weird optimization in sin+cos, x86 backend

[Michael Matz]

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.