LI77515: LONG COMPILE TIME IN XLFENTRY AT -O2

XL Fortran for Blue Gene/Q Fix Pack 12 (May 2015 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 14 (May 2016 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 15 (October 2017 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 6 (November 2013 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 7 (February 2014 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 8 (May 2014 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 9 (August 2014 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 10 (November 2014 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 11 (February 2015 Update) for 14.1
XL Fortran for Blue Gene/Q Fix Pack 13 (August 2015 Update) for 14.1

APAR status

• Closed as program error.

Error description

• Compiling an application at optimization level -O2 has a drastic
  increase in compile time as compared to -O0.  The -qphsinfo
  compile timing report shows excess time spent in the FORTRAN
  stage of the compiler, which corresponds to the 'xlfentry'
  component of the compiler.
  

Local fix

• Compile at -O0
  

Problem summary

• PROBLEM DESCRIPTION:
  The Fortran component of the compiler may take a long time to
  compile at -O2 and above in cases where the compilation unit
  has a large number of I/O statements.
  
  USERS AFFECTED:
  Users may see this problem if their applications have a large
  number of I/O statements in individual compilation units.  The
  problem is visible at -O2 and above.
  

Problem conclusion

• An improvement has been made that reduces compile time when -O2
  or above is used.
  

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:

  IV53301

Fix information

• Fixed component name

  XL FORTRAN FOR

• Fixed component ID

  5799AH100

Applicable component levels

• RE10 PSY

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