http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52397
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-02-28 15:40:40 UTC --- Ok, with additional -fno-inline -gnatpg I can reproduce even with the commands I tried. The dead_debug* stuff doesn't handle this probably because the hard reg isn't ever becoming REG_DEAD or REG_UNUSED etc. in the IL, it is just unused altogether plus set on entry. I wonder if df_reg_chain_unlink/df_install_ref shouldn't just ignore DEBUG_INSN refs when updating df->hard_regs_live_count array, do we care at all when testing regs_ever_live if something is live in debug insns?
