JDK-8003848 : Make ConstMethod::generic_signature_index optional and move Method::_max_stack to ConstMethod
  • Type: Enhancement
  • Status: Closed
  • Resolution: Fixed
  • Component: hotspot
  • Sub-Component: runtime
  • Priority: P3
  • OS: generic
  • CPU: generic
  • Submit Date: 2012-11-21
  • Updated Date: 2014-06-26
  • Resolved Date: 2012-11-28
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availabitlity Release.

To download the current JDK release, click here.
JDK 8 Other
8Fixed hs25Fixed
Description
Majority of java methods do not have generic signature. For those methods, ConstMethod::generic_signature_index is always 0. ConstMethod::generic_signature_index can be optional and only allocated for methods with generic signature.

The Method class has a 2-byte unused space due to padding. Method::_max_stack can be moved to ConstMethod after changing ConstMethod::generic_signature_index to be optionally allocated. This removes an u2 field in Method, and can avoid wasting 2-byte unused space due to padding.

Together, above would save 4-bytes for method without generic signature.