This page describes the command line for the experimental Java compiler, the Java launcher and HotSpot JVM for the support of L-World LW2 Inline Types in the Valhalla project.

L-World Value Types flags:


 

Flag

Description

hotspot


-XX:EnableValhallaBoolean value, default value is `true`
If true enable support for L-World value types.

-XX:ValueArrayElemMaxFlatSizeInteger value, default is -1
Max size for flattening an array of values, < 0 means no limit, 0 = disable

-XX:ValueArrayElemMaxFlatOopsInteger value, default is 4
Max number of embedded object references in value type to flatten in an array, < 0 means no limit 

-XX:ValueArrayAtomicAccessBoolean value, default value is `false`
Enable atomic access to values in an array, by treating value types as references.

-XX:EnableValhallaC1

Boolean value, default "false"

If true enable experimental C1 support of inline type


-XX:AcmpOnValues

Integer value, default is "3"

0 = regular acmp (i.e. ptr compare only)

1 = always false for value, perturbation scheme

2 = always false for value

3 = substitutability test

java

javac


-XDallowWithFieldOperator

Allow experimental direct use of the withfield bytecode via "__WithField(<field ref>, <value>)" synatx