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LI78434: TOO MANY GROUP BREAKING NOPS

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • Too many group breaking XNOP ori instructions are scheduled into
    the code, resulting in multiple consecutive XNOPs or affecting
    dispatch groups.
    
    
       === EXAMPLE ===
    
    23| 00000C stw      90010070 1 ST4A
     0| 000010 ori      60420000 1 XNOP
     0| 000014 ori      60420000 1 XNOP    ** Multiple ori
     0| 000018 ori      60420000 1 XNOP
     0| 00001C ori      60420000 1 XNOP
     0| 000020 ori      60420000 1 XNOP
    23| 000024 lxvd2x   7C011E98 1 VLQD
    
    
    15| 000058 addi     38600080 1 LI
    14| 00005C stxvd2x  7C410799 1 VSTQD
     0| 000060 ori      60420000 1 XNOP
    15| 000064 stxvd2x  7C611F99 1 VSTQD
     0| 000068 ori      60420000 1 XNOP
    16| 00006C ld       E8010070 1 L8
     0| 000070 ori      60420000 1 XNOP    ** Superfluous ori
    16| 000074 ld       E8610080 1 L8
    17| 000078 addi     38210090 1 AI
    

Local fix

Problem summary

  • PROBLEM DESCRIPTION:
    Inefficient scheduling with -qtune=pwr7.
    
    USERS AFFECTED:
    Those using -qtune=pwr7 with -O2 and up.
    

Problem conclusion

  • Fixed an instruction scheduling issue that was causing
    inefficient scheduling of XNOP ori instructions.
    

Temporary fix

Comments

APAR Information

  • APAR number

    LI78434

  • Reported component name

    XL C/C++ FOR LI

  • Reported component ID

    5725C7300

  • Reported release

    D10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2015-02-25

  • Closed date

    2015-02-25

  • Last modified date

    2015-02-25

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

    IV61672

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

Fix information

  • Fixed component name

    XL C/C++ FOR LI

  • Fixed component ID

    5725C7300

Applicable component levels



Document information

More support for: XL C/C++ for Linux
Compiler

Software version: 13.1

Reference #: LI78434

Modified date: 25 February 2015