1 /* IEEE754 floating point arithmetic
5 * MIPS floating point support
6 * Copyright (C) 1994-2000 Algorithmics Ltd.
8 * This program is free software; you can distribute it and/or modify it
9 * under the terms of the GNU General Public License (Version 2) as
10 * published by the Free Software Foundation.
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
22 #include "ieee754sp.h"
23 #include "ieee754dp.h"
25 union ieee754sp
ieee754sp_fdp(union ieee754dp x
)
39 case IEEE754_CLASS_SNAN
:
40 ieee754_setcx(IEEE754_INVALID_OPERATION
);
41 return ieee754sp_nanxcpt(ieee754sp_indef());
43 case IEEE754_CLASS_QNAN
:
44 nan
= buildsp(xs
, SP_EMAX
+ 1 + SP_EBIAS
, (u32
)
45 (xm
>> (DP_FBITS
- SP_FBITS
)));
46 if (!ieee754sp_isnan(nan
))
47 nan
= ieee754sp_indef();
48 return ieee754sp_nanxcpt(nan
);
50 case IEEE754_CLASS_INF
:
51 return ieee754sp_inf(xs
);
53 case IEEE754_CLASS_ZERO
:
54 return ieee754sp_zero(xs
);
56 case IEEE754_CLASS_DNORM
:
57 /* can't possibly be sp representable */
58 ieee754_setcx(IEEE754_UNDERFLOW
);
59 ieee754_setcx(IEEE754_INEXACT
);
60 if ((ieee754_csr
.rm
== FPU_CSR_RU
&& !xs
) ||
61 (ieee754_csr
.rm
== FPU_CSR_RD
&& xs
))
62 return ieee754sp_mind(xs
);
63 return ieee754sp_zero(xs
);
65 case IEEE754_CLASS_NORM
:
70 * Convert from DP_FBITS to SP_FBITS+3 with sticky right shift.
72 rm
= (xm
>> (DP_FBITS
- (SP_FBITS
+ 3))) |
73 ((xm
<< (64 - (DP_FBITS
- (SP_FBITS
+ 3)))) != 0);
75 return ieee754sp_format(xs
, xe
, rm
);