GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libm/src/s_csin.c Lines: 0 11 0.0 %
Date: 2017-11-13 Branches: 0 2 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: s_csin.c,v 1.7 2016/09/12 19:47:02 guenther Exp $	*/
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/*
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 * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
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 *
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 * Permission to use, copy, modify, and distribute this software for any
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 * purpose with or without fee is hereby granted, provided that the above
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 * copyright notice and this permission notice appear in all copies.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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 */
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/*							csin()
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 *
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 *	Complex circular sine
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 *
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 *
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 *
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 * SYNOPSIS:
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 *
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 * double complex csin();
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 * double complex z, w;
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 *
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 * w = csin (z);
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 *
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 *
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 *
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 * DESCRIPTION:
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 *
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 * If
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 *     z = x + iy,
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 *
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 * then
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 *
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 *     w = sin x  cosh y  +  i cos x sinh y.
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 *
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 * csin(z) = -i csinh(iz).
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 *
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 * ACCURACY:
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 *
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 *                      Relative error:
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 * arithmetic   domain     # trials      peak         rms
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 *    DEC       -10,+10      8400       5.3e-17     1.3e-17
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 *    IEEE      -10,+10     30000       3.8e-16     1.0e-16
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 * Also tested by csin(casin(z)) = z.
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 *
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 */
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#include <complex.h>
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#include <float.h>
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#include <math.h>
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/* calculate cosh and sinh */
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static void
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cchsh(double x, double *c, double *s)
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{
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	double e, ei;
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	if (fabs(x) <= 0.5) {
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		*c = cosh(x);
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		*s = sinh(x);
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	}
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	else {
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		e = exp(x);
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		ei = 0.5/e;
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		e = 0.5 * e;
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		*s = e - ei;
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		*c = e + ei;
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	}
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}
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double complex
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csin(double complex z)
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{
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	double complex w;
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	double ch, sh;
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	cchsh( cimag (z), &ch, &sh );
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	w = sin (creal(z)) * ch + (cos (creal(z)) * sh) * I;
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	return (w);
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}
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DEF_STD(csin);
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LDBL_MAYBE_UNUSED_CLONE(csin);