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/* auxiliary functions for MPFR tests.
Copyright (C) 1999-2000 Free Software Foundation.
This file is part of the MPFR Library.
The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
The MPFR Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
License for more details.
You should have received a copy of the GNU Library General Public License
along with the MPFR Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include <math.h>
#ifdef __mips
#include <sys/fpu.h>
#endif
#if defined (hpux)
#define srandom srand48
#define random mrand48
#endif
double drand _PROTO ((void));
int ulp _PROTO ((double, double));
double dbl _PROTO ((double, int));
double Ulp _PROTO ((double));
#define MINNORM 2.2250738585072013831e-308 /* 2^(-1022), smallest normalized */
#define MAXNORM 1.7976931348623157081e308 /* 2^(1023)*(2-2^(-52)) */
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define ABS(x) (((x)>0) ? (x) : (-x))
/* generate a random double using the whole range of possible values,
including denormalized numbers, NaN, infinities, ... */
double drand ()
{
double d; int *i, expo;
i = (int*) &d;
d = 1.0;
if (i[0]==0) expo=1; /* little endian, exponent in i[1] */
else expo=0;
i[0] = lrand48();
i[1] = lrand48();
while (i[expo]>=2146435072) i[expo] = lrand48(); /* avoids NaNs */
if (lrand48()%2 && !isnan(d)) d=-d; /* generates negative numbers */
return d;
}
/* returns ulp(x) for x a 'normal' double-precision number */
double Ulp (double x)
{
double y, eps;
if (x < 0) x = -x;
y = x * 2.220446049250313080847263336181640625e-16 ; /* x / 2^52 */
/* as ulp(x) <= y = x/2^52 < 2*ulp(x),
we have x + ulp(x) <= x + y <= x + 2*ulp(x),
therefore o(x + y) = x + ulp(x) or x + 2*ulp(x) */
eps = x + y;
eps = eps - x; /* ulp(x) or 2*ulp(x) */
return (eps > y) ? 0.5 * eps : eps;
}
/* returns the number of ulp's between a and b */
int ulp (double a, double b)
{
if (a==0.0) {
if (b==0.0) return 0;
else if (b<0.0) return 2147483647;
else return -2147483647;
}
return (a-b)/Ulp(a);
}
/* return double m*2^e */
double dbl (double m, int e)
{
if (e>=0) while (e-->0) m *= 2.0;
else while (e++<0) m /= 2.0;
return m;
}
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