Using OPS/REXX › The Interaction of OPS/REXX with Other Languages › Register Contents
Register Contents
On entry to a REXX function, the registers contain the following:
- Register 0 contains the address of an ENVBLOCK
- Register 1 contains the address of an EFPL
- Registers 2 through 12 are unpredictable
- Register 13 points to a save area for the routine
- Register 14 contains the return address to the caller
- Register 15 contains the entry point address of the routine
