On x86_64-apple-darwin10 at r168176 with... Index: gcc/opts.c =================================================================== --- gcc/opts.c (revision 168176) +++ gcc/opts.c (working copy) @@ -458,6 +458,9 @@ { OPT_LEVELS_1_PLUS, OPT_fcombine_stack_adjustments, NULL, 1 }, /* -O2 optimizations. */ +#ifdef HAVE_cloog + { OPT_LEVELS_2_PLUS, OPT_fgraphite_identity, NULL, 1 }, +#endif { OPT_LEVELS_2_PLUS, OPT_finline_small_functions, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_findirect_inlining, NULL, 1 }, { OPT_LEVELS_2_PLUS, OPT_fpartial_inlining, NULL, 1 }, applied to default on -fgraphite-identity at -O2, a bootstrap comparison failure occurs... Comparing stages 2 and 3 warning: gcc/cc1-checksum.o differs warning: gcc/cc1obj-checksum.o differs warning: gcc/cc1objplus-checksum.o differs warning: gcc/cc1plus-checksum.o differs Bootstrap comparison failure! gcc/alias.o differs gcc/attribs.o differs gcc/bb-reorder.o differs gcc/bitmap.o differs gcc/bt-load.o differs gcc/build/genattrtab.o differs gcc/build/genautomata.o differs gcc/build/genflags.o differs gcc/build/gengenrtl.o differs gcc/build/gengtype-lex.o differs gcc/build/gengtype-state.o differs ... This problem did not occur at r167670. http://gcc.gnu.org/ml/gcc-testresults/2010-12/msg00852.html ../gcc-4.6-20101222/configure --prefix=/sw --prefix=/sw/lib/gcc4.6 --mandir=/sw/share/man --infodir=/sw/lib/gcc4.6/info --enable-languages=c,c++,fortran,objc,obj-c++,java --with-gmp=/sw --with-libiconv-prefix=/sw --with-ppl=/sw --with-cloog=/sw --with-mpc=/sw --with-system-zlib --x-includes=/usr/X11R6/include --x-libraries=/usr/X11R6/lib --program-suffix=-fsf-4.6 --enable-checking=yes --enable-cloog-backend=isl --enable-build-with-cxx
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.
Same bootstrap comparison failure obtained with unpatched r168197 using... make -j 8 BOOT_CFLAGS="-g -O2 -fgraphite-identity" with --enable-build-with-cxx on x86_64-apple-darwin10.
Same bootstrap comparison failure can be reproduced on x86_64 Fedora10 with... ../gcc/configure --with-gmp=/usr --with-mpfr=/usr --with-mpc=/usr --prefix=/home/howarth/dist --enable-languages=c,c++ --enable-checking=yes --enable-build-with-cxx make -j 8 BOOT_CFLAGS="-g -O2 -fgraphite-identity"
This issue appears to be resolved at r169520 with http://gcc.gnu.org/ml/gcc-patches/2011-02/msg00070.html (omitting the TODO_update_address_taken part) and http://gcc.gnu.org/ml/gcc-patches/2011-02/msg00095.html.
Author: spop Date: Wed Feb 2 15:52:21 2011 New Revision: 169531 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=169531 Log: Fix PR40979 and PR47044: after LIM call copy_prop and DCE to clean up. 2011-02-02 Sebastian Pop <sebastian.pop@amd.com> Richard Guenther <rguenther@suse.de> PR tree-optimization/40979 PR bootstrap/47044 * passes.c (init_optimization_passes): After LIM call copy_prop and DCE to clean up. * tree-ssa-loop.c (pass_graphite_transforms): Add TODO_dump_func. * gcc.dg/graphite/graphite.exp (DEFAULT_VECTCFLAGS): Add -ffast-math. * gcc.dg/graphite/pr35356-2.c: Adjust pattern. * gfortran.dg/graphite/graphite.exp: Run vect_files conditionally to check_vect_support_and_set_flags. * gfortran.dg/graphite/vect-pr40979.f90: New. Added: trunk/gcc/testsuite/gfortran.dg/graphite/vect-pr40979.f90 Modified: trunk/gcc/ChangeLog trunk/gcc/passes.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gcc.dg/graphite/graphite.exp trunk/gcc/testsuite/gcc.dg/graphite/pr35356-2.c trunk/gcc/testsuite/gfortran.dg/graphite/graphite.exp trunk/gcc/tree-ssa-loop.c
Fixed.