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 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
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 | Lesser General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Lesser General Public |
17 | License along with the GNU C Library; if not, see |
18 | <https://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <errno.h> |
21 | #include <math.h> |
22 | |
23 | #include <math_private.h> |
24 | #include <fenv_private.h> |
25 | #include <math-underflow.h> |
26 | #include <libm-alias-double.h> |
27 | |
28 | #define IN_SINCOS |
29 | #include "s_sin.c" |
30 | |
31 | void |
32 | __sincos (double x, double *sinx, double *cosx) |
33 | { |
34 | mynumber u; |
35 | int k; |
36 | |
37 | SET_RESTORE_ROUND_53BIT (FE_TONEAREST); |
38 | |
39 | u.x = x; |
40 | k = u.i[HIGH_HALF] & 0x7fffffff; |
41 | |
42 | if (k < 0x400368fd) |
43 | { |
44 | double a, da, y; |
45 | /* |x| < 2^-27 => cos (x) = 1, sin (x) = x. */ |
46 | if (k < 0x3e400000) |
47 | { |
48 | if (k < 0x3e500000) |
49 | math_check_force_underflow (x); |
50 | *sinx = x; |
51 | *cosx = 1.0; |
52 | return; |
53 | } |
54 | /* |x| < 0.855469. */ |
55 | else if (k < 0x3feb6000) |
56 | { |
57 | *sinx = do_sin (x, 0); |
58 | *cosx = do_cos (x, 0); |
59 | return; |
60 | } |
61 | |
62 | /* |x| < 2.426265. */ |
63 | y = hp0 - fabs (x); |
64 | a = y + hp1; |
65 | da = (y - a) + hp1; |
66 | *sinx = copysign (do_cos (a, da), x); |
67 | *cosx = do_sin (a, da); |
68 | return; |
69 | } |
70 | /* |x| < 2^1024. */ |
71 | if (k < 0x7ff00000) |
72 | { |
73 | double a, da, xx; |
74 | unsigned int n; |
75 | |
76 | /* If |x| < 105414350 use simple range reduction. */ |
77 | n = k < 0x419921FB ? reduce_sincos (x, &a, &da) : __branred (x, &a, &da); |
78 | n = n & 3; |
79 | |
80 | if (n == 1 || n == 2) |
81 | { |
82 | a = -a; |
83 | da = -da; |
84 | } |
85 | |
86 | if (n & 1) |
87 | { |
88 | double *temp = cosx; |
89 | cosx = sinx; |
90 | sinx = temp; |
91 | } |
92 | |
93 | *sinx = do_sin (a, da); |
94 | xx = do_cos (a, da); |
95 | *cosx = (n & 2) ? -xx : xx; |
96 | return; |
97 | } |
98 | |
99 | if (isinf (x)) |
100 | __set_errno (EDOM); |
101 | |
102 | *sinx = *cosx = x / x; |
103 | } |
104 | libm_alias_double (__sincos, sincos) |
105 | |