http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58295
--- Comment #5 from Eric Botcazou <ebotcazou at gcc dot gnu.org> --- > Therefore, we can conclude that the original case tried by the combiner is > the best way to merge/reduce the redundant zero extension insn. Yes and, although x86 is the dominant architecture, it shouldn't be allowed to penalize all the others. I think we should restrict the effect of r191928, in particular it makes little sense as-is if you also define PROMOTE_MODE as on most RISC architectures.
