/* Data references and dependences detectors.
- Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
Contributed by Sebastian Pop <s.pop@laposte.net>
This file is part of GCC.
- polyhedron dependence
or with the chains of recurrences based representation,
- - to define a knowledge base for storing the data dependences
+ - to define a knowledge base for storing the data dependence
information,
- to define an interface to access this data.
#include "tree-data-ref.h"
#include "tree-scalar-evolution.h"
#include "tree-pass.h"
-#include "lambda.h"
-\f
/* This is the simplest data dependence test: determines whether the
- data references A and B access the same array/region. If can't determine -
- return false; Otherwise, return true, and DIFFER_P will record
- the result. This utility will not be necessary when alias_sets_conflict_p
- will be less conservative. */
+ data references A and B access the same array/region. Returns
+ false when the property is not computable at compile time.
+ Otherwise return true, and DIFFER_P will record the result. This
+ utility will not be necessary when alias_sets_conflict_p will be
+ less conservative. */
bool
array_base_name_differ_p (struct data_reference *a,
{
tree base_a = DR_BASE_NAME (a);
tree base_b = DR_BASE_NAME (b);
- tree ta = TREE_TYPE (base_a);
- tree tb = TREE_TYPE (base_b);
-
- /** Determine if same base **/
+ if (!base_a || !base_b)
+ return false;
- /* array accesses: a[i],b[i] or pointer accesses: *a,*b. bases are a,b. */
+ /* Determine if same base. Example: for the array accesses
+ a[i], b[i] or pointer accesses *a, *b, bases are a, b. */
if (base_a == base_b)
{
*differ_p = false;
return true;
}
- /* pointer based accesses - (*p)[i],(*q)[j]. bases are (*p),(*q) */
+ /* For pointer based accesses, (*p)[i], (*q)[j], the bases are (*p)
+ and (*q) */
if (TREE_CODE (base_a) == INDIRECT_REF && TREE_CODE (base_b) == INDIRECT_REF
&& TREE_OPERAND (base_a, 0) == TREE_OPERAND (base_b, 0))
{
return true;
}
- /* record/union based accesses - s.a[i], t.b[j]. bases are s.a,t.b. */
+ /* Record/union based accesses - s.a[i], t.b[j]. bases are s.a,t.b. */
if (TREE_CODE (base_a) == COMPONENT_REF && TREE_CODE (base_b) == COMPONENT_REF
&& TREE_OPERAND (base_a, 0) == TREE_OPERAND (base_b, 0)
&& TREE_OPERAND (base_a, 1) == TREE_OPERAND (base_b, 1))
}
- /** Determine if different bases **/
+ /* Determine if different bases. */
- /* at this point we know that base_a != base_b. However, pointer accesses
- of the form x=(*p) and y=(*q), which bases are p and q, may still by pointing
- to the same base. In SSAed GIMPLE p and q will be SSA_NAMES in this case.
- Therefore, here we check if it's really two diferent declarations. */
+ /* At this point we know that base_a != base_b. However, pointer
+ accesses of the form x=(*p) and y=(*q), whose bases are p and q,
+ may still be pointing to the same base. In SSAed GIMPLE p and q will
+ be SSA_NAMES in this case. Therefore, here we check if they are
+ really two different declarations. */
if (TREE_CODE (base_a) == VAR_DECL && TREE_CODE (base_b) == VAR_DECL)
{
*differ_p = true;
return true;
}
- /* compare two record/union bases s.a and t.b:
- s != t or (a != b and s and t are not unions) */
+ /* Compare two record/union bases s.a and t.b: s != t or (a != b and
+ s and t are not unions). */
if (TREE_CODE (base_a) == COMPONENT_REF && TREE_CODE (base_b) == COMPONENT_REF
&& ((TREE_CODE (TREE_OPERAND (base_a, 0)) == VAR_DECL
&& TREE_CODE (TREE_OPERAND (base_b, 0)) == VAR_DECL
return true;
}
- /* compare a record/union access and an array access. */
+ /* Compare a record/union access and an array access. */
if ((TREE_CODE (base_a) == VAR_DECL
&& (TREE_CODE (base_b) == COMPONENT_REF
&& TREE_CODE (TREE_OPERAND (base_b, 0)) == VAR_DECL))
return true;
}
- if (!alias_sets_conflict_p (get_alias_set (base_a), get_alias_set (base_b)))
- {
- *differ_p = true;
- return true;
- }
-
- /* An insn writing through a restricted pointer is "independent" of any
- insn reading or writing through a different pointer, in the same
- block/scope.
