[Bug preprocessor/53525] New: Performance regression due to enabling track-macro-expansion

[jimis at gmx dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53525

             Bug #: 53525
           Summary: Performance regression due to enabling
                    track-macro-expansion
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: preprocessor
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: ji...@gmx.net


About 3% regression on cc1 -O0 compilation time has been noticed between
gcc-4.8-20120429 and gcc-4.8-20120513. The culprit seems to be enabling by
default -ftrack-macro-expansion (TME). Example time, instruction count and
memory usage for compiling reload.c follow.

    time    M Instr    KB RAM
noTME    0.744s    2081    28608
TME    0.785s    2201    31672