1 /* IEEE754 floating point arithmetic
2 * double precision: common utilities
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
8 * ########################################################################
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.
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
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.
23 * ########################################################################
27 #include "ieee754dp.h"
29 int ieee754dp_tint(union ieee754dp x
)
39 case IEEE754_CLASS_SNAN
:
40 case IEEE754_CLASS_QNAN
:
41 case IEEE754_CLASS_INF
:
42 ieee754_setcx(IEEE754_INVALID_OPERATION
);
43 return ieee754si_indef();
44 case IEEE754_CLASS_ZERO
:
46 case IEEE754_CLASS_DNORM
:
47 case IEEE754_CLASS_NORM
:
51 /* Set invalid. We will only use overflow for floating
53 ieee754_setcx(IEEE754_INVALID_OPERATION
);
54 return ieee754si_indef();
59 } else if (xe
< DP_FBITS
) {
68 sticky
= residue
!= 0;
71 residue
= xm
<< (64 - DP_FBITS
+ xe
);
72 round
= (residue
>> 63) != 0;
73 sticky
= (residue
<< 1) != 0;
76 /* Note: At this point upper 32 bits of xm are guaranteed
78 odd
= (xm
& 0x1) != 0x0;
79 switch (ieee754_csr
.rm
) {
81 if (round
&& (sticky
|| odd
))
86 case IEEE754_RU
: /* toward +Infinity */
87 if ((round
|| sticky
) && !xs
)
90 case IEEE754_RD
: /* toward -Infinity */
91 if ((round
|| sticky
) && xs
)
95 /* look for valid corner case 0x80000000 */
96 if ((xm
>> 31) != 0 && (xs
== 0 || xm
!= 0x80000000)) {
97 /* This can happen after rounding */
98 ieee754_setcx(IEEE754_INVALID_OPERATION
);
99 return ieee754si_indef();
102 ieee754_setcx(IEEE754_INEXACT
);