- */
- if ((TREE_CODE (ta) == POINTER_TYPE && TYPE_RESTRICT (ta)
- && !DR_IS_READ(a))
- || (TREE_CODE (tb) == POINTER_TYPE && TYPE_RESTRICT (tb)
- && !DR_IS_READ(b)))
- {
- *differ_p = true;
- return true;
- }
-
- *differ_p = false; /* Don't know, but be conservative. */
return false;
}
tree a,
tree b)
{
- if (integer_onep (a))
- return true;
-
/* Determines whether (A == gcd (A, B)). */
return integer_zerop
(fold (build (MINUS_EXPR, type, a, tree_fold_gcd (a, b))));
}
-/* Bezout: Let A1 and A2 be two integers; there exist two integers U11
- and U12 such that,
-
- | U11 * A1 + U12 * A2 = gcd (A1, A2).
-
- This function computes the greatest common divisor using the
- Blankinship algorithm. The gcd is returned, and the coefficients
- of the unimodular matrix U are (U11, U12, U21, U22) such that,
+/* Compute the greatest common denominator of two numbers using
+ Euclid's algorithm. */
- | U.A = S
-
- | (U11 U12) (A1) = (gcd)
- | (U21 U22) (A2) (0)
-
- FIXME: Use lambda_..._hermite for implementing this function.
-*/
-
-static tree
-tree_fold_bezout (tree a1,
- tree a2,
- tree *u11, tree *u12,
- tree *u21, tree *u22)
+static int
+gcd (int a, int b)
{
- tree s1, s2;
-
- /* Initialize S with the coefficients of A. */
- s1 = a1;
- s2 = a2;
- /* Initialize the U matrix */
- *u11 = integer_one_node;
- *u12 = integer_zero_node;
- *u21 = integer_zero_node;
- *u22 = integer_one_node;
+ int x, y, z;
- if (integer_zerop (a1)
- || integer_zerop (a2))
- return integer_zero_node;
-
- while (!integer_zerop (s2))
- {
- int sign;
- tree z, zu21, zu22, zs2;
-
- sign = tree_int_cst_sgn (s1) * tree_int_cst_sgn (s2);
- z = fold (build (FLOOR_DIV_EXPR, integer_type_node,
- fold (build1 (ABS_EXPR, integer_type_node, s1)),
- fold (build1 (ABS_EXPR, integer_type_node, s2))));
- zu21 = fold (build (MULT_EXPR, integer_type_node, z, *u21));
- zu22 = fold (build (MULT_EXPR, integer_type_node, z, *u22));
- zs2 = fold (build (MULT_EXPR, integer_type_node, z, s2));
-
- /* row1 -= z * row2. */
- if (sign < 0)
- {
- *u11 = fold (build (PLUS_EXPR, integer_type_node, *u11, zu21));
- *u12 = fold (build (PLUS_EXPR, integer_type_node, *u12, zu22));
- s1 = fold (build (PLUS_EXPR, integer_type_node, s1, zs2));
- }
- else if (sign > 0)
- {
- *u11 = fold (build (MINUS_EXPR, integer_type_node, *u11, zu21));
- *u12 = fold (build (MINUS_EXPR, integer_type_node, *u12, zu22));
- s1 = fold (build (MINUS_EXPR, integer_type_node, s1, zs2));
- }
- else
- /* Should not happen. */
- abort ();
-
- /* Interchange row1 and row2. */
- {
- tree flip;
-
- flip = *u11;
- *u11 = *u21;
- *u21 = flip;
-
- flip = *u12;
- *u12 = *u22;
- *u22 = flip;
-
- flip = s1;
- s1 = s2;
- s2 = flip;
- }
- }
-
- if (tree_int_cst_sgn (s1) < 0)
+ x = abs (a);
+ y = abs (b);
+
+ while (x>0)
{
- *u11 = fold (build (MULT_EXPR, integer_type_node, *u11,
- integer_minus_one_node));
- *u12 = fold (build (MULT_EXPR, integer_type_node, *u12,
- integer_minus_one_node));
- s1 = fold (build (MULT_EXPR, integer_type_node, s1, integer_minus_one_node));
+ z = y % x;
+ y = x;
+ x = z;
}
-
- return s1;
+
+ return (y);
+}
+
+/* Returns true iff A divides B. */
+
+static inline bool
+int_divides_p (int a, int b)
+{
