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
30ieee754dp 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
72ieee754dp 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