LI76798: MEMORY FAULT WITH -QSMP=OMP

June 2012 Update for XL Fortran for Linux, V13.1
October 2012 Update for XL Fortran for Linux, V13.1
XL Fortran for Linux Fix Pack 8 (June 2013 Update) for 13.1

APAR status

• Closed as program error.

Error description

• When compiling with -qsmp=omp, the resulting executable
  segfaults at runtime.
  
  The complete set of compile options used are:
  xlf90_r -q64 -qfixed=72 -qlist
  -qdebug=listoffset:d_dumpstr:tracetpo:finalc -O2 -qsmp=omp
  -qmaxmem=-1 -qdbg -qfullpath -qwarn64 -qstrict
  -qfloat=nans:rrm:norsqrt:nofold -qreport
  -qflttrap=ov:zero:inv:enable -qsigtrap -qsuppress=1501-245
  -qalias=intptr -qextname -qintsize=8 -qrealsize=8 -qarch=pwr7
  -qtune=pwr7 -qnocheck -qspillsize=32648 -qnoescape
  -qxflag=ngenstub -bmaxstack:0xF0000000 -qnoundef -qnosave
  -qtbtable=full -qxref -qattr -qinitauto=7FF7FFFF -bnoquiet
  -bdatapsize:64K -bstackpsize:64K -btextpsize:64K
  

Local fix

• A workaround is to reduce the -qspillsize=32648 option, with the
  bonus of slightly smaller code, less stack space needed and
  slightly faster execution.
  

Problem summary

• USERS AFFECTED:
  Users with functions using far auto caused by a large
  -qspillsize option may be affected by this issue.
  
  PROBLEM DESCRIPTION:
  The resulting code leads to incorrect output. The incorrect
  output was caused by an incorrect address calculation for a
  parameter.
  

Problem conclusion

• Fixed a rare but possible incorrect parameter address
  calculation in a function using a stack frame > 32K caused by a
  large -qspillsize option when generating object file.
  

Temporary fix

Comments

APAR Information

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

  IV16153

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

Fix information

• Fixed component name

  XL FORTRAN LINU

• Fixed component ID

  5724X1600

Applicable component levels

• RD10 PSN IV16153

     UP06/09/13