RFR: 8265129: Add intrinsic support for JVM.getClassId

[Denghui Dong]

On Tue, 13 Apr 2021 16:52:44 GMT, Denghui Dong <ddong at openjdk.org> wrote:

> 8265129: Add intrinsic support for JVM.getClassId

Hi,

Could I have a review of this change that adding intrinsic support for JVM.getClassId.

In the current patch, I didn't completely implement c1 intrinsic support on arm/ppc/s390 platform, but I believe it can be easily achieved,
but before that, I hope someone can do a preliminary review of this patch because I am not familiar with the implementation of jit.

JMH benchmark:

@State(Scope.Benchmark)
public class MyBenchmark {

    @Setup
    public void setup() {
        JVM.getJVM().createNativeJFR();
    }

    @Benchmark
    @Fork(value=1, jvmArgs = {"--add-exports", "jdk.jfr/jdk.jfr.internal=ALL-UNNAMED"})
    @Warmup(iterations = 5, time = 1)
    public void testIntrinsic(Blackhole bh) {
        bh.consume(JVM.getClassId(boolean.class));
        bh.consume(JVM.getClassId(void.class));
        bh.consume(JVM.getClassId(MyBenchmark.class));
    }

    @Benchmark
    @Fork(value=1, jvmArgs = {"--add-exports", "jdk.jfr/jdk.jfr.internal=ALL-UNNAMED"})
    @Warmup(iterations = 5, time = 1)
    public void testNoIntrinsic(Blackhole bh) {
        bh.consume(JVM.getClassIdNonIntrinsic(boolean.class));
        bh.consume(JVM.getClassIdNonIntrinsic(void.class));
        bh.consume(JVM.getClassIdNonIntrinsic(MyBenchmark.class));
    }

    @TearDown
    public void tearDown() {
      if (JVM.getClassIdNonIntrinsic(boolean.class) != JVM.getClassId(boolean.class)
          || JVM.getClassIdNonIntrinsic(void.class) != JVM.getClassId(void.class)
          || JVM.getClassIdNonIntrinsic(MyBenchmark.class) != JVM.getClassId(MyBenchmark.class)) {
          throw new RuntimeException();
      }
    }
}


result on x86_64:

Benchmark                           Mode  Samples          Score  Score error  Units
o.s.MyBenchmark.testIntrinsic      thrpt       20  195662934.056   566744.281  ops/s
o.s.MyBenchmark.testNoIntrinsic    thrpt       20    7997200.373     6424.038  ops/s

-------------

PR: https://git.openjdk.java.net/jdk/pull/3470