[Bug pch/53880] New: [4.8 Regression] compile time regression when generating precompiled headers for boost

["markus at trippelsdorf dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53880

             Bug #: 53880
           Summary: [4.8 Regression] compile time regression when
                    generating precompiled headers for boost
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: pch
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: markus@trippelsdorf.de


There is a huge compile time regression in 4.8 when one generates 
a precompiled header for boost's /math/special_functions.hpp.

gcc-4.7:
 % time c++ -c -o pch.hpp.gch /usr/include/boost/math/special_functions.hpp
c++ -c -o pch.hpp.gch /usr/include/boost/math/special_functions.hpp  2.26s user
0.13s system 99% cpu 2.407 total

gcc-4.8:
 % time c++ -c -o pch.hpp.gch /usr/include/boost/math/special_functions.hpp
c++ -c -o pch.hpp.gch /usr/include/boost/math/special_functions.hpp  172.42s
user 0.37s system 99% cpu 2:53.44 total