http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60438
--- Comment #34 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Richard Henderson from comment #33) > It sounds like inhibiting this stack combining would affect more > 32-bit code than I'd like. > > I don't like the idea of REG_ARGS_SIZE_DELTA. The reason I went > with absolute values in the first place for REG_ARGS_SIZE is that > there were too many places where "deltas" matched up, but absolute > values did not. And so we'd wind up cross-jumping illegally. > > I wonder if the best fix is to change the patterns not to rely on > ix86_force_to_memory and ix86_free_from_memory, but instead have a > memory operand to clobber right from the start. No fighting with > dwarf2 or unwind info after the fact at all. > > I'll whip that up today and see what it looks like. Perhaps. In this particular case I think it the r in a m,?r constraints, just removing the ?r option probably would have done the job.
