https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63175
--- Comment #27 from David Edelsohn <dje at gcc dot gnu.org> --- The vector alignment cost varies with processor implementation, not defined by the architecture. Bill has a patch that adjusts unaligned vector cost for POWER8, which may affect this. Because this PR depends on the cost model, this may vary with processor. Because of the change in cost model usage between 4.8 and 4.9, the code generation will change. On the other hand, the vectorizer tuning is encoding x86 preferences.
