84d9c625bf
- Fix for possible unset uid/gid in toproto
- Fix for default mtree style
- Update libelf
- Importing libexecinfo
- Resynchronize GCC, mpc, gmp, mpfr
- build.sh: Replace params with show-params.
This has been done as the make target has been renamed in the same
way, while a new target named params has been added. This new
target generates a file containing all the parameters, instead of
printing it on the console.
- Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
get getservbyport() out of the inner loop
Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
129 lines
4 KiB
C
129 lines
4 KiB
C
/* $NetBSD: n_cbrt.c,v 1.6 2013/11/24 14:49:00 martin Exp $ */
|
|
/*
|
|
* 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. 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[] = "@(#)cbrt.c 8.1 (Berkeley) 6/4/93";
|
|
#endif /* not lint */
|
|
|
|
#include <sys/cdefs.h>
|
|
|
|
/* kahan's cube root (53 bits IEEE double precision)
|
|
* for IEEE machines only
|
|
* coded in C by K.C. Ng, 4/30/85
|
|
*
|
|
* Accuracy:
|
|
* better than 0.667 ulps according to an error analysis. Maximum
|
|
* error observed was 0.666 ulps in an 1,000,000 random arguments test.
|
|
*
|
|
* Warning: this code is semi machine dependent; the ordering of words in
|
|
* a floating point number must be known in advance. I assume that the
|
|
* long interger at the address of a floating point number will be the
|
|
* leading 32 bits of that floating point number (i.e., sign, exponent,
|
|
* and the 20 most significant bits).
|
|
* On a National machine, it has different ordering; therefore, this code
|
|
* must be compiled with flag -DNATIONAL.
|
|
*/
|
|
#if !defined(__vax__)&&!defined(tahoe)
|
|
|
|
static const unsigned long
|
|
B1 = 715094163, /* B1 = (682-0.03306235651)*2**20 */
|
|
B2 = 696219795; /* B2 = (664-0.03306235651)*2**20 */
|
|
static const double
|
|
C= 19./35.,
|
|
D= -864./1225.,
|
|
E= 99./70.,
|
|
F= 45./28.,
|
|
G= 5./14.;
|
|
|
|
float
|
|
cbrtf(float x)
|
|
{
|
|
return (float)cbrt(x);
|
|
}
|
|
|
|
long double
|
|
cbrtl(long double x)
|
|
{
|
|
return cbrt((double)x);
|
|
}
|
|
|
|
double
|
|
cbrt(double x)
|
|
{
|
|
double r,s,t=0.0,w;
|
|
unsigned long *px = (unsigned long *) &x,
|
|
*pt = (unsigned long *) &t,
|
|
mexp,sign;
|
|
|
|
#ifdef national /* ordering of words in a floating points number */
|
|
const int n0=1,n1=0;
|
|
#else /* national */
|
|
const int n0=0,n1=1;
|
|
#endif /* national */
|
|
|
|
mexp=px[n0]&0x7ff00000;
|
|
if(mexp==0x7ff00000) return(x); /* cbrt(NaN,INF) is itself */
|
|
if(x==0.0) return(x); /* cbrt(0) is itself */
|
|
|
|
sign=px[n0]&0x80000000; /* sign= sign(x) */
|
|
px[n0] ^= sign; /* x=|x| */
|
|
|
|
|
|
/* rough cbrt to 5 bits */
|
|
if(mexp==0) /* subnormal number */
|
|
{pt[n0]=0x43500000; /* set t= 2**54 */
|
|
t*=x; pt[n0]=pt[n0]/3+B2;
|
|
}
|
|
else
|
|
pt[n0]=px[n0]/3+B1;
|
|
|
|
|
|
/* new cbrt to 23 bits, may be implemented in single precision */
|
|
r=t*t/x;
|
|
s=C+r*t;
|
|
t*=G+F/(s+E+D/s);
|
|
|
|
/* chopped to 20 bits and make it larger than cbrt(x) */
|
|
pt[n1]=0; pt[n0]+=0x00000001;
|
|
|
|
|
|
/* one step newton iteration to 53 bits with error less than 0.667 ulps */
|
|
s=t*t; /* t*t is exact */
|
|
r=x/s;
|
|
w=t+t;
|
|
r=(r-t)/(w+r); /* r-t is exact */
|
|
t=t+t*r;
|
|
|
|
|
|
/* retore the sign bit */
|
|
pt[n0] |= sign;
|
|
return(t);
|
|
}
|
|
#endif
|