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Diffstat (limited to 'sysdeps/generic/acosh.c')
| -rw-r--r-- | sysdeps/generic/acosh.c | 102 |
1 files changed, 0 insertions, 102 deletions
diff --git a/sysdeps/generic/acosh.c b/sysdeps/generic/acosh.c deleted file mode 100644 index bc16cc7b46..0000000000 --- a/sysdeps/generic/acosh.c +++ /dev/null @@ -1,102 +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[] = "@(#)acosh.c 8.1 (Berkeley) 6/4/93"; -#endif /* not lint */ - -/* ACOSH(X) - * RETURN THE INVERSE HYPERBOLIC COSINE OF X - * DOUBLE PRECISION (VAX D FORMAT 56 BITS, IEEE DOUBLE 53 BITS) - * CODED IN C BY K.C. NG, 2/16/85; - * REVISED BY K.C. NG on 3/6/85, 3/24/85, 4/16/85, 8/17/85. - * - * Required system supported functions : - * sqrt(x) - * - * Required kernel function: - * log1p(x) ...return log(1+x) - * - * Method : - * Based on - * acosh(x) = log [ x + sqrt(x*x-1) ] - * we have - * acosh(x) := log1p(x)+ln2, if (x > 1.0E20); else - * acosh(x) := log1p( sqrt(x-1) * (sqrt(x-1) + sqrt(x+1)) ) . - * These formulae avoid the over/underflow complication. - * - * Special cases: - * acosh(x) is NaN with signal if x<1. - * acosh(NaN) is NaN without signal. - * - * Accuracy: - * acosh(x) returns the exact inverse hyperbolic cosine of x nearly - * rounded. In a test run with 512,000 random arguments on a VAX, the - * maximum observed error was 3.30 ulps (units of the last place) at - * x=1.0070493753568216 . - * - * Constants: - * The hexadecimal values are the intended ones for the following constants. - * The decimal values may be used, provided that the compiler will convert - * from decimal to binary accurately enough to produce the hexadecimal values - * shown. - */ - -#include "mathimpl.h" - -vc(ln2hi, 6.9314718055829871446E-1 ,7217,4031,0000,f7d0, 0, .B17217F7D00000) -vc(ln2lo, 1.6465949582897081279E-12 ,bcd5,2ce7,d9cc,e4f1, -39, .E7BCD5E4F1D9CC) - -ic(ln2hi, 6.9314718036912381649E-1, -1, 1.62E42FEE00000) -ic(ln2lo, 1.9082149292705877000E-10,-33, 1.A39EF35793C76) - -#ifdef vccast -#define ln2hi vccast(ln2hi) -#define ln2lo vccast(ln2lo) -#endif - -double acosh(x) -double x; -{ - double t,big=1.E20; /* big+1==big */ - -#if !defined(vax)&&!defined(tahoe) - if(x!=x) return(x); /* x is NaN */ -#endif /* !defined(vax)&&!defined(tahoe) */ - - /* return log1p(x) + log(2) if x is large */ - if(x>big) {t=log1p(x)+ln2lo; return(t+ln2hi);} - - t=sqrt(x-1.0); - return(log1p(t*(t+sqrt(x+1.0)))); -} |