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      1 /* $NetBSD: ctanf.c,v 1.2 2011/07/03 06:45:24 mrg Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2007 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software written by Stephen L. Moshier.
      8  * It is redistributed by the NetBSD Foundation by permission of the author.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include "../src/namespace.h"
     33 #include <complex.h>
     34 #include <math.h>
     35 #include <float.h>
     36 #include "cephes_subrf.h"
     37 
     38 #define MAXNUMF FLT_MAX
     39 
     40 float complex
     41 ctanf(float complex z)
     42 {
     43 	float complex w;
     44 	float d;
     45 
     46 	d = cosf(2.0f * crealf(z)) + coshf(2.0f * cimagf(z));
     47 
     48 	if (fabsf(d) < 0.25f)
     49 		d = _ctansf(z);
     50 
     51 	if (d == 0.0f) {
     52 		/* mtherr ("ctan", OVERFLOW); */
     53 		w = MAXNUMF + MAXNUMF * I;
     54 		return w;
     55 	}
     56 
     57 	w = sinf(2.0f * crealf(z)) / d + (sinhf(2.0f * cimagf(z)) / d) * I;
     58 	return w;
     59 }
     60