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