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: }
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