/* Data references and dependences detectors. Copyright (C) 2003, 2004 Free Software Foundation, Inc. Contributed by Sebastian Pop This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifndef GCC_TREE_DATA_REF_H #define GCC_TREE_DATA_REF_H #include "lambda.h" struct data_reference { /* A pointer to the statement that contains this DR. */ tree stmt; /* A pointer to the ARRAY_REF node. */ tree ref; /* The name of the array. */ tree base_name; /* A list of chrecs. */ varray_type access_fns; /* Auxiliary info specific to a pass. */ int aux; /* True when the data reference is in RHS of a stmt. */ bool is_read; }; #define DR_STMT(DR) DR->stmt #define DR_REF(DR) DR->ref #define DR_BASE_NAME(DR) DR->base_name #define DR_ACCESS_FNS(DR) DR->access_fns #define DR_ACCESS_FN(DR, I) VARRAY_TREE (DR_ACCESS_FNS (DR), I) #define DR_NUM_DIMENSIONS(DR) VARRAY_ACTIVE_SIZE (DR_ACCESS_FNS (DR)) #define DR_IS_READ(DR) DR->is_read enum data_dependence_direction { dir_positive, dir_negative, dir_equal, dir_positive_or_negative, dir_positive_or_equal, dir_negative_or_equal, dir_star, dir_independent }; /* What is a subscript? Given two array accesses a subscript is the tuple composed of the access functions for a given dimension. Example: Given A[f1][f2][f3] and B[g1][g2][g3], there are three subscripts: (f1, g1), (f2, g2), (f3, g3). These three subscripts are stored in the data_dependence_relation structure under the form of an array of subscripts. */ struct subscript { /* A description of the iterations for which the elements are accessed twice. */ tree conflicting_iterations_in_a; tree conflicting_iterations_in_b; /* This field stores the information about the iteration domain validity of the dependence relation. */ tree last_conflict; /* Distance from the iteration that access a conflicting element in A to the iteration that access this same conflicting element in B. The distance is a tree scalar expression, i.e. a constant or a symbolic expression, but certainly not a chrec function. */ tree distance; }; #define SUB_CONFLICTS_IN_A(SUB) SUB->conflicting_iterations_in_a #define SUB_CONFLICTS_IN_B(SUB) SUB->conflicting_iterations_in_b #define SUB_LAST_CONFLICT(SUB) SUB->last_conflict #define SUB_DISTANCE(SUB) SUB->distance /* A data_dependence_relation represents a relation between two data_references A and B. */ struct data_dependence_relation { struct data_reference *a; struct data_reference *b; /* When the dependence relation is affine, it can be represented by a distance vector. */ bool affine_p; /* A "yes/no/maybe" field for the dependence relation: - when "ARE_DEPENDENT == NULL_TREE", there exist a dependence relation between A and B, and the description of this relation is given in the SUBSCRIPTS array, - when "ARE_DEPENDENT == chrec_known", there is no dependence and SUBSCRIPTS is empty, - when "ARE_DEPENDENT == chrec_dont_know", there may be a dependence, but the analyzer cannot be more specific. */ tree are_dependent; /* For each subscript in the dependence test, there is an element in this array. This is the attribute that labels the edge A->B of the data_dependence_relation. */ varray_type subscripts; /* The size of the direction/distance vectors. */ int size_vect; /* The classic direction vector. */ lambda_vector dir_vect; /* The classic distance vector. */ lambda_vector dist_vect; }; #define DDR_A(DDR) DDR->a #define DDR_B(DDR) DDR->b #define DDR_AFFINE_P(DDR) DDR->affine_p #define DDR_ARE_DEPENDENT(DDR) DDR->are_dependent #define DDR_SUBSCRIPTS(DDR) DDR->subscripts #define DDR_SUBSCRIPTS_VECTOR_INIT(DDR, N) \ VARRAY_GENERIC_PTR_INIT (DDR_SUBSCRIPTS (DDR), N, "subscripts_vector"); #define DDR_SUBSCRIPT(DDR, I) VARRAY_GENERIC_PTR (DDR_SUBSCRIPTS (DDR), I) #define DDR_NUM_SUBSCRIPTS(DDR) VARRAY_ACTIVE_SIZE (DDR_SUBSCRIPTS (DDR)) #define DDR_SIZE_VECT(DDR) DDR->size_vect #define DDR_DIR_VECT(DDR) DDR->dir_vect #define DDR_DIST_VECT(DDR) DDR->dist_vect extern tree find_data_references_in_loop (struct loop *, varray_type *); extern struct data_dependence_relation *initialize_data_dependence_relation (struct data_reference *, struct data_reference *); extern void compute_affine_dependence (struct data_dependence_relation *); extern void analyze_all_data_dependences (struct loops *); extern void compute_data_dependences_for_loop (unsigned, struct loop *, varray_type *, varray_type *); extern struct data_reference * init_data_ref (tree, tree, tree, tree, bool); extern struct data_reference *analyze_array (tree, tree, bool); extern void dump_subscript (FILE *, struct subscript *); extern void dump_ddrs (FILE *, varray_type); extern void dump_dist_dir_vectors (FILE *, varray_type); extern void dump_data_reference (FILE *, struct data_reference *); extern void dump_data_references (FILE *, varray_type); extern void dump_data_dependence_relation (FILE *, struct data_dependence_relation *); extern void dump_data_dependence_relations (FILE *, varray_type); extern void dump_data_dependence_direction (FILE *, enum data_dependence_direction); extern bool array_base_name_differ_p (struct data_reference *, struct data_reference *, bool *); extern void free_dependence_relation (struct data_dependence_relation *); extern void free_dependence_relations (varray_type); extern void free_data_refs (varray_type); #endif /* GCC_TREE_DATA_REF_H */