1  typedef enum
       2  {
       3    LODI,
       4    STO,
       5    ADDI,
       6    ADD,
       7    SUBI,
       8    SUB,
       9    MULI,
      10    MUL,
      11    DIVI,
      12    DIV,
      13    INC,
      14    DEC
      15  } INSN;
      16  
      17  f (pc)
      18       short *pc;
      19  {
      20    long long stack[16], *sp = &stack[16], acc = 0;
      21  
      22    for (;;)
      23      {
      24        switch ((INSN)*pc++)
      25  	{
      26  	case LODI:
      27  	  *--sp = acc;
      28  	  acc = ((long long)*pc++) << 32;
      29  	  break;
      30  	case STO:
      31  	  return (acc >> 32) + (((((unsigned long long) acc) & 0xffffffff)  & (1 << 31)) != 0);
      32  	  break;
      33  	case ADDI:
      34  	  acc += ((long long)*pc++) << 32;
      35  	  break;
      36  	case ADD:
      37  	  acc = *sp++ + acc;
      38  	  break;
      39  	case SUBI:
      40  	  acc -= ((long long)*pc++) << 32;
      41  	  break;
      42  	case SUB:
      43  	  acc = *sp++ - acc;
      44  	  break;
      45  	case MULI:
      46  	  acc *= *pc++;
      47  	  break;
      48  	case MUL:
      49  	  {
      50  	    long long aux;
      51  	    unsigned char minus;
      52  
      53  	    minus = 0;
      54  	    aux = *sp++;
      55  	    if (aux < 0)
      56  	      {
      57  		minus = ~minus;
      58  		aux = -aux;
      59  	      }
      60  	    if (acc < 0)
      61  	      {
      62  		minus = ~minus;
      63  		acc = -acc;
      64  	      }
      65  	    acc = ((((((unsigned long long) acc) & 0xffffffff)  * (((unsigned long long) aux) & 0xffffffff)) >> 32)
      66  		   + ((((unsigned long long) acc) >> 32)  * (((unsigned long long) aux) & 0xffffffff)  + (((unsigned long long) acc) & 0xffffffff)  + (((unsigned long long) aux) >> 32))
      67  		   + (((((unsigned long long) acc) >> 32)  * (((unsigned long long) aux) >> 32)) << 32));
      68  	    if (minus)
      69  	      acc = -acc;
      70  	  }
      71  	  break;
      72  	case DIVI:
      73  	  {
      74  	    short aux;
      75  
      76  	    aux = *pc++;
      77  	    acc = (acc + aux / 2) / aux;
      78  	  }
      79  	  break;
      80  	case DIV:
      81  	  {
      82  	    long long aux;
      83  	    unsigned char minus;
      84  
      85  	    minus = 0;
      86  	    aux = *sp++;
      87  	    if (aux < 0)
      88  	      {
      89  		minus = ~minus;
      90  		aux = -aux;
      91  	      }
      92  	    if (acc < 0)
      93  	      {
      94  		minus = ~minus;
      95  		acc = -acc;
      96  	      }
      97  
      98  	    if (((unsigned long long)acc)  == 0)
      99  	      acc = (unsigned long long)-1 / 2;
     100  	    else if ((((unsigned long long) ((unsigned long long)acc)) & 0xffffffff)  == 0)
     101  	      acc = ((unsigned long long)aux)  / (((unsigned long long) ((unsigned long long)acc)) >> 32);
     102  	    else if ((((unsigned long long) ((unsigned long long)acc)) >> 32)  == 0)
     103  	      acc = ((((unsigned long long)aux)  / ((unsigned long long)acc)) << 32)
     104  		+ ((((unsigned long long)aux)  % ((unsigned long long)acc)) << 32) / ((unsigned long long)acc);
     105  	    else
     106  	      {
     107  		unsigned char shift;
     108  		unsigned long hi;
     109  
     110  		shift = 32;
     111  		hi = (((unsigned long long) ((unsigned long long)acc)) >> 32);
     112  		do {
     113  		  if (hi & ((unsigned long)1 << (shift - 1)))
     114  		    break;
     115  		} while (--shift != 0);
     116  		printf("shift = %d\n", shift);
     117  		acc = ((((unsigned long long)aux)  / ((unsigned long long)acc)) << 32)
     118  		  + (((((unsigned long long)aux)  % ((unsigned long long)acc)) << (32 - shift)) + ((((unsigned long long)acc)  >> shift) / 2)) / (((unsigned long long)acc)  >> shift);
     119  	      }
     120  
     121  	    if (minus)
     122  	      acc = -acc;
     123  	  }
     124  	  break;
     125  	case INC:
     126  	  acc += 1;
     127  	  break;
     128  	case DEC:
     129  	  acc -= 1;
     130  	  break;
     131  	}
     132        printf("%08lx.%08lx\n", (long)(((unsigned long long) acc) >> 32) , (long)(((unsigned long long) acc) & 0xffffffff));
     133      }
     134  }