mirror of https://github.com/macssh/macssh.git
59 lines
1.6 KiB
C
Executable File
59 lines
1.6 KiB
C
Executable File
/* Utilities for MPFR developers, not exported.
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Copyright (C) 1999 PolKA project, Inria Lorraine and Loria
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This file is part of the MPFR Library.
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The MPFR Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Library General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at your
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option) any later version.
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The MPFR Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
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License for more details.
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You should have received a copy of the GNU Library General Public License
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along with the MPFR Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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MA 02111-1307, USA. */
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#include <math.h>
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/* generate a random double using the whole range of possible values,
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including denormalized numbers, NaN, infinities, ... */
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double drand()
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{
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volatile double d; int *i;
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i = (int*) &d;
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i[0] = mrand48();
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i[1] = mrand48();
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return d;
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}
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/* returns the number of ulp's between a and b */
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int ulp(a,b) double a,b;
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{
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double eps=1.1102230246251565404e-16; /* 2^(-53) */
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if (a==0.0) {
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if (b==0.0) return 0;
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else if (b<0.0) return 2147483647;
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else return -2147483647;
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}
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b = (a-b)/a;
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if (b>0)
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return (int) floor(b/eps);
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else
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return (int) ceil(b/eps);
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}
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/* return double m*2^e */
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double dbl(m,e) double m; int e;
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{
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if (e>=0) while (e-->0) m *= 2.0;
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else while (e++<0) m /= 2.0;
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return m;
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}
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