100 lines
3.2 KiB
C
100 lines
3.2 KiB
C
/* $NetBSD: cacos.c,v 1.1 2007/08/20 16:01:30 drochner Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2007 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software written by Stephen L. Moshier.
|
|
* It is redistributed by the NetBSD Foundation by permission of the author.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
* imported and modified include for newlib 2010/10/03
|
|
* Marco Atzeri <marco_atzeri@yahoo.it>
|
|
*/
|
|
|
|
/*
|
|
FUNCTION
|
|
<<cacos>>, <<cacosf>>---complex arc cosine
|
|
|
|
INDEX
|
|
cacos
|
|
INDEX
|
|
cacosf
|
|
|
|
SYNOPSIS
|
|
#include <complex.h>
|
|
double complex cacos(double complex <[z]>);
|
|
float complex cacosf(float complex <[z]>);
|
|
|
|
|
|
DESCRIPTION
|
|
These functions compute the complex arc cosine of <[z]>,
|
|
with branch cuts outside the interval [-1, +1] along the real axis.
|
|
|
|
<<cacosf>> is identical to <<cacos>>, except that it performs
|
|
its calculations on <<floats complex>>.
|
|
|
|
RETURNS
|
|
@ifnottex
|
|
These functions return the complex arc cosine value, in the range
|
|
of a strip mathematically unbounded along the imaginary axis
|
|
and in the interval [0, pi] along the real axis.
|
|
@end ifnottex
|
|
@tex
|
|
These functions return the complex arc cosine value, in the range
|
|
of a strip mathematically unbounded along the imaginary axis
|
|
and in the interval [<<0>>, $\pi$] along the real axis.
|
|
@end tex
|
|
|
|
PORTABILITY
|
|
<<cacos>> and <<cacosf>> are ISO C99
|
|
|
|
QUICKREF
|
|
<<cacos>> and <<cacosf>> are ISO C99
|
|
|
|
*/
|
|
|
|
#include <complex.h>
|
|
#include <math.h>
|
|
|
|
double complex
|
|
cacos(double complex z)
|
|
{
|
|
double complex w;
|
|
|
|
/* FIXME: The original NetBSD code results in an ICE when trying to
|
|
build this function on ARM/Thumb using gcc 4.5.1. For now we use
|
|
a hopefully temporary workaround. */
|
|
#if 0
|
|
w = casin(z);
|
|
w = (M_PI_2 - creal(w)) - cimag(w) * I;
|
|
#else
|
|
double complex tmp0, tmp1;
|
|
|
|
tmp0 = casin(z);
|
|
tmp1 = M_PI_2 - creal(tmp0);
|
|
w = tmp1 - (cimag(tmp0) * I);
|
|
#endif
|
|
return w;
|
|
}
|