* tree.def (REDUC_MAX_EXPR, REDUC_MIN_EXPR, REDUC_PLUS_EXPR): New
        tree-codes.
        * optabs.h (OTI_reduc_smax, OTI_reduc_umax, OTI_reduc_smin,
        OTI_reduc_umin, OTI_reduc_plus): New optabs for reduction.
        (reduc_smax_optab, reduc_umax_optab, reduc_smin_optab, reduc_umin_optab,
        reduc_plus_optab): New optabs for reduction.
        * expr.c (expand_expr_real_1): Handle new tree-codes.
        * tree-inline.c (estimate_num_insns_1): Handle new tree-codes.
        * tree-pretty-print.c (dump_generic_node, op_prio, op_symbol): Handle
        new tree-codes.
        * optabs.c (optab_for_tree_code): Handle new tree-codes.
        (init_optabs): Initialize new optabs.
        * genopinit.c (optabs): Define handlers for new optabs.

        * tree-vect-analyze.c (vect_analyze_operations): Fail vectorization in
        case of a phi that is marked as relevant. Call vectorizable_reduction.
        (vect_mark_relevant): Phis may be marked as relevant.
        (vect_mark_stmts_to_be_vectorized): The use corresponding to the
        reduction variable in a reduction stmt does not mark its defining phi
        as relevant. Update documentation accordingly.
        (vect_can_advance_ivs_p): Skip reduction phis.
        * tree-vect-transform.c (vect_get_vec_def_for_operand): Takes
        additional argument. Handle reduction.
        (vect_create_destination_var): Update call to vect_get_new_vect_var.
        Handle non-vector argument.
        (get_initial_def_for_reduction): New function.
        (vect_create_epilog_for_reduction): New function.
        (vectorizable_reduction): New function.
        (vect_get_new_vect_var): Handle new vect_var_kind.
        (vectorizable_assignment, vectorizable_operation, vectorizable_store,
        vectorizable_condition): Update call to vect_get_new_vect_var.
        (vect_transform_stmt): Call vectorizable_reduction.
        (vect_update_ivs_after_vectorizer): Skip reduction phis.
        (vect_transform_loop): Skip if stmt is both not relevant and not live.
        * tree-vectorizer.c (reduction_code_for_scalar_code): New function.
        (vect_is_simple_reduction): Was empty - added implementation.
        * tree-vectorizer.h (vect_scalar_var): New enum vect_var_kind value.
        (reduc_vec_info_type): New enum vect_def_type value.
        * config/rs6000/altivec.md (reduc_smax_v4si, reduc_smax_v4sf,
        reduc_umax_v4si, reduc_smin_v4si, reduc_umin_v4sf, reduc_smin_v4sf,
        reduc_plus_v4si, reduc_plus_v4sf): New define_expands.

        * tree-vect-analyze.c (vect_determine_vectorization_factor): Remove
        ENABLE_CHECKING around gcc_assert.
        * tree-vect-transform.c (vect_do_peeling_for_loop_bound,
        (vect_do_peeling_for_alignment, vect_transform_loop,
        vect_get_vec_def_for_operand): Likewise.

From-SVN: r101155