Sure, the JVM can use a 5-bit value for doing shifts on 32-bit integers, there's no problem there. But why would Java compile "x << 37" to "x << 5"? If you're working raw in the JVM, there's no such concept as x << 37, because 37 requires more than 5 bits to specify. Java explicitly allows you to say x << 37, but secretly defines it to do something insane.