[RTL-ifcvt] Make non-conditional execution if-conversion more aggressive

[RTL-ifcvt] Make non-conditional execution if-conversion more aggressive

	* ifcvt.c (struct noce_if_info): Add then_simple, else_simple,
	then_cost, else_cost fields.  Change branch_cost field to unsigned
	int.
	(end_ifcvt_sequence): Call set_used_flags on each insn in the
	sequence.
	Include rtl-iter.h.
	(noce_simple_bbs): New function.
	(noce_try_move): Bail if basic blocks are not simple.
	(noce_try_store_flag): Likewise.
	(noce_try_store_flag_constants): Likewise.
	(noce_try_addcc): Likewise.
	(noce_try_store_flag_mask): Likewise.
	(noce_try_cmove): Likewise.
	(noce_try_minmax): Likewise.
	(noce_try_abs): Likewise.
	(noce_try_sign_mask): Likewise.
	(noce_try_bitop): Likewise.
	(bbs_ok_for_cmove_arith): New function.
	(noce_emit_all_but_last): Likewise.
	(noce_emit_insn): Likewise.
	(noce_emit_bb): Likewise.
	(noce_try_cmove_arith): Handle non-simple basic blocks.
	(insn_valid_noce_process_p): New function.
	(contains_mem_rtx_p): Likewise.
	(bb_valid_for_noce_process_p): Likewise.
	(noce_process_if_block): Allow non-simple basic blocks
	where appropriate.

	* gcc.dg/ifcvt-1.c: New test.
	* gcc.dg/ifcvt-2.c: Likewise.
	* gcc.dg/ifcvt-3.c: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@227368 138bc75d-0d04-0410-961f-82ee72b054a4