+ return ((b % a) == 0);
}
\f
fprintf (outf, ")\n");
}
+/* Dump function for a SUBSCRIPT structure. */
+
+void
+dump_subscript (FILE *outf, struct subscript *subscript)
+{
+ tree chrec = SUB_CONFLICTS_IN_A (subscript);
+
+ fprintf (outf, "\n (subscript \n");
+ fprintf (outf, " iterations_that_access_an_element_twice_in_A: ");
+ print_generic_stmt (outf, chrec, 0);
+ if (chrec == chrec_known)
+ fprintf (outf, " (no dependence)\n");
+ else if (chrec_contains_undetermined (chrec))
+ fprintf (outf, " (don't know)\n");
+ else
+ {
+ tree last_iteration = SUB_LAST_CONFLICT (subscript);
+ fprintf (outf, " last_conflict: ");
+ print_generic_stmt (outf, last_iteration, 0);
+ }
+
+ chrec = SUB_CONFLICTS_IN_B (subscript);
+ fprintf (outf, " iterations_that_access_an_element_twice_in_B: ");
+ print_generic_stmt (outf, chrec, 0);
+ if (chrec == chrec_known)
+ fprintf (outf, " (no dependence)\n");
+ else if (chrec_contains_undetermined (chrec))
+ fprintf (outf, " (don't know)\n");
+ else
+ {
+ tree last_iteration = SUB_LAST_CONFLICT (subscript);
+ fprintf (outf, " last_conflict: ");
+ print_generic_stmt (outf, last_iteration, 0);
+ }
+
+ fprintf (outf, " (Subscript distance: ");
+ print_generic_stmt (outf, SUB_DISTANCE (subscript), 0);
+ fprintf (outf, " )\n");
+ fprintf (outf, " )\n");
+}
+
/* Dump function for a DATA_DEPENDENCE_RELATION structure. */
void
dump_data_dependence_relation (FILE *outf,
struct data_dependence_relation *ddr)
{
- unsigned int i;
struct data_reference *dra, *drb;
-
+
dra = DDR_A (ddr);
drb = DDR_B (ddr);
-
- if (dra && drb)
- fprintf (outf, "(Data Dep:");
- else
- fprintf (outf, "(Data Dep:");
-
- if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (ddr)))
+ fprintf (outf, "(Data Dep: \n");
+ if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
fprintf (outf, " (don't know)\n");
else if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
fprintf (outf, " (no dependence)\n");
- else
+ else if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
{
+ unsigned int i;
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
{
- tree chrec;
- struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
-
- fprintf (outf, "\n (subscript %d:\n", i);
fprintf (outf, " access_fn_A: ");
print_generic_stmt (outf, DR_ACCESS_FN (dra, i), 0);
fprintf (outf, " access_fn_B: ");
print_generic_stmt (outf, DR_ACCESS_FN (drb, i), 0);
-
- chrec = SUB_CONFLICTS_IN_A (subscript);
- fprintf (outf, " iterations_that_access_an_element_twice_in_A: ");
- print_generic_stmt (outf, chrec, 0);
- if (chrec == chrec_known)
- fprintf (outf, " (no dependence)\n");
- else if (chrec_contains_undetermined (chrec))
- fprintf (outf, " (don't know)\n");
- else
- {
- tree last_iteration = SUB_LAST_CONFLICT_IN_A (subscript);
- fprintf (outf, " last_iteration_that_access_an_element_twice_in_A: ");
- print_generic_stmt (outf, last_iteration, 0);
- }
-
- chrec = SUB_CONFLICTS_IN_B (subscript);
- fprintf (outf, " iterations_that_access_an_element_twice_in_B: ");
- print_generic_stmt (outf, chrec, 0);
- if (chrec == chrec_known)
- fprintf (outf, " (no dependence)\n");
- else if (chrec_contains_undetermined (chrec))
- fprintf (outf, " (don't know)\n");
- else
- {
