Bochs/bochs/cpu/lazy_flags.cc

/////////////////////////////////////////////////////////////////////////
// $Id: lazy_flags.cc,v 1.30 2006-01-25 22:20:00 sshwarts Exp $
/////////////////////////////////////////////////////////////////////////
//
//  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
/////////////////////////////////////////////////////////////////////////


#define NEED_CPU_REG_SHORTCUTS 1
#include "bochs.h"
#define LOG_THIS BX_CPU_THIS_PTR

// This array defines a look-up table for the even parity-ness
// of an 8bit quantity, for optimal assignment of the parity bit
// in the EFLAGS register
const bx_bool bx_parity_lookup[256] = {
  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
};

bx_bool BX_CPU_C::get_CFLazy(void)
{
  unsigned cf;

  switch ( BX_CPU_THIS_PTR lf_flags_status & 0x00000f ) {
    case BX_LF_INDEX_OSZAPC:
      switch (BX_CPU_THIS_PTR oszapc.instr) {
        case BX_INSTR_ADD8:
          cf = (BX_CPU_THIS_PTR oszapc.result_8 <
                              BX_CPU_THIS_PTR oszapc.op1_8);
          break;
        case BX_INSTR_ADD16:
          cf = (BX_CPU_THIS_PTR oszapc.result_16 <
                              BX_CPU_THIS_PTR oszapc.op1_16);
          break;
        case BX_INSTR_ADD32:
          cf = (BX_CPU_THIS_PTR oszapc.result_32 <
                              BX_CPU_THIS_PTR oszapc.op1_32);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_ADD64:
          cf = (BX_CPU_THIS_PTR oszapc.result_64 <
                              BX_CPU_THIS_PTR oszapc.op1_64);
          break;
#endif
        // used only if CF = 1 when executing ADC instruction
        case BX_INSTR_ADC8:
          cf = (BX_CPU_THIS_PTR oszapc.result_8 <=
                              BX_CPU_THIS_PTR oszapc.op1_8);
          break;
        // used only if CF = 1 when executing ADC instruction
        case BX_INSTR_ADC16:
          cf = (BX_CPU_THIS_PTR oszapc.result_16 <=
                              BX_CPU_THIS_PTR oszapc.op1_16);
          break;
        // used only if CF = 1 when executing ADC instruction
        case BX_INSTR_ADC32:
          cf = (BX_CPU_THIS_PTR oszapc.result_32 <=
                              BX_CPU_THIS_PTR oszapc.op1_32);
          break;
#if BX_SUPPORT_X86_64
        // used only if CF = 1 when executing ADC instruction
        case BX_INSTR_ADC64:
          cf = (BX_CPU_THIS_PTR oszapc.result_64 <=
                              BX_CPU_THIS_PTR oszapc.op1_64);
          break;
#endif
        case BX_INSTR_SUB8:
          cf = (BX_CPU_THIS_PTR oszapc.op1_8 <
                              BX_CPU_THIS_PTR oszapc.op2_8);
          break;
        case BX_INSTR_SUB16:
          cf = (BX_CPU_THIS_PTR oszapc.op1_16 <
                              BX_CPU_THIS_PTR oszapc.op2_16);
          break;
        case BX_INSTR_SUB32:
          cf = (BX_CPU_THIS_PTR oszapc.op1_32 <
                              BX_CPU_THIS_PTR oszapc.op2_32);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_SUB64:
          cf = (BX_CPU_THIS_PTR oszapc.op1_64 <
                              BX_CPU_THIS_PTR oszapc.op2_64);
          break;
#endif
        // used only if CF = 1 when executing SBB instruction
        case BX_INSTR_SBB8:
          cf =
            (BX_CPU_THIS_PTR oszapc.op1_8 < BX_CPU_THIS_PTR oszapc.result_8) ||
            (BX_CPU_THIS_PTR oszapc.op2_8==0xff);
          break;
        // used only if CF = 1 when executing SBB instruction
        case BX_INSTR_SBB16:
          cf = 
            (BX_CPU_THIS_PTR oszapc.op1_16 < BX_CPU_THIS_PTR oszapc.result_16) ||
            (BX_CPU_THIS_PTR oszapc.op2_16==0xffff);
          break;
        // used only if CF = 1 when executing SBB instruction
        case BX_INSTR_SBB32:
          cf = 
            (BX_CPU_THIS_PTR oszapc.op1_32 < BX_CPU_THIS_PTR oszapc.result_32) ||
            (BX_CPU_THIS_PTR oszapc.op2_32==0xffffffff);
          break;
#if BX_SUPPORT_X86_64
        // used only if CF = 1 when executing SBB instruction
        case BX_INSTR_SBB64:
          cf = 
            (BX_CPU_THIS_PTR oszapc.op1_64 < BX_CPU_THIS_PTR oszapc.result_64) ||
            (BX_CPU_THIS_PTR oszapc.op2_64==BX_CONST64(0xffffffffffffffff));
          break;
#endif
        case BX_INSTR_NEG8:
          cf = (BX_CPU_THIS_PTR oszapc.result_8 != 0);
          break;
        case BX_INSTR_NEG16:
          cf = (BX_CPU_THIS_PTR oszapc.result_16 != 0);
          break;
        case BX_INSTR_NEG32:
          cf = (BX_CPU_THIS_PTR oszapc.result_32 != 0);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_NEG64:
          cf = (BX_CPU_THIS_PTR oszapc.result_64 != 0);
          break;
#endif
        case BX_INSTR_LOGIC8:
        case BX_INSTR_LOGIC16:
        case BX_INSTR_LOGIC32:
        case BX_INSTR_BITSCAN16:
        case BX_INSTR_BITSCAN32:
#if BX_SUPPORT_X86_64
        case BX_INSTR_LOGIC64:
        case BX_INSTR_BITSCAN64:
#endif
          cf = 0;
          break;
        case BX_INSTR_SAR8:
	  if (BX_CPU_THIS_PTR oszapc.op2_8 < 8) {
	    cf =
	      (BX_CPU_THIS_PTR oszapc.op1_8 >>
	        (BX_CPU_THIS_PTR oszapc.op2_8 - 1)) & 0x01;
	  }
	  else {
	    cf = (BX_CPU_THIS_PTR oszapc.op1_8 & 0x80) > 0;
	  }
          break;
        case BX_INSTR_SHR8:
          cf =
            (BX_CPU_THIS_PTR oszapc.op1_8 >>
              (BX_CPU_THIS_PTR oszapc.op2_8 - 1)) & 0x01;
          break;
        case BX_INSTR_SAR16:
	  if (BX_CPU_THIS_PTR oszapc.op2_16 < 16) {
	    cf =
	      (BX_CPU_THIS_PTR oszapc.op1_16 >>
	        (BX_CPU_THIS_PTR oszapc.op2_16 - 1)) & 0x01;
	  }
	  else {
	    cf = (BX_CPU_THIS_PTR oszapc.op1_16 & 0x8000) > 0;
	  }
          break;
        case BX_INSTR_SHR16:
        case BX_INSTR_SHRD16:
          cf =
            (BX_CPU_THIS_PTR oszapc.op1_16 >>
              (BX_CPU_THIS_PTR oszapc.op2_16 - 1)) & 0x01;
          break;
        case BX_INSTR_SAR32:
        case BX_INSTR_SHR32:
        case BX_INSTR_SHRD32:
          cf =
            (BX_CPU_THIS_PTR oszapc.op1_32 >>
              (BX_CPU_THIS_PTR oszapc.op2_32 - 1)) & 0x01;
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_SAR64:
        case BX_INSTR_SHR64:
        case BX_INSTR_SHRD64:
          cf =
            (BX_CPU_THIS_PTR oszapc.op1_64 >>
              (BX_CPU_THIS_PTR oszapc.op2_64 - 1)) & 0x01;
          break;
#endif
        case BX_INSTR_SHL8:
          if (BX_CPU_THIS_PTR oszapc.op2_8 <= 8) {
            cf =
              (BX_CPU_THIS_PTR oszapc.op1_8 >>
                (8 - BX_CPU_THIS_PTR oszapc.op2_8)) & 0x01;
          }
          else {
            cf = 0;
          }
          break;
        case BX_INSTR_SHL16:
          if (BX_CPU_THIS_PTR oszapc.op2_16 <= 16) {
            cf =
              (BX_CPU_THIS_PTR oszapc.op1_16 >>
                (16 - BX_CPU_THIS_PTR oszapc.op2_16)) & 0x01;
          }
          else {
            cf = 0;
          }
          break;
        case BX_INSTR_SHL32:
          cf =
            (BX_CPU_THIS_PTR oszapc.op1_32 >>
              (32 - BX_CPU_THIS_PTR oszapc.op2_32)) & 0x01;
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_SHL64:
          cf =
            (BX_CPU_THIS_PTR oszapc.op1_64 >>
              (64 - BX_CPU_THIS_PTR oszapc.op2_64)) & 0x01;
          break;
#endif
        case BX_INSTR_IMUL8:
          cf = ! ((BX_CPU_THIS_PTR oszapc.op1_8 < 0x80 &&
                   BX_CPU_THIS_PTR oszapc.op2_8 == 0) ||
                ((BX_CPU_THIS_PTR oszapc.op1_8 & 0x80) && 
                  BX_CPU_THIS_PTR oszapc.op2_8 == 0xff));
          break;
        case BX_INSTR_IMUL16:
          cf = ! ((BX_CPU_THIS_PTR oszapc.op1_16 < 0x8000 &&
                   BX_CPU_THIS_PTR oszapc.op2_16 == 0) ||
                ((BX_CPU_THIS_PTR oszapc.op1_16 & 0x8000) && 
                  BX_CPU_THIS_PTR oszapc.op2_16 == 0xffff));
          break;
        case BX_INSTR_IMUL32:
          cf = ! ((BX_CPU_THIS_PTR oszapc.op1_32 < 0x80000000 &&
                   BX_CPU_THIS_PTR oszapc.op2_32 == 0) ||
                ((BX_CPU_THIS_PTR oszapc.op1_32 & 0x80000000) && 
                  BX_CPU_THIS_PTR oszapc.op2_32 == 0xffffffff));
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_IMUL64:
          cf = ! ((BX_CPU_THIS_PTR oszapc.op1_64 < BX_CONST64(0x8000000000000000) &&
                   BX_CPU_THIS_PTR oszapc.op2_64 == 0) ||
                ((BX_CPU_THIS_PTR oszapc.op1_64 & BX_CONST64(0x8000000000000000)) && 
                  BX_CPU_THIS_PTR oszapc.op2_64 == BX_CONST64(0xffffffffffffffff)));
          break;
#endif
        case BX_INSTR_MUL8:
          cf = (BX_CPU_THIS_PTR oszapc.op2_8 != 0);
          break;
        case BX_INSTR_MUL16:
          cf = (BX_CPU_THIS_PTR oszapc.op2_16 != 0);
          break;
        case BX_INSTR_MUL32:
          cf = (BX_CPU_THIS_PTR oszapc.op2_32 != 0);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_MUL64:
          cf = (BX_CPU_THIS_PTR oszapc.op2_64 != 0);
          break;
#endif
        default:
          cf = 0; // Keep compiler quiet.
          BX_PANIC(("get_CF: OSZAPC: unknown instr %u",
            (unsigned) BX_CPU_THIS_PTR oszapc.instr));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xfffff0;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<0);
      BX_CPU_THIS_PTR eflags.val32 |= (!!cf)<<0;
      return(cf);

