http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60438
--- Comment #27 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Jakub Jelinek from comment #25) > Perhaps we can handle some most common cases of frame related insns (e.g. if > both have REG_CFA_ADJUST_CFA notes, etc.), perhaps it would be worth it to > run a bootstrap which would log when the above hunk prevented some merging > and append both insns to some /tmp/ file across whole bootstrap, then we > could see what is common enough to care about. Wonder if we just shouldn't pass the other insn (the one we'd like to delete) to try_apply_stack_adjustment and if either of them is frame related insn, check harder to see if we can handle it or give up if we can't handle it. At least merging of a frame related stack adjustment and following non-frame related one (or vice versa?) is I think very common.
