Output Register Information

When control returns to the caller, the GPRs contain:

Register

Contents

0

Reason code if GR15 return code is non-zero

1

Used as a work register by the macro

14

Used as a work register by the macro

15

Return code

When control returns to the caller, the ARs contain:

Register

Contents

0

Used as a work register by the macro

1

Used as a work register by the macro

14

Used as a work register by the macro

15

Used as a work register by the macro

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