1 /* $NetBSD: divsir.c,v 1.4 2007/02/22 05:46:29 thorpej Exp $ */ 2 3 /* $OpenBSD: divsir.c,v 1.5 2001/03/29 03:58:18 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: divsir.c,v 1.4 2007/02/22 05:46:29 thorpej Exp $"); 46 47 #include "md.h" 48 49 void 50 divsir(opnd1,opnd2,result) 51 52 int opnd1, opnd2; 53 struct mdsfu_register *result; 54 { 55 int sign, op1_sign; 56 57 /* check divisor for zero */ 58 if (opnd2 == 0) { 59 overflow = true; 60 return; 61 } 62 63 /* get sign of result */ 64 sign = opnd1 ^ opnd2; 65 66 /* get absolute value of operands */ 67 if (opnd1 < 0) { 68 opnd1 = -opnd1; 69 op1_sign = true; 70 } 71 else op1_sign = false; 72 if (opnd2 < 0) opnd2 = -opnd2; 73 74 /* check for opnd2 = -2**31 */ 75 if (opnd2 + opnd2 == 0) { 76 if (opnd1 == opnd2) { 77 result_hi = 0; /* remainder = 0 */ 78 result_lo = 1; 79 } 80 else { 81 result_hi = opnd1; /* remainder = opnd1 */ 82 result_lo = 0; 83 } 84 } 85 else { 86 /* do the divide */ 87 divu(0,opnd1,opnd2,result); 88 89 /* 90 * check for overflow 91 * 92 * at this point, the only way we can get overflow 93 * is with opnd1 = -2**31 and opnd2 = -1 94 */ 95 if (sign>0 && result_lo<0) { 96 overflow = true; 97 return; 98 } 99 } 100 overflow = false; 101 102 /* return appropriately signed remainder and result */ 103 if (op1_sign) result_hi = -result_hi; 104 if (sign<0) result_lo = -result_lo; 105 return; 106 } 107