#!/usr/local/bin/lua51

local bit = { }

bit.rshift = function(value, bit)
	return math.floor(value / (2 ^ bit))
end

bit.lshift = function(value, bit)
	return value * (2 ^ bit)
end

bit.band = function(a, b)
	local result = 0
	local bitval = 1

	while a > 0 and b > 0 do
		if (a % 2 == 1) and (b % 2 == 1) then
			result = result + bitval
		end
		a = math.floor(a / 2)
		b = math.floor(b / 2)
		bitval = bitval * 2
	end

	return result
end

bit.bor = function(a, b)
	local result = 0
	local shift = 1

	while a > 0 or b > 0 do
		local r1 = a % 2
		local r2 = b % 2

		if r1 == 1 or r2 == 1 then
			result = result + shift
		end

		a = math.floor(a / 2)
		b = math.floor(b / 2)
		shift = shift * 2
	end

	return result
end

bit.bytes = function(value)
	local bytes = { }

	if value == 0 then return { 0 } end

	while value > 0 do
		bytes[#bytes + 1] = value % 256
		value = math.floor(value / 256)
	end

	return bytes
end

bit.nbytes = function(value, num)
	local bytes = { }
	num = num or 1

	for i = 1, num do
		bytes[i] = value % 256
		value = math.floor(value / 256)
	end

	return bytes
end


bit.align16bytes = function(value)
	return math.ceil(value / 16) * 16
end


return bit