Non-effective codegeneration for non-flattened array to flattened array manual loop copying.

A non-flattened array may have runtime types of the array as <Value type>.ref, interface, or Object.
The case when the source runtime type is <Value type>.ref is ~50%-20% faster than the case when the runtime type is interface or Object. It does not depend on the static type.


Benchmark (size) Mode Cnt Score Error Units
InlineCopy.Int_to_Val_as_Int_to_Int_copy 100 avgt 5 124.747 ± 3.068 ns/op
InlineCopy.Int_to_Val_as_Int_to_Obj_copy 100 avgt 5 124.267 ± 1.778 ns/op
InlineCopy.Int_to_Val_as_Int_to_Ref_copy 100 avgt 5 107.654 ± 1.185 ns/op
InlineCopy.Int_to_Val_as_Int_to_Val_copy 100 avgt 5 114.008 ± 2.815 ns/op

InlineCopy.Ref_to_Val_as_Int_to_Int_copy 100 avgt 5 76.784 ± 0.355 ns/op
InlineCopy.Ref_to_Val_as_Int_to_Obj_copy 100 avgt 5 77.690 ± 3.007 ns/op
InlineCopy.Ref_to_Val_as_Int_to_Ref_copy 100 avgt 5 79.112 ± 1.973 ns/op
InlineCopy.Ref_to_Val_as_Int_to_Val_copy 100 avgt 5 74.372 ± 4.112 ns/op

Benchmarks: http://cr.openjdk.java.net/~skuksenko/valhalla/array_q_vs_l/benchmarks/

Cmd line:
${JAVA_HOME}/bin/java -XX:+EnablePrimitiveClasses --enable-preview -jar target/benchmarks.jar "InlineCopy.Ref_to_Val_as_Int.*" "InlineCopy.Int_to_Val_as_Int.*"