Java intrinsic functions are mentioned in various places (e.g. here). My understanding is that these are methods that handled with special native code. This seems similar to a JNI method which is also a block of native code. What is the difference? Answer The JIT knows about intrinsics, so it can inline the relevant machine instruction into the code it’s
There are many methods in the Java API that are intrinsics, but still have code associated with them when looking at the source code. For an example, Integer.bitCount() is an intrinsic, but if you open the Integer class file, you can see code with it. What purposes might this code serve if it is not necessarily used by the compiler/jvm?