ZSIZE

NM and CM callable.

Alters current DB to Z area of the compatibility mode (CM) stack.

Syntax

     I16         I16V
   newsize:=ZSIZE(size);

Functional Return

newsize

16-bit signed integer (assigned functional return)

Passes the size, in half words (CM words) actually granted.

Parameters

size

16-bit signed integer by value (required)

Passes the desired register value of Z, relative to DB. This is the number of half words (CM words) from DB to Z. This value must be >=0.

Operation Notes

When called from programs running in NM, only the CM stack is affected. Programmatic expansion and contraction of the NM stack is not necessary.

Allows an NM program to alter the size of the current DB to Z area of the CM stack by adjusting the register offset of the Z address from the DB address (DB to Z).

Increases the Z address (CM stack expands) or decreases the Z address (CM stack contracts). If the Z to DB area size requested exceeds the maximum size permitted for the DL to Z (CM stack) area, only the maximum size allowed is granted.

All changes to the DB to Z area are made in increments or decrements of 128 half words (CM words); the size granted may differ from the size requested.

Condition Codes

CCE (2): Request granted.
CCG (0): Request granted. The requested size exceeded the maximum limits of the DL to Z (CM stack) area. The maximum limit is granted, and the value is returned in newsize.
CCL (1): An illegal size parameter, less than (S - DB) + 64 half words was specified. The minimum value is assigned by default.

Related Information

None