From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thomas Munro <thomas.munro@gmail.com>
cc: Noah Misch <noah@leadboat.com>, Michael Paquier <michael@paquier.xyz>,
        Vik Fearing <vik@postgresfriends.org>,
 cary huang <hcary328@gmail.com>,
        pgsql-hackers@lists.postgresql.org
Subject: Re: Add support for AT LOCAL
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Comments: In-reply-to Thomas Munro <thomas.munro@gmail.com>
	message dated "Mon, 16 Oct 2023 16:07:20 +1300"
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Date: Sun, 15 Oct 2023 23:30:17 -0400
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Thomas Munro <thomas.munro@gmail.com> writes:
> On Mon, Oct 16, 2023 at 4:02 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I'm having a hard time not believing that this is a compiler bug.
>> Looking back at 8d2a01ae12cd and its speculation that xlc is overly
>> liberal about reordering code around sequence points ... I wonder
>> if it'd help to do this calculation in a local variable, and only
>> assign the final value to result->time ?  But we have to reproduce
>> the problem first.

> If that can be shown I would vote for switching to /opt/IBM/xlc/16.1.0
> and not changing a single bit of PostgreSQL.

If switching to 16.1 removes the failure, I'd agree.  It's hard
to believe that any significant number of users still care about
building PG with xlc 12.

			regards, tom lane