Move computation of SLP_TREE_NUMBER_OF_VEC_STMTS

Move computation of SLP_TREE_NUMBER_OF_VEC_STMTS

Previously SLP_TREE_NUMBER_OF_VEC_STMTS was calculated while scheduling
an SLP tree after analysis, but sometimes it can be useful to know the
value during analysis too.  This patch moves the calculation to
vect_slp_analyze_node_operations instead.

2017-09-18  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* tree-vectorizer.h (vect_slp_analyze_operations): Replace parameters
	with a vec_info *.
	* tree-vect-loop.c (vect_analyze_loop_operations): Update call
	accordingly.
	* tree-vect-slp.c (vect_slp_analyze_node_operations): Add vec_info *
	parameter.  Set SLP_TREE_NUMBER_OF_VEC_STMTS here rather than in
	vect_schedule_slp_instance.
	(vect_slp_analyze_operations): Replace parameters with a vec_info *.
	Update call to vect_slp_analyze_node_operations.  Simplify return
	value.
	(vect_slp_analyze_bb_1): Update call accordingly.
	(vect_schedule_slp_instance): Remove vectorization_factor parameter.
	Don't calculate SLP_TREE_NUMBER_OF_VEC_STMTS here.
	(vect_schedule_slp): Update call accordingly.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>
From-SVN: r252935