1 /* Compute sine and cosine of argument.
2 Copyright (C) 1997-2022 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 #ifndef SECTION
28 # define SECTION
29 #endif
30
31 #define IN_SINCOS
32 #include "s_sin.c"
33
34 void
35 SECTION
__sincos(double x,double * sinx,double * cosx)36 __sincos (double x, double *sinx, double *cosx)
37 {
38 mynumber u;
39 int k;
40
41 SET_RESTORE_ROUND_53BIT (FE_TONEAREST);
42
43 u.x = x;
44 k = u.i[HIGH_HALF] & 0x7fffffff;
45
46 if (k < 0x400368fd)
47 {
48 double a, da, y;
49 /* |x| < 2^-27 => cos (x) = 1, sin (x) = x. */
50 if (k < 0x3e400000)
51 {
52 if (k < 0x3e500000)
53 math_check_force_underflow (x);
54 *sinx = x;
55 *cosx = 1.0;
56 return;
57 }
58 /* |x| < 0.855469. */
59 else if (k < 0x3feb6000)
60 {
61 *sinx = do_sin (x, 0);
62 *cosx = do_cos (x, 0);
63 return;
64 }
65
66 /* |x| < 2.426265. */
67 y = hp0 - fabs (x);
68 a = y + hp1;
69 da = (y - a) + hp1;
70 *sinx = copysign (do_cos (a, da), x);
71 *cosx = do_sin (a, da);
72 return;
73 }
74 /* |x| < 2^1024. */
75 if (k < 0x7ff00000)
76 {
77 double a, da, xx;
78 unsigned int n;
79
80 /* If |x| < 105414350 use simple range reduction. */
81 n = k < 0x419921FB ? reduce_sincos (x, &a, &da) : __branred (x, &a, &da);
82 n = n & 3;
83
84 if (n == 1 || n == 2)
85 {
86 a = -a;
87 da = -da;
88 }
89
90 if (n & 1)
91 {
92 double *temp = cosx;
93 cosx = sinx;
94 sinx = temp;
95 }
96
97 *sinx = do_sin (a, da);
98 xx = do_cos (a, da);
99 *cosx = (n & 2) ? -xx : xx;
100 return;
101 }
102
103 if (isinf (x))
104 __set_errno (EDOM);
105
106 *sinx = *cosx = x / x;
107 }
108 #ifndef __sincos
109 libm_alias_double (__sincos, sincos)
110 #endif
111