bdfp1m32 | Programming Concepts and Reference |
Use this macro to support TPFDF fast-link segments. Parameters are
provided to do the following:
- Call a fast-link segment
- Return from a fast-link segment
- Reestablish the program base
- Call the TPFDF error handler.
Format
- label
- is a symbolic name assigned to the macro statement.
- BASE
- reestablishes register (R8) as the program base.
- RETURN
- specifies that control is returned to the TPFDF macro call.
- ERROR
- specifies the error code condition.
- dump
- is the dump number assigned for the central error handler.
- prog
- is the name of the fast-link segment that gets control.
- case
- is the case number, which is a decimal number in the range
0-7. The case number is in the segment specified with the
prog parameter.
Entry Requirements
R1 must point to the current TPFDF stack area.
Normal Return
None.
Error Return
None.
Programming Considerations
If you specify the prog parameter value with a UWAx
segment and the calling segment is not a UWxx program, all data
levels are preserved and registers in the range R0-R7 are saved and
restored. If the calling segment is a UWxx program, an
internal fast-link call is used and registers in the range R0-R7, R14,
or R15 are not saved.
Examples
- The following example provides a fast link to case number 4 of segment
UWB0:
DFLNK UWB0,4
- The following example calls the case for DB0100 in the central error
handler:
DFLNK ERROR,DB0100
- The following example issues a GETCC macro on level DD and restores the
correct program base:
GETCC DD
DFLNK BASE
Related Macros
None.