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divsir.c revision 1.1.4.2 
      1  1.1.4.2  gehenna /*	$NetBSD: divsir.c,v 1.1.4.2 2002/07/14 17:47:40 gehenna Exp $	*/
      2  1.1.4.2  gehenna 
      3  1.1.4.2  gehenna /*	$OpenBSD: divsir.c,v 1.5 2001/03/29 03:58:18 mickey Exp $	*/
      4  1.1.4.2  gehenna 
      5  1.1.4.2  gehenna /*
      6  1.1.4.2  gehenna  * Copyright 1996 1995 by Open Software Foundation, Inc.
      7  1.1.4.2  gehenna  *              All Rights Reserved
      8  1.1.4.2  gehenna  *
      9  1.1.4.2  gehenna  * Permission to use, copy, modify, and distribute this software and
     10  1.1.4.2  gehenna  * its documentation for any purpose and without fee is hereby granted,
     11  1.1.4.2  gehenna  * provided that the above copyright notice appears in all copies and
     12  1.1.4.2  gehenna  * that both the copyright notice and this permission notice appear in
     13  1.1.4.2  gehenna  * supporting documentation.
     14  1.1.4.2  gehenna  *
     15  1.1.4.2  gehenna  * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
     16  1.1.4.2  gehenna  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     17  1.1.4.2  gehenna  * FOR A PARTICULAR PURPOSE.
     18  1.1.4.2  gehenna  *
     19  1.1.4.2  gehenna  * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
     20  1.1.4.2  gehenna  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
     21  1.1.4.2  gehenna  * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
     22  1.1.4.2  gehenna  * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
     23  1.1.4.2  gehenna  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     24  1.1.4.2  gehenna  *
     25  1.1.4.2  gehenna  */
     26  1.1.4.2  gehenna /*
     27  1.1.4.2  gehenna  * pmk1.1
     28  1.1.4.2  gehenna  */
     29  1.1.4.2  gehenna /*
     30  1.1.4.2  gehenna  * (c) Copyright 1986 HEWLETT-PACKARD COMPANY
     31  1.1.4.2  gehenna  *
     32  1.1.4.2  gehenna  * To anyone who acknowledges that this file is provided "AS IS"
     33  1.1.4.2  gehenna  * without any express or implied warranty:
     34  1.1.4.2  gehenna  *     permission to use, copy, modify, and distribute this file
     35  1.1.4.2  gehenna  * for any purpose is hereby granted without fee, provided that
     36  1.1.4.2  gehenna  * the above copyright notice and this notice appears in all
     37  1.1.4.2  gehenna  * copies, and that the name of Hewlett-Packard Company not be
     38  1.1.4.2  gehenna  * used in advertising or publicity pertaining to distribution
     39  1.1.4.2  gehenna  * of the software without specific, written prior permission.
     40  1.1.4.2  gehenna  * Hewlett-Packard Company makes no representations about the
     41  1.1.4.2  gehenna  * suitability of this software for any purpose.
     42  1.1.4.2  gehenna  */
     43  1.1.4.2  gehenna 
     44  1.1.4.2  gehenna 
     45  1.1.4.2  gehenna #include "md.h"
     46  1.1.4.2  gehenna 
     47  1.1.4.2  gehenna void
     48  1.1.4.2  gehenna divsir(opnd1,opnd2,result)
     49  1.1.4.2  gehenna 
     50  1.1.4.2  gehenna int opnd1, opnd2;
     51  1.1.4.2  gehenna struct mdsfu_register *result;
     52  1.1.4.2  gehenna {
     53  1.1.4.2  gehenna 	int sign, op1_sign;
     54  1.1.4.2  gehenna 
     55  1.1.4.2  gehenna 	/* check divisor for zero */
     56  1.1.4.2  gehenna 	if (opnd2 == 0) {
     57  1.1.4.2  gehenna 		overflow = TRUE;
     58  1.1.4.2  gehenna 		return;
     59  1.1.4.2  gehenna 	}
     60  1.1.4.2  gehenna 
     61  1.1.4.2  gehenna 	/* get sign of result */
     62  1.1.4.2  gehenna 	sign = opnd1 ^ opnd2;
     63  1.1.4.2  gehenna 
     64  1.1.4.2  gehenna 	/* get absolute value of operands */
     65  1.1.4.2  gehenna 	if (opnd1 < 0) {
     66  1.1.4.2  gehenna 		opnd1 = -opnd1;
     67  1.1.4.2  gehenna 		op1_sign = TRUE;
     68  1.1.4.2  gehenna 	}
     69  1.1.4.2  gehenna 	else op1_sign = FALSE;
     70  1.1.4.2  gehenna 	if (opnd2 < 0) opnd2 = -opnd2;
     71  1.1.4.2  gehenna 
     72  1.1.4.2  gehenna 	/* check for opnd2 = -2**31 */
     73  1.1.4.2  gehenna 	if (opnd2 + opnd2 == 0) {
     74  1.1.4.2  gehenna 		if (opnd1 == opnd2) {
     75  1.1.4.2  gehenna 			result_hi = 0;    /* remainder = 0 */
     76  1.1.4.2  gehenna 			result_lo = 1;
     77  1.1.4.2  gehenna 		}
     78  1.1.4.2  gehenna 		else {
     79  1.1.4.2  gehenna 			result_hi = opnd1;  /* remainder = opnd1 */
     80  1.1.4.2  gehenna 			result_lo = 0;
     81  1.1.4.2  gehenna 		}
     82  1.1.4.2  gehenna 	}
     83  1.1.4.2  gehenna 	else {
     84  1.1.4.2  gehenna 		/* do the divide */
     85  1.1.4.2  gehenna 		divu(0,opnd1,opnd2,result);
     86  1.1.4.2  gehenna 
     87  1.1.4.2  gehenna 		/*
     88  1.1.4.2  gehenna 		 * check for overflow
     89  1.1.4.2  gehenna 		 *
     90  1.1.4.2  gehenna 		 * at this point, the only way we can get overflow
     91  1.1.4.2  gehenna 		 * is with opnd1 = -2**31 and opnd2 = -1
     92  1.1.4.2  gehenna 		 */
     93  1.1.4.2  gehenna 		if (sign>0 && result_lo<0) {
     94  1.1.4.2  gehenna 			overflow = TRUE;
     95  1.1.4.2  gehenna 			return;
     96  1.1.4.2  gehenna 		}
     97  1.1.4.2  gehenna 	}
     98  1.1.4.2  gehenna 	overflow = FALSE;
     99  1.1.4.2  gehenna 
    100  1.1.4.2  gehenna 	/* return appropriately signed remainder and result */
    101  1.1.4.2  gehenna 	if (op1_sign) result_hi = -result_hi;
    102  1.1.4.2  gehenna 	if (sign<0) result_lo = -result_lo;
    103  1.1.4.2  gehenna 	return;
    104  1.1.4.2  gehenna }
    105