Planet MVS Dave's HLASM web pages AI and mainframe assembler IEFBR14

Prompt: Change the following HLASM program to use register equates from the IBM YREGS macro. Add consise comments on what the code is doing. IEFBR14 CSECT , SR 15,15 BR 14 END

IEFBR14  CSECT ,
         YREGS                          * Define register equates R0–R15
         SR     R15,R15                 * Clear return code (set R15 to 0)
         BR     R14                     * Return to caller
         END

IEFBR14  CSECT ,           Define program control section
         YREGS ,                   Include IBM register equates
* Clear return code by setting R15 to 0
         SR    R15,R15             Subtract R15 from itself to set to 0
* Return to caller using R14 (return address)
         BR    R14                 Branch to return address in R14
         END                      End of program

         YREGS                          * PULL IN REGISTER EQUATES
IEFBR14  CSECT                          * DEFINE A CONTROL SECTION
         SR    R15,R15                  * SET REGISTER 15 TO ZERO (SUCCESSFUL RETURN CODE)
         BR    R14                      * BRANCH TO THE RETURN ADDRESS IN REGISTER 14
         END                            * END OF THE ASSEMBLY

IEFBR14  CSECT 
         YREGS             Define register equates
         SR    R15,R15     Set return code to zero
         BR    R14         Return to caller
         END

IEFBR14  CSECT ,                Program entry point
         YREGS ,                    Include IBM register equates
*
* Simple do-nothing program that sets return code to zero
* and returns to caller
*
         SR    R15,R15              Clear return code register (RC=0)
         BR    R14                  Return to caller
         END

My take on these results:

• All of these chatbots know registers in a mainframe assembler program and a basic IBM macro
• All tested chatbots had similar results on this simple program.

Same prompt, different results