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 *
8 * ########################################################################
9 *
10 * This program is free software; you can distribute it and/or modify it
11 * under the terms of the GNU General Public License (Version 2) as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 * for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * ########################################################################
24 */
25
26
27 #include "ieee754dp.h"
28
ieee754dp_flong(s64 x)29 ieee754dp ieee754dp_flong(s64 x)
30 {
31 u64 xm;
32 int xe;
33 int xs;
34
35 CLEARCX;
36
37 if (x == 0)
38 return ieee754dp_zero(0);
39 if (x == 1 || x == -1)
40 return ieee754dp_one(x < 0);
41 if (x == 10 || x == -10)
42 return ieee754dp_ten(x < 0);
43
44 xs = (x < 0);
45 if (xs) {
46 if (x == (1ULL << 63))
47 xm = (1ULL << 63); /* max neg can't be safely negated */
48 else
49 xm = -x;
50 } else {
51 xm = x;
52 }
53
54 /* normalize */
55 xe = DP_MBITS + 3;
56 if (xm >> (DP_MBITS + 1 + 3)) {
57 /* shunt out overflow bits */
58 while (xm >> (DP_MBITS + 1 + 3)) {
59 XDPSRSX1();
60 }
61 } else {
62 /* normalize in grs extended double precision */
63 while ((xm >> (DP_MBITS + 3)) == 0) {
64 xm <<= 1;
65 xe--;
66 }
67 }
68 DPNORMRET1(xs, xe, xm, "dp_flong", x);
69 }
70
ieee754dp_fulong(u64 u)71 ieee754dp ieee754dp_fulong(u64 u)
72 {
73 if ((s64) u < 0)
74 return ieee754dp_add(ieee754dp_1e63(),
75 ieee754dp_flong(u & ~(1ULL << 63)));
76 return ieee754dp_flong(u);
77 }
78