re PR middle-end/51389 (GCC uses up to 75GB of virtual memory)

re PR middle-end/51389 (GCC uses up to 75GB of virtual memory)

        PR middle-end/51389
        * Makefile.in (tree-data-ref.o): Depend on $(PARAMS_H).
        * tree-data-ref.h (find_data_references_in_loop): Remove declaration.
        * tree-data-ref.c (find_data_references_in_loop): Make static.
        (compute_all_dependences): Change return type to bool.  Bail out
        for too many datarefs in a loop.  Move the hunk resetting the data
        dependences vector from ...
        (compute_data_dependences_for_loop): ... here.  Account for
        compute_all_dependences returning false.
        (compute_data_dependences_for_bb): Likewise.
        * params.def (PARAM_LOOP_MAX_DATAREFS_FOR_DATADEPS): New param.
        * doc/invoke.texi (loop-max-datarefs-for-datadeps): Document it.

From-SVN: r183624