- tree last_iteration = SUB_LAST_CONFLICT_IN_B (subscript);
- fprintf (outf, " last_iteration_that_access_an_element_twice_in_B: ");
- print_generic_stmt (outf, last_iteration, 0);
- }
-
- fprintf (outf, " )\n");
+ dump_subscript (outf, DDR_SUBSCRIPT (ddr, i));
}
-
- fprintf (outf, " (Distance Vector: \n");
- for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
+ if (DDR_DIST_VECT (ddr))
{
- struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
-
- fprintf (outf, "(");
- print_generic_stmt (outf, SUB_DISTANCE (subscript), 0);
- fprintf (outf, ")\n");
+ fprintf (outf, " distance_vect: ");
+ print_lambda_vector (outf, DDR_DIST_VECT (ddr), DDR_SIZE_VECT (ddr));
+ }
+ if (DDR_DIR_VECT (ddr))
+ {
+ fprintf (outf, " direction_vect: ");
+ print_lambda_vector (outf, DDR_DIR_VECT (ddr), DDR_SIZE_VECT (ddr));
}
- fprintf (outf, " )\n");
}
fprintf (outf, ")\n");
}
}
+/* Dumps the distance and direction vectors in FILE. DDRS contains
+ the dependence relations, and VECT_SIZE is the size of the
+ dependence vectors, or in other words the number of loops in the
+ considered nest. */
+
+void
+dump_dist_dir_vectors (FILE *file, varray_type ddrs)
+{
+ unsigned int i;
+
+ for (i = 0; i < VARRAY_ACTIVE_SIZE (ddrs); i++)
+ {
+ struct data_dependence_relation *ddr =
+ (struct data_dependence_relation *)
+ VARRAY_GENERIC_PTR (ddrs, i);
+ if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE
+ && DDR_AFFINE_P (ddr))
+ {
+ fprintf (file, "DISTANCE_V (");
+ print_lambda_vector (file, DDR_DIST_VECT (ddr), DDR_SIZE_VECT (ddr));
+ fprintf (file, ")\n");
+ fprintf (file, "DIRECTION_V (");
+ print_lambda_vector (file, DDR_DIR_VECT (ddr), DDR_SIZE_VECT (ddr));
+ fprintf (file, ")\n");
+ }
+ }
+ fprintf (file, "\n\n");
+}
+
+/* Dumps the data dependence relations DDRS in FILE. */
+
+void
+dump_ddrs (FILE *file, varray_type ddrs)
+{
+ unsigned int i;
+
+ for (i = 0; i < VARRAY_ACTIVE_SIZE (ddrs); i++)
+ {
+ struct data_dependence_relation *ddr =
+ (struct data_dependence_relation *)
+ VARRAY_GENERIC_PTR (ddrs, i);
+ dump_data_dependence_relation (file, ddr);
+ }
+ fprintf (file, "\n\n");
+}
+
\f
+/* Compute the lowest iteration bound for LOOP. It is an
+ INTEGER_CST. */
+
+static void
+compute_estimated_nb_iterations (struct loop *loop)
+{
+ tree estimation;
+ struct nb_iter_bound *bound, *next;
+
+ for (bound = loop->bounds; bound; bound = next)
+ {
+ next = bound->next;
+ estimation = bound->bound;
+
+ if (TREE_CODE (estimation) != INTEGER_CST)
+ continue;
+
+ if (loop->estimated_nb_iterations)
+ {
+ /* Update only if estimation is smaller. */
+ if (tree_int_cst_lt (estimation, loop->estimated_nb_iterations))
+ loop->estimated_nb_iterations = estimation;
+ }
+ else
+ loop->estimated_nb_iterations = estimation;
+ }
+}
+
+/* Estimate the number of iterations from the size of the data and the
+ access functions. */
+
+static void
+estimate_niter_from_size_of_data (struct loop *loop,
+ tree opnd0,
+ tree access_fn,
+ tree stmt)
+{
+ tree estimation;
+ tree array_size, data_size, element_size;
+ tree init, step;
+
+ init = initial_condition (access_fn);
+ step = evolution_part_in_loop_num (access_fn, loop->num);
+
+ array_size = TYPE_SIZE (TREE_TYPE (opnd0));
