typedef enum { LODI, STO, ADDI, ADD, SUBI, SUB, MULI, MUL, DIVI, DIV, INC, DEC } INSN; f (pc) short *pc; { long long stack[16], *sp = &stack[16], acc = 0; for (;;) { switch ((INSN)*pc++) { case LODI: *--sp = acc; acc = ((long long)*pc++) << 32; break; case STO: return (acc >> 32) + (((((unsigned long long) acc) & 0xffffffff) & (1 << 31)) != 0); break; case ADDI: acc += ((long long)*pc++) << 32; break; case ADD: acc = *sp++ + acc; break; case SUBI: acc -= ((long long)*pc++) << 32; break; case SUB: acc = *sp++ - acc; break; case MULI: acc *= *pc++; break; case MUL: { long long aux; unsigned char minus; minus = 0; aux = *sp++; if (aux < 0) { minus = ~minus; aux = -aux; } if (acc < 0) { minus = ~minus; acc = -acc; } acc = ((((((unsigned long long) acc) & 0xffffffff) * (((unsigned long long) aux) & 0xffffffff)) >> 32) + ((((unsigned long long) acc) >> 32) * (((unsigned long long) aux) & 0xffffffff) + (((unsigned long long) acc) & 0xffffffff) + (((unsigned long long) aux) >> 32)) + (((((unsigned long long) acc) >> 32) * (((unsigned long long) aux) >> 32)) << 32)); if (minus) acc = -acc; } break; case DIVI: { short aux; aux = *pc++; acc = (acc + aux / 2) / aux; } break; case DIV: { long long aux; unsigned char minus; minus = 0; aux = *sp++; if (aux < 0) { minus = ~minus; aux = -aux; } if (acc < 0) { minus = ~minus; acc = -acc; } if (((unsigned long long)acc) == 0) acc = (unsigned long long)-1 / 2; else if ((((unsigned long long) ((unsigned long long)acc)) & 0xffffffff) == 0) acc = ((unsigned long long)aux) / (((unsigned long long) ((unsigned long long)acc)) >> 32); else if ((((unsigned long long) ((unsigned long long)acc)) >> 32) == 0) acc = ((((unsigned long long)aux) / ((unsigned long long)acc)) << 32) + ((((unsigned long long)aux) % ((unsigned long long)acc)) << 32) / ((unsigned long long)acc); else { unsigned char shift; unsigned long hi; shift = 32; hi = (((unsigned long long) ((unsigned long long)acc)) >> 32); do { if (hi & ((unsigned long)1 << (shift - 1))) break; } while (--shift != 0); printf("shift = %d\n", shift); acc = ((((unsigned long long)aux) / ((unsigned long long)acc)) << 32) + (((((unsigned long long)aux) % ((unsigned long long)acc)) << (32 - shift)) + ((((unsigned long long)acc) >> shift) / 2)) / (((unsigned long long)acc) >> shift); } if (minus) acc = -acc; } break; case INC: acc += 1; break; case DEC: acc -= 1; break; } printf("%08lx.%08lx\n", (long)(((unsigned long long) acc) >> 32) , (long)(((unsigned long long) acc) & 0xffffffff)); } }