http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51902
--- Comment #3 from Mark Wielaard <mark at gcc dot gnu.org> 2012-01-20 13:31:04 UTC --- (In reply to comment #2) > Mark, can you please look at this if it does the right thing you want from it? Yes, this seems to do what I was thinking of. And it works on my testcases. It does a bit more by searching up the block supercontext and by trying to find a partial range. I think it would be fine to look for and pick the first block supercontext and only check the chains are equal (but haven't tried that yet).