tree-ssa-pre.c: Update comments.

tree-ssa-pre.c: Update comments.

2004-06-17  Daniel Berlin  <dberlin@dberlin.org>

	* tree-ssa-pre.c:  Update comments.
	(val_expr_pair_eq): Factor code from here.
	(expr_pred_trans_eq): and here.
	(expressions_equal_p): To here.
	(print_value_set): Print value for expression.
	(phi_trans_lookup): Rename some variables.
	(lookup): Ditto.
	(value_exists_in_set_bitmap): Ditto.
	(value_remove_from_set_bitmap): Ditto.
	(value_insert_into_set_bitmap): Ditto.

From-SVN: r83290