Class: LFSR::Fast::Size8

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

Constant Summary collapse

MASK = 
ULL2NUM(0xffLLU)

Instance Method Summary collapse

Instance Method Details

#next_i ⇒ Object 



79
80
81
82
83
84
85
86
87
88
89
 
# File 'ext/lfsr/lfsr.c', line 79

VALUE rb_lfsr_next_i_8(VALUE self) {
  unsigned long long reg = NUM2ULL(ROBJECT(self)->as.ary[0]), max = NUM2ULL(ROBJECT(self)->as.ary[1]);

  label_shift8:
  reg = (reg >> 1) | ((bit(0)^bit(2)^bit(3)^bit(4)) << 0x7);
  if (reg > max) goto label_shift8;

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

  return ULL2NUM(reg - 1);
}