    default:
      BX_PANIC(("get_CF: unknown case"));
      return(0);
  }
}

bx_bool BX_CPU_C::get_AFLazy(void)
{
  unsigned af;

  switch ( (BX_CPU_THIS_PTR lf_flags_status>>8) & 0x00000f ) {
    case BX_LF_INDEX_OSZAPC:
      switch (BX_CPU_THIS_PTR oszapc.instr) {
        case BX_INSTR_ADD8:
        case BX_INSTR_ADC8:
        case BX_INSTR_SUB8:
        case BX_INSTR_SBB8:
          af =
            ((BX_CPU_THIS_PTR oszapc.op1_8 ^
              BX_CPU_THIS_PTR oszapc.op2_8) ^
             BX_CPU_THIS_PTR oszapc.result_8) & 0x10;
          break;
        case BX_INSTR_ADD16:
        case BX_INSTR_ADC16:
        case BX_INSTR_SUB16:
        case BX_INSTR_SBB16:
          af =
            ((BX_CPU_THIS_PTR oszapc.op1_16 ^
              BX_CPU_THIS_PTR oszapc.op2_16) ^
             BX_CPU_THIS_PTR oszapc.result_16) & 0x10;
          break;
        case BX_INSTR_ADD32:
        case BX_INSTR_ADC32:
        case BX_INSTR_SUB32:
        case BX_INSTR_SBB32:
          af =
            ((BX_CPU_THIS_PTR oszapc.op1_32 ^
              BX_CPU_THIS_PTR oszapc.op2_32) ^
             BX_CPU_THIS_PTR oszapc.result_32) & 0x10;
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_ADD64:
        case BX_INSTR_ADC64:
        case BX_INSTR_SUB64:
        case BX_INSTR_SBB64:
          af =
            ((BX_CPU_THIS_PTR oszapc.op1_64 ^
              BX_CPU_THIS_PTR oszapc.op2_64) ^
             BX_CPU_THIS_PTR oszapc.result_64) & 0x10;
          break;
#endif
        case BX_INSTR_NEG8:
          af = (BX_CPU_THIS_PTR oszapc.result_8 & 0x0f) != 0;
          break;
        case BX_INSTR_NEG16:
          af = (BX_CPU_THIS_PTR oszapc.result_16 & 0x0f) != 0;
          break;
        case BX_INSTR_NEG32:
          af = (BX_CPU_THIS_PTR oszapc.result_32 & 0x0f) != 0;
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_NEG64:
          af = (BX_CPU_THIS_PTR oszapc.result_64 & 0x0f) != 0;
          break;
#endif
        case BX_INSTR_LOGIC8:
        case BX_INSTR_LOGIC16:
        case BX_INSTR_LOGIC32:
        case BX_INSTR_BITSCAN16:
        case BX_INSTR_BITSCAN32:
#if BX_SUPPORT_X86_64
        case BX_INSTR_LOGIC64:
        case BX_INSTR_BITSCAN64:
        case BX_INSTR_SAR64:
        case BX_INSTR_SHR64:
        case BX_INSTR_SHRD64:
        case BX_INSTR_SHL64:
        case BX_INSTR_IMUL64:
        case BX_INSTR_MUL64:
#endif
        case BX_INSTR_SAR8:
        case BX_INSTR_SAR16:
        case BX_INSTR_SAR32:
        case BX_INSTR_SHR8:
        case BX_INSTR_SHR16:
        case BX_INSTR_SHR32:
        case BX_INSTR_SHRD16:
        case BX_INSTR_SHRD32:
        case BX_INSTR_SHL8:
        case BX_INSTR_SHL16:
        case BX_INSTR_SHL32:
        case BX_INSTR_IMUL8:
        case BX_INSTR_IMUL16:
        case BX_INSTR_IMUL32:
        case BX_INSTR_MUL8:
        case BX_INSTR_MUL16:
        case BX_INSTR_MUL32:
          af = 0;
          break;
        default:
          af = 0; // Keep compiler quiet.
          BX_PANIC(("get_AF: OSZAPC: unknown instr %u",
            (unsigned) BX_CPU_THIS_PTR oszapc.instr));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xfff0ff;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<4);
      BX_CPU_THIS_PTR eflags.val32 |= (!!af)<<4;
      return(af);

    case BX_LF_INDEX_OSZAP:
      switch (BX_CPU_THIS_PTR oszap.instr) {
        case BX_INSTR_INC8:
          af = (BX_CPU_THIS_PTR oszap.result_8 & 0x0f) == 0;
          break;
        case BX_INSTR_INC16:
          af = (BX_CPU_THIS_PTR oszap.result_16 & 0x0f) == 0;
          break;
        case BX_INSTR_INC32:
          af = (BX_CPU_THIS_PTR oszap.result_32 & 0x0f) == 0;
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_INC64:
          af = (BX_CPU_THIS_PTR oszap.result_64 & 0x0f) == 0;
          break;
#endif
        case BX_INSTR_DEC8:
          af = (BX_CPU_THIS_PTR oszap.result_8 & 0x0f) == 0x0f;
          break;
        case BX_INSTR_DEC16:
          af = (BX_CPU_THIS_PTR oszap.result_16 & 0x0f) == 0x0f;
          break;
        case BX_INSTR_DEC32:
          af = (BX_CPU_THIS_PTR oszap.result_32 & 0x0f) == 0x0f;
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_DEC64:
          af = (BX_CPU_THIS_PTR oszap.result_64 & 0x0f) == 0x0f;
          break;
#endif
        default:
          af = 0; // Keep compiler quiet.
          BX_PANIC(("get_AF: OSZAP: unknown instr %u",
            (unsigned) BX_CPU_THIS_PTR oszap.instr));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xfff0ff;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<4);
      BX_CPU_THIS_PTR eflags.val32 |= (!!af)<<4;
      return(af);

