Accommodate new assembler mnemonics for new machine instructions

Description: System z introduces new instructions having mnemonics that might collide with existing macro instruction names. Collisions can be managed by using a different OPTABLE option (described in HLASM 1.6 Programmer’s Guide or mnemonic tags (described in the HLASM 1.6 Language Reference).

Element or feature:

HLASM

When change was introduced:

z/OS V2R1, z/OS V1R13, and z/OS V1R12, all with hardware support HLASM APARs, the latest of which are APARs PM49761 and PM86821.

Applies to migration from:

z/OS V2R1, z/OS V1R13, and z/OS V1R12, all without hardware support HLASM APARs installed. The latest of which are APARs PM49761 and PM86821.

Timing:

Before installing z/OS V2R1.

Is the migration action required?

Yes, if you have a collision with a new instruction mnemonic.

Target system hardware requirements:

None.

Target system software requirements:

None.

Other system (coexistence or fallback) requirements:

None.

Restrictions:

None.

System impacts:

None.

Related IBM Health Checker for z/OS check:

None.

Steps to take: Look for possible conflicts between new mnemonics and existing macro instructions with the same name:

Assemble an END statement with the OPTABLE(UNI,LIST) option to cause HLASM to display all mnemonics in the UNI opcode table.
If a conflicting name appears, do one of the following:
- Use either a different OPTABLE option to avoid the new mnemonics or mnemonic tags to distinguish machine instruction use from macro instruction use.
- Change the macro names.

Reference information: For the OPTABLE option, see HLASM Programmer's Guide.. For mnemonic tags, see HLASM Language Reference.