Re: strict aliasing (was: const correctness)

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

From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Kevin Grittner" <Kevin.Grittner@wicourts.gov>
Cc: "Florian Pflug" <fgp@phlo.org>, "Robert Haas" <robertmhaas@gmail.com>, "Thomas Munro" <munro@ip9.org>, pgsql-hackers@postgresql.org
Date: 2011-11-14T20:19:01Z
Lists: pgsql-hackers
"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> The results were interesting.  While the small overlap between
> samples from the two builds at most levels means that this was
> somewhat unlikely to be just sampling noise, there could have been
> alignment issues that account for some of the differences.  In
> short, the strict aliasing build always beat the other with 4
> clients or fewer (on this 4 core machine), but always lost with more
> than 4 clients.

That is *weird*.

> Also, is there something I should do to deal with the warnings
> before this would be considered a meaningful test?

Dunno ... where were the warnings exactly?  Also, did you run the
regression tests (particularly the parallel version) against the
build?

			regards, tom lane