* tree-vectorizer.c (supportable_widening_operation): Support
	multi-step conversion, return the number of steps in such conversion
	and the required intermediate types.
	(supportable_narrowing_operation): Likewise.
	* tree-vectorizer.h (vect_pow2): New function.
	(supportable_widening_operation): Change argument types.
	(supportable_narrowing_operation): Likewise.
	(vectorizable_type_promotion): Add an argument.
	(vectorizable_type_demotion): Likewise.
	* tree-vect-analyze.c (vect_analyze_operations): Call 
	vectorizable_type_promotion and vectorizable_type_demotion with
	additional argument.
	(vect_get_and_check_slp_defs): Detect patterns.
	(vect_build_slp_tree): Add an argument, don't fail in case of multiple
	types. 
	(vect_analyze_slp_instance): Don't fail in case of multiple types. Call
	vect_build_slp_tree with correct arguments. Calculate unrolling factor
	according to the smallest type in the loop.
	(vect_detect_hybrid_slp_stmts): Include statements from patterns.
	* tree-vect-patterns.c (vect_recog_widen_mult_pattern): Call 
	supportable_widening_operation with correct arguments. 
	* tree-vect-transform.c (vect_get_slp_defs): Allocate output vector 
	operands lists according to the number of vector statements in left
	or right node, if exists.
	(vect_gen_widened_results_half): Remove unused argument.
	(vectorizable_conversion): Call supportable_widening_operation, 
	supportable_narrowing_operation, and vect_gen_widened_results_half
	with correct arguments. 
	(vectorizable_assignment): Change documentation, support multiple
	types in SLP. 
	(vectorizable_operation): Likewise.
	(vect_get_loop_based_defs): New function.
	(vect_create_vectorized_demotion_stmts): Likewise.
	(vectorizable_type_demotion): Support loop-aware SLP and general
	multi-step conversion. Call vect_get_loop_based_defs and
	vect_create_vectorized_demotion_stmts for transformation.
	(vect_create_vectorized_promotion_stmts): New function.
	(vectorizable_type_promotion): Support loop-aware SLP and general
	multi-step conversion. Call vect_create_vectorized_promotion_stmts
	for transformation.	
	(vectorizable_store): Change documentation, support multiple
	types in SLP. 
	(vectorizable_load): Likewise.
	(vect_transform_stmt): Pass SLP_NODE to 
	vectorizable_type_promotion and vectorizable_type_demotion.
	(vect_schedule_slp_instance): Move here the calculation of number
	of vectorized statements for each node from...
	(vect_schedule_slp): ... here.
	(vect_transform_loop): Call vect_schedule_slp without the last
	argument.

From-SVN: r139225