1 /*-
2 * Copyright (c) 2007 Steven G. Kargl
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 //__FBSDID("$FreeBSD: src/lib/msun/src/s_cosl.c,v 1.3 2011/05/30 19:41:28 kargl Exp $");
28
29 /*
30 * Limited testing on pseudorandom numbers drawn within [-2e8:4e8] shows
31 * an accuracy of <= 0.7412 ULP.
32 */
33
34
35 #include "e_rem_pio2l.h"
36
37 long double
cosl(long double x)38 cosl(long double x)
39 {
40 union IEEEl2bits z;
41 int e0;
42 long double y[2];
43 long double hi, lo;
44
45 z.e = x;
46 z.bits.sign = 0;
47
48 /* If x = +-0, then cos(x) = 1 */
49 if (x == 0)
50 return (1.0L);
51
52 /* If x = NaN or Inf, then cos(x) = NaN. */
53 if (z.bits.exp == 32767)
54 return __math_invalidl(x);
55
56 /* Optimize the case where x is already within range. */
57 if (z.e < _M_PI_4L)
58 return (__kernel_cosl(z.e, 0));
59
60 e0 = __ieee754_rem_pio2l(x, y);
61 hi = y[0];
62 lo = y[1];
63
64 switch (e0 & 3) {
65 case 0:
66 hi = __kernel_cosl(hi, lo);
67 break;
68 case 1:
69 hi = - __kernel_sinl(hi, lo, 1);
70 break;
71 case 2:
72 hi = - __kernel_cosl(hi, lo);
73 break;
74 case 3:
75 hi = __kernel_sinl(hi, lo, 1);
76 break;
77 }
78
79 return (hi);
80 }
81
82 #if defined(_HAVE_ALIAS_ATTRIBUTE)
83 #ifndef __clang__
84 #pragma GCC diagnostic ignored "-Wmissing-attributes"
85 #endif
86 __strong_reference(cosl, _cosl);
87 #endif
88
89
