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Diffstat (limited to 'sysdeps/generic/atanh.c')
| -rw-r--r-- | sysdeps/generic/atanh.c | 83 |
1 files changed, 0 insertions, 83 deletions
diff --git a/sysdeps/generic/atanh.c b/sysdeps/generic/atanh.c deleted file mode 100644 index 89cb61cca2..0000000000 --- a/sysdeps/generic/atanh.c +++ /dev/null @@ -1,83 +0,0 @@ -/* - * Copyright (c) 1985, 1993 - * The Regents of the University of California. All rights reserved. - * - * 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. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. - */ - -#ifndef lint -static char sccsid[] = "@(#)atanh.c 8.1 (Berkeley) 6/4/93"; -#endif /* not lint */ - -/* ATANH(X) - * RETURN THE HYPERBOLIC ARC TANGENT OF X - * DOUBLE PRECISION (VAX D format 56 bits, IEEE DOUBLE 53 BITS) - * CODED IN C BY K.C. NG, 1/8/85; - * REVISED BY K.C. NG on 2/7/85, 3/7/85, 8/18/85. - * - * Required kernel function: - * log1p(x) ...return log(1+x) - * - * Method : - * Return - * 1 2x x - * atanh(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------) - * 2 1 - x 1 - x - * - * Special cases: - * atanh(x) is NaN if |x| > 1 with signal; - * atanh(NaN) is that NaN with no signal; - * atanh(+-1) is +-INF with signal. - * - * Accuracy: - * atanh(x) returns the exact hyperbolic arc tangent of x nearly rounded. - * In a test run with 512,000 random arguments on a VAX, the maximum - * observed error was 1.87 ulps (units in the last place) at - * x= -3.8962076028810414000e-03. - */ -#include "mathimpl.h" - -#if defined(vax)||defined(tahoe) -#include <errno.h> -#endif /* defined(vax)||defined(tahoe) */ - -double atanh(x) -double x; -{ - double z; - z = copysign(0.5,x); - x = copysign(x,1.0); -#if defined(vax)||defined(tahoe) - if (x == 1.0) { - return(copysign(1.0,z)*infnan(ERANGE)); /* sign(x)*INF */ - } -#endif /* defined(vax)||defined(tahoe) */ - x = x/(1.0-x); - return( z*log1p(x+x) ); -} |