Use the extract stacked registers (EREG) instruction to load ARs and GPRs from the current linkage stack entry. A typical use of EREG is in the middle of a subroutine after the caller's input registers have been modified for other purposes. Use EREG to restore the contents of the AR/GPR pairs.

In the following example, EREG extracts the contents of the calling program's ARs 0-1 and GPRs 0-1 from the current entry and loads them into ARs 0-1 and GPRs 0-1. The entry in this example was caused by the BAKR instruction.

.
L    15,=A(SUBR)
BALR 14,15
.
.
.
.

SUBR EQU  *
     BAKR 14,0
     .
     .
     .
     EREG 0,1
     .
     .
     PR

The EREG instruction does not change the current stack pointer.

Another example of using EREG to extract the contents of an AR/GPR pair appears in Example of using TESTART.