"Marco Vieira" <maovieira@gmail.com> writes:
> If I query select round(sin(2.0*pi()*0.51)) I get "-0" as return but zero is
> unsigned.
In IEEE-standard float arithmetic, that isn't true --- zero and minus
zero are distinguishable values. This is not a bug but just the way
your platform chooses to define the result of rounding a small
negative value.
(Or at least, if you are convinced it's a bug, take it up with the
glibc authors not us.)
regards, tom lane
