diff.diff

 data = [] of UInt32
 File.open(filename, "rb") do |file|
-  (file.size/4).times do
-    a = (file.read_byte || 0).to_u32
-    b = (file.read_byte || 0).to_u32
-    c = (file.read_byte || 0).to_u32
-    d = (file.read_byte || 0).to_u32
+  slice = Slice(UInt8).new(file.size.to_i)
+  file.read(slice)
+  (file.size/4).times do |w|
+    a, b, c, d = slice[(w.to_i32 * 4), 4].map{|v| v.to_u32}
     data << ((a << 24) + (b << 16) + (c << 8) + d)
   end
 end