1/* origin: FreeBSD /usr/src/lib/msun/src/s_ctanhf.c */ 2/*- 3 * Copyright (c) 2011 David Schultz 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 tangent of a complex argument z. See s_ctanh.c for details. 29 */ 30 31#include "libm.h" 32 33float complex ctanhf(float complex z) 34{ 35 float x, y; 36 float t, beta, s, rho, denom; 37 uint32_t hx, ix; 38 39 x = crealf(z); 40 y = cimagf(z); 41 42 GET_FLOAT_WORD(hx, x); 43 ix = hx & 0x7fffffff; 44 45 if (ix >= 0x7f800000) { 46 if (ix & 0x7fffff) 47 return CMPLXF(x, (y == 0 ? y : x * y)); 48 SET_FLOAT_WORD(x, hx - 0x40000000); 49 return CMPLXF(x, copysignf(0, isinf(y) ? y : sinf(y) * cosf(y))); 50 } 51 52 if (!isfinite(y)) 53 return CMPLXF(ix ? y - y : x, y - y); 54 55 if (ix >= 0x41300000) { /* x >= 11 */ 56 float exp_mx = expf(-fabsf(x)); 57 return CMPLXF(copysignf(1, x), 4 * sinf(y) * cosf(y) * exp_mx * exp_mx); 58 } 59 60 t = tanf(y); 61 beta = 1.0 + t * t; 62 s = sinhf(x); 63 rho = sqrtf(1 + s * s); 64 denom = 1 + beta * s * s; 65 return CMPLXF((beta * rho * s) / denom, t / denom); 66} 67