1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2005-2025 Bruce D. Evans and Steven G. Kargl
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
12 * disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 /*
30 * Float version of ccosh(). See s_ccosh.c for details.
31 */
32
33 #include <complex.h>
34 #include <math.h>
35
36 #include "math_private.h"
37
38 static const float huge = 0x1p127;
39
40 float complex
ccoshf(float complex z)41 ccoshf(float complex z)
42 {
43 float c, h, s, x, y;
44 int32_t hx, hy, ix, iy;
45
46 x = crealf(z);
47 y = cimagf(z);
48
49 GET_FLOAT_WORD(hx, x);
50 GET_FLOAT_WORD(hy, y);
51
52 ix = 0x7fffffff & hx;
53 iy = 0x7fffffff & hy;
54
55 if (ix < 0x7f800000 && iy < 0x7f800000) {
56 if (iy == 0)
57 return (CMPLXF(coshf(x), x * y));
58
59 sincosf(y, &s, &c);
60 if (ix < 0x41100000) /* |x| < 9: normal case */
61 return (CMPLXF(coshf(x) * c, sinhf(x) * s));
62
63 /* |x| >= 9, so cosh(x) ~= exp(|x|) */
64 if (ix < 0x42b17218) {
65 /* x < 88.7: expf(|x|) won't overflow */
66 h = expf(fabsf(x)) / 2;
67 return (CMPLXF(h * c, copysignf(h, x) * s));
68 } else if (ix < 0x4340b1e7) {
69 /* x < 192.7: scale to avoid overflow */
70 z = __ldexp_cexpf(CMPLXF(fabsf(x), y), -1);
71 return (CMPLXF(crealf(z), cimagf(z) * copysignf(1, x)));
72 } else {
73 /* x >= 192.7: the result always overflows */
74 h = huge * x;
75 return (CMPLXF(h * h * c, h * s));
76 }
77 }
78
79 if (ix == 0) /* && iy >= 0x7f800000 */
80 return (CMPLXF(y - y, x * copysignf(0, y)));
81
82 if (iy == 0) /* && ix >= 0x7f800000 */
83 return (CMPLXF(x * x, copysignf(0, x) * y));
84
85 if (ix < 0x7f800000) /* && iy >= 0x7f800000 */
86 return (CMPLXF(y - y, x * (y - y)));
87
88 if (ix == 0x7f800000) {
89 if (iy >= 0x7f800000)
90 return (CMPLXF(INFINITY, x * (y - y)));
91
92 sincosf(y, &s, &c);
93 return (CMPLXF(INFINITY * c, x * s));
94 }
95
96 return (CMPLXF(((long double)x * x) * (y - y),
97 ((long double)x + x) * (y - y)));
98 }
99
100 float complex
ccosf(float complex z)101 ccosf(float complex z)
102 {
103
104 return (ccoshf(CMPLXF(-cimagf(z), crealf(z))));
105 }
106