[Bug other/55793] New: Compile hog with -gdwarf-4 and -O2 (-fvar-tracking issue)

[Bug other/55793] New: Compile hog with -gdwarf-4 and -O2 (-fvar-tracking issue)

[jan.smets@alcatel-lucent.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55793

             Bug #: 55793
           Summary: Compile hog with -gdwarf-4 and -O2 (-fvar-tracking
                    issue)
    Classification: Unclassified
           Product: gcc
           Version: 4.6.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: jan.smets@alcatel-lucent.com


Created attachment 29029
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29029
testcase

Following testcase takes a very long time to compile when debugging info is
enabled.

The 'real life' scenario contained around 900 entries. 
The testcase is reduced to 500.  

With more than 500 entries -> variable tracking size limit exceeded.


gcc -c test.c -o test.o -O2 -gdwarf-4  -fno-builtin

[Bug other/55793] Compile hog with -gdwarf-4 and -O2 (-fvar-tracking issue)

[jan.smets@alcatel-lucent.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55793

--- Comment #1 from Jan Smets <jan.smets@alcatel-lucent.com> 2012-12-22 20:44:32 UTC ---
85%+ of the time is spent in "var-tracking dataflow". This may just be a
duplicate of #54402 but the testcase there is different.

[Bug other/55793] Compile hog with -gdwarf-4 and -O2 (-fvar-tracking issue)

[aoliva at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55793

Alexandre Oliva <aoliva at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aoliva at gcc dot gnu.org

--- Comment #2 from Alexandre Oliva <aoliva at gcc dot gnu.org> 2013-01-18 11:10:08 UTC ---
Is this better after the patch for var-tracking that I just checked in?  (I'm
not sure it's related, given that this is reported against 4.6.3, which didn't
have the compile-time regression that the patch addressed, but I thought I'd
ask just to be sure)

[Bug other/55793] Compile hog with -gdwarf-4 and -O2 (-fvar-tracking issue)

[jan.smets@alcatel-lucent.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55793

--- Comment #3 from Jan Smets <jan.smets@alcatel-lucent.com> 2013-04-19 11:57:36 UTC ---
Can't confirm since the patch can not be applied to 4.6.
(Even though the branch is dead already..)