http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47044
--- Comment #1 from Jack Howarth <howarth at nitro dot med.uc.edu> 2010-12-22 19:53:23 UTC --- The trigger appears to be the use of --enable-build-with-cxx with -O2 defaulted to -fgraphite-identity. Removing that configure option eliminates the bootstrap comparison failures.