// Copyright (C) 2001 MandrakeSoft S.A. // // MandrakeSoft S.A. // 43, rue d'Aboukir // 75002 Paris - France // http://www.linux-mandrake.com/ // http://www.mandrakesoft.com/ // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #include "bochs.h" void BX_CPU_C::MUL_ALEb(BxInstruction_t *i) { Bit8u op2, op1; Bit16u product_16; Boolean temp_flag; op1 = AL; /* op2 is a register or memory reference */ if (i->mod == 0xc0) { op2 = BX_READ_8BIT_REG(i->rm); } else { /* pointer, segment address pair */ read_virtual_byte(i->seg, i->rm_addr, &op2); } product_16 = op1 * op2; /* set EFLAGS: * MUL affects the following flags: C,O */ temp_flag = ((product_16 & 0xFF00) != 0); SET_FLAGS_OxxxxC(temp_flag, temp_flag); /* now write product back to destination */ AX = product_16; } void BX_CPU_C::IMUL_ALEb(BxInstruction_t *i) { Bit8s op2, op1; Bit16s product_16; Bit16u upper_bits; op1 = AL; /* op2 is a register or memory reference */ if (i->mod == 0xc0) { op2 = BX_READ_8BIT_REG(i->rm); } else { /* pointer, segment address pair */ read_virtual_byte(i->seg, i->rm_addr, (Bit8u *) &op2); } product_16 = op1 * op2; /* now write product back to destination */ AX = product_16; /* set EFLAGS: * IMUL affects the following flags: C,O * IMUL r/m8: condition for clearing CF & OF: * AL = sign-extend of AL to 16 bits */ upper_bits = AX & 0xff80; if (upper_bits==0xff80 || upper_bits==0x0000) { SET_FLAGS_OxxxxC(0, 0); } else { SET_FLAGS_OxxxxC(1, 1); } } void BX_CPU_C::DIV_ALEb(BxInstruction_t *i) { Bit8u op2, quotient_8l, remainder_8; Bit16u quotient_16, op1; op1 = AX; /* op2 is a register or memory reference */ if (i->mod == 0xc0) { op2 = BX_READ_8BIT_REG(i->rm); } else { /* pointer, segment address pair */ read_virtual_byte(i->seg, i->rm_addr, &op2); } if (op2 == 0) { exception(BX_DE_EXCEPTION, 0, 0); } quotient_16 = op1 / op2; remainder_8 = op1 % op2; quotient_8l = quotient_16 & 0xFF; if (quotient_16 != quotient_8l) { exception(BX_DE_EXCEPTION, 0, 0); } /* set EFLAGS: * DIV affects the following flags: O,S,Z,A,P,C are undefined */ #if INTEL_DIV_FLAG_BUG == 1 set_CF(1); #endif /* now write quotient back to destination */ AL = quotient_8l; AH = remainder_8; } void BX_CPU_C::IDIV_ALEb(BxInstruction_t *i) { Bit8s op2, quotient_8l, remainder_8; Bit16s quotient_16, op1; op1 = AX; /* op2 is a register or memory reference */ if (i->mod == 0xc0) { op2 = BX_READ_8BIT_REG(i->rm); } else { /* pointer, segment address pair */ read_virtual_byte(i->seg, i->rm_addr, (Bit8u *) &op2); } if (op2 == 0) { exception(BX_DE_EXCEPTION, 0, 0); } quotient_16 = op1 / op2; remainder_8 = op1 % op2; quotient_8l = quotient_16 & 0xFF; if (quotient_16 != quotient_8l) { bx_printf("quotient_16: %04x, remainder_8: %02x, quotient_8l: %02x\n", (unsigned) quotient_16, (unsigned) remainder_8, (unsigned) quotient_8l); AL = quotient_8l; AH = remainder_8; bx_printf("AH: %02x, AL: %02x\n", (unsigned) AH, (unsigned) AL); exception(BX_DE_EXCEPTION, 0, 0); } /* set EFLAGS: * DIV affects the following flags: O,S,Z,A,P,C are undefined */ #if INTEL_DIV_FLAG_BUG == 1 set_CF(1); #endif /* now write quotient back to destination */ AL = quotient_8l; AH = remainder_8; }