| /* origin: FreeBSD /usr/src/lib/msun/src/s_ctanhf.c */ |
| /*- |
| * Copyright (c) 2011 David Schultz |
| * 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 tangent of a complex argument z. See s_ctanh.c for details. |
| */ |
| |
| #include "complex_impl.h" |
| |
| float complex ctanhf(float complex z) |
| { |
| float x, y; |
| float t, beta, s, rho, denom; |
| uint32_t hx, ix; |
| |
| x = crealf(z); |
| y = cimagf(z); |
| |
| GET_FLOAT_WORD(hx, x); |
| ix = hx & 0x7fffffff; |
| |
| if (ix >= 0x7f800000) { |
| if (ix & 0x7fffff) |
| return CMPLXF(x, (y == 0 ? y : x * y)); |
| SET_FLOAT_WORD(x, hx - 0x40000000); |
| return CMPLXF(x, copysignf(0, isinf(y) ? y : sinf(y) * cosf(y))); |
| } |
| |
| if (!isfinite(y)) |
| return CMPLXF(ix ? y - y : x, y - y); |
| |
| if (ix >= 0x41300000) { /* x >= 11 */ |
| float exp_mx = expf(-fabsf(x)); |
| return CMPLXF(copysignf(1, x), 4 * sinf(y) * cosf(y) * exp_mx * exp_mx); |
| } |
| |
| t = tanf(y); |
| beta = 1.0 + t * t; |
| s = sinhf(x); |
| rho = sqrtf(1 + s * s); |
| denom = 1 + beta * s * s; |
| return CMPLXF((beta * rho * s) / denom, t / denom); |
| } |