That's just the placeholder implementation that will work on any platform and even with the interpreter. If you look at the openjdk9 sources you will notice th

That's just the placeholder implementation that will work on any platform and even with the interpreter. If you look at the openjdk9 sources you will notice that it is annotated as intrinsic candidate[0]. But earlier versions also have intrinsics for that[1], it's just not annotated as such. [0] http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/23721aa1d87f/src/java.base/share/classes/java/lang/Integer.java#l1676 http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/23721aa1d87f/s... [1] https://gist.github.com/apangin/7a9b7062a4bd0cd41fcc#file-hotspot-jvm-intrinsics-L38 https://gist.github.com/apangin/7a9b7062a4bd0cd41fcc#file-ho...