* doc/passes.texi: Document predictive commoning.
	* doc/invoke.texi (-fpredictive-commoning): Document.
	* opts.c (decode_options): Enable flag_predictive_commoning on -O3.
	* tree-ssa-loop-im.c (get_lsm_tmp_name): Export.  Allow
	adding indices to the generated name.
	(schedule_sm): Pass 0 to get_lsm_tmp_name.
	* tree-ssa-loop-niter.c (stmt_dominates_stmt_p): Export.
	* tree-pretty-print.c (op_symbol_1): Renamed to ...
	(op_symbol_code): ... and exported.
	(dump_omp_clause, op_symbol): Use op_symbol_code
	instead of op_symbol_1.
	* tree-pass.h (pass_predcom): Declare.
	* timevar.def (TV_PREDCOM): New timevar.
	* tree-ssa-loop.c (run_tree_predictive_commoning,
	gate_tree_predictive_commoning, pass_predcom): New.
	* tree-data-ref.c (find_data_references_in_loop): Find the
	references in dominance order.
	(canonicalize_base_object_address): Ensure that the result has
	pointer type.
	(dr_analyze_innermost): Export.
	(create_data_ref): Code to fail for references with invariant
	address moved ...
	(find_data_references_in_stmt): ... here.
	* tree-data-ref.h (dr_analyze_innermost): Declare.
	* tree-affine.c: Include tree-gimple.h and hashtab.h.
	(aff_combination_find_elt, name_expansion_hash,
	name_expansion_eq, tree_to_aff_combination_expand,
	double_int_constant_multiple_p, aff_combination_constant_multiple_p):
	New functions.
	* tree-affine.h (aff_combination_constant_multiple_p,
	tree_to_aff_combination_expand): Declare.
	* tree-predcom.c: New file.
	* common.opt (fpredictive-commoning): New option.
	* tree-flow.h (op_symbol_code, tree_predictive_commoning,
	stmt_dominates_stmt_p, get_lsm_tmp_name): Declare.
	* Makefile.in (tree-predcom.o): Add.
	(tree-affine.o): Add TREE_GIMPLE_H dependency.
	* passes.c (init_optimization_passes):  Add dceloop after
	copy propagation in loop optimizer.  Add predictive commoning
	to loop optimizer passes.

	* gcc.dg/tree-ssa/predcom-1.c: New test.
	* gcc.dg/tree-ssa/predcom-2.c: New test.
	* gcc.dg/tree-ssa/predcom-3.c: New test.
	* gcc.dg/tree-ssa/predcom-4.c: New test.
	* gcc.dg/tree-ssa/predcom-5.c: New test.
	* gcc.dg/vect/dump-tree-dceloop-pr26359.c: Test dceloop2 dumps.

From-SVN: r125030