1/* $NetBSD: divsfm.c,v 1.4 2007/02/22 05:46:29 thorpej Exp $ */ 2 3/* $OpenBSD: divsfm.c,v 1.4 2001/03/29 03:58:17 mickey Exp $ */ 4 5/* 6 * Copyright 1996 1995 by Open Software Foundation, Inc. 7 * All Rights Reserved 8 * 9 * Permission to use, copy, modify, and distribute this software and 10 * its documentation for any purpose and without fee is hereby granted, 11 * provided that the above copyright notice appears in all copies and 12 * that both the copyright notice and this permission notice appear in 13 * supporting documentation. 14 * 15 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 16 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 17 * FOR A PARTICULAR PURPOSE. 18 * 19 * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR 20 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 21 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, 22 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 23 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 24 * 25 */ 26/* 27 * pmk1.1 28 */ 29/* 30 * (c) Copyright 1986 HEWLETT-PACKARD COMPANY 31 * 32 * To anyone who acknowledges that this file is provided "AS IS" 33 * without any express or implied warranty: 34 * permission to use, copy, modify, and distribute this file 35 * for any purpose is hereby granted without fee, provided that 36 * the above copyright notice and this notice appears in all 37 * copies, and that the name of Hewlett-Packard Company not be 38 * used in advertising or publicity pertaining to distribution 39 * of the software without specific, written prior permission. 40 * Hewlett-Packard Company makes no representations about the 41 * suitability of this software for any purpose. 42 */ 43 44#include <sys/cdefs.h> 45__KERNEL_RCSID(0, "$NetBSD: divsfm.c,v 1.4 2007/02/22 05:46:29 thorpej Exp $"); 46 47#include "md.h" 48 49void 50divsfm(int opnd1, int opnd2, struct mdsfu_register *result) 51{ 52 register int sign, op1_sign; 53 54 /* check divisor for zero */ 55 if (opnd2 == 0) { 56 overflow = true; 57 return; 58 } 59 60 /* get sign of result */ 61 sign = opnd1 ^ opnd2; 62 63 /* get absolute value of operands */ 64 if (opnd1 < 0) { 65 opnd1 = -opnd1; 66 op1_sign = true; 67 } 68 else op1_sign = false; 69 if (opnd2 < 0) opnd2 = -opnd2; 70 71 /* 72 * check for overflow 73 * 74 * if abs(opnd1) < 0, then opnd1 = -2**31 75 * and abs(opnd1) >= abs(opnd2) always 76 */ 77 if (opnd1 >= opnd2 || opnd1 < 0) { 78 /* check for opnd2 = -2**31 */ 79 if (opnd2 < 0 && opnd1 != opnd2) { 80 result_hi = 0; /* remainder = 0 */ 81 result_lo = opnd1 << 1; 82 } 83 else { 84 overflow = true; 85 return; 86 } 87 } 88 else { 89 /* do the divide */ 90 divu(opnd1,0,opnd2,result); 91 92 /* return positive residue */ 93 if (op1_sign && result_hi) { 94 result_hi = opnd2 - result_hi; 95 result_lo++; 96 } 97 } 98 99 /* check for overflow */ 100 if (result_lo < 0) { 101 overflow = true; 102 return; 103 } 104 overflow = false; 105 106 /* return appropriately signed result */ 107 if (sign<0) result_lo = -result_lo; 108 return; 109} 110