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authorbde <bde@FreeBSD.org>2002-03-21 00:42:48 +0000
committerbde <bde@FreeBSD.org>2002-03-21 00:42:48 +0000
commitbe2cf84b24905468b296d0b27d7c0459acd4dec8 (patch)
tree57bd79659e7f6862429527509385c95663b5c33b /lib/libm/common_source/expm1.c
parente1ec4d77dcf9547ad4c02a371fcae1d9f176c338 (diff)
downloadFreeBSD-src-be2cf84b24905468b296d0b27d7c0459acd4dec8.zip
FreeBSD-src-be2cf84b24905468b296d0b27d7c0459acd4dec8.tar.gz
Removed all files in libm except README-FREEBSD and files needed to
implement tgamma().
Diffstat (limited to 'lib/libm/common_source/expm1.c')
-rw-r--r--lib/libm/common_source/expm1.c170
1 files changed, 0 insertions, 170 deletions
diff --git a/lib/libm/common_source/expm1.c b/lib/libm/common_source/expm1.c
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--- a/lib/libm/common_source/expm1.c
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-/*
- * 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.
- */
-
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#ifndef lint
-static char sccsid[] = "@(#)expm1.c 8.1 (Berkeley) 6/4/93";
-#endif /* not lint */
-
-/* EXPM1(X)
- * RETURN THE EXPONENTIAL OF X MINUS ONE
- * DOUBLE PRECISION (IEEE 53 BITS, VAX D FORMAT 56 BITS)
- * CODED IN C BY K.C. NG, 1/19/85;
- * REVISED BY K.C. NG on 2/6/85, 3/7/85, 3/21/85, 4/16/85.
- *
- * Required system supported functions:
- * scalb(x,n)
- * copysign(x,y)
- * finite(x)
- *
- * Kernel function:
- * exp__E(x,c)
- *
- * Method:
- * 1. Argument Reduction: given the input x, find r and integer k such
- * that
- * x = k*ln2 + r, |r| <= 0.5*ln2 .
- * r will be represented as r := z+c for better accuracy.
- *
- * 2. Compute EXPM1(r)=exp(r)-1 by
- *
- * EXPM1(r=z+c) := z + exp__E(z,c)
- *
- * 3. EXPM1(x) = 2^k * ( EXPM1(r) + 1-2^-k ).
- *
- * Remarks:
- * 1. When k=1 and z < -0.25, we use the following formula for
- * better accuracy:
- * EXPM1(x) = 2 * ( (z+0.5) + exp__E(z,c) )
- * 2. To avoid rounding error in 1-2^-k where k is large, we use
- * EXPM1(x) = 2^k * { [z+(exp__E(z,c)-2^-k )] + 1 }
- * when k>56.
- *
- * Special cases:
- * EXPM1(INF) is INF, EXPM1(NaN) is NaN;
- * EXPM1(-INF)= -1;
- * for finite argument, only EXPM1(0)=0 is exact.
- *
- * Accuracy:
- * EXPM1(x) returns the exact (exp(x)-1) nearly rounded. In a test run with
- * 1,166,000 random arguments on a VAX, the maximum observed error was
- * .872 ulps (units of 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(ln2hi, 6.9314718055829871446E-1 ,7217,4031,0000,f7d0, 0, .B17217F7D00000)
-vc(ln2lo, 1.6465949582897081279E-12 ,bcd5,2ce7,d9cc,e4f1, -39, .E7BCD5E4F1D9CC)
-vc(lnhuge, 9.4961163736712506989E1 ,ec1d,43bd,9010,a73e, 7, .BDEC1DA73E9010)
-vc(invln2, 1.4426950408889634148E0 ,aa3b,40b8,17f1,295c, 1, .B8AA3B295C17F1)
-
-ic(ln2hi, 6.9314718036912381649E-1, -1, 1.62E42FEE00000)
-ic(ln2lo, 1.9082149292705877000E-10, -33, 1.A39EF35793C76)
-ic(lnhuge, 7.1602103751842355450E2, 9, 1.6602B15B7ECF2)
-ic(invln2, 1.4426950408889633870E0, 0, 1.71547652B82FE)
-
-#ifdef vccast
-#define ln2hi vccast(ln2hi)
-#define ln2lo vccast(ln2lo)
-#define lnhuge vccast(lnhuge)
-#define invln2 vccast(invln2)
-#endif
-
-double expm1(x)
-double x;
-{
- const static double one=1.0, half=1.0/2.0;
- double z,hi,lo,c;
- int k;
-#if defined(vax)||defined(tahoe)
- static prec=56;
-#else /* defined(vax)||defined(tahoe) */
- static prec=53;
-#endif /* defined(vax)||defined(tahoe) */
-
-#if !defined(vax)&&!defined(tahoe)
- if(x!=x) return(x); /* x is NaN */
-#endif /* !defined(vax)&&!defined(tahoe) */
-
- if( x <= lnhuge ) {
- if( x >= -40.0 ) {
-
- /* argument reduction : x - k*ln2 */
- k= invln2 *x+copysign(0.5,x); /* k=NINT(x/ln2) */
- hi=x-k*ln2hi ;
- z=hi-(lo=k*ln2lo);
- c=(hi-z)-lo;
-
- if(k==0) return(z+__exp__E(z,c));
- if(k==1)
- if(z< -0.25)
- {x=z+half;x +=__exp__E(z,c); return(x+x);}
- else
- {z+=__exp__E(z,c); x=half+z; return(x+x);}
- /* end of k=1 */
-
- else {
- if(k<=prec)
- { x=one-scalb(one,-k); z += __exp__E(z,c);}
- else if(k<100)
- { x = __exp__E(z,c)-scalb(one,-k); x+=z; z=one;}
- else
- { x = __exp__E(z,c)+z; z=one;}
-
- return (scalb(x+z,k));
- }
- }
- /* end of x > lnunfl */
-
- else
- /* expm1(-big#) rounded to -1 (inexact) */
- if(finite(x))
- { ln2hi+ln2lo; return(-one);}
-
- /* expm1(-INF) is -1 */
- else return(-one);
- }
- /* end of x < lnhuge */
-
- else
- /* expm1(INF) is INF, expm1(+big#) overflows to INF */
- return( finite(x) ? scalb(one,5000) : x);
-}
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