+ for (i = 0; i < DR_NUM_DIMENSIONS (a); i++)
+ if (!eq_evolutions_p (DR_ACCESS_FN (a, i), DR_ACCESS_FN (b, i)))
+ return false;
+
+ return true;
+}
+
+/* Return true when the DDR contains two data references that have the
+ same access functions. */
+
+static inline bool
+same_access_functions (const struct data_dependence_relation *ddr)
+{
+ unsigned i;
+
+ for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
+ if (!eq_evolutions_p (DR_ACCESS_FN (DDR_A (ddr), i),
+ DR_ACCESS_FN (DDR_B (ddr), i)))
+ return false;
+
+ return true;
+}
+
+/* Return true when DDR is an anti-dependence relation. */
+
+static inline bool
+ddr_is_anti_dependent (ddr_p ddr)
+{
+ return (DDR_ARE_DEPENDENT (ddr) == NULL_TREE
+ && DR_IS_READ (DDR_A (ddr))
+ && DR_IS_WRITE (DDR_B (ddr))
+ && !same_access_functions (ddr));
+}
+
+/* Return true when DEPENDENCE_RELATIONS contains an anti-dependence. */
+
+static inline bool
+ddrs_have_anti_deps (VEC (ddr_p, heap) *dependence_relations)
+{
+ unsigned i;
+ ddr_p ddr;
+
+ for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++)
+ if (ddr_is_anti_dependent (ddr))
+ return true;
+
+ return false;
+}
+
+/* Returns the dependence level for a vector DIST of size LENGTH.
+ LEVEL = 0 means a lexicographic dependence, i.e. a dependence due
+ to the sequence of statements, not carried by any loop. */
+
+static inline unsigned
+dependence_level (lambda_vector dist_vect, int length)
+{
+ int i;
+
+ for (i = 0; i < length; i++)
+ if (dist_vect[i] != 0)
+ return i + 1;
+
+ return 0;
+}
+
+/* Return the dependence level for the DDR relation. */
+
+static inline unsigned
+ddr_dependence_level (ddr_p ddr)
+{
+ unsigned vector;
+ unsigned level = 0;
+
+ if (DDR_DIST_VECTS (ddr))
+ level = dependence_level (DDR_DIST_VECT (ddr, 0), DDR_NB_LOOPS (ddr));
+
+ for (vector = 1; vector < DDR_NUM_DIST_VECTS (ddr); vector++)
+ level = MIN (level, dependence_level (DDR_DIST_VECT (ddr, vector),
+ DDR_NB_LOOPS (ddr)));
+ return level;
+}
+
+\f
+
+/* A Reduced Dependence Graph (RDG) vertex representing a statement. */
+typedef struct rdg_vertex
+{
+ /* The statement represented by this vertex. */
+ gimple stmt;
+
+ /* True when the statement contains a write to memory. */
+ bool has_mem_write;
+
+ /* True when the statement contains a read from memory. */
+ bool has_mem_reads;
+} *rdg_vertex_p;
+
+#define RDGV_STMT(V) ((struct rdg_vertex *) ((V)->data))->stmt
+#define RDGV_HAS_MEM_WRITE(V) ((struct rdg_vertex *) ((V)->data))->has_mem_write
+#define RDGV_HAS_MEM_READS(V) ((struct rdg_vertex *) ((V)->data))->has_mem_reads
+#define RDG_STMT(RDG, I) RDGV_STMT (&(RDG->vertices[I]))
+#define RDG_MEM_WRITE_STMT(RDG, I) RDGV_HAS_MEM_WRITE (&(RDG->vertices[I]))
+#define RDG_MEM_READS_STMT(RDG, I) RDGV_HAS_MEM_READS (&(RDG->vertices[I]))
+
+void dump_rdg_vertex (FILE *, struct graph *, int);
+void debug_rdg_vertex (struct graph *, int);
+void dump_rdg_component (FILE *, struct graph *, int, bitmap);
+void debug_rdg_component (struct graph *, int);
+void dump_rdg (FILE *, struct graph *);
+void debug_rdg (struct graph *);
+int rdg_vertex_for_stmt (struct graph *, gimple);
+
+/* Data dependence type. */
+
+enum rdg_dep_type
+{
+ /* Read After Write (RAW). */
+ flow_dd = 'f',
+
+ /* Write After Read (WAR). */
+ anti_dd = 'a',
+
+ /* Write After Write (WAW). */
+ output_dd = 'o',
+
+ /* Read After Read (RAR). */
+ input_dd = 'i'
+};
+
+/* Dependence information attached to an edge of the RDG. */
+
+typedef struct rdg_edge
+{
+ /* Type of the dependence. */
+ enum rdg_dep_type type;
+
+ /* Levels of the dependence: the depth of the loops that carry the
+ dependence. */
+ unsigned level;
+
+ /* Dependence relation between data dependences, NULL when one of
+ the vertices is a scalar. */
+ ddr_p relation;
+} *rdg_edge_p;
+
+#define RDGE_TYPE(E) ((struct rdg_edge *) ((E)->data))->type
+#define RDGE_LEVEL(E) ((struct rdg_edge *) ((E)->data))->level
+#define RDGE_RELATION(E) ((struct rdg_edge *) ((E)->data))->relation
+
+struct graph *build_rdg (struct loop *,
+ VEC (loop_p, heap) **,
+ VEC (ddr_p, heap) **,
+ VEC (data_reference_p, heap) **);
+struct graph *build_empty_rdg (int);
+void free_rdg (struct graph *);