1 /* Data references and dependences detectors.
2 Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
3 Contributed by Sebastian Pop <pop@cri.ensmp.fr>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
22 #ifndef GCC_TREE_DATA_REF_H
23 #define GCC_TREE_DATA_REF_H
27 /** {base_address + offset + init} is the first location accessed by data-ref
28 in the loop, and step is the stride of data-ref in the loop in bytes;
32 data-ref a[j].b[i][j] a + x + 16B (a is int*)
36 offset j_0*D_j + i_0*D_i + C_a x
39 access_fn NULL {16, +, 1}
43 access_fn <access_fns of indexes of b> NULL
46 struct first_location_in_loop
52 /* Access function related to first location in the loop. */
53 VEC(tree,heap) *access_fns;
57 struct base_object_info
62 /* A list of chrecs. Access functions related to BASE_OBJECT. */
63 VEC(tree,heap) *access_fns;
73 /* A pointer to the statement that contains this DR. */
76 /* A pointer to the ARRAY_REF node. */
79 /* Auxiliary info specific to a pass. */
82 /* True when the data reference is in RHS of a stmt. */
85 /* First location accessed by the data-ref in the loop. */
86 struct first_location_in_loop first_location;
88 /* Base object related info. */
89 struct base_object_info object_info;
91 /* Aliasing information. This field represents the symbol that
92 should be aliased by a pointer holding the address of this data
93 reference. If the original data reference was a pointer
94 dereference, then this field contains the memory tag that should
95 be used by the new vector-pointer. */
97 struct ptr_info_def *ptr_info;
100 /* Alignment information. */
101 /* The offset of the data-reference from its base in bytes. */
103 /* The maximum data-ref's alignment. */
106 /* The type of the data-ref. */
107 enum data_ref_type type;
110 #define DR_STMT(DR) (DR)->stmt
111 #define DR_REF(DR) (DR)->ref
112 #define DR_BASE_OBJECT(DR) (DR)->object_info.base_object
113 #define DR_TYPE(DR) (DR)->type
114 #define DR_ACCESS_FNS(DR)\
115 (DR_TYPE(DR) == ARRAY_REF_TYPE ? \
116 (DR)->object_info.access_fns : (DR)->first_location.access_fns)
117 #define DR_ACCESS_FN(DR, I) VEC_index (tree, DR_ACCESS_FNS (DR), I)
118 #define DR_NUM_DIMENSIONS(DR) VEC_length (tree, DR_ACCESS_FNS (DR))
119 #define DR_IS_READ(DR) (DR)->is_read
120 #define DR_BASE_ADDRESS(DR) (DR)->first_location.base_address
121 #define DR_OFFSET(DR) (DR)->first_location.offset
122 #define DR_INIT(DR) (DR)->first_location.init
123 #define DR_STEP(DR) (DR)->first_location.step
124 #define DR_MEMTAG(DR) (DR)->memtag
125 #define DR_ALIGNED_TO(DR) (DR)->aligned_to
126 #define DR_OFFSET_MISALIGNMENT(DR) (DR)->misalignment
127 #define DR_PTR_INFO(DR) (DR)->ptr_info
128 #define DR_SUBVARS(DR) (DR)->subvars
130 #define DR_ACCESS_FNS_ADDR(DR) \
131 (DR_TYPE(DR) == ARRAY_REF_TYPE ? \
132 &((DR)->object_info.access_fns) : &((DR)->first_location.access_fns))
133 #define DR_SET_ACCESS_FNS(DR, ACC_FNS) \
135 if (DR_TYPE(DR) == ARRAY_REF_TYPE) \
136 (DR)->object_info.access_fns = ACC_FNS; \
138 (DR)->first_location.access_fns = ACC_FNS; \
140 #define DR_FREE_ACCESS_FNS(DR) \
142 if (DR_TYPE(DR) == ARRAY_REF_TYPE) \
143 VEC_free (tree, heap, (DR)->object_info.access_fns); \
145 VEC_free (tree, heap, (DR)->first_location.access_fns); \
148 enum data_dependence_direction {
152 dir_positive_or_negative,
153 dir_positive_or_equal,
154 dir_negative_or_equal,
159 /* What is a subscript? Given two array accesses a subscript is the
160 tuple composed of the access functions for a given dimension.
