.com
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/effaa464afd355e8927bf430cfe6a0ddd2ee5695
Modified Files
--------------
configure | 20 ++++++++++++--------
configure.ac | 30 +++++++++++++++++-------------
meson.build | 13 ++++++++++---
src/port/pg_cpu_x86.c | 8 +++-----
4 files changed, 42 insertions(+), 29 deletions(-)
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To: pgsql-committers@postgresql.org
Cc: john.naylor@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Check for __cpuidex and __get_cpuid_count separately
In-Reply-To: <E1w8HR9-002boq-0q@gemulon.postgresql.org>
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