Accommodate new assembler mnemonics for new machine instructions

Description

IBM z Systems introduced new instructions with mnemonics that might collide with existing macro instruction names. Collisions can be managed by using a different OPTABLE option or mnemonic tag.

Note: HLASM APAR PM79901 provides new hardware support for IBM z13. New instructions have been added to the UNI and ZS7 optables. The ESA vector facility instructions have been removed from the UNI optable. For a complete list of the instructions that are affected, see the technote New hardware support - APAR PM79901 at the following web site: IBM® Support Portal.

Table 1 provides more details about this migration action. Use this information to plan your changes to the system.

Table 1. Information about this migration action
Element or feature: HLASM
When change was introduced: z/OS V2R1, z/OS V1R13, and z/OS V1R12, all with hardware support HLASM APARs. Some of the most recent APARs include PM79901, PM49761, and PM86821.
Applies to migration from: z/OS V2R1 and z/OS V1R13, without hardware support HLASM APARs installed.
Timing: Before installing z/OS V2R2.
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:
  1. Assemble an END statement with the OPTABLE(UNI,LIST) option to cause HLASM to display all mnemonics in the UNI opcode table.
  2. 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.
Tip: For a tool to help in identifying mnemonic conflicts, see Techdoc PRS5289 at the IBM Techdocs website.

Reference information

For more information, see the following references:
Parent topic: HLASM actions to perform before installing z/OS V2R2