Output Register Information

When control returns to the caller of the Register_For_Allocates service, the general purpose registers (GPRs) contain:

Register: Contents
0 - 1: Used as work registers by the system
2 - 14: Unchanged
15: Used as a work register by the system

When control returns to the caller of the Register_For_Allocates service, the access registers (ARs) contain:

Register: Contents
0 - 1: Used as work registers by the system
2 - 14: Unchanged
15: Used as a work register by the system

Some callers depend on register contents remaining the same before and after issuing a service. If the system changes the contents of registers on which the caller depends, the caller must save them before issuing the service, and restore them after the system returns control.