1 /*-
2 * Copyright (c) 2017,2023 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 #include <sys/cdefs.h>
28 /*
29 * See ../src/s_cospi.c for implementation details.
30 */
31 #define INLINE_KERNEL_SINDF
32 #define INLINE_KERNEL_COSDF
33
34 #include "namespace.h"
35 __weak_alias(cospif, _cospif)
36
37 #include "math.h"
38 #include "math_private.h"
39 #include "k_cosdf.c"
40 #include "k_sindf.c"
41
42 #define __kernel_cospif(x) (__kernel_cosdf(M_PI * (x)))
43 #define __kernel_sinpif(x) (__kernel_sindf(M_PI * (x)))
44
45 static volatile const float vzero = 0;
46
47 float
cospif(float x)48 cospif(float x)
49 {
50 float ax, c;
51 uint32_t ix, jj0;
52
53 GET_FLOAT_WORD(ix, x);
54 ix = ix & 0x7fffffff;
55 SET_FLOAT_WORD(ax, ix);
56
57 if (ix < 0x3f800000) { /* |x| < 1 */
58 if (ix < 0x3e800000) { /* |x| < 0.25 */
59 if (ix < 0x38800000) { /* |x| < 0x1p-14 */
60 /* Raise inexact iff != 0. */
61 if ((int)ax == 0)
62 return (1);
63 }
64 return (__kernel_cospif(ax));
65 }
66
67 if (ix < 0x3f000000) /* |x| < 0.5 */
68 c = __kernel_sinpif(0.5F - ax);
69 else if (ix < 0x3f400000) { /* |x| < 0.75 */
70 if (ix == 0x3f000000)
71 return (0);
72 c = -__kernel_sinpif(ax - 0.5F);
73 } else
74 c = -__kernel_cospif(1 - ax);
75 return (c);
76 }
77
78 if (ix < 0x4b000000) { /* 1 <= |x| < 0x1p23 */
79 FFLOORF(x, jj0, ix); /* Integer part of ax. */
80 ax -= x;
81 GET_FLOAT_WORD(ix, ax);
82
83 if (ix < 0x3f000000) { /* |x| < 0.5 */
84 if (ix < 0x3e800000) /* |x| < 0.25 */
85 c = ix == 0 ? 1 : __kernel_cospif(ax);
86 else
87 c = __kernel_sinpif(0.5F - ax);
88 } else {
89 if (ix < 0x3f400000) { /* |x| < 0.75 */
90 if (ix == 0x3f000000)
91 return (0);
92 c = -__kernel_sinpif(ax - 0.5F);
93 } else
94 c = -__kernel_cospif(1 - ax);
95 }
96
97 jj0 = (uint32_t)x;
98 return (jj0 & 1 ? -c : c);
99 }
100
101 /* x = +-inf or nan. */
102 if (ix >= 0x7f800000)
103 return (vzero / vzero);
104
105 /*
106 * For 0x1p23 <= |x| < 0x1p24 need to determine if x is an even
107 * or odd integer to return +1 or -1.
108 * For |x| >= 0x1p24, it is always an even integer, so return 1.
109 */
110 return (ix < 0x4b800000 ? ((ix & 1) ? -1 : 1) : 1);
111 }
112