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-rw-r--r--gcc/tree-data-ref.c158
1 files changed, 118 insertions, 40 deletions
diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c
index de2ad5f921b..2181f469ca0 100644
--- a/gcc/tree-data-ref.c
+++ b/gcc/tree-data-ref.c
@@ -668,8 +668,9 @@ canonicalize_base_object_address (tree addr)
return build_fold_addr_expr (TREE_OPERAND (addr, 0));
}
-/* Analyzes the behavior of the memory reference DR in the innermost loop that
- contains it. Returns true if analysis succeed or false otherwise. */
+/* Analyzes the behavior of the memory reference DR in the innermost loop or
+ basic block that contains it. Returns true if analysis succeed or false
+ otherwise. */
bool
dr_analyze_innermost (struct data_reference *dr)
@@ -683,6 +684,7 @@ dr_analyze_innermost (struct data_reference *dr)
int punsignedp, pvolatilep;
affine_iv base_iv, offset_iv;
tree init, dinit, step;
+ bool in_loop = (loop && loop->num);
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "analyze_innermost: ");
@@ -699,23 +701,43 @@ dr_analyze_innermost (struct data_reference *dr)
}
base = build_fold_addr_expr (base);
- if (!simple_iv (loop, loop_containing_stmt (stmt), base, &base_iv, false))
+ if (in_loop)
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "failed: evolution of base is not affine.\n");
- return false;
+ if (!simple_iv (loop, loop_containing_stmt (stmt), base, &base_iv,
+ false))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "failed: evolution of base is not affine.\n");
+ return false;
+ }
}
+ else
+ {
+ base_iv.base = base;
+ base_iv.step = ssize_int (0);
+ base_iv.no_overflow = true;
+ }
+
if (!poffset)
{
offset_iv.base = ssize_int (0);
offset_iv.step = ssize_int (0);
}
- else if (!simple_iv (loop, loop_containing_stmt (stmt),
- poffset, &offset_iv, false))
+ else
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "failed: evolution of offset is not affine.\n");
- return false;
+ if (!in_loop)
+ {
+ offset_iv.base = poffset;
+ offset_iv.step = ssize_int (0);
+ }
+ else if (!simple_iv (loop, loop_containing_stmt (stmt),
+ poffset, &offset_iv, false))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "failed: evolution of offset is not"
+ " affine.\n");
+ return false;
+ }
}
init = ssize_int (pbitpos / BITS_PER_UNIT);
@@ -752,17 +774,23 @@ dr_analyze_indices (struct data_reference *dr, struct loop *nest)
struct loop *loop = loop_containing_stmt (stmt);
VEC (tree, heap) *access_fns = NULL;
tree ref = unshare_expr (DR_REF (dr)), aref = ref, op;
- tree base, off, access_fn;
- basic_block before_loop = block_before_loop (nest);
-
+ tree base, off, access_fn = NULL_TREE;
+ basic_block before_loop = NULL;
+
+ if (nest)
+ before_loop = block_before_loop (nest);
+
while (handled_component_p (aref))
{
if (TREE_CODE (aref) == ARRAY_REF)
{
op = TREE_OPERAND (aref, 1);
- access_fn = analyze_scalar_evolution (loop, op);
- access_fn = instantiate_scev (before_loop, loop, access_fn);
- VEC_safe_push (tree, heap, access_fns, access_fn);
+ if (nest)
+ {
+ access_fn = analyze_scalar_evolution (loop, op);
+ access_fn = instantiate_scev (before_loop, loop, access_fn);
+ VEC_safe_push (tree, heap, access_fns, access_fn);
+ }
TREE_OPERAND (aref, 1) = build_int_cst (TREE_TYPE (op), 0);
}
@@ -770,7 +798,7 @@ dr_analyze_indices (struct data_reference *dr, struct loop *nest)
aref = TREE_OPERAND (aref, 0);
}
- if (INDIRECT_REF_P (aref))
+ if (nest && INDIRECT_REF_P (aref))
{
op = TREE_OPERAND (aref, 0);
access_fn = analyze_scalar_evolution (loop, op);
@@ -1223,7 +1251,17 @@ dr_may_alias_p (const struct data_reference *a, const struct data_reference *b)
return false;
/* Query the alias oracle. */
- if (!refs_may_alias_p (DR_REF (a), DR_REF (b)))
+ 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;
if (!addr_a || !addr_b)
@@ -1322,8 +1360,9 @@ initialize_data_dependence_relation (struct data_reference *a,
/* If the base of the object is not invariant in the loop nest, we cannot
analyze it. TODO -- in fact, it would suffice to record that there may
be arbitrary dependences in the loops where the base object varies. */
