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 | #define IN_SINCOS |
28 | #include "s_sin.c" |
29 | |
30 | void |
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 | |