Thomas Munro <thomas.mu...@gmail.com> writes: > On Mon, Oct 16, 2023 at 2:58 PM Michael Paquier <mich...@paquier.xyz> wrote: >> Another theory would be one of these weird compiler optimization issue >> from xlc? In recent history, there was 8d2a01ae12cd.
> Yeah, there are more like that too. xlc 12.1 is dead (like the OS > version it shipped with). New versions are available on cfarm if we > care about this target. But I am conscious of the cosmic law that if > you blame the compiler too soon you can cause the bug to move into > your code... 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. regards, tom lane