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Re: weird optimization in sin+cos, x86 backend
Hi,
On Fri, 3 Feb 2012, Vincent Lefevre wrote:
> > > For the glibc, I've finally reported a bug here:
> > >
> > > http://sourceware.org/bugzilla/show_bug.cgi?id=13658
> >
> > That is about 1.0e22, not the obscene 4.47460300787e+182 of the
> > original poster.
>
> But 1.0e22 cannot be handled correctly.
I'm not sure what you're getting at. Yes, 1e22 isn't handled correctly,
but this thread was about 4.47460300787e+182 until you changed topics.
> > If you want to have precise numbers use an arbitrary precision math
> > library.
>
> This is double precision. An arbitrary precision math library (even
> though I develop one) shouldn't be needed.
But the reduction step needs much more precision than it currently uses to
handle inputs as large as 4e182 correctly.
Ciao,
Michael.