1 /* Compute sine and cosine of argument.
2 Copyright (C) 1997-2021 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 <fenv_private.h>
24 #include <math-underflow.h>
25 #include <libm-alias-double.h>
26
27 #define IN_SINCOS
28 #include "s_sin.c"
29
30 void
__sincos(double x,double * sinx,double * cosx)31 __sincos (double x, double *sinx, double *cosx)
32 {
33 mynumber u;
34 int k;
35
36 SET_RESTORE_ROUND_53BIT (FE_TONEAREST);
37
38 u.x = x;
39 k = u.i[HIGH_HALF] & 0x7fffffff;
40
41 if (k < 0x400368fd)
42 {
43 double a, da, y;
44 /* |x| < 2^-27 => cos (x) = 1, sin (x) = x. */
45 if (k < 0x3e400000)
46 {
47 if (k < 0x3e500000)
48 math_check_force_underflow (x);
49 *sinx = x;
50 *cosx = 1.0;
51 return;
52 }
53 /* |x| < 0.855469. */
54 else if (k < 0x3feb6000)
55 {
56 *sinx = do_sin (x, 0);
57 *cosx = do_cos (x, 0);
58 return;
59 }
60
61 /* |x| < 2.426265. */
62 y = hp0 - fabs (x);
63 a = y + hp1;
64 da = (y - a) + hp1;
65 *sinx = copysign (do_cos (a, da), x);
66 *cosx = do_sin (a, da);
67 return;
68 }
69 /* |x| < 2^1024. */
70 if (k < 0x7ff00000)
71 {
72 double a, da, xx;
73 unsigned int n;
74
75 /* If |x| < 105414350 use simple range reduction. */
76 n = k < 0x419921FB ? reduce_sincos (x, &a, &da) : __branred (x, &a, &da);
77 n = n & 3;
78
79 if (n == 1 || n == 2)
80 {
81 a = -a;
82 da = -da;
83 }
84
85 if (n & 1)
86 {
87 double *temp = cosx;
88 cosx = sinx;
89 sinx = temp;
90 }
91
92 *sinx = do_sin (a, da);
93 xx = do_cos (a, da);
94 *cosx = (n & 2) ? -xx : xx;
95 return;
96 }
97
98 if (isinf (x))
99 __set_errno (EDOM);
100
101 *sinx = *cosx = x / x;
102 }
103 libm_alias_double (__sincos, sincos)
104