Saving Registers

IMS exit routines need to save registers in the save area pointed to by Register 13. This save area is provided at entry. In general, the save area passed to the exit is in 31-bit storage. You should save and restore registers in 31-bit mode.

There are two types of save areas that exit routines use to save registers:

• A prechained save area passed to the exit routine by IMS or the calling application

• A single save area used by exit routines that use the standard user exit parameter list