+ element_size = TYPE_SIZE (TREE_TYPE (TREE_TYPE (opnd0)));
+ if (array_size == NULL_TREE
+ || TREE_CODE (array_size) != INTEGER_CST
+ || TREE_CODE (element_size) != INTEGER_CST)
+ return;
+
+ data_size = fold (build2 (EXACT_DIV_EXPR, integer_type_node,
+ array_size, element_size));
+
+ if (init != NULL_TREE
+ && step != NULL_TREE
+ && TREE_CODE (init) == INTEGER_CST
+ && TREE_CODE (step) == INTEGER_CST)
+ {
+ estimation = fold (build2 (CEIL_DIV_EXPR, integer_type_node,
+ fold (build2 (MINUS_EXPR, integer_type_node,
+ data_size, init)), step));
+
+ record_estimate (loop, estimation, boolean_true_node, stmt);
+ }
+}
+
/* Given an ARRAY_REF node REF, records its access functions.
Example: given A[i][3], record in ACCESS_FNS the opnd1 function,
- ie. the constant "3", then recursively call the function on opnd0,
- ie. the ARRAY_REF "A[i]". The function returns the base name:
+ i.e. the constant "3", then recursively call the function on opnd0,
+ i.e. the ARRAY_REF "A[i]". The function returns the base name:
"A". */
static tree
analyze_array_indexes (struct loop *loop,
- varray_type access_fns,
- tree ref)
+ VEC(tree,heap) **access_fns,
+ tree ref, tree stmt)
{
tree opnd0, opnd1;
tree access_fn;
the optimizers. */
access_fn = instantiate_parameters
(loop, analyze_scalar_evolution (loop, opnd1));
+
+ if (loop->estimated_nb_iterations == NULL_TREE)
+ estimate_niter_from_size_of_data (loop, opnd0, access_fn, stmt);
- VARRAY_PUSH_TREE (access_fns, access_fn);
+ VEC_safe_push (tree, heap, *access_fns, access_fn);
/* Recursively record other array access functions. */
if (TREE_CODE (opnd0) == ARRAY_REF)
- return analyze_array_indexes (loop, access_fns, opnd0);
+ return analyze_array_indexes (loop, access_fns, opnd0, stmt);
/* Return the base name of the data access. */
else
return opnd0;
}
-/* For a data reference REF contained in the statemet STMT, initialize
+/* For a data reference REF contained in the statement STMT, initialize
a DATA_REFERENCE structure, and return it. IS_READ flag has to be
set to true when REF is in the right hand side of an
assignment. */
DR_STMT (res) = stmt;
DR_REF (res) = ref;
- VARRAY_TREE_INIT (DR_ACCESS_FNS (res), 3, "access_fns");
+ DR_ACCESS_FNS (res) = VEC_alloc (tree, heap, 3);
DR_BASE_NAME (res) = analyze_array_indexes
- (loop_containing_stmt (stmt), DR_ACCESS_FNS (res), ref);
+ (loop_containing_stmt (stmt), &(DR_ACCESS_FNS (res)), ref, stmt);
DR_IS_READ (res) = is_read;
if (dump_file && (dump_flags & TDF_DETAILS))
return res;
}
-/* For a data reference REF contained in the statemet STMT, initialize
+/* For a data reference REF contained in the statement STMT, initialize
a DATA_REFERENCE structure, and return it. */
struct data_reference *
DR_STMT (res) = stmt;
DR_REF (res) = ref;
- VARRAY_TREE_INIT (DR_ACCESS_FNS (res), 5, "access_fns");
+ DR_ACCESS_FNS (res) = VEC_alloc (tree, heap, 5);
DR_BASE_NAME (res) = base;
- VARRAY_PUSH_TREE (DR_ACCESS_FNS (res), access_fn);
+ VEC_quick_push (tree, DR_ACCESS_FNS (res), access_fn);
DR_IS_READ (res) = is_read;
if (dump_file && (dump_flags & TDF_DETAILS))
\f
-/* When there exists a dependence relation, determine its distance
- vector. */
