loop->num);
}
-/* Returns true if A and B are accesses to different objects, or to different
- fields of the same object. */
-
-static bool
-disjoint_objects_p (tree a, tree b)
-{
- tree base_a, base_b;
- VEC (tree, heap) *comp_a = NULL, *comp_b = NULL;
- bool ret;
-
- base_a = get_base_address (a);
- base_b = get_base_address (b);
-
- if (DECL_P (base_a)
- && DECL_P (base_b)
- && base_a != base_b)
- return true;
-
- if (!operand_equal_p (base_a, base_b, 0))
- return false;
-
- /* Compare the component references of A and B. We must start from the inner
- ones, so record them to the vector first. */
- while (handled_component_p (a))
- {
- VEC_safe_push (tree, heap, comp_a, a);
- a = TREE_OPERAND (a, 0);
- }
- while (handled_component_p (b))
- {
- VEC_safe_push (tree, heap, comp_b, b);
- b = TREE_OPERAND (b, 0);
- }
-
- ret = false;
- while (1)
- {
- if (VEC_length (tree, comp_a) == 0
- || VEC_length (tree, comp_b) == 0)
- break;
-
- a = VEC_pop (tree, comp_a);
- b = VEC_pop (tree, comp_b);
-
- /* Real and imaginary part of a variable do not alias. */
- if ((TREE_CODE (a) == REALPART_EXPR
- && TREE_CODE (b) == IMAGPART_EXPR)
- || (TREE_CODE (a) == IMAGPART_EXPR
- && TREE_CODE (b) == REALPART_EXPR))
- {
- ret = true;
- break;
- }
-
- if (TREE_CODE (a) != TREE_CODE (b))
- break;
-
- /* Nothing to do for ARRAY_REFs, as the indices of array_refs in
- DR_BASE_OBJECT are always zero. */
- if (TREE_CODE (a) == ARRAY_REF)
- continue;
- else if (TREE_CODE (a) == COMPONENT_REF)
- {
- if (operand_equal_p (TREE_OPERAND (a, 1), TREE_OPERAND (b, 1), 0))
- continue;
-
- /* Different fields of unions may overlap. */
- base_a = TREE_OPERAND (a, 0);
- if (TREE_CODE (TREE_TYPE (base_a)) == UNION_TYPE)
- break;
-
- /* Different fields of structures cannot. */
- ret = true;
- break;
- }
- else
- break;
- }
-
- VEC_free (tree, heap, comp_a);
- VEC_free (tree, heap, comp_b);
-
- return ret;
-}
-
/* Returns false if we can prove that data references A and B do not alias,
true otherwise. */
bool
dr_may_alias_p (const struct data_reference *a, const struct data_reference *b)
{
- const_tree addr_a = DR_BASE_ADDRESS (a);
- const_tree addr_b = DR_BASE_ADDRESS (b);
- const_tree type_a, type_b;
- const_tree decl_a = NULL_TREE, decl_b = NULL_TREE;
-
- /* If the accessed objects are disjoint, the memory references do not
- alias. */
- if (disjoint_objects_p (DR_BASE_OBJECT (a), DR_BASE_OBJECT (b)))
- return false;
-
- /* Query the alias oracle. */
- if (!DR_IS_READ (a) && !DR_IS_READ (b))
- {
- if (!refs_output_dependent_p (DR_REF (a), DR_REF (b)))
- return false;
- }
- else if (DR_IS_READ (a) && !DR_IS_READ (b))
- {
- if (!refs_anti_dependent_p (DR_REF (a), DR_REF (b)))
- return false;
- }
- else if (!refs_may_alias_p (DR_REF (a), DR_REF (b)))
- return false;
+ tree addr_a = DR_BASE_OBJECT (a);
+ tree addr_b = DR_BASE_OBJECT (b);
- if (!addr_a || !addr_b)
- return true;
-
- /* If the references are based on different static objects, they cannot
- alias (PTA should be able to disambiguate such accesses, but often
- it fails to). */
- if (TREE_CODE (addr_a) == ADDR_EXPR
- && TREE_CODE (addr_b) == ADDR_EXPR)
- return TREE_OPERAND (addr_a, 0) == TREE_OPERAND (addr_b, 0);
-
- /* An instruction writing through a restricted pointer is "independent" of any
- instruction reading or writing through a different restricted pointer,
- in the same block/scope. */
-
- type_a = TREE_TYPE (addr_a);
- type_b = TREE_TYPE (addr_b);
- gcc_assert (POINTER_TYPE_P (type_a) && POINTER_TYPE_P (type_b));
-
- if (TREE_CODE (addr_a) == SSA_NAME)
- decl_a = SSA_NAME_VAR (addr_a);
- if (TREE_CODE (addr_b) == SSA_NAME)
- decl_b = SSA_NAME_VAR (addr_b);
-
- if (TYPE_RESTRICT (type_a) && TYPE_RESTRICT (type_b)
- && (!DR_IS_READ (a) || !DR_IS_READ (b))
- && decl_a && DECL_P (decl_a)
- && decl_b && DECL_P (decl_b)
- && decl_a != decl_b
- && TREE_CODE (DECL_CONTEXT (decl_a)) == FUNCTION_DECL
- && DECL_CONTEXT (decl_a) == DECL_CONTEXT (decl_b))
- return false;
-
- return true;
+ if (DR_IS_WRITE (a) && DR_IS_WRITE (b))
