sysdeps/ieee754/dbl-64/s_sincos.c

   1 /* Compute sine and cosine of argument.
   2    Copyright (C) 1997-2016 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <errno.h>
  21 #include <math.h>
  22
  23 #include <math_private.h>
  24
  25 #define __sin __sin_local
  26 #define __cos __cos_local
  27 #define IN_SINCOS 1
  28 #include "s_sin.c"
  29
  30 /* Consolidated version of reduce_and_compute in s_sin.c that does range
  31    reduction only once and computes sin and cos together.  */
  32 static inline void
  33 __always_inline
  34 reduce_and_compute_sincos (double x, double *sinx, double *cosx)
  35 {
  36   double a, da;
  37   unsigned int n = __branred (x, &a, &da);
  38
  39   n = n & 3;
  40
  41   if (n == 1 || n == 2)
  42     {
  43       a = -a;
  44       da = -da;
  45     }
  46
  47   if (n & 1)
  48     {
  49       double *temp = cosx;
  50       cosx = sinx;
  51       sinx = temp;
  52     }
  53
  54   if (a * a < 0.01588)
  55     *sinx = bsloww (a, da, x, n);
  56   else
  57     *sinx = bsloww1 (a, da, x, n);
  58   *cosx = bsloww2 (a, da, x, n);
  59 }
  60
  61 void
  62 __sincos (double x, double *sinx, double *cosx)
  63 {
  64   mynumber u;
  65   int k;
  66
  67   SET_RESTORE_ROUND_53BIT (FE_TONEAREST);
  68
  69   u.x = x;
  70   k = 0x7fffffff & u.i[HIGH_HALF];
  71
  72   if (k < 0x400368fd)
  73     {
  74       *sinx = __sin_local (x);
  75       *cosx = __cos_local (x);
  76       return;
  77     }
  78   if (k < 0x419921FB)
  79     {
  80       double a, da;
  81       int4 n = reduce_sincos_1 (x, &a, &da);
  82
  83       *sinx = do_sincos_1 (a, da, x, n, 0);
  84       *cosx = do_sincos_1 (a, da, x, n, 1);
  85
  86       return;
  87     }
  88   if (k < 0x42F00000)
  89     {
  90       double a, da;
  91       int4 n = reduce_sincos_2 (x, &a, &da);
  92
  93       *sinx = do_sincos_2 (a, da, x, n, 0);
  94       *cosx = do_sincos_2 (a, da, x, n, 1);
  95
  96       return;
  97     }
  98   if (k < 0x7ff00000)
  99     {
 100       reduce_and_compute_sincos (x, sinx, cosx);
 101       return;
 102     }
 103
 104   if (isinf (x))
 105     __set_errno (EDOM);
 106
 107   *sinx = *cosx = x / x;
 108 }
 109 weak_alias (__sincos, sincos)
 110 #ifdef NO_LONG_DOUBLE
 111 strong_alias (__sincos, __sincosl)
 112 weak_alias (__sincos, sincosl)
 113 #endif