161 Example: Given A[f1][f2][f3] and B[g1][g2][g3], there are three
162 subscripts: (f1, g1), (f2, g2), (f3, g3). These three subscripts
163 are stored in the data_dependence_relation structure under the form
164 of an array of subscripts. */
168 /* A description of the iterations for which the elements are
170 tree conflicting_iterations_in_a;
171 tree conflicting_iterations_in_b;
173 /* This field stores the information about the iteration domain
174 validity of the dependence relation. */
177 /* Distance from the iteration that access a conflicting element in
178 A to the iteration that access this same conflicting element in
179 B. The distance is a tree scalar expression, i.e. a constant or a
180 symbolic expression, but certainly not a chrec function. */
184 #define SUB_CONFLICTS_IN_A(SUB) SUB->conflicting_iterations_in_a
185 #define SUB_CONFLICTS_IN_B(SUB) SUB->conflicting_iterations_in_b
186 #define SUB_LAST_CONFLICT(SUB) SUB->last_conflict
187 #define SUB_DISTANCE(SUB) SUB->distance
189 typedef struct loop *loop_p;
191 DEF_VEC_ALLOC_P (loop_p, heap);
193 /* A data_dependence_relation represents a relation between two
194 data_references A and B. */
196 struct data_dependence_relation
199 struct data_reference *a;
200 struct data_reference *b;
202 /* When the dependence relation is affine, it can be represented by
203 a distance vector. */
206 /* A "yes/no/maybe" field for the dependence relation:
208 - when "ARE_DEPENDENT == NULL_TREE", there exist a dependence
209 relation between A and B, and the description of this relation
210 is given in the SUBSCRIPTS array,
212 - when "ARE_DEPENDENT == chrec_known", there is no dependence and
215 - when "ARE_DEPENDENT == chrec_dont_know", there may be a dependence,
216 but the analyzer cannot be more specific. */
219 /* For each subscript in the dependence test, there is an element in
220 this array. This is the attribute that labels the edge A->B of
221 the data_dependence_relation. */
222 varray_type subscripts;
224 /* The analyzed loop nest. */
225 VEC (loop_p, heap) *loop_nest;
227 /* The classic direction vector. */
228 VEC(lambda_vector,heap) *dir_vects;
230 /* The classic distance vector. */
231 VEC(lambda_vector,heap) *dist_vects;
234 typedef struct data_dependence_relation *ddr_p;
236 DEF_VEC_ALLOC_P(ddr_p,heap);
238 #define DDR_A(DDR) DDR->a
239 #define DDR_B(DDR) DDR->b
240 #define DDR_AFFINE_P(DDR) DDR->affine_p
241 #define DDR_ARE_DEPENDENT(DDR) DDR->are_dependent
242 #define DDR_SUBSCRIPTS(DDR) DDR->subscripts
243 #define DDR_SUBSCRIPTS_VECTOR_INIT(DDR, N) \
244 VARRAY_GENERIC_PTR_INIT (DDR_SUBSCRIPTS (DDR), N, "subscripts_vector");
245 #define DDR_SUBSCRIPT(DDR, I) VARRAY_GENERIC_PTR (DDR_SUBSCRIPTS (DDR), I)
246 #define DDR_NUM_SUBSCRIPTS(DDR) VARRAY_ACTIVE_SIZE (DDR_SUBSCRIPTS (DDR))
248 #define DDR_LOOP_NEST(DDR) DDR->loop_nest
249 /* The size of the direction/distance vectors: the number of loops in
251 #define DDR_NB_LOOPS(DDR) (VEC_length (loop_p, DDR_LOOP_NEST (DDR)))
253 #define DDR_DIST_VECTS(DDR) ((DDR)->dist_vects)
254 #define DDR_DIR_VECTS(DDR) ((DDR)->dir_vects)
255 #define DDR_NUM_DIST_VECTS(DDR) \
256 (VEC_length (lambda_vector, DDR_DIST_VECTS (DDR)))
257 #define DDR_NUM_DIR_VECTS(DDR) \
258 (VEC_length (lambda_vector, DDR_DIR_VECTS (DDR)))
259 #define DDR_DIR_VECT(DDR, I) \
260 VEC_index (lambda_vector, DDR_DIR_VECTS (DDR), I)
261 #define DDR_DIST_VECT(DDR, I) \
262 VEC_index (lambda_vector, DDR_DIST_VECTS (DDR), I)
266 extern tree find_data_references_in_loop (struct loop *, varray_type *);
267 extern void compute_data_dependences_for_loop (struct loop *, bool,
268 varray_type *, varray_type *);
269 extern void print_direction_vector (FILE *, lambda_vector, int);
270 extern void print_dir_vectors (FILE *, VEC (lambda_vector, heap) *, int);
271 extern void print_dist_vectors (FILE *, VEC (lambda_vector, heap) *, int);
272 extern void dump_subscript (FILE *, struct subscript *);
273 extern void dump_ddrs (FILE *, varray_type);
274 extern void dump_dist_dir_vectors (FILE *, varray_type);
275 extern void dump_data_reference (FILE *, struct data_reference *);
276 extern void dump_data_references (FILE *, varray_type);
277 extern void debug_data_dependence_relation (struct data_dependence_relation *);
278 extern void dump_data_dependence_relation (FILE *,
279 struct data_dependence_relation *);
280 extern void dump_data_dependence_relations (FILE *, varray_type);
281 extern void dump_data_dependence_direction (FILE *,
282 enum data_dependence_direction);
283 extern void free_dependence_relation (struct data_dependence_relation *);
284 extern void free_dependence_relations (varray_type);
285 extern void free_data_refs (varray_type);
286 extern struct data_reference *analyze_array (tree, tree, bool);
287 extern void estimate_iters_using_array (tree, tree);
289 /* Return the index of the variable VAR in the LOOP_NEST array. */
292 index_in_loop_nest (int var, VEC (loop_p, heap) *loop_nest)
297 for (var_index = 0; VEC_iterate (loop_p, loop_nest, var_index, loopi);
299 if (loopi->num == var)
307 #endif /* GCC_TREE_DATA_REF_H */