    default:
      BX_PANIC(("get_AF: unknown case"));
      return(0);
  }
}

bx_bool BX_CPU_C::get_ZFLazy(void)
{
  unsigned zf;

  switch ( (BX_CPU_THIS_PTR lf_flags_status>>12) & 0x00000f ) {
    case BX_LF_INDEX_OSZAPC:
      switch (BX_CPU_THIS_PTR oszapc.instr) {
        case BX_INSTR_LOGIC8:
        case BX_INSTR_ADD8:
        case BX_INSTR_ADC8:
        case BX_INSTR_SUB8:
        case BX_INSTR_SBB8:
        case BX_INSTR_NEG8:
        case BX_INSTR_SAR8:
        case BX_INSTR_SHR8:
        case BX_INSTR_SHL8:
          zf = (BX_CPU_THIS_PTR oszapc.result_8 == 0);
          break;
        case BX_INSTR_LOGIC16:
        case BX_INSTR_ADD16:
        case BX_INSTR_ADC16:
        case BX_INSTR_SUB16:
        case BX_INSTR_SBB16:
        case BX_INSTR_NEG16:
        case BX_INSTR_SAR16:
        case BX_INSTR_SHR16:
        case BX_INSTR_SHRD16:
        case BX_INSTR_SHL16:
          zf = (BX_CPU_THIS_PTR oszapc.result_16 == 0);
          break;
        case BX_INSTR_LOGIC32:
        case BX_INSTR_ADD32:
        case BX_INSTR_ADC32:
        case BX_INSTR_SUB32:
        case BX_INSTR_SBB32:
        case BX_INSTR_NEG32:
        case BX_INSTR_SAR32:
        case BX_INSTR_SHR32:
        case BX_INSTR_SHRD32:
        case BX_INSTR_SHL32:
          zf = (BX_CPU_THIS_PTR oszapc.result_32 == 0);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_LOGIC64:
        case BX_INSTR_ADD64:
        case BX_INSTR_ADC64:
        case BX_INSTR_SUB64:
        case BX_INSTR_SBB64:
        case BX_INSTR_NEG64:
        case BX_INSTR_SAR64:
        case BX_INSTR_SHR64:
        case BX_INSTR_SHRD64:
        case BX_INSTR_SHL64:
          zf = (BX_CPU_THIS_PTR oszapc.result_64 == 0);
          break;
#endif
        case BX_INSTR_IMUL8:
        case BX_INSTR_MUL8:
          zf = (BX_CPU_THIS_PTR oszapc.op1_8 == 0);
          break;
        case BX_INSTR_IMUL16:
        case BX_INSTR_MUL16:
          zf = (BX_CPU_THIS_PTR oszapc.op1_16 == 0);
          break;
        case BX_INSTR_IMUL32:
        case BX_INSTR_MUL32:
          zf = (BX_CPU_THIS_PTR oszapc.op1_32 == 0);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_IMUL64:
        case BX_INSTR_MUL64:
          zf = (BX_CPU_THIS_PTR oszapc.op1_64 == 0);
          break;
#endif
        case BX_INSTR_BITSCAN16:
        case BX_INSTR_BITSCAN32:
#if BX_SUPPORT_X86_64
        case BX_INSTR_BITSCAN64:
#endif
          zf = 0;
          break;
        default:
          zf = 0;
          BX_PANIC(("get_ZF: OSZAPC: unknown instr"));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xff0fff;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<6);
      BX_CPU_THIS_PTR eflags.val32 |= zf<<6; // zf always exactly 0 or 1.
      return(zf);

    case BX_LF_INDEX_OSZAP:
      switch (BX_CPU_THIS_PTR oszap.instr) {
        case BX_INSTR_INC8:
        case BX_INSTR_DEC8:
          zf = (BX_CPU_THIS_PTR oszap.result_8 == 0);
          break;
        case BX_INSTR_INC16:
        case BX_INSTR_DEC16:
          zf = (BX_CPU_THIS_PTR oszap.result_16 == 0);
          break;
        case BX_INSTR_INC32:
        case BX_INSTR_DEC32:
          zf = (BX_CPU_THIS_PTR oszap.result_32 == 0);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_INC64:
        case BX_INSTR_DEC64:
          zf = (BX_CPU_THIS_PTR oszap.result_64 == 0);
          break;
#endif
        default:
          zf = 0;
          BX_PANIC(("get_ZF: OSZAP: unknown instr"));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xff0fff;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<6);
      BX_CPU_THIS_PTR eflags.val32 |= zf<<6; // zf always exactly 0 or 1.
      return(zf);

    default:
      BX_PANIC(("get_ZF: unknown case"));
      return(0);
  }
}

bx_bool BX_CPU_C::get_SFLazy(void)
{
  unsigned sf;

