Update.
[glibc.git] / sysdeps / libm-ieee754 / s_sincos.c
blob5bc564ba5b501a1f33179e51d1c7cb4660733249
1 /* Compute sine and cosine of argument.
2 Copyright (C) 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
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 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 #include <math.h>
23 #include "math_private.h"
26 void
27 __sincos (double x, double *sinx, double *cosx)
29 int32_t ix;
31 /* High word of x. */
32 GET_HIGH_WORD (ix, x);
34 /* |x| ~< pi/4 */
35 ix &= 0x7fffffff;
36 if (ix <= 0x3fe921fb)
38 *sinx = __kernel_sin (x, 0.0, 0);
39 *cosx = __kernel_cos (x, 0.0);
41 else if (ix>=0x7ff00000)
43 /* sin(Inf or NaN) is NaN */
44 *sinx = *cosx = x - x;
46 else
48 /* Argument reduction needed. */
49 double y[2];
50 int n;
52 n = __ieee754_rem_pio2 (x, y);
53 switch (n & 3)
55 case 0:
56 *sinx = __kernel_sin (y[0], y[1], 1);
57 *cosx = __kernel_cos (y[0], y[1]);
58 break;
59 case 1:
60 *sinx = __kernel_cos (y[0], y[1]);
61 *cosx = -__kernel_sin (y[0], y[1], 1);
62 break;
63 case 2:
64 *sinx = -__kernel_sin (y[0], y[1], 1);
65 *cosx = -__kernel_cos (y[0], y[1]);
66 break;
67 default:
68 *sinx = -__kernel_cos (y[0], y[1]);
69 *cosx = __kernel_sin (y[0], y[1], 1);
70 break;
74 weak_alias (__sincos, sincos)
75 #ifdef NO_LONG_DOUBLE
76 strong_alias (__sincos, __sincosl)
77 weak_alias (__sincos, sincosl)
78 #endif