1 /* IEEE754 floating point arithmetic
2 * double precision: common utilities
3 */
4 /*
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd. All rights reserved.
7 * http://www.algor.co.uk
8 *
9 * ########################################################################
10 *
11 * This program is free software; you can distribute it and/or modify it
12 * under the terms of the GNU General Public License (Version 2) as
13 * published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 * for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
23 *
24 * ########################################################################
25 */
26
27
28 #include "ieee754dp.h"
29
ieee754dp_fint(int x)30 ieee754dp ieee754dp_fint(int x)
31 {
32 COMPXDP;
33
34 CLEARCX;
35
36 xc = ( 0 ? xc : xc );
37
38 if (x == 0)
39 return ieee754dp_zero(0);
40 if (x == 1 || x == -1)
41 return ieee754dp_one(x < 0);
42 if (x == 10 || x == -10)
43 return ieee754dp_ten(x < 0);
44
45 xs = (x < 0);
46 if (xs) {
47 if (x == (1 << 31))
48 xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */
49 else
50 xm = -x;
51 } else {
52 xm = x;
53 }
54
55 #if 1
56 /* normalize - result can never be inexact or overflow */
57 xe = DP_MBITS;
58 while ((xm >> DP_MBITS) == 0) {
59 xm <<= 1;
60 xe--;
61 }
62 return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT);
63 #else
64 /* normalize */
65 xe = DP_MBITS + 3;
66 while ((xm >> (DP_MBITS + 3)) == 0) {
67 xm <<= 1;
68 xe--;
69 }
70 DPNORMRET1(xs, xe, xm, "fint", x);
71 #endif
72 }
73
ieee754dp_funs(unsigned int u)74 ieee754dp ieee754dp_funs(unsigned int u)
75 {
76 if ((int) u < 0)
77 return ieee754dp_add(ieee754dp_1e31(),
78 ieee754dp_fint(u & ~(1 << 31)));
79 return ieee754dp_fint(u);
80 }
81