1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2011 David Schultz 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice unmodified, this list of conditions, and the following 12 * disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /* 30 * Hyperbolic tangent of a complex argument z. See s_ctanh.c for details. 31 */ 32 33 #include <complex.h> 34 #include <math.h> 35 36 #include "math_private.h" 37 38 float complex 39 ctanhf(float complex z) 40 { 41 float x, y; 42 float t, beta, s, rho, denom; 43 uint32_t hx, ix; 44 45 x = crealf(z); 46 y = cimagf(z); 47 48 GET_FLOAT_WORD(hx, x); 49 ix = hx & 0x7fffffff; 50 51 if (ix >= 0x7f800000) { 52 if (ix & 0x7fffff) 53 return (CMPLXF(nan_mix(x, y), 54 y == 0 ? y : nan_mix(x, y))); 55 SET_FLOAT_WORD(x, hx - 0x40000000); 56 return (CMPLXF(x, 57 copysignf(0, isinf(y) ? y : sinf(y) * cosf(y)))); 58 } 59 60 if (!isfinite(y)) 61 return (CMPLXF(ix ? y - y : x, y - y)); 62 63 if (ix >= 0x41300000) { /* |x| >= 11 */ 64 float exp_mx = expf(-fabsf(x)); 65 return (CMPLXF(copysignf(1, x), 66 4 * sinf(y) * cosf(y) * exp_mx * exp_mx)); 67 } 68 69 t = tanf(y); 70 beta = 1.0 + t * t; 71 s = sinhf(x); 72 rho = sqrtf(1 + s * s); 73 denom = 1 + beta * s * s; 74 return (CMPLXF((beta * rho * s) / denom, t / denom)); 75 } 76 77 float complex 78 ctanf(float complex z) 79 { 80 81 z = ctanhf(CMPLXF(cimagf(z), crealf(z))); 82 return (CMPLXF(cimagf(z), crealf(z))); 83 } 84 85