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