+ return refs_output_dependent_p (addr_a, addr_b);
+ else if (DR_IS_READ (a) && DR_IS_WRITE (b))
+ return refs_anti_dependent_p (addr_a, addr_b);
+ return refs_may_alias_p (addr_a, addr_b);
}
static void compute_self_dependence (struct data_dependence_relation *);
estimated_loop_iterations (struct loop *loop, bool conservative,
double_int *nit)
{
- estimate_numbers_of_iterations_loop (loop);
+ estimate_numbers_of_iterations_loop (loop, true);
if (conservative)
{
if (!loop->any_upper_bound)
FOR_EACH_VEC_ELT (data_reference_p, datarefs, i, a)
for (j = i + 1; VEC_iterate (data_reference_p, datarefs, j, b); j++)
- if (!DR_IS_READ (a) || !DR_IS_READ (b) || compute_self_and_rr)
+ if (DR_IS_WRITE (a) || DR_IS_WRITE (b) || compute_self_and_rr)
{
ddr = initialize_data_dependence_relation (a, b, loop_nest);
VEC_safe_push (ddr_p, heap, *dependence_relations, ddr);
dump_rdg (stderr, rdg);
}
+static void
+dot_rdg_1 (FILE *file, struct graph *rdg)
+{
+ int i;
+
+ fprintf (file, "digraph RDG {\n");
+
+ for (i = 0; i < rdg->n_vertices; i++)
+ {
+ struct vertex *v = &(rdg->vertices[i]);
+ struct graph_edge *e;
+
+ /* Highlight reads from memory. */
+ if (RDG_MEM_READS_STMT (rdg, i))
+ fprintf (file, "%d [style=filled, fillcolor=green]\n", i);
+
+ /* Highlight stores to memory. */
+ if (RDG_MEM_WRITE_STMT (rdg, i))
+ fprintf (file, "%d [style=filled, fillcolor=red]\n", i);
+
+ if (v->succ)
+ for (e = v->succ; e; e = e->succ_next)
+ switch (RDGE_TYPE (e))
+ {
+ case input_dd:
+ fprintf (file, "%d -> %d [label=input] \n", i, e->dest);
+ break;
+
+ case output_dd:
+ fprintf (file, "%d -> %d [label=output] \n", i, e->dest);
+ break;
+
+ case flow_dd:
+ /* These are the most common dependences: don't print these. */
+ fprintf (file, "%d -> %d \n", i, e->dest);
+ break;
+
+ case anti_dd:
+ fprintf (file, "%d -> %d [label=anti] \n", i, e->dest);
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+ }
+
+ fprintf (file, "}\n\n");
+}
+
+/* Display the Reduced Dependence Graph using dotty. */
+extern void dot_rdg (struct graph *);
+
+DEBUG_FUNCTION void
+dot_rdg (struct graph *rdg)
+{
+ /* When debugging, enable the following code. This cannot be used
+ in production compilers because it calls "system". */
+#if 0
+ FILE *file = fopen ("/tmp/rdg.dot", "w");
+ gcc_assert (file != NULL);
+
+ dot_rdg_1 (file, rdg);
+ fclose (file);
+
+ system ("dotty /tmp/rdg.dot &");
+#else
+ dot_rdg_1 (stderr, rdg);
+#endif
+}
+
/* This structure is used for recording the mapping statement index in
the RDG. */
/* Determines the type of the data dependence. */
if (DR_IS_READ (dra) && DR_IS_READ (drb))
RDGE_TYPE (e) = input_dd;
- else if (!DR_IS_READ (dra) && !DR_IS_READ (drb))
+ else if (DR_IS_WRITE (dra) && DR_IS_WRITE (drb))
RDGE_TYPE (e) = output_dd;
- else if (!DR_IS_READ (dra) && DR_IS_READ (drb))
+ else if (DR_IS_WRITE (dra) && DR_IS_READ (drb))
RDGE_TYPE (e) = flow_dd;
- else if (DR_IS_READ (dra) && !DR_IS_READ (drb))
+ else if (DR_IS_READ (dra) && DR_IS_WRITE (drb))
RDGE_TYPE (e) = anti_dd;
}
free (bbs);
}
+/* Returns true when STMT is an assignment that contains a data
+ reference on its LHS with a stride of the same size as its unit
+ type. */
+
+static bool
+mem_write_stride_of_same_size_as_unit_type_p (gimple stmt)
+{
+ struct data_reference *dr = XCNEW (struct data_reference);
+ tree op0 = gimple_assign_lhs (stmt);
+ bool res;
+
+ DR_STMT (dr) = stmt;
+ DR_REF (dr) = op0;
+
+ res = dr_analyze_innermost (dr)
+ && stride_of_unit_type_p (DR_STEP (dr), TREE_TYPE (op0));
+
+ free_data_ref (dr);
+ return res;
+}
+
/* Initialize STMTS with all the statements of LOOP that contain a
store to memory of the form "A[i] = 0". */
&& is_gimple_assign (stmt)
&& gimple_assign_rhs_code (stmt) == INTEGER_CST
&& (op = gimple_assign_rhs1 (stmt))
- && (integer_zerop (op) || real_zerop (op)))
+ && (integer_zerop (op) || real_zerop (op))
+ && mem_write_stride_of_same_size_as_unit_type_p (stmt))
VEC_safe_push (gimple, heap, *stmts, gsi_stmt (si));
free (bbs);
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