- if (!object_address_invariant_in_loop_p (VEC_index (loop_p, loop_nest, 0),
- DR_BASE_OBJECT (a)))
+ if (loop_nest
+ && !object_address_invariant_in_loop_p (VEC_index (loop_p, loop_nest, 0),
+ DR_BASE_OBJECT (a)))
{
DDR_ARE_DEPENDENT (res) = chrec_dont_know;
return res;
@@ -3993,7 +4032,8 @@ compute_all_dependences (VEC (data_reference_p, heap) *datarefs,
{
ddr = initialize_data_dependence_relation (a, b, loop_nest);
VEC_safe_push (ddr_p, heap, *dependence_relations, ddr);
- compute_affine_dependence (ddr, VEC_index (loop_p, loop_nest, 0));
+ if (loop_nest)
+ compute_affine_dependence (ddr, VEC_index (loop_p, loop_nest, 0));
}
if (compute_self_and_rr)
@@ -4100,9 +4140,10 @@ find_data_references_in_stmt (struct loop *nest, gimple stmt,
dr = create_data_ref (nest, *ref->pos, stmt, ref->is_read);
gcc_assert (dr != NULL);
- /* FIXME -- data dependence analysis does not work correctly for objects with
- invariant addresses. Let us fail here until the problem is fixed. */
- if (dr_address_invariant_p (dr))
+ /* FIXME -- data dependence analysis does not work correctly for objects
+ with invariant addresses in loop nests. Let us fail here until the
+ problem is fixed. */
+ if (dr_address_invariant_p (dr) && nest)
{
free_data_ref (dr);
if (dump_file && (dump_flags & TDF_DETAILS))
@@ -4119,6 +4160,33 @@ find_data_references_in_stmt (struct loop *nest, gimple stmt,
/* Search the data references in LOOP, and record the information into
DATAREFS. Returns chrec_dont_know when failing to analyze a
+ difficult case, returns NULL_TREE otherwise. */
+
+static tree
+find_data_references_in_bb (struct loop *loop, basic_block bb,
+ VEC (data_reference_p, heap) **datarefs)
+{
+ gimple_stmt_iterator bsi;
+
+ for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+ {
+ gimple stmt = gsi_stmt (bsi);
+
+ if (!find_data_references_in_stmt (loop, stmt, datarefs))
+ {
+ struct data_reference *res;
+ res = XCNEW (struct data_reference);
+ VEC_safe_push (data_reference_p, heap, *datarefs, res);
+
+ return chrec_dont_know;
+ }
+ }
+
+ return NULL_TREE;
+}
+
+/* Search the data references in LOOP, and record the information into
+ DATAREFS. Returns chrec_dont_know when failing to analyze a
difficult case, returns NULL_TREE otherwise.
TODO: This function should be made smarter so that it can handle address
@@ -4130,7 +4198,6 @@ find_data_references_in_loop (struct loop *loop,
{
basic_block bb, *bbs;
unsigned int i;
- gimple_stmt_iterator bsi;
bbs = get_loop_body_in_dom_order (loop);
@@ -4138,20 +4205,11 @@ find_data_references_in_loop (struct loop *loop,
{
bb = bbs[i];
- for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
- {
- gimple stmt = gsi_stmt (bsi);
-
- if (!find_data_references_in_stmt (loop, stmt, datarefs))
- {
- struct data_reference *res;
- res = XCNEW (struct data_reference);
- VEC_safe_push (data_reference_p, heap, *datarefs, res);
-
- free (bbs);
- return chrec_dont_know;
- }
- }
+ if (find_data_references_in_bb (loop, bb, datarefs) == chrec_dont_know)
+ {
+ free (bbs);
+ return chrec_dont_know;
+ }
}
free (bbs);
@@ -4288,6 +4346,26 @@ compute_data_dependences_for_loop (struct loop *loop,
return res;
}
+/* Returns true when the data dependences for the basic block BB have been
+ computed, false otherwise.
+ DATAREFS is initialized to all the array elements contained in this basic
+ block, DEPENDENCE_RELATIONS contains the relations between the data
+ references. Compute read-read and self relations if
+ COMPUTE_SELF_AND_READ_READ_DEPENDENCES is TRUE. */
+bool
+compute_data_dependences_for_bb (basic_block bb,
+ bool compute_self_and_read_read_dependences,
+ VEC (data_reference_p, heap) **datarefs,
+ VEC (ddr_p, heap) **dependence_relations)
+{
+ if (find_data_references_in_bb (NULL, bb, datarefs) == chrec_dont_know)
+ return false;
+
+ compute_all_dependences (*datarefs, dependence_relations, NULL,
+ compute_self_and_read_read_dependences);
+ return true;
+}
+
/* Entry point (for testing only). Analyze all the data references
and the dependence relations in LOOP.
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-19 04:02:24 +0000