Function clz [src]

Returns the number of leading zeros in twos-complement form.

Prototype

pub fn clz(a: Const, bits: Limb) Limb

Parameters

a: Constbits: Limb

Source

  pub fn clz(a: Const, bits: Limb) Limb {
    // Limbs are stored in little-endian order but we need to iterate big-endian.
    if (!a.positive and !a.eqlZero()) return 0;
    var total_limb_lz: Limb = 0;
    var i: usize = a.limbs.len;
    const bits_per_limb = @bitSizeOf(Limb);
    while (i != 0) {
        i -= 1;
        const this_limb_lz = @clz(a.limbs[i]);
        total_limb_lz += this_limb_lz;
        if (this_limb_lz != bits_per_limb) break;
    }
    const total_limb_bits = a.limbs.len * bits_per_limb;
    return total_limb_lz + bits - total_limb_bits;
}  