http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45394
--- Comment #10 from Alexandre Oliva <aoliva at gcc dot gnu.org> 2010-10-07 06:15:15 UTC --- (In reply to comment #6) > The combiner swaps 2 insns. This swap looks correct to me. Presumably reg 85 is being dropped, so moving the debug_insn down to a point at which it can refer to the used value should be fine, no? Is this move even related with the bug? Why? I'm trying to figure out why this change that drops “after”, presumably needed for this very kind of situation, is correct, but I can't easily get an environment in which I can duplicate the problem. A cross compiler (without target libs) doesn't seem to be enough (or at least I don't know how to run it to trigger the problem). Help?