/* da.c */

#include <stdio.h>
#include <stdlib.h>
#include "as.h"

typedef unsigned char byte;

union { int i;
        float f;
        struct { byte a,b,c,d; } b; } converter;

FILE *fin;
int location_counter;

void main(void)
{ fin=fopen("a.exe","r");
  if (fin==NULL)
  { fprintf(stderr,"Can't open a.exe\n");
    exit(1); }
  converter.b.a=fgetc(fin);
  converter.b.b=fgetc(fin);
  converter.b.c=fgetc(fin);
  converter.b.d=fgetc(fin);
  printf("MAIN = %d\n", converter.i);
  converter.b.a=fgetc(fin);
  converter.b.b=fgetc(fin);
  converter.b.c=fgetc(fin);
  converter.b.d=fgetc(fin);
  location_counter=converter.i;
  printf("start loading at address %d\n", location_counter);
  while (1)
  { int b, opc, opd, i;
    b=fgetc(fin);
    if (b==EOF) break;
    printf("%6d:  ", location_counter);
    location_counter+=1;
    opc=b&~OPERAND;
    opd=b&OPERAND;
    if (opd!=0) opc|=OPERAND;
    switch (opc)
    { case BADP    : i=0;
                     while (b==0)
                     { b=fgetc(fin);
                       i+=1; }
                     location_counter+=i-1;
                     ungetc(b, fin);
                     printf("%d zeros", i); break;
      case LOAD    : printf("LOAD  "); break;
      case STOR    : printf("STOR  "); break;
      case LOADN   : printf("LOADN "); break;
      case LOADF   : printf("LOADF "); break;
      case POP     : printf("POP   "); break;
      case STI     : printf("STI   "); break;
      case LDI     : printf("LDI   "); break;
      case DUP     : printf("DUP   "); break;
      case ADD     : printf("ADD   "); break;
      case ADDF    : printf("ADDF  "); break;
      case SUB     : printf("SUB   "); break;
      case SUBF    : printf("SUBF  "); break;
      case MUL     : printf("MUL   "); break;
      case MULF    : printf("MULF  "); break;
      case DIV     : printf("DIV   "); break;
      case DIVF    : printf("DIVF  "); break;
      case MOD     : printf("MOD   "); break;
      case FLOAT   : printf("FLOAT "); break;
      case FIX     : printf("FIX   "); break;
      case NOT     : printf("NOT   "); break;
      case AND     : printf("AND   "); break;
      case OR      : printf("OR    "); break;
      case EQL     : printf("EQL   "); break;
      case EQLF    : printf("EQLF  "); break;
      case NEQ     : printf("NEQ   "); break;
      case NEQF    : printf("NEQF  "); break;
      case LSS     : printf("LSS   "); break;
      case LSSF    : printf("LSSF  "); break;
      case GTR     : printf("GTR   "); break;
      case GTRF    : printf("GTRF  "); break;
      case LEQ     : printf("LEQ   "); break;
      case LEQF    : printf("LEQF  "); break;
      case GEQ     : printf("GEQ   "); break;
      case GEQF    : printf("GEQF  "); break;
      case INCSP   : printf("INCSP "); break;
      case DECSP   : printf("DECSP "); break;
      case INCFP   : printf("INCFP "); break;
      case DECFP   : printf("DECFP "); break;
      case JUMP    : printf("JUMP  "); break;
      case PJZ     : printf("PJZ   "); break;
      case POPJMP  : printf("POPJMP"); break;
      case POPFP   : printf("POPFP "); break;
      case LDFP    : printf("LDFP  "); break;
      case INIT    : printf("INIT  "); break;
      case STOP    : printf("STOP  "); break;
      case BADN    : printf("BADN  "); break;
      default: printf("#%03d  ",opc); break; }
    if (opd==0)
      printf("\n");
    else if (opd==CONSTANT_OPERAND)
    { converter.b.a=fgetc(fin);
      converter.b.b=fgetc(fin);
      converter.b.c=fgetc(fin);
      converter.b.d=fgetc(fin);
      location_counter+=4;
      if (opc==LOADF)
        printf(" %f\n", converter.f);
      else
        printf(" %d\n", converter.i); }
    else if (opd=FP_RELATIVE_OPERAND)
    { converter.b.a=fgetc(fin);
      converter.b.b=fgetc(fin);
      converter.b.c=fgetc(fin);
      converter.b.d=fgetc(fin);
      location_counter+=4;
      if (converter.i<0)
        printf(" FP%d\n", converter.i);
      else
        printf(" FP+%d\n", converter.i); }
    else
      printf(" BAD\n"); }
  fclose(fin); }