This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH 2/5] Use fabs(x) instead of branching on signedness of input to sin and cos
On Tue, 23 Aug 2016, Manfred wrote:
> If eps is known to be >=0 then
> > + cor = 1.0005 * cor + ((cor > 0) ? eps : -eps);
> might be written as
> cor = 1.0005 * cor + copysign(eps, cor);
>
> Similarly to fabs(), copysign() avoids a branch - or a potential one from the
> ternary.
That should be __copysign for namespace reasons (though they should
generally do the same thing because of inlines in math_private.h).
--
Joseph S. Myers
joseph@codesourcery.com