re PR tree-optimization/91568 (internal compiler error: in vect_schedule_slp_instance, at tree-vect-slp.c:3922)

2019-08-29  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/91568
	* tree-vectorizer.h (_slp_tree::max_nunits): Add.
	(vect_update_max_nunits): Add overload for poly_uint64.
	* tree-vect-slp.c (vect_create_new_slp_node): Initialize it.
	(vect_build_slp_tree): Record max_nunits into the subtree
	and merge it upwards.
	(vect_print_slp_tree): Print max_nunits.

	* gfortran.dg/pr91568.f: New testcase.

From-SVN: r275023