* df.c (df_bitmaps_free): Only work for bbs for that structures are

	allocated.
	(df_bb_modify): Realloc tables to the new index.
	(df_find_use): New function.
	(df_find_def, df_reg_used): Handle subregs.
	* df.h (df_find_use): Declare.

	* loop-invariant.c: Include hashtab.h.
	(struct invariant): Remove processed field, add eqto and reg fields.
	(struct invariant_expr_entry): New.
	(invariant_for_use, hash_invariant_expr_1, invariant_expr_equal_p,
	hash_invariant_expr, eq_invariant_expr, find_or_insert_inv,
	find_identical_invariants, merge_identical_invariants): New functions.
	(create_new_invariant): Return the new invariant.  Initialize new
	fields.
	(find_invariants): Call merge_identical_invariants.
	(get_inv_cost, best_gain_for_invariant, set_move_mark,
	move_invariant_reg): Handle equivalent invariants.
	* Makefile.in (loop-invariant.o): Add HASHTAB_H dependency.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@108949 138bc75d-0d04-0410-961f-82ee72b054a4