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Annotation of OpenXM_contrib/gmp/mpfr/mpfr-impl.h, Revision 1.1

1.1     ! maekawa     1: /* Utilities for MPFR developers, not exported.
        !             2:
        !             3: Copyright (C) 1999 PolKA project, Inria Lorraine and Loria
        !             4:
        !             5: This file is part of the MPFR Library.
        !             6:
        !             7: The MPFR Library is free software; you can redistribute it and/or modify
        !             8: it under the terms of the GNU Library General Public License as published by
        !             9: the Free Software Foundation; either version 2 of the License, or (at your
        !            10: option) any later version.
        !            11:
        !            12: The MPFR Library is distributed in the hope that it will be useful, but
        !            13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
        !            14: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
        !            15: License for more details.
        !            16:
        !            17: You should have received a copy of the GNU Library General Public License
        !            18: along with the MPFR Library; see the file COPYING.LIB.  If not, write to
        !            19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
        !            20: MA 02111-1307, USA. */
        !            21:
        !            22: #include <math.h>
        !            23:
        !            24: /* generate a random double using the whole range of possible values,
        !            25:    including denormalized numbers, NaN, infinities, ... */
        !            26: double drand()
        !            27: {
        !            28:   volatile double d; int *i;
        !            29:
        !            30:   i = (int*) &d;
        !            31:   i[0] = mrand48();
        !            32:   i[1] = mrand48();
        !            33:   return d;
        !            34: }
        !            35:
        !            36: /* returns the number of ulp's between a and b */
        !            37: int ulp(a,b) double a,b;
        !            38: {
        !            39:   double eps=1.1102230246251565404e-16; /* 2^(-53) */
        !            40:   if (a==0.0) {
        !            41:     if (b==0.0) return 0;
        !            42:     else if (b<0.0) return 2147483647;
        !            43:     else return -2147483647;
        !            44:   }
        !            45:   b = (a-b)/a;
        !            46:   if (b>0)
        !            47:     return (int) floor(b/eps);
        !            48:   else
        !            49:     return (int) ceil(b/eps);
        !            50: }
        !            51:
        !            52: /* return double m*2^e */
        !            53: double dbl(m,e) double m; int e;
        !            54: {
        !            55:   if (e>=0) while (e-->0) m *= 2.0;
        !            56:   else while (e++<0) m /= 2.0;
        !            57:   return m;
        !            58: }