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 s64 ieee754sp_tlong(union ieee754sp x)
32 COMPXDP; /* <-- need 64-bit mantissa tmp */
40 case IEEE754_CLASS_SNAN:
41 case IEEE754_CLASS_QNAN:
42 case IEEE754_CLASS_INF:
43 ieee754_setcx(IEEE754_INVALID_OPERATION);
44 return ieee754di_indef();
46 case IEEE754_CLASS_ZERO:
49 case IEEE754_CLASS_DNORM:
50 case IEEE754_CLASS_NORM:
54 /* look for valid corner case */
55 if (xe == 63 && xs && xm == SP_HIDDEN_BIT)
56 return -0x8000000000000000LL;
57 /* Set invalid. We will only use overflow for floating
59 ieee754_setcx(IEEE754_INVALID_OPERATION);
60 return ieee754di_indef();
65 } else if (xe < SP_FBITS) {
69 sticky = residue != 0;
72 residue = xm << (32 - SP_FBITS + xe);
73 round = (residue >> 31) != 0;
74 sticky = (residue << 1) != 0;
77 odd = (xm & 0x1) != 0x0;
78 switch (ieee754_csr.rm) {
80 if (round && (sticky || odd))
85 case FPU_CSR_RU: /* toward +Infinity */
86 if ((round || sticky) && !xs)
89 case FPU_CSR_RD: /* toward -Infinity */
90 if ((round || sticky) && xs)
94 if ((xm >> 63) != 0) {
95 /* This can happen after rounding */
96 ieee754_setcx(IEEE754_INVALID_OPERATION);
97 return ieee754di_indef();
100 ieee754_setcx(IEEE754_INEXACT);