[444] | 1 | /* origin: FreeBSD /usr/src/lib/msun/src/s_ccoshf.c */
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| 2 | /*-
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| 3 | * Copyright (c) 2005 Bruce D. Evans and Steven G. Kargl
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| 4 | * All rights reserved.
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| 5 | *
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| 6 | * Redistribution and use in source and binary forms, with or without
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| 7 | * modification, are permitted provided that the following conditions
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| 8 | * are met:
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| 9 | * 1. Redistributions of source code must retain the above copyright
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| 10 | * notice unmodified, this list of conditions, and the following
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| 11 | * disclaimer.
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| 12 | * 2. Redistributions in binary form must reproduce the above copyright
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| 13 | * notice, this list of conditions and the following disclaimer in the
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| 14 | * documentation and/or other materials provided with the distribution.
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| 15 | *
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| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 17 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 18 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 19 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 21 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 22 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 23 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 25 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 26 | */
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| 27 | /*
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| 28 | * Hyperbolic cosine of a complex argument. See s_ccosh.c for details.
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| 29 | */
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| 30 |
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| 31 | #include "libm.h"
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| 32 |
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| 33 | static const float huge = 0x1p127;
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| 34 |
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| 35 | float complex ccoshf(float complex z)
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| 36 | {
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| 37 | float x, y, h;
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| 38 | int32_t hx, hy, ix, iy;
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| 39 |
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| 40 | x = crealf(z);
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| 41 | y = cimagf(z);
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| 42 |
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| 43 | GET_FLOAT_WORD(hx, x);
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| 44 | GET_FLOAT_WORD(hy, y);
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| 45 |
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| 46 | ix = 0x7fffffff & hx;
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| 47 | iy = 0x7fffffff & hy;
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| 48 |
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| 49 | if (ix < 0x7f800000 && iy < 0x7f800000) {
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| 50 | if (iy == 0)
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| 51 | return CMPLXF(coshf(x), x * y);
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| 52 | if (ix < 0x41100000) /* small x: normal case */
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| 53 | return CMPLXF(coshf(x) * cosf(y), sinhf(x) * sinf(y));
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| 54 |
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| 55 | /* |x| >= 9, so cosh(x) ~= exp(|x|) */
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| 56 | if (ix < 0x42b17218) {
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| 57 | /* x < 88.7: expf(|x|) won't overflow */
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| 58 | h = expf(fabsf(x)) * 0.5f;
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| 59 | return CMPLXF(h * cosf(y), copysignf(h, x) * sinf(y));
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| 60 | } else if (ix < 0x4340b1e7) {
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| 61 | /* x < 192.7: scale to avoid overflow */
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| 62 | z = __ldexp_cexpf(CMPLXF(fabsf(x), y), -1);
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| 63 | return CMPLXF(crealf(z), cimagf(z) * copysignf(1, x));
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| 64 | } else {
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| 65 | /* x >= 192.7: the result always overflows */
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| 66 | h = huge * x;
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| 67 | return CMPLXF(h * h * cosf(y), h * sinf(y));
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| 68 | }
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| 69 | }
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| 70 |
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| 71 | if (ix == 0 && iy >= 0x7f800000)
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| 72 | return CMPLXF(y - y, copysignf(0, x * (y - y)));
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| 73 |
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| 74 | if (iy == 0 && ix >= 0x7f800000) {
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| 75 | if ((hx & 0x7fffff) == 0)
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| 76 | return CMPLXF(x * x, copysignf(0, x) * y);
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| 77 | return CMPLXF(x * x, copysignf(0, (x + x) * y));
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| 78 | }
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| 79 |
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| 80 | if (ix < 0x7f800000 && iy >= 0x7f800000)
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| 81 | return CMPLXF(y - y, x * (y - y));
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| 82 |
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| 83 | if (ix >= 0x7f800000 && (hx & 0x7fffff) == 0) {
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| 84 | if (iy >= 0x7f800000)
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| 85 | return CMPLXF(x * x, x * (y - y));
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| 86 | return CMPLXF((x * x) * cosf(y), x * sinf(y));
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| 87 | }
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| 88 |
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| 89 | return CMPLXF((x * x) * (y - y), (x + x) * (y - y));
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| 90 | }
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