This exit routine is given control each time MFX is about to place a record in the output area after the final merge. In passing control to the E35 exit routine, MFX places the address of a parameter list in Register 1. The parameter list contains three entries.
For 32-bit parameter lists, each entry is one word. The first byte of each word contains binary zeros. The first word contains the address of the record about to leave Phase 3; after the last record has been passed, this word will contain zeros. The second word contains the address of the record already in the output area; when the first record is passed, this word will contain zeros.
The third word contains the user address constant. It contains either the last value set in it by an E15 exit routine or, if not modified by an E15 exit routine, the initial value from the user exit address constant provided in the invoking parameter list. If the value was obtained from the 24-bit invoking parameter list, it is limited to 24 bits with the high-order byte set to X'00'.
If the user exit address constant was not provided or if MFX was JCL-invoked, it will contain binary zeros. This word may be changed by the E35 exit routine whenever it is entered, and it will remain the same on all subsequent entries to the E35 exit routine.
The 64-bit E35 parameter list can be enabled from the 64-bit sort invocation parameter list. See p. 7.4 for information on returning records to MFX in register 1 and see ”Register Conventions” on p 7.4 for a description of the register 13 save area for exits called with the 64-bit exit parameter list. The same information is passed to the exit as for the 32-bit parameter list, but double-word entries are used:
