i386.h (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES_EPILOGUES): New tuning flag.
* i386.h (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES_EPILOGUES): New tuning flag.
* x86-tune.def (TARGET_MISALIGNED_MOVE_STRING_PROLOGUES): Define it.
* i386.c (expand_small_movmem_or_setmem): New function.
(expand_set_or_movmem_prologue_epilogue_by_misaligned_moves): New function
(alg_usable_p): Add support for value ranges; cleanup.
(ix86_expand_set_or_movmem): Add support for misaligned moves.