This subtask is to specify what performance tests and results are for the implementation of JEP483: Ahead-of-Time Class Loading & Linking (JDK-8315737 ).

(A) Confirmation of expected performance gain

As described in the JEP document, we expect modest start-up improvements for applications that use a significant amount of invokedynamic operations. We can validate this claim using two simple startup benchmarks:

[1] StreamTest - a small Java program that uses a few stream operations

Expected performance improvement ~15-30%

[2] javac HelloWorld.java - run the Java compiler on a small source file

Expected performance improvement ~10-20%

(See attachment perf-results-jep483-20241015.txt for details, as well as sample numbers collected by [~iklam])

HelloStream BEFORE 0.0259389
HelloStream AFTER  0.0185902 
javac HelloWorld.java BEFORE 0.182298
javac HelloWorld.java AFTER  0.149146

(B) No performance degradation in baseline cases

Validate that there is no performance degradation on CDS-enabled startup tests and benchmarks such as Renaissance, Dacapo, and SPECjbb2015 when class linking is not enabled (OOTB/-XX:-AOTClassLinking)

(C) No/minimal performance degradation when enabled

Validate that there are no or minimal performance degradation on CDS-enabled benchmarks such as Renaissance, Dacapo, and SPECjbb2015 when class linking is enabled (OOTB/-XX:+AOTClassLinking)