Class: LFSR::Fast::Size42

Inherits:
LFSR_Base
  • Object
show all
Defined in:
ext/lfsr/lfsr.c

Constant Summary collapse

MASK = 
ULL2NUM(0x3ffffffffffLLU)

Instance Method Summary collapse

Instance Method Details

#next_i ⇒ Object 



487
488
489
490
491
492
493
494
495
496
497
 
# File 'ext/lfsr/lfsr.c', line 487

VALUE rb_lfsr_next_i_42(VALUE self) {
  unsigned long long reg = NUM2ULL(ROBJECT(self)->as.ary[0]), max = NUM2ULL(ROBJECT(self)->as.ary[1]);

  label_shift42:
  reg = (reg >> 1) | ((bit(0)^bit(2)^bit(5)^bit(7)) << 0x29);
  if (reg > max) goto label_shift42;

  ROBJECT(self)->as.ary[0] = ULL2NUM(reg);

  return ULL2NUM(reg - 1);
}