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Diffstat (limited to 'sysdeps/generic/cosh.c')
| -rw-r--r-- | sysdeps/generic/cosh.c | 133 |
1 files changed, 0 insertions, 133 deletions
diff --git a/sysdeps/generic/cosh.c b/sysdeps/generic/cosh.c deleted file mode 100644 index e2b30731b8..0000000000 --- a/sysdeps/generic/cosh.c +++ /dev/null @@ -1,133 +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[] = "@(#)cosh.c 8.1 (Berkeley) 6/4/93"; -#endif /* not lint */ - -/* COSH(X) - * RETURN THE HYPERBOLIC COSINE 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 2/8/85, 2/23/85, 3/7/85, 3/29/85, 4/16/85. - * - * Required system supported functions : - * copysign(x,y) - * scalb(x,N) - * - * Required kernel function: - * exp(x) - * exp__E(x,c) ...return exp(x+c)-1-x for |x|<0.3465 - * - * Method : - * 1. Replace x by |x|. - * 2. - * [ exp(x) - 1 ]^2 - * 0 <= x <= 0.3465 : cosh(x) := 1 + ------------------- - * 2*exp(x) - * - * exp(x) + 1/exp(x) - * 0.3465 <= x <= 22 : cosh(x) := ------------------- - * 2 - * 22 <= x <= lnovfl : cosh(x) := exp(x)/2 - * lnovfl <= x <= lnovfl+log(2) - * : cosh(x) := exp(x)/2 (avoid overflow) - * log(2)+lnovfl < x < INF: overflow to INF - * - * Note: .3465 is a number near one half of ln2. - * - * Special cases: - * cosh(x) is x if x is +INF, -INF, or NaN. - * only cosh(0)=1 is exact for finite x. - * - * Accuracy: - * cosh(x) returns the exact hyperbolic cosine of x nearly rounded. - * In a test run with 768,000 random arguments on a VAX, the maximum - * observed error was 1.23 ulps (units in the last place). - * - * 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(mln2hi, 8.8029691931113054792E1 ,0f33,43b0,2bdb,c7e2, 7, .B00F33C7E22BDB) -vc(mln2lo,-4.9650192275318476525E-16 ,1b60,a70f,582a,279e, -50,-.8F1B60279E582A) -vc(lnovfl, 8.8029691931113053016E1 ,0f33,43b0,2bda,c7e2, 7, .B00F33C7E22BDA) - -ic(mln2hi, 7.0978271289338397310E2, 10, 1.62E42FEFA39EF) -ic(mln2lo, 2.3747039373786107478E-14, -45, 1.ABC9E3B39803F) -ic(lnovfl, 7.0978271289338397310E2, 9, 1.62E42FEFA39EF) - -#ifdef vccast -#define mln2hi vccast(mln2hi) -#define mln2lo vccast(mln2lo) -#define lnovfl vccast(lnovfl) -#endif - -#if defined(vax)||defined(tahoe) -static max = 126 ; -#else /* defined(vax)||defined(tahoe) */ -static max = 1023 ; -#endif /* defined(vax)||defined(tahoe) */ - -double cosh(x) -double x; -{ - static const double half=1.0/2.0, - one=1.0, small=1.0E-18; /* fl(1+small)==1 */ - double t; - -#if !defined(vax)&&!defined(tahoe) - if(x!=x) return(x); /* x is NaN */ -#endif /* !defined(vax)&&!defined(tahoe) */ - if((x=copysign(x,one)) <= 22) - if(x<0.3465) - if(x<small) return(one+x); - else {t=x+__exp__E(x,0.0);x=t+t; return(one+t*t/(2.0+x)); } - - else /* for x lies in [0.3465,22] */ - { t=exp(x); return((t+one/t)*half); } - - if( lnovfl <= x && x <= (lnovfl+0.7)) - /* for x lies in [lnovfl, lnovfl+ln2], decrease x by ln(2^(max+1)) - * and return 2^max*exp(x) to avoid unnecessary overflow - */ - return(scalb(exp((x-mln2hi)-mln2lo), max)); - - else - return(exp(x)*half); /* for large x, cosh(x)=exp(x)/2 */ -} |