gcc/ChangeLog

2020-01-16  Kewen Lin  <linkw@gcc.gnu.org>

	* cfgloop.h (struct loop): New field estimated_uf.
	* config/rs6000/rs6000.c (TARGET_LOOP_UNROLL_ADJUST_TREE): New macro.
	(rs6000_loop_unroll_adjust_tree): New function.
	* doc/tm.texi: Regenerate.
	* doc/tm.texi.in (TARGET_LOOP_UNROLL_ADJUST_TREE): New hook.
	* target.def (loop_unroll_adjust_tree): New hook.
	* tree-ssa-loop-manip.c (decide_uf_const_iter): New function.
	(decide_uf_runtime_iter): Likewise.
	(decide_uf_stupid): Likewise.
	(estimate_unroll_factor): Likewise.
	* tree-ssa-loop-manip.h (estimate_unroll_factor): New declare.
	* tree-ssa-loop.c (tree_average_num_loop_insns): New function.
	* tree-ssa-loop.h (tree_average_num_loop_insns): New declare.