| Andrew Top | 286dd78 | 2018-10-02 16:52:45 -0700 | [diff] [blame] | 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 | |
| Kaido Kert | 788710a | 2023-06-05 07:50:22 -0700 | [diff] [blame] | 31 | #include "complex_impl.h" |
| Andrew Top | 286dd78 | 2018-10-02 16:52:45 -0700 | [diff] [blame] | 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 | } |