+/* Returns true when all the functions of a tree_vec CHREC are the
+ same. */
-static void
-compute_distance_vector (struct data_dependence_relation *ddr)
+static bool
+all_chrecs_equal_p (tree chrec)
+{
+ int j;
+
+ for (j = 0; j < TREE_VEC_LENGTH (chrec) - 1; j++)
+ {
+ tree chrec_j = TREE_VEC_ELT (chrec, j);
+ tree chrec_j_1 = TREE_VEC_ELT (chrec, j + 1);
+ if (!integer_zerop
+ (chrec_fold_minus
+ (integer_type_node, chrec_j, chrec_j_1)))
+ return false;
+ }
+ return true;
+}
+
+/* Determine for each subscript in the data dependence relation DDR
+ the distance. */
+
+void
+compute_subscript_distance (struct data_dependence_relation *ddr)
{
if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
{
subscript = DDR_SUBSCRIPT (ddr, i);
conflicts_a = SUB_CONFLICTS_IN_A (subscript);
conflicts_b = SUB_CONFLICTS_IN_B (subscript);
- difference = chrec_fold_minus
+
+ if (TREE_CODE (conflicts_a) == TREE_VEC)
+ {
+ if (!all_chrecs_equal_p (conflicts_a))
+ {
+ SUB_DISTANCE (subscript) = chrec_dont_know;
+ return;
+ }
+ else
+ conflicts_a = TREE_VEC_ELT (conflicts_a, 0);
+ }
+
+ if (TREE_CODE (conflicts_b) == TREE_VEC)
+ {
+ if (!all_chrecs_equal_p (conflicts_b))
+ {
+ SUB_DISTANCE (subscript) = chrec_dont_know;
+ return;
+ }
+ else
+ conflicts_b = TREE_VEC_ELT (conflicts_b, 0);
+ }
+
+ difference = chrec_fold_minus
(integer_type_node, conflicts_b, conflicts_a);
if (evolution_function_is_constant_p (difference))
else
{
unsigned int i;
+ DDR_AFFINE_P (res) = true;
DDR_ARE_DEPENDENT (res) = NULL_TREE;
DDR_SUBSCRIPTS_VECTOR_INIT (res, DR_NUM_DIMENSIONS (a));
+ DDR_SIZE_VECT (res) = 0;
+ DDR_DIST_VECT (res) = NULL;
+ DDR_DIR_VECT (res) = NULL;
for (i = 0; i < DR_NUM_DIMENSIONS (a); i++)
{
subscript = xmalloc (sizeof (struct subscript));
SUB_CONFLICTS_IN_A (subscript) = chrec_dont_know;
SUB_CONFLICTS_IN_B (subscript) = chrec_dont_know;
- SUB_LAST_CONFLICT_IN_A (subscript) = chrec_dont_know;
- SUB_LAST_CONFLICT_IN_B (subscript) = chrec_dont_know;
+ SUB_LAST_CONFLICT (subscript) = chrec_dont_know;
SUB_DISTANCE (subscript) = chrec_dont_know;
VARRAY_PUSH_GENERIC_PTR (DDR_SUBSCRIPTS (res), subscript);
}
varray_clear (DDR_SUBSCRIPTS (ddr));
}
+/* The dependence relation DDR cannot be represented by a distance
+ vector. */
+
+static inline void
+non_affine_dependence_relation (struct data_dependence_relation *ddr)
+{
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "(Dependence relation cannot be represented by distance vector.) \n");
+
+ DDR_AFFINE_P (ddr) = false;
+}
+
\f
/* This section contains the classic Banerjee tests. */
analyze_ziv_subscript (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
tree difference;
overlaps for each iteration in the loop. */
*overlaps_a = integer_zero_node;
*overlaps_b = integer_zero_node;
+ *last_conflicts = chrec_dont_know;
}
else
{
/* The accesses do not overlap. */
*overlaps_a = chrec_known;
- *overlaps_b = chrec_known;
+ *overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
}
break;
/* We're not sure whether the indexes overlap. For the moment,
conservatively answer "don't know". */
*overlaps_a = chrec_dont_know;
- *overlaps_b = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
break;
}
