1 /* $OpenBSD: divsfm.c,v 1.5 2002/05/07 22:19:30 mickey Exp $ */ 2 /* 3 (c) Copyright 1986 HEWLETT-PACKARD COMPANY 4 To anyone who acknowledges that this file is provided "AS IS" 5 without any express or implied warranty: 6 permission to use, copy, modify, and distribute this file 7 for any purpose is hereby granted without fee, provided that 8 the above copyright notice and this notice appears in all 9 copies, and that the name of Hewlett-Packard Company not be 10 used in advertising or publicity pertaining to distribution 11 of the software without specific, written prior permission. 12 Hewlett-Packard Company makes no representations about the 13 suitability of this software for any purpose. 14 */ 15 /* @(#)divsfm.c: Revision: 1.6.88.1 Date: 93/12/07 15:05:51 */ 16 17 #include "md.h" 18 19 void 20 divsfm(opnd1,opnd2,result) 21 int opnd1, opnd2; 22 struct mdsfu_register *result; 23 { 24 register int sign, op1_sign; 25 26 /* check divisor for zero */ 27 if (opnd2 == 0) { 28 overflow = TRUE; 29 return; 30 } 31 32 /* get sign of result */ 33 sign = opnd1 ^ opnd2; 34 35 /* get absolute value of operands */ 36 if (opnd1 < 0) { 37 opnd1 = -opnd1; 38 op1_sign = TRUE; 39 } 40 else op1_sign = FALSE; 41 if (opnd2 < 0) opnd2 = -opnd2; 42 43 /* 44 * check for overflow 45 * 46 * if abs(opnd1) < 0, then opnd1 = -2**31 47 * and abs(opnd1) >= abs(opnd2) always 48 */ 49 if (opnd1 >= opnd2 || opnd1 < 0) { 50 /* check for opnd2 = -2**31 */ 51 if (opnd2 < 0 && opnd1 != opnd2) { 52 result_hi = 0; /* remainder = 0 */ 53 result_lo = opnd1 << 1; 54 } 55 else { 56 overflow = TRUE; 57 return; 58 } 59 } 60 else { 61 /* do the divide */ 62 divu(opnd1,0,opnd2,result); 63 64 /* return positive residue */ 65 if (op1_sign && result_hi) { 66 result_hi = opnd2 - result_hi; 67 result_lo++; 68 } 69 } 70 71 /* check for overflow */ 72 if (result_lo < 0) { 73 overflow = TRUE; 74 return; 75 } 76 overflow = FALSE; 77 78 /* return appropriately signed result */ 79 if (sign<0) result_lo = -result_lo; 80 return; 81 } 82