[linux-2.6-block.git] / arch / mips / math-emu / sp_flong.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_flong(s64 x)
{
	u64 xm;		/* <--- need 64-bit mantissa temp */
	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 == (1ULL << 63))
			xm = (1ULL << 63);	/* 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);
}
Commit	Line	Data
1da177e4 LT	1	/* IEEE754 floating point arithmetic
	2	* single precision
	3	*/
	4	/*
	5	* MIPS floating point support
	6	* Copyright (C) 1994-2000 Algorithmics Ltd.
1da177e4	7	*
1da177e4 LT	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.
	11	*
	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
	15	* for more details.
	16	*
	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.,
3f7cac41	19	* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1da177e4 LT	20	*/
1da177e4 LT	21
1da177e4 LT	22	#include "ieee754sp.h"
1da177e4 LT	23
2209bcb1	24	union ieee754sp ieee754sp_flong(s64 x)
1da177e4	25	{
ecf52d3c AN	26	u64 xm; /* <--- need 64-bit mantissa temp */
	27	int xe;
	28	int xs;
1da177e4	29
9e8bad1f	30	ieee754_clearcx();
1da177e4	31
1da177e4 LT	32	if (x == 0)
	33	return ieee754sp_zero(0);
	34	if (x == 1 \|\| x == -1)
	35	return ieee754sp_one(x < 0);
	36	if (x == 10 \|\| x == -10)
	37	return ieee754sp_ten(x < 0);
	38
	39	xs = (x < 0);
	40	if (xs) {
	41	if (x == (1ULL << 63))
	42	xm = (1ULL << 63); /* max neg can't be safely negated */
	43	else
	44	xm = -x;
	45	} else {
	46	xm = x;
	47	}
ad8fb553	48	xe = SP_FBITS + 3;
1da177e4	49
ad8fb553	50	if (xm >> (SP_FBITS + 1 + 3)) {
1da177e4 LT	51	/* shunt out overflow bits
1da177e4 LT	52	*/
ad8fb553	53	while (xm >> (SP_FBITS + 1 + 3)) {
1da177e4 LT	54	SPXSRSX1();
	55	}
	56	} else {
	57	/* normalize in grs extended single precision */
ad8fb553	58	while ((xm >> (SP_FBITS + 3)) == 0) {
1da177e4 LT	59	xm <<= 1;
	60	xe--;
	61	}
	62	}
90efba36	63	return ieee754sp_format(xs, xe, xm);
1da177e4	64	}