PI79788: COBOL V5 AND V6 NOT PRESERVING GPR0 AND GPR1

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Assembler program calling COBOL V5+ program expects all general
  purpose registers to be restored upon return.  Gpr0 and gpr1
  were not, leadinbg to an exception in the assembler program.
  

Local fix

• Don't use gpr0 or gpr1 as key registers in assembler
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: Users of Enterprise COBOL V6.1 compiling     *
  *                 and running COBOL programs that are called   *
  *                 from assembler programs.                     *
  *                                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Incorrect output: Following linkage     *
  *                      conventions, the compiler did not       *
  *                      generate instructions to restore        *
  *                      Register 0 or Register 1 before         *
  *                      returning control to the assembler      *
  *                      program, unlike Enterprise COBOL V4.2   *
  *                      and earlier compilers. If the           *
  *                      assembler program depended on R0 or R1  *
  *                      being preserved while calling a COBOL   *
  *                      program, the assembler program would    *
  *                      have an incorrect value in R0 or R1     *
  *                      upon return from the COBOL program.     *
  *                                                              *
  ****************************************************************
  * RECOMMENDATION: Apply the provided PTF.                      *
  *                                                              *
  ****************************************************************
  The compiler did not restore R0 or R1 when control was returned
  to a calling assembly program, which caused a difference in
  behavior when the COBOL program was migrated from COBOL V4 to
  COBOL V5/V6.
  

Problem conclusion

• The compiler was fixed to generate instructions to restore R0
  and R1 when control was returned to a calling program, as long
  as the COBOL program wasn't returning a 64-bit binary value. In
  that case, R0 contains part of the return value.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  PI81139

Modules/Macros

•    IGYQCBE
  

Fix information

• Fixed component name

  ENT COBOL FOR Z

• Fixed component ID

  5655EC600

Applicable component levels

• R610 PSY UI46711

     UP17/04/29 P F704

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.