/*
   Copyright (C) 1998-2003 T. Scott Dattalo

This file is part of gpsim.

gpsim is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

gpsim 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with gpsim; see the file COPYING.  If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include <stdio.h>

#include "bit.h"
#include "registers.h"


Bit::Bit(RegisterValue &rv, unsigned int bit_mask)
{
  d = rv.get() & bit_mask ? true : false;
  i = rv.geti() & bit_mask ? false : true;
}


static void pr(const char *s,Bit &bv)
{
  printf("%s:%d,%d\n",s,bv.isOne(), bv.isKnown());
}



///-- Class test

void test_bits()
{
  static bool tested =false;
  if(tested)
    return;

  tested = true;

  Bit bOne(true,true);
  pr("one",bOne);
  Bit a = bOne;
  Bit b = bOne;
  Bit c = bOne;
  b.clear();

  pr("a",a);
  pr("b",b);

  for (int i=0; i < 4; i++) {
    switch (i) {

    case 0:
      printf("Both known\n");
      a.set(true,true);
      b.set(false,true);
      break;

    case 1:
      printf("a is unknown\n");
      a.set(true,false);
      b.set(false,true);
      break;
    case 2:
      printf("b is unknown\n");
      a.set(true,true);
      b.set(false,false);
      break;
    case 3:
      printf("a and b are unknown\n");
      a.set(true,false);
      b.set(false,false);
      break;
    }

    pr("a",a);
    pr("b",b);

    c = a;
    pr("c=a ->c",c);

    c = b;
    pr("c=b ->c",c);

    c |= a;
    pr("c|=a ->c",c);

    c &= a;
    pr("c&=a ->c",c);

    c |= b;
    pr("c|=b ->c",c);

    c &= b;
    pr("c&=b ->c",c);

    c = b;
    if (c == b)
      pr("c=b ->c",c);
    else
      pr("assignment failed c=b ->c",c);

    c = a;
    if (c == a)
      pr("c=a ->c",c);
    else
      pr("assignment failed c=a ->c",c);

    c = a | a;
    pr("c=a|a ->c",c);

    c = a | b;
    pr("c=a|b ->c",c);

    c = b | a;
    pr("c=b|a ->c",c);

    c = b | b;
    pr("c=b|b ->c",c);

    c = !b;
    pr("c=!b ->c",c);
    pr("     ->b",b);


    c = a & a;
    pr("c=a&a ->c",c);

    c = a & b;
    pr("c=a&b ->c",c);

    c = b & a;
    pr("c=b&a ->c",c);

    c = b & b;
    pr("c=b&b ->c",c);

    c = a & !a;
    pr("c=a&!a ->c",c);

    c = a & !b;
    pr("c=a&!b ->c",c);

    c = b & !a;
    pr("c=b&!a ->c",c);

    c = b & !b;
    pr("c=b&!b ->c",c);
  }

  Bit d(false,true);
  a.set(false,false);
  b.set(false,false);

  c = a & b & d;
  pr("a",a);
  pr("b",b);
  pr("d",d);
  pr("c=a&b&d ->c",c);

  c = !a & !b;
  pr("c=!a & !b ->c",c);

  a.set(true,false);
  b.set(false,true);
  Bit e = a & !b;
  pr("a",a);
  pr("b",b);
  pr("e=a & !b ->e",e);

  a.set(false,false);
  b.set(false,true);
  e = a & !b;
  pr("a",a);
  pr("b",b);
  pr("e=a & !b ->e",e);

  a.set(false,false);
  b.set(true,true);
  e = a & !b;
  pr("a",a);
  pr("b",b);
  pr("e=a & !b ->e",e);

  a.set(true,false);
  b.set(true,true);
  e = a & !b;
  pr("a",a);
  pr("b",b);
  pr("e=a & !b ->e",e);

}