  switch ( (BX_CPU_THIS_PTR lf_flags_status>>16) & 0x00000f ) {
    case BX_LF_INDEX_OSZAPC:
      switch (BX_CPU_THIS_PTR oszapc.instr) {
        case BX_INSTR_LOGIC8:
        case BX_INSTR_ADD8:
        case BX_INSTR_ADC8:
        case BX_INSTR_SUB8:
        case BX_INSTR_SBB8:
        case BX_INSTR_NEG8:
        case BX_INSTR_SAR8:
        case BX_INSTR_SHR8:
        case BX_INSTR_SHL8:
          sf = (BX_CPU_THIS_PTR oszapc.result_8 >= 0x80);
          break;
        case BX_INSTR_LOGIC16:
        case BX_INSTR_ADD16:
        case BX_INSTR_ADC16:
        case BX_INSTR_SUB16:
        case BX_INSTR_SBB16:
        case BX_INSTR_NEG16:
        case BX_INSTR_SAR16:
        case BX_INSTR_SHR16:
        case BX_INSTR_SHRD16:
        case BX_INSTR_SHL16:
        case BX_INSTR_BITSCAN16:
          sf = (BX_CPU_THIS_PTR oszapc.result_16 >= 0x8000);
          break;
        case BX_INSTR_LOGIC32:
        case BX_INSTR_ADD32:
        case BX_INSTR_ADC32:
        case BX_INSTR_SUB32:
        case BX_INSTR_SBB32:
        case BX_INSTR_NEG32:
        case BX_INSTR_SAR32:
        case BX_INSTR_SHR32:
        case BX_INSTR_SHRD32:
        case BX_INSTR_SHL32:
        case BX_INSTR_BITSCAN32:
          sf = (BX_CPU_THIS_PTR oszapc.result_32 >= 0x80000000);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_LOGIC64:
        case BX_INSTR_ADD64:
        case BX_INSTR_ADC64:
        case BX_INSTR_SUB64:
        case BX_INSTR_SBB64:
        case BX_INSTR_NEG64:
        case BX_INSTR_SAR64:
        case BX_INSTR_SHR64:
        case BX_INSTR_SHRD64:
        case BX_INSTR_SHL64:
        case BX_INSTR_BITSCAN64:
          sf = (BX_CPU_THIS_PTR oszapc.result_64 >= BX_CONST64(0x8000000000000000));
          break;
#endif
        case BX_INSTR_IMUL8:
        case BX_INSTR_MUL8:
          sf = (BX_CPU_THIS_PTR oszapc.op1_8 >= 0x80);
          break;
        case BX_INSTR_IMUL16:
        case BX_INSTR_MUL16:
          sf = (BX_CPU_THIS_PTR oszapc.op1_16 >= 0x8000);
          break;
        case BX_INSTR_IMUL32:
        case BX_INSTR_MUL32:
          sf = (BX_CPU_THIS_PTR oszapc.op1_32 >= 0x80000000);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_IMUL64:
        case BX_INSTR_MUL64:
          sf = (BX_CPU_THIS_PTR oszapc.op1_64 >= BX_CONST64(0x8000000000000000));
          break;
#endif
        default:
          sf = 0; // Keep compiler quiet.
          BX_PANIC(("get_SF: OSZAPC: unknown instr"));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xf0ffff;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<7);
      BX_CPU_THIS_PTR eflags.val32 |= (!!sf)<<7;
      return(sf);

    case BX_LF_INDEX_OSZAP:
      switch (BX_CPU_THIS_PTR oszap.instr) {
        case BX_INSTR_INC8:
        case BX_INSTR_DEC8:
          sf = (BX_CPU_THIS_PTR oszap.result_8 >= 0x80);
          break;
        case BX_INSTR_INC16:
        case BX_INSTR_DEC16:
          sf = (BX_CPU_THIS_PTR oszap.result_16 >= 0x8000);
          break;
        case BX_INSTR_INC32:
        case BX_INSTR_DEC32:
          sf = (BX_CPU_THIS_PTR oszap.result_32 >= 0x80000000);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_INC64:
        case BX_INSTR_DEC64:
          sf = (BX_CPU_THIS_PTR oszap.result_64 >= BX_CONST64(0x8000000000000000));
          break;
#endif
        default:
          sf = 0; // Keep compiler quiet.
          BX_PANIC(("get_SF: OSZAP: unknown instr"));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xf0ffff;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<7);
      BX_CPU_THIS_PTR eflags.val32 |= (!!sf)<<7;
      return(sf);

    default:
      BX_PANIC(("get_SF: unknown case"));
      return(0);
  }
}

bx_bool BX_CPU_C::get_OFLazy(void)
{
  Bit8u op1_b7, op2_b7, result_b7;
  Bit16u op1_b15, op2_b15, result_b15;
  Bit32u op1_b31, op2_b31, result_b31;
#if BX_SUPPORT_X86_64
  Bit64u op1_b63, op2_b63, result_b63;
#endif
  unsigned of;