analyze_siv_subscript_cst_affine (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
bool value0, value1, value2;
tree difference = chrec_fold_minus
{
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
return;
}
else
{
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
return;
}
else
(build (EXACT_DIV_EXPR, integer_type_node,
fold (build1 (ABS_EXPR, integer_type_node, difference)),
CHREC_RIGHT (chrec_b)));
+ *last_conflicts = integer_one_node;
return;
}
{
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
return;
}
}
In this case, chrec_a will not overlap with chrec_b. */
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
return;
}
}
{
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
return;
}
else
*overlaps_b = fold
(build (EXACT_DIV_EXPR, integer_type_node, difference,
CHREC_RIGHT (chrec_b)));
+ *last_conflicts = integer_one_node;
return;
}
{
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
return;
}
}
In this case, chrec_a will not overlap with chrec_b. */
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
return;
}
}
}
}
-/* Analyze a SIV (Single Index Variable) subscript where CHREC_A is an
- affine function, and CHREC_B is a constant. *OVERLAPS_A and
- *OVERLAPS_B are initialized to the functions that describe the
- relation between the elements accessed twice by CHREC_A and
- CHREC_B. For k >= 0, the following property is verified:
+/* Helper recursive function for initializing the matrix A. Returns
+ the initial value of CHREC. */
- CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */
+static int
+initialize_matrix_A (lambda_matrix A, tree chrec, unsigned index, int mult)
+{
+ gcc_assert (chrec);
+
+ if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
+ return int_cst_value (chrec);
+
+ A[index][0] = mult * int_cst_value (CHREC_RIGHT (chrec));
+ return initialize_matrix_A (A, CHREC_LEFT (chrec), index + 1, mult);
+}
+
+#define FLOOR_DIV(x,y) ((x) / (y))
+
+/* Solves the special case of the Diophantine equation:
+ | {0, +, STEP_A}_x (OVERLAPS_A) = {0, +, STEP_B}_y (OVERLAPS_B)
+
+ Computes the descriptions OVERLAPS_A and OVERLAPS_B. NITER is the
+ number of iterations that loops X and Y run. The overlaps will be
+ constructed as evolutions in dimension DIM. */
static void
-analyze_siv_subscript_affine_cst (tree chrec_a,
- tree chrec_b,
- tree *overlaps_a,
- tree *overlaps_b)
+compute_overlap_steps_for_affine_univar (int niter, int step_a, int step_b,
+ tree *overlaps_a, tree *overlaps_b,
+ tree *last_conflicts, int dim)
{
- analyze_siv_subscript_cst_affine (chrec_b, chrec_a, overlaps_b, overlaps_a);
+ if (((step_a > 0 && step_b > 0)
+ || (step_a < 0 && step_b < 0)))
+ {
+ int step_overlaps_a, step_overlaps_b;
+ int gcd_steps_a_b, last_conflict, tau2;
+
+ gcd_steps_a_b = gcd (step_a, step_b);
+ step_overlaps_a = step_b / gcd_steps_a_b;
+ step_overlaps_b = step_a / gcd_steps_a_b;
+
+ tau2 = FLOOR_DIV (niter, step_overlaps_a);
+ tau2 = MIN (tau2, FLOOR_DIV (niter, step_overlaps_b));
+ last_conflict = tau2;
+
+ *overlaps_a = build_polynomial_chrec
+ (dim, integer_zero_node,
+ build_int_cst (NULL_TREE, step_overlaps_a));
+ *overlaps_b = build_polynomial_chrec
+ (dim, integer_zero_node,
