-XX:[+|-]UseCompressedOops
(64-bit only)
This Oracle HotSpot option enables or disables compressed references in 64-bit JVMs. The option is recognized by the Eclipse OpenJ9™ VM and is provided to help when porting applications from the HotSpot JVM to the OpenJ9 VM. This option might not be supported in subsequent releases.
Syntax
    -XX:[+|-]UseCompressedOops
| Setting | Effect | Default | 
|---|---|---|
-XX:+UseCompressedOops | 
Enable | |
-XX:-UseCompressedOops | 
Disable | 
The -XX:+UseCompressedOops option is similar to specifying -Xcompressedrefs. Compressed references are used by default when the maximum memory size for an application is set above a platform-specific value. For more information, see -Xcompressedrefs.