[linux-2.6-block.git] / arch / mips / math-emu / dp_fsp.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 "ieee754sp.h"
#include "ieee754dp.h"

union ieee754dp ieee754dp_fsp(union ieee754sp x)
{
	COMPXSP;

	EXPLODEXSP;

	ieee754_clearcx();

	FLUSHXSP;

	switch (xc) {
	case IEEE754_CLASS_SNAN:
		ieee754_setcx(IEEE754_INVALID_OPERATION);
		return ieee754dp_nanxcpt(ieee754dp_indef());

	case IEEE754_CLASS_QNAN:
		return ieee754dp_nanxcpt(builddp(xs,
						 DP_EMAX + 1 + DP_EBIAS,
						 ((u64) xm
						  << (DP_FBITS -
						      SP_FBITS))));
	case IEEE754_CLASS_INF:
		return ieee754dp_inf(xs);

	case IEEE754_CLASS_ZERO:
		return ieee754dp_zero(xs);

	case IEEE754_CLASS_DNORM:
		/* normalize */
		while ((xm >> SP_FBITS) == 0) {
			xm <<= 1;
			xe--;
		}
		break;

	case IEEE754_CLASS_NORM:
		break;
	}

	/*
	 * Can't possibly overflow,underflow, or need rounding
	 */

	/* drop the hidden bit */
	xm &= ~SP_HIDDEN_BIT;

	return builddp(xs, xe + DP_EBIAS,
		       (u64) xm << (DP_FBITS - SP_FBITS));
}
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
b3a7ad2b	22	#include "ieee754sp.h"
1da177e4 LT	23	#include "ieee754dp.h"
1da177e4 LT	24
2209bcb1	25	union ieee754dp ieee754dp_fsp(union ieee754sp x)
1da177e4 LT	26	{
	27	COMPXSP;
	28
	29	EXPLODEXSP;
	30
9e8bad1f	31	ieee754_clearcx();
1da177e4 LT	32
	33	FLUSHXSP;
	34
	35	switch (xc) {
	36	case IEEE754_CLASS_SNAN:
9e8bad1f	37	ieee754_setcx(IEEE754_INVALID_OPERATION);
90efba36	38	return ieee754dp_nanxcpt(ieee754dp_indef());
3f7cac41	39
1da177e4 LT	40	case IEEE754_CLASS_QNAN:
	41	return ieee754dp_nanxcpt(builddp(xs,
	42	DP_EMAX + 1 + DP_EBIAS,
	43	((u64) xm
ad8fb553	44	<< (DP_FBITS -
90efba36	45	SP_FBITS))));
1da177e4 LT	46	case IEEE754_CLASS_INF:
1da177e4 LT	47	return ieee754dp_inf(xs);
3f7cac41	48
1da177e4 LT	49	case IEEE754_CLASS_ZERO:
1da177e4 LT	50	return ieee754dp_zero(xs);
3f7cac41	51
1da177e4 LT	52	case IEEE754_CLASS_DNORM:
1da177e4 LT	53	/* normalize */
ad8fb553	54	while ((xm >> SP_FBITS) == 0) {
1da177e4 LT	55	xm <<= 1;
	56	xe--;
	57	}
	58	break;
3f7cac41	59
1da177e4 LT	60	case IEEE754_CLASS_NORM:
	61	break;
	62	}
	63
3f7cac41 RB	64	/*
3f7cac41 RB	65	* Can't possibly overflow,underflow, or need rounding
1da177e4 LT	66	*/
	67
	68	/* drop the hidden bit */
	69	xm &= ~SP_HIDDEN_BIT;
	70
	71	return builddp(xs, xe + DP_EBIAS,
ad8fb553	72	(u64) xm << (DP_FBITS - SP_FBITS));
1da177e4	73	}