1 /* IEEE754 floating point arithmetic
2 * double precision: common utilities
3 */
4 /*
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
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_flong(s64 x)30 ieee754dp ieee754dp_flong(s64 x)
31 {
32 u64 xm;
33 int xe;
34 int xs;
35
36 CLEARCX;
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 == (1ULL << 63))
48 xm = (1ULL << 63); /* max neg can't be safely negated */
49 else
50 xm = -x;
51 } else {
52 xm = x;
53 }
54
55 /* normalize */
56 xe = DP_MBITS + 3;
57 if (xm >> (DP_MBITS + 1 + 3)) {
58 /* shunt out overflow bits */
59 while (xm >> (DP_MBITS + 1 + 3)) {
60 XDPSRSX1();
61 }
62 } else {
63 /* normalize in grs extended double precision */
64 while ((xm >> (DP_MBITS + 3)) == 0) {
65 xm <<= 1;
66 xe--;
67 }
68 }
69 DPNORMRET1(xs, xe, xm, "dp_flong", x);
70 }
71
ieee754dp_fulong(u64 u)72 ieee754dp ieee754dp_fulong(u64 u)
73 {
74 if ((s64) u < 0)
75 return ieee754dp_add(ieee754dp_1e63(),
76 ieee754dp_flong(u & ~(1ULL << 63)));
77 return ieee754dp_flong(u);
78 }
79