Class: LFSR::Fast::Size31
- Inherits:
-
LFSR_Base
- Object
- LFSR_Base
- LFSR::Fast::Size31
- Defined in:
- ext/lfsr/lfsr.c
Constant Summary collapse
- MASK =
ULL2NUM(0x7fffffffLLU)
Instance Method Summary collapse
Instance Method Details
#next_i ⇒ Object
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# File 'ext/lfsr/lfsr.c', line 355
VALUE rb_lfsr_next_i_31(VALUE self) {
unsigned long long reg = NUM2ULL(ROBJECT(self)->as.ary[0]), max = NUM2ULL(ROBJECT(self)->as.ary[1]);
label_shift31:
reg = (reg >> 1) | ((bit(0)^bit(1)^bit(2)^bit(3)) << 0x1e);
if (reg > max) goto label_shift31;
ROBJECT(self)->as.ary[0] = ULL2NUM(reg);
return ULL2NUM(reg - 1);
}
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