66 lines
1.5 KiB
C
66 lines
1.5 KiB
C
|
/* IEEE754 floating point arithmetic
|
||
|
|
* single precision
|
||
|
|
*/
|
||
|
|
/*
|
||
|
|
* MIPS floating point support
|
||
|
|
* Copyright (C) 1994-2000 Algorithmics Ltd.
|
||
|
|
*
|
||
|
|
* 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.,
|
||
|
|
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "ieee754sp.h"
|
||
|
|
|
||
|
|
union ieee754sp ieee754sp_fint(int x)
|
||
|
|
{
|
||
|
|
unsigned xm;
|
||
|
|
int xe;
|
||
|
|
int xs;
|
||
|
|
|
||
|
|
ieee754_clearcx();
|
||
|
|
|
||
|
|
if (x == 0)
|
||
|
|
return ieee754sp_zero(0);
|
||
|
|
if (x == 1 || x == -1)
|
||
|
|
return ieee754sp_one(x < 0);
|
||
|
|
if (x == 10 || x == -10)
|
||
|
|
return ieee754sp_ten(x < 0);
|
||
|
|
|
||
|
|
xs = (x < 0);
|
||
|
|
if (xs) {
|
||
|
|
if (x == (1 << 31))
|
||
|
|
xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */
|
||
|
|
else
|
||
|
|
xm = -x;
|
||
|
|
} else {
|
||
|
|
xm = x;
|
||
|
|
}
|
||
|
|
xe = SP_FBITS + 3;
|
||
|
|
|
||
|
|
if (xm >> (SP_FBITS + 1 + 3)) {
|
||
|
|
/* shunt out overflow bits
|
||
|
|
*/
|
||
|
|
while (xm >> (SP_FBITS + 1 + 3)) {
|
||
|
|
SPXSRSX1();
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
/* normalize in grs extended single precision
|
||
|
|
*/
|
||
|
|
while ((xm >> (SP_FBITS + 3)) == 0) {
|
||
|
|
xm <<= 1;
|
||
|
|
xe--;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return ieee754sp_format(xs, xe, xm);
|
||
|
|
}
|