[PATCH][BZ #14412] Define __sincos_finite as a fast version of sincos

[Ondřej Bílka]

On Mon, Apr 29, 2013 at 01:34:42PM +0000, Joseph S. Myers wrote:
> On Mon, 29 Apr 2013, Siddhesh Poyarekar wrote:
> 
> > This patch brings back the assembly implementation of sincos (with
> > some changes) to give a fast alternative to the default sincos
> > implementation.  This is defined as __sincos_finite and is used if the
> > implementing program is compiled with the -ffinite-math-only gcc flag.
> 
> The changes don't seem to include accurate range reduction.  Without that, 
> I think this is inappropriate, as it will result in wildly inaccurate 
> results for large but finite inputs.
>
These inputs contain zero significant digits. You cannot expect any
accuracty from them.
 
> (I've stated before that all libm tests with finite inputs and outputs 
> should be run with -ffinite-math-only - and I consider that they should 
> pass when they pass without that option, and should not need different 
> ulps for the different ways of running them.)
> 
> -- 
> Joseph S. Myers
> joseph@codesourcery.com