Annotation of OpenXM_contrib/gmp/mpfr/mpfr-impl.h, Revision 1.1.1.1
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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