sysdeps/ieee754/ldbl-96/s_sincosl.c

   1 /* Compute sine and cosine of argument.
   2    Copyright (C) 1997-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <math.h>
  21
  22 #include <math_private.h>
  23 #include <libm-alias-ldouble.h>
  24
  25
  26 void
  27 __sincosl (long double x, long double *sinx, long double *cosx)
  28 {
  29   int32_t se, i0, i1 __attribute__ ((unused));
  30
  31   /* High word of x. */
  32   GET_LDOUBLE_WORDS (se, i0, i1, x);
  33
  34   /* |x| ~< pi/4 */
  35   se &= 0x7fff;
  36   if (se < 0x3ffe || (se == 0x3ffe && i0 <= 0xc90fdaa2))
  37     {
  38       *sinx = __kernel_sinl (x, 0.0, 0);
  39       *cosx = __kernel_cosl (x, 0.0);
  40     }
  41   else if (se == 0x7fff)
  42     {
  43       /* sin(Inf or NaN) is NaN */
  44       *sinx = *cosx = x - x;
  45       if (isinf (x))
  46         __set_errno (EDOM);
  47     }
  48   else
  49     {
  50       /* Argument reduction needed.  */
  51       long double y[2];
  52       int n;
  53
  54       n = __ieee754_rem_pio2l (x, y);
  55       switch (n & 3)
  56         {
  57         case 0:
  58           *sinx = __kernel_sinl (y[0], y[1], 1);
  59           *cosx = __kernel_cosl (y[0], y[1]);
  60           break;
  61         case 1:
  62           *sinx = __kernel_cosl (y[0], y[1]);
  63           *cosx = -__kernel_sinl (y[0], y[1], 1);
  64           break;
  65         case 2:
  66           *sinx = -__kernel_sinl (y[0], y[1], 1);
  67           *cosx = -__kernel_cosl (y[0], y[1]);
  68           break;
  69         default:
  70           *sinx = -__kernel_cosl (y[0], y[1]);
  71           *cosx = __kernel_sinl (y[0], y[1], 1);
  72           break;
  73         }
  74     }
  75 }
  76 libm_alias_ldouble (__sincos, sincos)