1 /* origin: FreeBSD /usr/src/lib/msun/src/s_ccoshf.c */
2 /*-
3 * Copyright (c) 2005 Bruce D. Evans and Steven G. Kargl
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice unmodified, this list of conditions, and the following
11 * disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27 /*
28 * Hyperbolic cosine of a complex argument. See s_ccosh.c for details.
29 */
30 31 #include "complex_impl.h"
32 33 static const float huge = 0x1p127;
34 35 float complex ccoshf(float complex z)
36 {
37 float x, y, h;
38 int32_t hx, hy, ix, iy;
39 40 x = crealf(z);
41 y = cimagf(z);
42 43 GET_FLOAT_WORD(hx, x);
44 GET_FLOAT_WORD(hy, y);
45 46 ix = 0x7fffffff & hx;
47 iy = 0x7fffffff & hy;
48 49 if (ix < 0x7f800000 && iy < 0x7f800000) {
50 if (iy == 0)
51 return CMPLXF(coshf(x), x * y);
52 if (ix < 0x41100000) /* small x: normal case */
53 return CMPLXF(coshf(x) * cosf(y), sinhf(x) * sinf(y));
54 55 /* |x| >= 9, so cosh(x) ~= exp(|x|) */
56 if (ix < 0x42b17218) {
57 /* x < 88.7: expf(|x|) won't overflow */
58 h = expf(fabsf(x)) * 0.5f;
59 return CMPLXF(h * cosf(y), copysignf(h, x) * sinf(y));
60 } else if (ix < 0x4340b1e7) {
61 /* x < 192.7: scale to avoid overflow */
62 z = __ldexp_cexpf(CMPLXF(fabsf(x), y), -1);
63 return CMPLXF(crealf(z), cimagf(z) * copysignf(1, x));
64 } else {
65 /* x >= 192.7: the result always overflows */
66 h = huge * x;
67 return CMPLXF(h * h * cosf(y), h * sinf(y));
68 }
69 }
70 71 if (ix == 0 && iy >= 0x7f800000)
72 return CMPLXF(y - y, copysignf(0, x * (y - y)));
73 74 if (iy == 0 && ix >= 0x7f800000) {
75 if ((hx & 0x7fffff) == 0)
76 return CMPLXF(x * x, copysignf(0, x) * y);
77 return CMPLXF(x * x, copysignf(0, (x + x) * y));
78 }
79 80 if (ix < 0x7f800000 && iy >= 0x7f800000)
81 return CMPLXF(y - y, x * (y - y));
82 83 if (ix >= 0x7f800000 && (hx & 0x7fffff) == 0) {
84 if (iy >= 0x7f800000)
85 return CMPLXF(x * x, x * (y - y));
86 return CMPLXF((x * x) * cosf(y), x * sinf(y));
87 }
88 89 return CMPLXF((x * x) * (y - y), (x + x) * (y - y));
90 }
91