c/switch_split.c

   1 extern int sys_read(int,int);
   2 extern int sys_request(int,int);
   3 extern int sys_write(int,int);
   4 extern int vocab_get(int);
   5 extern int vocab_set(int,int);
   6 extern void push(int);
   7 extern int pop(void);
   8 extern void rpush(int);
   9 extern int rpop(void);
  10 extern void rinit(void);
  11 static char memseg[1024] =
  12   { 0, 0, 0, 9, 'i', 'n', 't', 'e', 'r', 'p', 'r', 'e', 't', 0, 0, 0,
  13     0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 0, 0, 0, 16, 0, 0, 0, 13, 0, 0, 0, 1
  14   };
  15 static int interpret(int,int);
  16 int main(void) {
  17   /* int start, here, eax, ebx, esi, mode;
  18   here = (int) memseg + 512;
  19   mode = here;
  20   *(int*) mode = 11; //executing
  21   here += 4;
  22   //string "interpret"
  23   eax = here;
  24   *(int*)here++ = 9;
  25   *(char*)here++ = 'i';
  26   *(char*)here++ = 'n';
  27   *(char*)here++ = 't';
  28   *(char*)here++ = 'e';
  29   *(char*)here++ = 'r';
  30   *(char*)here++ = 'p';
  31   *(char*)here++ = 'r';
  32   *(char*)here++ = 'e';
  33   *(char*)here++ = 't';
  34   here += 3; //align
  35   //initial definition of "interpret"
  36   esi = here;
  37   *(int*)here++ = 4;  //WORD
  38   *(int*)here++ = 2;  //LIT
  39   *(int*)here++ = mode; //addr of mode var
  40   *(int*)here++ = 10; //FETCH
  41   *(int*)here++ = 12; //EXECUTE
  42   *(int*)here++ = 13; //NOOP
  43   *(int*)here++ = 1;  //RET
  44   //insert into vocab
  45   vocab_set(eax, esi);
  46   //string "quit"
  47   ebx = esi;
  48   eax = here;
  49   *(int*)here++ = 4;
  50   *(char*)here++ = 'q';
  51   *(char*)here++ = 'u';
  52   *(char*)here++ = 'i';
  53   *(char*)here++ = 't';
  54   //initial definition of "quit"
  55   esi = here;
  56   *(int*)here++ = 3; //rinit
  57   *(int*)here++ = ebx; //interpret
  58   *(int*)here++ = 9; //JMP
  59   *(int*)here++ = esi; //jmp addr 0 (interpret)
  60   //insert into vocab
  61   vocab_set(eax, esi); */
  62   return interpret((int)memseg, (int)memseg);
  63 }
  64 static int interpret(int esi, int here) {
  65   int eax = 0, ebx = 0, ecx = 0, edi = 0;
  66  next:
  67   eax = *(int*) esi;
  68   esi += 4;
  69  exec:
  70   switch(eax) {
  71   case 0: //interpret
  72     esi = eax;
  73     eax = *(int*)eax;
  74     goto next;
  75   case 1: // ret (exit)
  76     esi = rpop();
  77     goto next;
  78   case 2: // pushnext (lit)
  79     push(*(int*)esi);
  80     esi += 4;
  81     goto next;
  82   case 3: // rinit
  83     rinit();
  84     goto next;
  85   case 4: // word
  86     esi += eax;
  87     eax += esi;
  88     goto next;
  89   case 5: // sys_read
  90     sys_read(pop(),pop());
  91     goto next;
  92   case 6: // sys_request
  93     sys_request(pop(),pop());
  94     goto next;
  95   case 7: // sys_write
  96     sys_write(pop(),pop());
  97     goto next;
  98   case 8: // bye
  99     break;
 100   case 9: // goto
 101     esi = *(int*) esi;
 102     goto next;
 103   case 10: // @ fetch
 104     push(*(int*)pop());
 105     goto next;
 106   case 11: // ! set
 107     *(int*)pop() = pop();
 108     goto next;
 109   case 12: // EXECUTE
 110     eax = pop();
 111     goto exec;
 112   case 13: // NOOP
 113     push(1);
 114     goto next;
 115   default: // eax is an addr, jump to it and push esi
 116     rpush(esi);
 117     esi = eax;
 118     goto next;
 119   }
 120   return 0;
 121 }