http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50682
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-23
16:43:36 UTC ---
The problem here is that with all the -fno-* options we end up with code like:
<bb 14>:
D.2284_38 = &__size;
<bb 35>:
# D.2281_58 = PHI <&__size(14)>
D.2283_59 = D.2281_58;
D.2281_60 = D.2281_58;
D.2281_61 = D.2281_58;
__r_62 = *D.2281_58;
at the beginning of ehcleanup2 pass. Then we clean up eh and as something
changed, TODO_cleanup_cfg is requested. Only the cfgcleanup after ehcleanup2
will attempt to merge the above two blocks, which changes it to
D.2284_38 = &__size;
D.2283_59 = &__size;
D.2281_60 = &__size;
D.2281_61 = &__size;
__r_62 = &__size;
which unfortunately means that the last stmt in thise bb is considered to no
longer throw and gimple_purge_dead_eh_edges is called on it. But there is no
further ehcleanup afterwards. Calling remove_unreachable_handlers () from
execute_cleanup_cfg_post_optimizing or scheduling another ehcleanup pass right
before it would fix it, but it would make compilation tiny bit slower because
of another pass through all stmts.
