path: root/sysdeps/i386/fpu/multiarch/s_sinf-sse2.S

/* Optimized with sse2 version of sinf
   Copyright (C) 2012-2015 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#define __need_Emath
#include <bits/errno.h>

/* Short algorithm description:
 *
 *  1) if |x| == 0: return x.
 *  2) if |x| <  2^-27: return x-x*DP_SMALL, raise underflow only when needed.
 *  3) if |x| <  2^-5 : return x+x^3*DP_SIN2_0+x^5*DP_SIN2_1.
 *  4) if |x| <   Pi/4: return x+x^3*(S0+x^2*(S1+x^2*(S2+x^2*(S3+x^2*S4)))).
 *  5) if |x| < 9*Pi/4:
 *      5.1) Range reduction: k=trunc(|x|/(Pi/4)), j=(k+1)&0x0e, n=k+1,
 *           t=|x|-j*Pi/4.
 *      5.2) Reconstruction:
 *          s = sign(x) * (-1.0)^((n>>2)&1)
 *          if(n&2 != 0) {
 *              using cos(t) polynomial for |t|<Pi/4, result is
 *              s     * (1.0+t^2*(C0+t^2*(C1+t^2*(C2+t^2*(C3+t^2*C4))))).
 *          } else {
 *              using sin(t) polynomial for |t|<Pi/4, result is
 *              s</