[cmake-developers] [CMake 0013469]: OpenMP flags enable IPA optimization for IBM xlC compiler

Mantis Bug Tracker mantis at public.kitware.com
Tue Aug 14 05:28:22 EDT 2012


The following issue has been SUBMITTED. 
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http://public.kitware.com/Bug/view.php?id=13469 
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Reported By:                Stefan Eilemann
Assigned To:                
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Project:                    CMake
Issue ID:                   13469
Category:                   CMake
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     new
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Date Submitted:             2012-08-14 05:28 EDT
Last Modified:              2012-08-14 05:28 EDT
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Summary:                    OpenMP flags enable IPA optimization for IBM xlC
compiler
Description: 
FindOpenMP sets '-qsmp' which turns on IPA, even in debug builds where it is
extremely inconvenient.

Our temporary workaround is to switch it off again:
https://github.com/Eyescale/CMake/commit/fbe0c8a87a1ba5fe683beeb697ecebaab26fd730

I'm new to xlC, but '-qsmp=noomp' looks better?


Steps to Reproduce: 
Compile simple test program in debug with:

  find_package(OpenMP REQUIRED)
  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")


And observer ipa process running, or examine optimized program in debugger.

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Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2012-08-14 05:28 Stefan EilemannNew Issue                                    
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