bit32 = {}

local N = 32
local P = 2^N

bit32.bnot = function(x)
	x = x%P
	return P-1-x
end

bit32.band = function(x, y)
	-- Common usecases, they deserve to be optimized
	if y == 0xff then return x%0x100 end
	if y == 0xffff then return x%0x10000 end
	if y == 0xffffffff then return x%0x100000000 end
	
	x, y = x%P, y%P
	local r = 0
	local p = 1
	for i = 1, N do
		a, b = x%2, y%2
		x, y = math.floor(x/2), math.floor(y/2)
		if a+b == 2 then
			r = r + p
		end
		p = 2*p
	end
	return r
end

bit32.bor = function(x, y)
	-- Common usecases, they deserve to be optimized
	if y == 0xff then return x - (x%0x100) + 0xff end
	if y == 0xffff then return x - (x%0x10000) + 0xffff end
	if y == 0xffffffff then return 0xffffffff end
	
	x, y = x%P, y%P
	local r = 0
	local p = 1
	for i = 1, N do
		a, b = x%2, y%2
		x, y = math.floor(x/2), math.floor(y/2)
		if a+b >= 1 then
			r = r + p
		end
		p = 2*p
	end
	return r
end

bit32.bxor = function(x, y)
	x, y = x%P, y%P
	local r = 0
	local p = 1
	for i = 1, N do
		a, b = x%2, y%2
		x, y = math.floor(x/2), math.floor(y/2)
		if a+b == 1 then
			r = r + p
		end
		p = 2*p
	end
	return r
end

bit32.lshift = function(x, s_amount)
	if math.abs(s_amount) >= N then return 0 end
	x = x%P
	if s_amount < 0 then
		return math.floor(x*(2^s_amount))
	else
		return (x*(2^s_amount))%P
	end
end

bit32.rshift = function(x, s_amount)
	if math.abs(s_amount) >= N then return 0 end
	x = x%P
	if s_amount > 0 then
		return math.floor(x*(2^-s_amount))
	else
		return (x*(2^-s_amount))%P
	end
end

bit32.arshift = function(x, s_amount)
	if math.abs(s_amount) >= N then return 0 end
	x = x%P
	if s_amount > 0 then
		local add = 0
		if x >= P/2 then
			add = P - 2^(N-s_amount)
		end
		return math.floor(x*(2^-s_amount))+add
	else
		return (x*(2^-s_amount))%P
	end
end