static int
interpret()
{
fetch:
Cyclecount++;
W = M[C++];
if ((W & DBIT) == 0)
D = W & ABITS;
else
D = M[C++];
if ((W & PBIT) != 0) D += P;
if ((W & GBIT) != 0) D += G;
if ((W & IBIT) != 0) D = M[D];
switch (W >> FSHIFT) {
error: default: printf("\nINTCODE ERROR AT C = %d\n", C - 1);
return -1;
case 0: B = A; A = D; goto fetch;
case 1: M[D] = A; goto fetch;
case 2: A = A + D; goto fetch;
case 3: C = D; goto fetch;
case 4: A = !A;
case 5: if (!A) C = D; goto fetch;
case 6: D += P;
M[D] = P; M[D + 1] = C;
P = D; C = A;
goto fetch;
case 7: switch (D) {
default: goto error;
case 1: A = M[A]; goto fetch;
case 2: A = -A; goto fetch;
case 3: A = ~A; goto fetch;
case 4: C = M[P + 1];
P = M[P];
goto fetch;
case 5: A = B * A; goto fetch;
case 6: A = B / A; goto fetch;
case 7: A = B % A; goto fetch;
case 8: A = B + A; goto fetch;
case 9: A = B - A; goto fetch;
case 10: A = B == A ? ~0 : 0; goto fetch;
case 11: A = B != A ? ~0 : 0; goto fetch;
case 12: A = B < A ? ~0 : 0; goto fetch;
case 13: A = B >= A ? ~0 : 0; goto fetch;
case 14: A = B > A ? ~0 : 0; goto fetch;
case 15: A = B <= A ? ~0 : 0; goto fetch;
case 16: A = B << A; goto fetch;
case 17: A = B >> A; goto fetch;
case 18: A = B & A; goto fetch;
case 19: A = B | A; goto fetch;
case 20: A = B ^ A; goto fetch;
case 21: A = B ^ ~A; goto fetch;
case 22: return 0;
case 23: B = M[C]; D = M[C + 1];
while (B != 0) {
B--; C += 2;
if (A == M[C]) { D = M[C + 1]; break; }
}
C = D;
goto fetch;
case 24: selectinput(A); goto fetch;
case 25: selectoutput(A); goto fetch;
case 26: A = rdch(); goto fetch;
case 27: wrch(A); goto fetch;
case 28: A = findinput(A); goto fetch;
case 29: A = findoutput(A); goto fetch;
case 30: return A;
case 31: A = M[P]; goto fetch;
case 32: P = A; C = B; goto fetch;
case 33: endread(); goto fetch;
case 34: endwrite(); goto fetch;
case 35: D = P + B + 1;
M[D] = M[P];
M[D + 1] = M[P + 1];
M[D + 2] = P;
M[D + 3] = B;
P = D;
C = A;
goto fetch;
case 36: A = getbyte(A, B); goto fetch;
case 37: putbyte(A, B, M[P + 4]); goto fetch;
case 38: A = input(); goto fetch;
case 39: A = output(); goto fetch;
}
}
}
PUBLIC WORD parse(INT old_nesting)
{
int nesting = (int) old_nesting;
int quoted;
nextsym();
if( symb==s_eof ) return nesting;
parse_depth++;
if( ( quoted = (symb==s_quote) ) != 0 ) nextsym();
/* trace("Parse %squoted depth %d",quoted?"":"un",parse_depth); */
for(;;)
{
switch ( (int)symb )
{
case s_builtin: if(!quoted) { builtin(); break; }
case s_macro: if(!quoted) { eval(); break; }
case s_hexvar:
case s_var: if(!quoted) { evalvar(); break; }
default:
case s_token:
if( toksize == 1 ) wrch(token[0]);
else wrstr(token);
break;
case s_lbra:
if( nesting++ > 0) wrch(c_lbra);
break;
case s_rbra:
if( --nesting > 0 ) wrch(c_rbra);
break;
case s_eof: return nesting;
case s_quote:
if( quoted ) wrch(c_quote);
pbchar(c_quote);
nesting = (int) parse((WORD)nesting);
break;
case s_concat:
if( quoted ) wrch(c_concat);
break;
}
if ( nesting <= old_nesting ) break;
nextsym();
}
parse_depth--;
return nesting;
}
