1 /* $NetBSD: divsfm.c,v 1.1 2002/06/05 01:04:24 fredette 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 45 #include "md.h" 46 47 void 48 divsfm(opnd1,opnd2,result) 49 50 int opnd1, opnd2; 51 struct mdsfu_register *result; 52 { 53 register int sign, op1_sign; 54 55 /* check divisor for zero */ 56 if (opnd2 == 0) { 57 overflow = TRUE; 58 return; 59 } 60 61 /* get sign of result */ 62 sign = opnd1 ^ opnd2; 63 64 /* get absolute value of operands */ 65 if (opnd1 < 0) { 66 opnd1 = -opnd1; 67 op1_sign = TRUE; 68 } 69 else op1_sign = FALSE; 70 if (opnd2 < 0) opnd2 = -opnd2; 71 72 /* 73 * check for overflow 74 * 75 * if abs(opnd1) < 0, then opnd1 = -2**31 76 * and abs(opnd1) >= abs(opnd2) always 77 */ 78 if (opnd1 >= opnd2 || opnd1 < 0) { 79 /* check for opnd2 = -2**31 */ 80 if (opnd2 < 0 && opnd1 != opnd2) { 81 result_hi = 0; /* remainder = 0 */ 82 result_lo = opnd1 << 1; 83 } 84 else { 85 overflow = TRUE; 86 return; 87 } 88 } 89 else { 90 /* do the divide */ 91 divu(opnd1,0,opnd2,result); 92 93 /* return positive residue */ 94 if (op1_sign && result_hi) { 95 result_hi = opnd2 - result_hi; 96 result_lo++; 97 } 98 } 99 100 /* check for overflow */ 101 if (result_lo < 0) { 102 overflow = TRUE; 103 return; 104 } 105 overflow = FALSE; 106 107 /* return appropriately signed result */ 108 if (sign<0) result_lo = -result_lo; 109 return; 110 } 111