Re: Fix typo 586/686 in atomics/arch-x86.h

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: John Naylor <johncnaylorls@gmail.com>
Cc: Zsolt Parragi <zsolt.parragi@percona.com>, Daniel Gustafsson <daniel@yesql.se>, Jakub Wartak <jakub.wartak@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Andres Freund <andres@anarazel.de>
Date: 2025-12-20T02:01:23Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Remove support for 8 byte tear free read/write on 32-bit

John Naylor <johncnaylorls@gmail.com> writes:
> On Fri, Dec 19, 2025 at 5:13 PM Zsolt Parragi <zsolt.parragi@percona.com> wrote:
>> I did some quick testing with this, normally only __i386__ gets
>> defined for 32 bit builds (-march=native -m32 for example, but also
>> the default -march=x86-64 -m32). __i586__ and __i686__ are only there
>> if I pass the matching -march (i586/i686) flag to gcc.

> What platform is this? I don't see that:

I can replicate Zsolt's result --- note the point about -march:

$ echo | gcc -m32 -dM -E - | grep -E '86[^0-9]'
#define __i386 1
#define __i386__ 1
#define i386 1
$ echo | gcc -m32 -march=i586 -dM -E - | grep -E '86[^0-9]'
#define __i586 1
#define __tune_i586__ 1
#define __i386 1
#define __i586__ 1
#define __i386__ 1
#define i386 1
$ echo | gcc -m32 -march=i686 -dM -E - | grep -E '86[^0-9]'
#define __tune_i686__ 1
#define __i686 1
#define __i686__ 1
#define __i386 1
#define __i386__ 1
#define i386 1

This is with gcc 8.5.0 from RHEL8, and the same with gcc 14.3.1
from Fedora 41.

			regards, tom lane