Re: Defend against -ffast-math in meson builds

Peter Eisentraut <peter@eisentraut.org> writes:
> The existing check in configure is because certain Linux distributions 
> used to compile everything with -ffast-math to be "faster", and that 
> kept breaking PostgreSQL and so we wanted to stop them very early. 
> These are gone, and the defenses in the code like date.c should be 
> sufficient for any new attempts.  I think we could remove the check in 
> configure.

The defenses in those modules are probably obsolete too: aren't they about
ensuring exact results with floating-point timestamps?  My gut reaction to
this was maybe we could remove *all* of that, so now I'm curious what
problem Bertrand ran into.

It could be that these old defenses are protecting us against roundoff
issues in some relatively-new floating-point functions, but if that's
true then we should move the checks to where they are important today.

            regards, tom lane