File: /usr/src/linux/arch/mips64/math-emu/dp_tint.c

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 <linux/kernel.h>
29     #include "ieee754dp.h"
30     
31     int ieee754dp_tint(ieee754dp x)
32     {
33     	COMPXDP;
34     
35     	CLEARCX;
36     
37     	EXPLODEXDP;
38     
39     	switch (xc) {
40     	case IEEE754_CLASS_SNAN:
41     	case IEEE754_CLASS_QNAN:
42     		SETCX(IEEE754_INVALID_OPERATION);
43     		return ieee754si_xcpt(ieee754si_indef(), "fixdp", x);
44     	case IEEE754_CLASS_INF:
45     		SETCX(IEEE754_OVERFLOW);
46     		return ieee754si_xcpt(ieee754si_indef(), "fixdp", x);
47     	case IEEE754_CLASS_ZERO:
48     		return 0;
49     	case IEEE754_CLASS_DNORM:	/* much to small */
50     		SETCX(IEEE754_UNDERFLOW);
51     		return ieee754si_xcpt(0, "fixdp", x);
52     	case IEEE754_CLASS_NORM:
53     		break;
54     	}
55     	if (xe >= 31) {
56     		SETCX(IEEE754_OVERFLOW);
57     		return ieee754si_xcpt(ieee754si_indef(), "fix", x);
58     	}
59     	if (xe < 0) {
60     		SETCX(IEEE754_UNDERFLOW);
61     		return ieee754si_xcpt(0, "fix", x);
62     	}
63     	/* oh gawd */
64     	if (xe > DP_MBITS) {
65     		xm <<= xe - DP_MBITS;
66     	} else if (xe < DP_MBITS) {
67     		/* XXX no rounding 
68     		 */
69     		xm >>= DP_MBITS - xe;
70     	}
71     	if (xs)
72     		return -xm;
73     	else
74     		return xm;
75     }
76     
77     
78     unsigned int ieee754dp_tuns(ieee754dp x)
79     {
80     	ieee754dp hb = ieee754dp_1e31();
81     
82     	/* what if x < 0 ?? */
83     	if (ieee754dp_lt(x, hb))
84     		return (unsigned) ieee754dp_tint(x);
85     
86     	return (unsigned) ieee754dp_tint(ieee754dp_sub(x, hb)) |
87     	    ((unsigned) 1 << 31);
88     }
89