[Bug tree-optimization/121004] float_var*0.0f if we know a is finite be just done as copysign(0.0, a)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121004

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #5)
> (In reply to Andrew Pinski from comment #4)
> > (In reply to Harald van Dijk from comment #3)
> > > I think comment #0's f could be optimised even more to just return a;
> > 
> > True.
> 
> But that is also a missing copysign missed optimization too.

Filed that off as PR 121006 so not to distract from this optimization ...