[444] | 1 | /* $NetBSD: cacos.c,v 1.1 2007/08/20 16:01:30 drochner 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 | * imported and modified include for newlib 2010/10/03 |
---|
| 32 | * Marco Atzeri <marco_atzeri@yahoo.it> |
---|
| 33 | */ |
---|
| 34 | |
---|
| 35 | /* |
---|
| 36 | FUNCTION |
---|
| 37 | <<cacos>>, <<cacosf>>---complex arc cosine |
---|
| 38 | |
---|
| 39 | INDEX |
---|
| 40 | cacos |
---|
| 41 | INDEX |
---|
| 42 | cacosf |
---|
| 43 | |
---|
| 44 | SYNOPSIS |
---|
| 45 | #include <complex.h> |
---|
| 46 | double complex cacos(double complex <[z]>); |
---|
| 47 | float complex cacosf(float complex <[z]>); |
---|
| 48 | |
---|
| 49 | |
---|
| 50 | DESCRIPTION |
---|
| 51 | These functions compute the complex arc cosine of <[z]>, |
---|
| 52 | with branch cuts outside the interval [-1, +1] along the real axis. |
---|
| 53 | |
---|
| 54 | <<cacosf>> is identical to <<cacos>>, except that it performs |
---|
| 55 | its calculations on <<floats complex>>. |
---|
| 56 | |
---|
| 57 | RETURNS |
---|
| 58 | @ifnottex |
---|
| 59 | These functions return the complex arc cosine value, in the range |
---|
| 60 | of a strip mathematically unbounded along the imaginary axis |
---|
| 61 | and in the interval [0, pi] along the real axis. |
---|
| 62 | @end ifnottex |
---|
| 63 | @tex |
---|
| 64 | These functions return the complex arc cosine value, in the range |
---|
| 65 | of a strip mathematically unbounded along the imaginary axis |
---|
| 66 | and in the interval [<<0>>, $\pi$] along the real axis. |
---|
| 67 | @end tex |
---|
| 68 | |
---|
| 69 | PORTABILITY |
---|
| 70 | <<cacos>> and <<cacosf>> are ISO C99 |
---|
| 71 | |
---|
| 72 | QUICKREF |
---|
| 73 | <<cacos>> and <<cacosf>> are ISO C99 |
---|
| 74 | |
---|
| 75 | */ |
---|
| 76 | |
---|
| 77 | #include <complex.h> |
---|
| 78 | #include <math.h> |
---|
| 79 | |
---|
| 80 | double complex |
---|
| 81 | cacos(double complex z) |
---|
| 82 | { |
---|
| 83 | double complex w; |
---|
| 84 | |
---|
| 85 | /* FIXME: The original NetBSD code results in an ICE when trying to |
---|
| 86 | build this function on ARM/Thumb using gcc 4.5.1. For now we use |
---|
| 87 | a hopefully temporary workaround. */ |
---|
| 88 | #if 0 |
---|
| 89 | w = casin(z); |
---|
| 90 | w = (M_PI_2 - creal(w)) - cimag(w) * I; |
---|
| 91 | #else |
---|
| 92 | double complex tmp0, tmp1; |
---|
| 93 | |
---|
| 94 | tmp0 = casin(z); |
---|
| 95 | tmp1 = M_PI_2 - creal(tmp0); |
---|
| 96 | w = tmp1 - (cimag(tmp0) * I); |
---|
| 97 | #endif |
---|
| 98 | return w; |
---|
| 99 | } |
---|