  switch ( (BX_CPU_THIS_PTR lf_flags_status>>20) & 0x00000f ) {
    case BX_LF_INDEX_OSZAPC:
      switch (BX_CPU_THIS_PTR oszapc.instr) {
        case BX_INSTR_ADD8:
        case BX_INSTR_ADC8:
          op1_b7 = BX_CPU_THIS_PTR oszapc.op1_8 & 0x80;
          op2_b7 = BX_CPU_THIS_PTR oszapc.op2_8 & 0x80;
          result_b7 = BX_CPU_THIS_PTR oszapc.result_8 & 0x80;
          of = (op1_b7 == op2_b7) && (result_b7 ^ op2_b7);
          break;
        case BX_INSTR_ADD16:
        case BX_INSTR_ADC16:
          op1_b15 = BX_CPU_THIS_PTR oszapc.op1_16 & 0x8000;
          op2_b15 = BX_CPU_THIS_PTR oszapc.op2_16 & 0x8000;
          result_b15 = BX_CPU_THIS_PTR oszapc.result_16 & 0x8000;
          of = (op1_b15 == op2_b15) && (result_b15 ^ op2_b15);
          break;
        case BX_INSTR_ADD32:
        case BX_INSTR_ADC32:
          op1_b31 = BX_CPU_THIS_PTR oszapc.op1_32 & 0x80000000;
          op2_b31 = BX_CPU_THIS_PTR oszapc.op2_32 & 0x80000000;
          result_b31 = BX_CPU_THIS_PTR oszapc.result_32 & 0x80000000;
          of = (op1_b31 == op2_b31) && (result_b31 ^ op2_b31);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_ADD64:
        case BX_INSTR_ADC64:
          op1_b63 = BX_CPU_THIS_PTR oszapc.op1_64 & BX_CONST64(0x8000000000000000);
          op2_b63 = BX_CPU_THIS_PTR oszapc.op2_64 & BX_CONST64(0x8000000000000000);
          result_b63 = BX_CPU_THIS_PTR oszapc.result_64 & BX_CONST64(0x8000000000000000);
          of = (op1_b63 == op2_b63) && (result_b63 ^ op2_b63);
          break;
#endif
        case BX_INSTR_SUB8:
        case BX_INSTR_SBB8:
          op1_b7 = BX_CPU_THIS_PTR oszapc.op1_8 & 0x80;
          op2_b7 = BX_CPU_THIS_PTR oszapc.op2_8 & 0x80;
          result_b7 = BX_CPU_THIS_PTR oszapc.result_8 & 0x80;
          of = (op1_b7 ^ op2_b7) && (op1_b7 ^ result_b7);
          break;
        case BX_INSTR_SUB16:
        case BX_INSTR_SBB16:
          op1_b15 = BX_CPU_THIS_PTR oszapc.op1_16 & 0x8000;
          op2_b15 = BX_CPU_THIS_PTR oszapc.op2_16 & 0x8000;
          result_b15 = BX_CPU_THIS_PTR oszapc.result_16 & 0x8000;
          of = (op1_b15 ^ op2_b15) && (op1_b15 ^ result_b15);
          break;
        case BX_INSTR_SUB32:
        case BX_INSTR_SBB32:
          op1_b31 = BX_CPU_THIS_PTR oszapc.op1_32 & 0x80000000;
          op2_b31 = BX_CPU_THIS_PTR oszapc.op2_32 & 0x80000000;
          result_b31 = BX_CPU_THIS_PTR oszapc.result_32 & 0x80000000;
          of = (op1_b31 ^ op2_b31) && (op1_b31 ^ result_b31);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_SUB64:
        case BX_INSTR_SBB64:
          op1_b63 = BX_CPU_THIS_PTR oszapc.op1_64 & BX_CONST64(0x8000000000000000);
          op2_b63 = BX_CPU_THIS_PTR oszapc.op2_64 & BX_CONST64(0x8000000000000000);
          result_b63 = BX_CPU_THIS_PTR oszapc.result_64 & BX_CONST64(0x8000000000000000);
          of = (op1_b63 ^ op2_b63) && (op1_b63 ^ result_b63);
          break;
#endif
        case BX_INSTR_NEG8:
          of = (BX_CPU_THIS_PTR oszapc.result_8 == 0x80);
          break;
        case BX_INSTR_NEG16:
          of = (BX_CPU_THIS_PTR oszapc.result_16 == 0x8000);
          break;
        case BX_INSTR_NEG32:
          of = (BX_CPU_THIS_PTR oszapc.result_32 == 0x80000000);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_NEG64:
          of = (BX_CPU_THIS_PTR oszapc.result_64 == BX_CONST64(0x8000000000000000));
          break;
#endif
        case BX_INSTR_LOGIC8:
        case BX_INSTR_LOGIC16:
        case BX_INSTR_LOGIC32:
        case BX_INSTR_BITSCAN16:
        case BX_INSTR_BITSCAN32:
        case BX_INSTR_SAR8:
        case BX_INSTR_SAR16:
        case BX_INSTR_SAR32:
#if BX_SUPPORT_X86_64
        case BX_INSTR_LOGIC64:
        case BX_INSTR_BITSCAN64:
        case BX_INSTR_SAR64:
#endif
          of = 0;
          break;
        case BX_INSTR_SHR8:
          if (BX_CPU_THIS_PTR oszapc.op2_8 == 1)
            of = (BX_CPU_THIS_PTR oszapc.op1_8 >= 0x80);
          else
            of = 0; /* undocumented, but hardware really does it */
          break;
        case BX_INSTR_SHR16:
          if (BX_CPU_THIS_PTR oszapc.op2_16 == 1)
            of = (BX_CPU_THIS_PTR oszapc.op1_16 >= 0x8000);
          else
            of = 0; /* undocumented, but hardware really does it */
          break;
        case BX_INSTR_SHR32:
          if (BX_CPU_THIS_PTR oszapc.op2_32 == 1)
            of = (BX_CPU_THIS_PTR oszapc.op1_32 >= 0x80000000);
          else
            of = 0; /* undocumented, but hardware really does it */
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_SHR64:
          if (BX_CPU_THIS_PTR oszapc.op2_64 == 1)
            of = (BX_CPU_THIS_PTR oszapc.op1_64 >= BX_CONST64(0x8000000000000000));
