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