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/////////////////////////////////////////////////////////////////////////

// $Id: mult8.cc 11313 2012-08-05 13:52:40Z sshwarts $

/////////////////////////////////////////////////////////////////////////

//

//  Copyright (C) 2001-2012  The Bochs Project

//

//  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., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA

/////////////////////////////////////////////////////////////////////////

#define NEED_CPU_REG_SHORTCUTS 1

#include "bochs.h"

#include "cpu.h"

#define LOG_THIS BX_CPU_THIS_PTR

BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::MUL_ALEbR(bxInstruction_c *i)

{

  Bit8u op1 = AL;

  Bit8u op2 = BX_READ_8BIT_REGx(i->src(), i->extend8bitL());

  Bit32u product_16 = ((Bit16u) op1) * ((Bit16u) op2);

  Bit8u product_8l = (product_16 & 0xFF);

  Bit8u product_8h =  product_16 >> 8;

  /* now write product back to destination */

  AX = product_16;

  /* set EFLAGS */

  SET_FLAGS_OSZAPC_LOGIC_8(product_8l);

  if(product_8h != 0)

  {

    ASSERT_FLAGS_OxxxxC();

  }

  BX_NEXT_INSTR(i);

}

BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::IMUL_ALEbR(bxInstruction_c *i)

{

  Bit8s op1 = AL;

  Bit8s op2 = BX_READ_8BIT_REGx(i->src(), i->extend8bitL());

  Bit16s product_16 = op1 * op2;

  Bit8u  product_8 = (product_16 & 0xFF);

  /* now write product back to destination */

  AX = product_16;

  /* set EFLAGS:

   * IMUL r/m8: condition for clearing CF & OF:

   *   AX = sign-extend of AL to 16 bits

   */

  SET_FLAGS_OSZAPC_LOGIC_8(product_8);

  if(product_16 != (Bit8s) product_16)

  {

    ASSERT_FLAGS_OxxxxC();

  }

  BX_NEXT_INSTR(i);

}

BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::DIV_ALEbR(bxInstruction_c *i)

{

  Bit8u op2 = BX_READ_8BIT_REGx(i->src(), i->extend8bitL());

  if (op2 == 0) {

    exception(BX_DE_EXCEPTION, 0);

  }

  Bit16u op1 = AX;

  Bit16u quotient_16 = op1 / op2;

  Bit8u remainder_8 = op1 % op2;

  Bit8u quotient_8l = quotient_16 & 0xFF;

  if (quotient_16 != quotient_8l)

  {

    exception(BX_DE_EXCEPTION, 0);

  }

  /* now write quotient back to destination */

  AL = quotient_8l;

  AH = remainder_8;

  BX_NEXT_INSTR(i);

}

BX_INSF_TYPE BX_CPP_AttrRegparmN(1) BX_CPU_C::IDIV_ALEbR(bxInstruction_c *i)

{

  Bit16s op1 = AX;

  /* check MIN_INT case */

  if (op1 == ((Bit16s)0x8000))

    exception(BX_DE_EXCEPTION, 0);

  Bit8s op2 = BX_READ_8BIT_REGx(i->src(), i->extend8bitL());

  if (op2 == 0)

    exception(BX_DE_EXCEPTION, 0);

  Bit16s quotient_16 = op1 / op2;

  Bit8s remainder_8 = op1 % op2;

  Bit8s quotient_8l = quotient_16 & 0xFF;

  if (quotient_16 != quotient_8l)

    exception(BX_DE_EXCEPTION, 0);

  /* now write quotient back to destination */

  AL = quotient_8l;

  AH = remainder_8;

  BX_NEXT_INSTR(i);

}