On Wed, 11 Dec 2024 10:24:03 GMT, Viktor Klang <vkl...@openjdk.org> wrote:
>> The Class.getModifiers() method is implemented as a native method in >> java.lang.Class to access a field that we've calculated when creating the >> mirror. The field is final after that point. The VM doesn't need it >> anymore, so there's no real need for the jdk code to call into the VM to get >> it. This moves the field to Java and removes the intrinsic code. I >> promoted the compute_modifiers() functions to return int since that's how >> java.lang.Class uses the value. It should really be an unsigned short >> though. >> >> There's a couple of JMH benchmarks added with this change. One does show >> that for array classes for non-bootstrap class loader, this results in one >> extra load which in a long loop of just that, is observable. I don't think >> this is real life code. The other benchmarks added show no regression. >> >> Tested with tier1-8. > > src/java.base/share/classes/java/lang/Class.java line 1006: > >> 1004: private final transient int modifiers; // Set by the VM >> 1005: >> 1006: // package-private > > @coleenp Could this field be @Stable, or does that only apply to `putfield`s? I don't think this needs to be stable - finals in java.lang is trusted by the JIT compiler. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/22652#discussion_r1880350790
