| /* origin: FreeBSD /usr/src/lib/msun/src/s_ccoshf.c */ | |
| /*- | |
| * Copyright (c) 2005 Bruce D. Evans and Steven G. Kargl | |
| * All rights reserved. | |
| * | |
| * Redistribution and use in source and binary forms, with or without | |
| * modification, are permitted provided that the following conditions | |
| * are met: | |
| * 1. Redistributions of source code must retain the above copyright | |
| * notice unmodified, this list of conditions, and the following | |
| * disclaimer. | |
| * 2. Redistributions in binary form must reproduce the above copyright | |
| * notice, this list of conditions and the following disclaimer in the | |
| * documentation and/or other materials provided with the distribution. | |
| * | |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| */ | |
| /* | |
| * Hyperbolic cosine of a complex argument. See s_ccosh.c for details. | |
| */ | |
| static const float huge = 0x1p127; | |
| float complex ccoshf(float complex z) | |
| { | |
| float x, y, h; | |
| int32_t hx, hy, ix, iy; | |
| x = crealf(z); | |
| y = cimagf(z); | |
| GET_FLOAT_WORD(hx, x); | |
| GET_FLOAT_WORD(hy, y); | |
| ix = 0x7fffffff & hx; | |
| iy = 0x7fffffff & hy; | |
| if (ix < 0x7f800000 && iy < 0x7f800000) { | |
| if (iy == 0) | |
| return CMPLXF(coshf(x), x * y); | |
| if (ix < 0x41100000) /* small x: normal case */ | |
| return CMPLXF(coshf(x) * cosf(y), sinhf(x) * sinf(y)); | |
| /* |x| >= 9, so cosh(x) ~= exp(|x|) */ | |
| if (ix < 0x42b17218) { | |
| /* x < 88.7: expf(|x|) won't overflow */ | |
| h = expf(fabsf(x)) * 0.5f; | |
| return CMPLXF(h * cosf(y), copysignf(h, x) * sinf(y)); | |
| } else if (ix < 0x4340b1e7) { | |
| /* x < 192.7: scale to avoid overflow */ | |
| z = __ldexp_cexpf(CMPLXF(fabsf(x), y), -1); | |
| return CMPLXF(crealf(z), cimagf(z) * copysignf(1, x)); | |
| } else { | |
| /* x >= 192.7: the result always overflows */ | |
| h = huge * x; | |
| return CMPLXF(h * h * cosf(y), h * sinf(y)); | |
| } | |
| } | |
| if (ix == 0 && iy >= 0x7f800000) | |
| return CMPLXF(y - y, copysignf(0, x * (y - y))); | |
| if (iy == 0 && ix >= 0x7f800000) { | |
| if ((hx & 0x7fffff) == 0) | |
| return CMPLXF(x * x, copysignf(0, x) * y); | |
| return CMPLXF(x * x, copysignf(0, (x + x) * y)); | |
| } | |
| if (ix < 0x7f800000 && iy >= 0x7f800000) | |
| return CMPLXF(y - y, x * (y - y)); | |
| if (ix >= 0x7f800000 && (hx & 0x7fffff) == 0) { | |
| if (iy >= 0x7f800000) | |
| return CMPLXF(x * x, x * (y - y)); | |
| return CMPLXF((x * x) * cosf(y), x * sinf(y)); | |
| } | |
| return CMPLXF((x * x) * (y - y), (x + x) * (y - y)); | |
| } | |