On 2018-03-19 14:20:33 -0400, Tom Lane wrote:
> I tried -O3 with gcc 7.3.1 (Fedora 26), and that passes check-world
> just fine. Then I tried -O3 with gcc 8.0.1 (prerelease Fedora 28),
> and indeed that's got some problems.
> Note that 1-D and 2-D arrays print fine, it's only 3-D or deeper
> that print wrong. Very odd. Maybe it's bad code on our part,
> but I think the odds are at least as good that it's a new gcc bug.
Might be worth trying with a new clang, I think it's been a bit ahead on
the quality of the ubsan (et al) integration quality.
Greetings,
Andres Freund