          else
            of = 0; /* undocumented, but hardware really does it */
          break;
#endif
        case BX_INSTR_SHRD16:
            /* undocumented, but this formula works right for any shift count */
            of = (((BX_CPU_THIS_PTR oszapc.result_16 << 1) ^ 
                    BX_CPU_THIS_PTR oszapc.result_16) & 0x8000) > 0;
          break;
        case BX_INSTR_SHRD32:
            /* undocumented, but this formula works right for any shift count */
            of = (((BX_CPU_THIS_PTR oszapc.result_32 << 1) ^ 
                    BX_CPU_THIS_PTR oszapc.result_32) & 0x80000000) > 0;
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_SHRD64:
            /* undocumented, but this formula works right for any shift count */
            of = (((BX_CPU_THIS_PTR oszapc.result_64 << 1) ^ 
                    BX_CPU_THIS_PTR oszapc.result_64) & BX_CONST64(0x8000000000000000)) > 0;
          break;
#endif
        case BX_INSTR_SHL8:
          if (BX_CPU_THIS_PTR oszapc.op2_8 == 1)
            of = ((BX_CPU_THIS_PTR oszapc.op1_8 ^
                BX_CPU_THIS_PTR oszapc.result_8) & 0x80) > 0;
          else
            of = (((BX_CPU_THIS_PTR oszapc.op1_8 <<
                   (BX_CPU_THIS_PTR oszapc.op2_8 - 1)) ^
                      BX_CPU_THIS_PTR oszapc.result_8) & 0x80) > 0;
          break;
        case BX_INSTR_SHL16:
          if (BX_CPU_THIS_PTR oszapc.op2_16 == 1)
            of = ((BX_CPU_THIS_PTR oszapc.op1_16 ^
                BX_CPU_THIS_PTR oszapc.result_16) & 0x8000) > 0;
          else
            of = (((BX_CPU_THIS_PTR oszapc.op1_16 <<
                   (BX_CPU_THIS_PTR oszapc.op2_16 - 1)) ^
                      BX_CPU_THIS_PTR oszapc.result_16) & 0x8000) > 0;
          break;
        case BX_INSTR_SHL32:
          if (BX_CPU_THIS_PTR oszapc.op2_32 == 1)
            of = ((BX_CPU_THIS_PTR oszapc.op1_32 ^
                BX_CPU_THIS_PTR oszapc.result_32) & 0x80000000) > 0;
          else
            of = (((BX_CPU_THIS_PTR oszapc.op1_32 <<
                   (BX_CPU_THIS_PTR oszapc.op2_32 - 1)) ^
                      BX_CPU_THIS_PTR oszapc.result_32) & 0x80000000) > 0;
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_SHL64:
          if (BX_CPU_THIS_PTR oszapc.op2_64 == 1)
            of = ((BX_CPU_THIS_PTR oszapc.op1_64 ^
                BX_CPU_THIS_PTR oszapc.result_64) & BX_CONST64(0x8000000000000000)) > 0;
          else
            of = (((BX_CPU_THIS_PTR oszapc.op1_64 <<
                   (BX_CPU_THIS_PTR oszapc.op2_64 - 1)) ^
                      BX_CPU_THIS_PTR oszapc.result_64) & BX_CONST64(0x8000000000000000)) > 0;
          break;
#endif
        case BX_INSTR_IMUL8:
          of = ! ((BX_CPU_THIS_PTR oszapc.op1_8 < 0x80 &&
                   BX_CPU_THIS_PTR oszapc.op2_8 == 0) ||
                ((BX_CPU_THIS_PTR oszapc.op1_8 & 0x80) && 
                  BX_CPU_THIS_PTR oszapc.op2_8 == 0xff));
          break;
        case BX_INSTR_IMUL16:
          of = ! ((BX_CPU_THIS_PTR oszapc.op1_16 < 0x8000 &&
                   BX_CPU_THIS_PTR oszapc.op2_16 == 0) ||
                ((BX_CPU_THIS_PTR oszapc.op1_16 & 0x8000) && 
                  BX_CPU_THIS_PTR oszapc.op2_16 == 0xffff));
          break;
        case BX_INSTR_IMUL32:
          of = ! ((BX_CPU_THIS_PTR oszapc.op1_32 < 0x80000000 &&
                   BX_CPU_THIS_PTR oszapc.op2_32 == 0) ||
                ((BX_CPU_THIS_PTR oszapc.op1_32 & 0x80000000) && 
                  BX_CPU_THIS_PTR oszapc.op2_32 == 0xffffffff));
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_IMUL64:
          of = ! ((BX_CPU_THIS_PTR oszapc.op1_64 < BX_CONST64(0x8000000000000000) &&
                   BX_CPU_THIS_PTR oszapc.op2_64 == 0) ||
                ((BX_CPU_THIS_PTR oszapc.op1_64 & BX_CONST64(0x8000000000000000)) && 
                  BX_CPU_THIS_PTR oszapc.op2_64 == BX_CONST64(0xffffffffffffffff)));
          break;
#endif
        case BX_INSTR_MUL8:
          of = (BX_CPU_THIS_PTR oszapc.op2_8 != 0);
          break;
        case BX_INSTR_MUL16:
          of = (BX_CPU_THIS_PTR oszapc.op2_16 != 0);
          break;
        case BX_INSTR_MUL32:
          of = (BX_CPU_THIS_PTR oszapc.op2_32 != 0);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_MUL64:
          of = (BX_CPU_THIS_PTR oszapc.op2_64 != 0);
          break;
#endif
        default:
          of = 0; // Keep compiler happy.
          BX_PANIC(("get_OF: OSZAPC: unknown instr"));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0x0fffff;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<11);
      BX_CPU_THIS_PTR eflags.val32 |= (!!of)<<11;
      return(of);

