STGOPT
- Default
- NOSTGOPT
- Recommended
- STGOPT
- Reasoning
- This is a new option introduced in V5 that is now orthogonal to OPT. In V4, the STGOPT behavior to remove unreferenced data items and the corresponding code to initialize their VALUE clauses is implied when going from OPT(STD) to OPT(FULL). Since V5, that behavior is now specified independently. Over a set of benchmark programs, the use of STGOPT results in an average 2.8% reduction in the size of the object file at OPT(2), and a maximum reduction of 11.8%.
- Considerations
- The same considerations
that applied in V4 to specifying OPT(FULL)
should be used in deciding to use STGOPT in V6. That is,
you cannot use neither OPT(FULL) nor STGOPT if you relies upon any of the following data items:
- Unreferenced
LOCAL-STORAGE
and non-externalWORKING-STORAGE
level-77 and level-01 elementary data items - Non-external level-01 group items if none of their subordinate items are referenced
- Unreferenced special registers
- Unreferenced
Note: The STGOPT option is ignored for data items that
have the VOLATILE clause.