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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [arch/] [mips/] [math-emu/] [dp_tint.c] - Blame information for rev 3

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/* IEEE754 floating point arithmetic
 * double precision: common utilities
 */
/*
 * MIPS floating point support
 * Copyright (C) 1994-2000 Algorithmics Ltd.
 * http://www.algor.co.uk
 *
 * ########################################################################
 *
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * ########################################################################
 */
 
 
#include <linux/kernel.h>
#include "ieee754dp.h"
 
int ieee754dp_tint(ieee754dp x)
{
        COMPXDP;
 
        CLEARCX;
 
        EXPLODEXDP;
        FLUSHXDP;
 
        switch (xc) {
        case IEEE754_CLASS_SNAN:
        case IEEE754_CLASS_QNAN:
        case IEEE754_CLASS_INF:
                SETCX(IEEE754_INVALID_OPERATION);
                return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);
        case IEEE754_CLASS_ZERO:
                return 0;
        case IEEE754_CLASS_DNORM:
        case IEEE754_CLASS_NORM:
                break;
        }
        if (xe > 31) {
                /* Set invalid. We will only use overflow for floating
                   point overflow */
                SETCX(IEEE754_INVALID_OPERATION);
                return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);
        }
        /* oh gawd */
        if (xe > DP_MBITS) {
                xm <<= xe - DP_MBITS;
        } else if (xe < DP_MBITS) {
                u64 residue;
                int round;
                int sticky;
                int odd;
 
                if (xe < -1) {
                        residue = xm;
                        round = 0;
                        sticky = residue != 0;
                        xm = 0;
                }
                else {
                        residue = xm << (64 - DP_MBITS + xe);
                        round = (residue >> 63) != 0;
                        sticky = (residue << 1) != 0;
                        xm >>= DP_MBITS - xe;
                }
                /* Note: At this point upper 32 bits of xm are guaranteed
                   to be zero */
                odd = (xm & 0x1) != 0x0;
                switch (ieee754_csr.rm) {
                case IEEE754_RN:
                        if (round && (sticky || odd))
                                xm++;
                        break;
                case IEEE754_RZ:
                        break;
                case IEEE754_RU:        /* toward +Infinity */
                        if ((round || sticky) && !xs)
                                xm++;
                        break;
                case IEEE754_RD:        /* toward -Infinity */
                        if ((round || sticky) && xs)
                                xm++;
                        break;
                }
                /* look for valid corner case 0x80000000 */
                if ((xm >> 31) != 0 && (xs == 0 || xm != 0x80000000)) {
                        /* This can happen after rounding */
                        SETCX(IEEE754_INVALID_OPERATION);
                        return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);
                }
                if (round || sticky)
                        SETCX(IEEE754_INEXACT);
        }
        if (xs)
                return -xm;
        else
                return xm;
}
 
 
unsigned int ieee754dp_tuns(ieee754dp x)
{
        ieee754dp hb = ieee754dp_1e31();
 
        /* what if x < 0 ?? */
        if (ieee754dp_lt(x, hb))
                return (unsigned) ieee754dp_tint(x);
 
        return (unsigned) ieee754dp_tint(ieee754dp_sub(x, hb)) |
            ((unsigned) 1 << 31);
}

Line No.	Rev	Author	Line
1	3	xianfeng	`/* 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 <linux/kernel.h>`
29			`#include "ieee754dp.h"`
30
31			`int ieee754dp_tint(ieee754dp x)`
32			`{`
33			`COMPXDP;`
34
35			`CLEARCX;`
36
37			`EXPLODEXDP;`
38			`FLUSHXDP;`
39
40			`switch (xc) {`
41			`case IEEE754_CLASS_SNAN:`
42			`case IEEE754_CLASS_QNAN:`
43			`case IEEE754_CLASS_INF:`
44			`SETCX(IEEE754_INVALID_OPERATION);`
45			`return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);`
46			`case IEEE754_CLASS_ZERO:`
47			`return 0;`
48			`case IEEE754_CLASS_DNORM:`
49			`case IEEE754_CLASS_NORM:`
50			`break;`
51			`}`
52			`if (xe > 31) {`
53			`/* Set invalid. We will only use overflow for floating`
54			`point overflow */`
55			`SETCX(IEEE754_INVALID_OPERATION);`
56			`return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);`
57			`}`
58			`/* oh gawd */`
59			`if (xe > DP_MBITS) {`
60			`xm <<= xe - DP_MBITS;`
61			`} else if (xe < DP_MBITS) {`
62			`u64 residue;`
63			`int round;`
64			`int sticky;`
65			`int odd;`
66
67			`if (xe < -1) {`
68			`residue = xm;`
69			`round = 0;`
70			`sticky = residue != 0;`
71			`xm = 0;`
72			`}`
73			`else {`
74			`residue = xm << (64 - DP_MBITS + xe);`
75			`round = (residue >> 63) != 0;`
76			`sticky = (residue << 1) != 0;`
77			`xm >>= DP_MBITS - xe;`
78			`}`
79			`/* Note: At this point upper 32 bits of xm are guaranteed`
80			`to be zero */`
81			`odd = (xm & 0x1) != 0x0;`
82			`switch (ieee754_csr.rm) {`
83			`case IEEE754_RN:`
84			`if (round && (sticky \|\| odd))`
85			`xm++;`
86			`break;`
87			`case IEEE754_RZ:`
88			`break;`
89			`case IEEE754_RU: /* toward +Infinity */`
90			`if ((round \|\| sticky) && !xs)`
91			`xm++;`
92			`break;`
93			`case IEEE754_RD: /* toward -Infinity */`
94			`if ((round \|\| sticky) && xs)`
95			`xm++;`
96			`break;`
97			`}`
98			`/* look for valid corner case 0x80000000 */`
99			`if ((xm >> 31) != 0 && (xs == 0 \|\| xm != 0x80000000)) {`
100			`/* This can happen after rounding */`
101			`SETCX(IEEE754_INVALID_OPERATION);`
102			`return ieee754si_xcpt(ieee754si_indef(), "dp_tint", x);`
103			`}`
104			`if (round \|\| sticky)`
105			`SETCX(IEEE754_INEXACT);`
106			`}`
107			`if (xs)`
108			`return -xm;`
109			`else`
110			`return xm;`
111			`}`
112
113
114			`unsigned int ieee754dp_tuns(ieee754dp x)`
115			`{`
116			`ieee754dp hb = ieee754dp_1e31();`
117
118			`/* what if x < 0 ?? */`
119			`if (ieee754dp_lt(x, hb))`
120			`return (unsigned) ieee754dp_tint(x);`
121
122			`return (unsigned) ieee754dp_tint(ieee754dp_sub(x, hb)) \|`
123			`((unsigned) 1 << 31);`
124			`}`

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Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [arch/] [mips/] [math-emu/] [dp_tint.c] - Blame information for rev 3