1 /* $OpenBSD: divsir.c,v 1.6 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 /* @(#)divsir.c: Revision: 1.6.88.1 Date: 93/12/07 15:05:58 */ 16 17 #include "md.h" 18 19 void 20 divsir(opnd1,opnd2,result) 21 int opnd1, opnd2; 22 struct mdsfu_register *result; 23 { 24 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 /* check for opnd2 = -2**31 */ 44 if (opnd2 + opnd2 == 0) { 45 if (opnd1 == opnd2) { 46 result_hi = 0; /* remainder = 0 */ 47 result_lo = 1; 48 } 49 else { 50 result_hi = opnd1; /* remainder = opnd1 */ 51 result_lo = 0; 52 } 53 } 54 else { 55 /* do the divide */ 56 divu(0,opnd1,opnd2,result); 57 58 /* 59 * check for overflow 60 * 61 * at this point, the only way we can get overflow 62 * is with opnd1 = -2**31 and opnd2 = -1 63 */ 64 if (sign>0 && result_lo<0) { 65 overflow = TRUE; 66 return; 67 } 68 } 69 overflow = FALSE; 70 71 /* return appropriately signed remainder and result */ 72 if (op1_sign) result_hi = -result_hi; 73 if (sign<0) result_lo = -result_lo; 74 return; 75 } 76