[deliverable/linux.git] / arch / mips / math-emu / dp_fint.c

/* IEEE754 floating point arithmetic
 * double precision: common utilities
 */
/*
 * 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 "ieee754dp.h"

union ieee754dp ieee754dp_fint(int x)
{
	u64 xm;
	int xe;
	int xs;

	ieee754_clearcx();

	if (x == 0)
		return ieee754dp_zero(0);
	if (x == 1 || x == -1)
		return ieee754dp_one(x < 0);
	if (x == 10 || x == -10)
		return ieee754dp_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;
	}

	/* normalize - result can never be inexact or overflow */
	xe = DP_FBITS;
	while ((xm >> DP_FBITS) == 0) {
		xm <<= 1;
		xe--;
	}
	return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT);
}
Commit	Line	Data
1da177e4 LT	1	/* IEEE754 floating point arithmetic
	2	* double precision: common utilities
	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 "ieee754dp.h"
1da177e4 LT	23
2209bcb1	24	union ieee754dp ieee754dp_fint(int x)
1da177e4	25	{
ecf52d3c AN	26	u64 xm;
	27	int xe;
	28	int xs;
1da177e4	29
9e8bad1f	30	ieee754_clearcx();
1da177e4	31
1da177e4 LT	32	if (x == 0)
	33	return ieee754dp_zero(0);
	34	if (x == 1 \|\| x == -1)
	35	return ieee754dp_one(x < 0);
	36	if (x == 10 \|\| x == -10)
	37	return ieee754dp_ten(x < 0);
	38
	39	xs = (x < 0);
	40	if (xs) {
	41	if (x == (1 << 31))
	42	xm = ((unsigned) 1 << 31); /* max neg can't be safely negated */
	43	else
	44	xm = -x;
	45	} else {
	46	xm = x;
	47	}
	48
1da177e4	49	/* normalize - result can never be inexact or overflow */
ad8fb553 RB	50	xe = DP_FBITS;
ad8fb553 RB	51	while ((xm >> DP_FBITS) == 0) {
1da177e4 LT	52	xm <<= 1;
	53	xe--;
	54	}
	55	return builddp(xs, xe + DP_EBIAS, xm & ~DP_HIDDEN_BIT);
1da177e4	56	}