Merge pull request #7 from airstruck/patch-1

support negative values passed to frexp

modules/utils.lua

@@ -2,9 +2,11 @@ local utils = {}
 
 -- reimplementation of math.frexp, due to its removal from Lua 5.3 :(
 -- courtesy of airstruck
+local log2 = math.log(2)
+
 local frexp = math.frexp or function(x)
 	if x == 0 then return 0, 0 end
-	local e = math.floor(math.log(x) / math.log(2) + 1)
+	local e = math.floor(math.log(math.abs(x)) / log2 + 1)
 	return x / 2 ^ e, e
 end