    case BX_LF_INDEX_OSZAP:
      switch (BX_CPU_THIS_PTR oszap.instr) {
        case BX_INSTR_INC8:
          of = (BX_CPU_THIS_PTR oszap.result_8 == 0x80);
          break;
        case BX_INSTR_INC16:
          of = (BX_CPU_THIS_PTR oszap.result_16 == 0x8000);
          break;
        case BX_INSTR_INC32:
          of = (BX_CPU_THIS_PTR oszap.result_32 == 0x80000000);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_INC64:
          of = (BX_CPU_THIS_PTR oszap.result_64 == BX_CONST64(0x8000000000000000));
          break;
#endif
        case BX_INSTR_DEC8:
          of = (BX_CPU_THIS_PTR oszap.result_8 == 0x7F);
          break;
        case BX_INSTR_DEC16:
          of = (BX_CPU_THIS_PTR oszap.result_16 == 0x7FFF);
          break;
        case BX_INSTR_DEC32:
          of = (BX_CPU_THIS_PTR oszap.result_32 == 0x7FFFFFFF);
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_DEC64:
          of = (BX_CPU_THIS_PTR oszap.result_64 == BX_CONST64(0x7FFFFFFFFFFFFFFF));
          break;
#endif
        default:
          of = 0; // Keep compiler happy.
          BX_PANIC(("get_OF: OSZAP: unknown instr"));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0x0fffff;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<11);
      BX_CPU_THIS_PTR eflags.val32 |= (!!of)<<11;
      return(of);

