32-bit unsigned integer multiplication in Lua

.lua

function dwordMultiply(a, b)
	a = a % 4294967296
	b = b % 4294967296
	local ah, al = math.floor(a / 65536), a % 65536
	local bh, bl = math.floor(b / 65536), b % 65536
	local high = ((ah * bl) + (al * bh)) % 65536
	return ((high * 65536) + (al * bl)) % 4294967296
end