IV38465: COMPILER ADDS UNNECESSARY STORE FOR VECTOR

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You can track all active APARs for this component.

APAR status

  • Closed as program error.

Error description

  • The compiler generates unnecessary store for vector in the
    following code:
    
    $ cat test.cpp
    double extract0(vector double v)
    {
      return v[0];
    }
    $
    $ cat test.lst
    .
    .
      VR's set/used:   --u- ---- ---- ----  ---- ---- ---- ----
         | 000000                           PDEF
    extract0(vector double)
         | 000000                           AKA       extract0__Fad
        1|                                  PROC      v,vs34
        0| 000000 stdu     F821FF81   1     ST8U
    gr1,#stack(gr1,-128)=gr1
        0| 000004 addi     38000070   1     LI        gr0=112
        3| 000008 xxlor    F0221496   1     VOR       vs1=vs34,vs34
        0| 00000C stxvd2x  7C410799   1     VSTQD
    v(gr1,gr0,0)=vs34
        4| 000010 addi     38210080   1     AI        gr1=gr1,128
        4| 000014 bclr     4E800020   1     BA        lr
    .
    .
    $
    
    No stack adjustment and no stxvd2x is required.
    

Local fix

  • N/A
    

Problem summary

  • USERS AFFECTED:
    Users who compile vector cases and are using vector elements
    may be affected by this issue.
    
    PROBLEM DESCRIPTION:
    The compiler generates unnecessary stores for vector cases when
    using vector elements.
    

Problem conclusion

  • A specific compiler optimization was enabled to remove the
    uncessary stores for vector cases when using vector elements.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV38465

  • Reported component name

    XL C/C++ FOR AI

  • Reported component ID

    5725C7200

  • Reported release

    C10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2013-03-21

  • Closed date

    2013-06-17

  • Last modified date

    2013-06-17

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

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

    LI77419 LI77659 IV65306

Fix information

  • Fixed component name

    XL C FOR AIX

  • Fixed component ID

    5725C7100

Applicable component levels

  • RC10 PSY U860046

       UP C



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Document information


More support for:

XL C for AIX
Compiler

Software version:

12.1

Reference #:

IV38465

Modified date:

2013-06-17

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