    default:
      BX_PANIC(("get_OF: unknown case"));
      return(0);
  }
}

bx_bool BX_CPU_C::get_PFLazy(void)
{
  unsigned pf;

  switch ( (BX_CPU_THIS_PTR lf_flags_status>>4) & 0x00000f ) {
    case BX_LF_INDEX_OSZAPC:
      switch (BX_CPU_THIS_PTR oszapc.instr) {
        case BX_INSTR_LOGIC8:
        case BX_INSTR_ADD8:
        case BX_INSTR_ADC8:
        case BX_INSTR_SUB8:
        case BX_INSTR_SBB8:
        case BX_INSTR_NEG8:
        case BX_INSTR_SAR8:
        case BX_INSTR_SHR8:
        case BX_INSTR_SHL8:
          pf = bx_parity_lookup[BX_CPU_THIS_PTR oszapc.result_8];
          break;
        case BX_INSTR_LOGIC16:
        case BX_INSTR_ADD16:
        case BX_INSTR_ADC16:
        case BX_INSTR_SUB16:
        case BX_INSTR_SBB16:
        case BX_INSTR_NEG16:
        case BX_INSTR_SAR16:
        case BX_INSTR_SHR16:
        case BX_INSTR_SHRD16:
        case BX_INSTR_SHL16:
        case BX_INSTR_BITSCAN16:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszapc.result_16];
          break;
        case BX_INSTR_LOGIC32:
        case BX_INSTR_ADD32:
        case BX_INSTR_ADC32:
        case BX_INSTR_SUB32:
        case BX_INSTR_SBB32:
        case BX_INSTR_NEG32:
        case BX_INSTR_SAR32:
        case BX_INSTR_SHR32:
        case BX_INSTR_SHRD32:
        case BX_INSTR_SHL32:
        case BX_INSTR_BITSCAN32:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszapc.result_32];
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_LOGIC64:
        case BX_INSTR_ADD64:
        case BX_INSTR_ADC64:
        case BX_INSTR_SUB64:
        case BX_INSTR_SBB64:
        case BX_INSTR_NEG64:
        case BX_INSTR_SAR64:
        case BX_INSTR_SHR64:
        case BX_INSTR_SHRD64:
        case BX_INSTR_SHL64:
        case BX_INSTR_BITSCAN64:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszapc.result_64];
          break;
#endif
        case BX_INSTR_IMUL8:
        case BX_INSTR_MUL8:
          pf = bx_parity_lookup[BX_CPU_THIS_PTR oszapc.op1_8];
          break;
        case BX_INSTR_IMUL16:
        case BX_INSTR_MUL16:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszapc.op1_16];
          break;
        case BX_INSTR_IMUL32:
        case BX_INSTR_MUL32:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszapc.op1_32];
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_IMUL64:
        case BX_INSTR_MUL64:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszapc.op1_64];
          break;
#endif
        default:
          pf = 0; // Keep compiler quiet.
          BX_PANIC(("get_PF: OSZAPC: unknown instr"));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xffff0f;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<2);
      BX_CPU_THIS_PTR eflags.val32 |= (pf)<<2; // pf is always 0 or 1 here
      return(pf);

    case BX_LF_INDEX_OSZAP:
      switch (BX_CPU_THIS_PTR oszap.instr) {
        case BX_INSTR_INC8:
        case BX_INSTR_DEC8:
          pf = bx_parity_lookup[BX_CPU_THIS_PTR oszap.result_8];
          break;
        case BX_INSTR_INC16:
        case BX_INSTR_DEC16:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszap.result_16];
          break;
        case BX_INSTR_INC32:
        case BX_INSTR_DEC32:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszap.result_32];
          break;
#if BX_SUPPORT_X86_64
        case BX_INSTR_INC64:
        case BX_INSTR_DEC64:
          pf = bx_parity_lookup[(Bit8u) BX_CPU_THIS_PTR oszap.result_64];
          break;
#endif
        default:
          pf = 0; // Keep compiler quiet.
          BX_PANIC(("get_PF: OSZAP: unknown instr"));
      }
      BX_CPU_THIS_PTR lf_flags_status &= 0xffff0f;
      BX_CPU_THIS_PTR eflags.val32 &= ~(1<<2);
      BX_CPU_THIS_PTR eflags.val32 |= (pf)<<2; // pf is always 0 or 1 here
      return(pf);

    default:
      BX_PANIC(("get_PF: unknown case"));
      return(0);
  }
}