* loop.h (struct loop_info): Add member has_prefetch.
	* loop.c (PREFETCH_CONDITIONAL): Change default to 1.
	(prescan_loop): Initialize has_prefetch.
	(struct prefetch_info): Change prefetch_in_loop and
	prefetch_before_loop from bit fields to ints.
	(emit_prefetch_instructions): Several small fixes.
	(check_dbra_loop): Don't reverse loop that uses prefetch.

From-SVN: r53524