MIPS: SB1250: Include correct header and fix a warning
[linux-2.6/linux-mips.git] / arch / mips / math-emu / dp_modf.c
blob25861a42c36f80b01e036e70b8d4dfd5f3c70694
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
9 * ########################################################################
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.
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.
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.
24 * ########################################################################
28 #include "ieee754dp.h"
30 /* modf function is always exact for a finite number
32 ieee754dp ieee754dp_modf(ieee754dp x, ieee754dp * ip)
34 COMPXDP;
36 CLEARCX;
38 EXPLODEXDP;
40 switch (xc) {
41 case IEEE754_CLASS_SNAN:
42 case IEEE754_CLASS_QNAN:
43 case IEEE754_CLASS_INF:
44 case IEEE754_CLASS_ZERO:
45 *ip = x;
46 return x;
47 case IEEE754_CLASS_DNORM:
48 /* far to small */
49 *ip = ieee754dp_zero(xs);
50 return x;
51 case IEEE754_CLASS_NORM:
52 break;
54 if (xe < 0) {
55 *ip = ieee754dp_zero(xs);
56 return x;
58 if (xe >= DP_MBITS) {
59 *ip = x;
60 return ieee754dp_zero(xs);
62 /* generate ipart mantissa by clearing bottom bits
64 *ip = builddp(xs, xe + DP_EBIAS,
65 ((xm >> (DP_MBITS - xe)) << (DP_MBITS - xe)) &
66 ~DP_HIDDEN_BIT);
68 /* generate fpart mantissa by clearing top bits
69 * and normalizing (must be able to normalize)
71 xm = (xm << (64 - (DP_MBITS - xe))) >> (64 - (DP_MBITS - xe));
72 if (xm == 0)
73 return ieee754dp_zero(xs);
75 while ((xm >> DP_MBITS) == 0) {
76 xm <<= 1;
77 xe--;
79 return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT);