Jochen Erwied <jochen@erwied.eu> writes:
> Thursday, June 9, 2011, 12:45:06 PM you wrote:
>> As the URL mentions, you can build with CFLAGS=-ffast-math, that
>> should work for PostgreSQL too.
> I just tried this with the source for 9.0.4, at least with this version the
> build will not complete since there is a check in
> src/backend/utils/adt/date.c throwing an error if FAST_MATH is active.
Yeah. See
http://archives.postgresql.org/pgsql-bugs/2002-09/msg00169.php
and following discussions, which eventually led to adding the #error.
Now this was all done in regards to PG's original floating-point
timestamp implementation. It's possible that in an integer-datetimes
build (which is now the default) we don't need to forbid -ffast-math to
prevent strange datetime results. But nobody's done the work to prove
that, because there isn't any particularly good reason to enable
-ffast-math in a database in the first place. (Other than coping with
brain-dead platforms, I guess.)
However ... I'm not sure I believe that this is related to the OP's
problem anyway. Postgres doesn't normally work with any denormalized
numbers, so the messages he's seeing probably stem from some other sort
of shortcoming in the hardware FP support. It would be interesting to
see specific examples of SQL operations that trigger the kernel message.
regards, tom lane