+ build_int_cst (NULL_TREE, step_overlaps_b));
+ *last_conflicts = build_int_cst (NULL_TREE, last_conflict);
+ }
+
+ else
+ {
+ *overlaps_a = integer_zero_node;
+ *overlaps_b = integer_zero_node;
+ *last_conflicts = integer_zero_node;
+ }
+}
+
+
+/* Solves the special case of a Diophantine equation where CHREC_A is
+ an affine bivariate function, and CHREC_B is an affine univariate
+ function. For example,
+
+ | {{0, +, 1}_x, +, 1335}_y = {0, +, 1336}_z
+
+ has the following overlapping functions:
+
+ | x (t, u, v) = {{0, +, 1336}_t, +, 1}_v
+ | y (t, u, v) = {{0, +, 1336}_u, +, 1}_v
+ | z (t, u, v) = {{{0, +, 1}_t, +, 1335}_u, +, 1}_v
+
+ FORNOW: This is a specialized implementation for a case occurring in
+ a common benchmark. Implement the general algorithm. */
+
+static void
+compute_overlap_steps_for_affine_1_2 (tree chrec_a, tree chrec_b,
+ tree *overlaps_a, tree *overlaps_b,
+ tree *last_conflicts)
+{
+ bool xz_p, yz_p, xyz_p;
+ int step_x, step_y, step_z;
+ int niter_x, niter_y, niter_z, niter;
+ tree numiter_x, numiter_y, numiter_z;
+ tree overlaps_a_xz, overlaps_b_xz, last_conflicts_xz;
+ tree overlaps_a_yz, overlaps_b_yz, last_conflicts_yz;
+ tree overlaps_a_xyz, overlaps_b_xyz, last_conflicts_xyz;
+
+ step_x = int_cst_value (CHREC_RIGHT (CHREC_LEFT (chrec_a)));
+ step_y = int_cst_value (CHREC_RIGHT (chrec_a));
+ step_z = int_cst_value (CHREC_RIGHT (chrec_b));
+
+ numiter_x = number_of_iterations_in_loop
+ (current_loops->parray[CHREC_VARIABLE (CHREC_LEFT (chrec_a))]);
+ numiter_y = number_of_iterations_in_loop
+ (current_loops->parray[CHREC_VARIABLE (chrec_a)]);
+ numiter_z = number_of_iterations_in_loop
+ (current_loops->parray[CHREC_VARIABLE (chrec_b)]);
+
+ if (TREE_CODE (numiter_x) != INTEGER_CST)
+ numiter_x = current_loops->parray[CHREC_VARIABLE (CHREC_LEFT (chrec_a))]
+ ->estimated_nb_iterations;
+ if (TREE_CODE (numiter_y) != INTEGER_CST)
+ numiter_y = current_loops->parray[CHREC_VARIABLE (chrec_a)]
+ ->estimated_nb_iterations;
+ if (TREE_CODE (numiter_z) != INTEGER_CST)
+ numiter_z = current_loops->parray[CHREC_VARIABLE (chrec_b)]
+ ->estimated_nb_iterations;
+
+ if (numiter_x == NULL_TREE || numiter_y == NULL_TREE
+ || numiter_z == NULL_TREE)
+ {
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
+ return;
+ }
+
+ niter_x = int_cst_value (numiter_x);
+ niter_y = int_cst_value (numiter_y);
+ niter_z = int_cst_value (numiter_z);
+
+ niter = MIN (niter_x, niter_z);
+ compute_overlap_steps_for_affine_univar (niter, step_x, step_z,
+ &overlaps_a_xz,
+ &overlaps_b_xz,
+ &last_conflicts_xz, 1);
+ niter = MIN (niter_y, niter_z);
+ compute_overlap_steps_for_affine_univar (niter, step_y, step_z,
+ &overlaps_a_yz,
+ &overlaps_b_yz,
+ &last_conflicts_yz, 2);
+ niter = MIN (niter_x, niter_z);
+ niter = MIN (niter_y, niter);
+ compute_overlap_steps_for_affine_univar (niter, step_x + step_y, step_z,
+ &overlaps_a_xyz,
+ &overlaps_b_xyz,
+ &last_conflicts_xyz, 3);
+
+ xz_p = !integer_zerop (last_conflicts_xz);
+ yz_p = !integer_zerop (last_conflicts_yz);
+ xyz_p = !integer_zerop (last_conflicts_xyz);
+
+ if (xz_p || yz_p || xyz_p)
+ {
+ *overlaps_a = make_tree_vec (2);
+ TREE_VEC_ELT (*overlaps_a, 0) = integer_zero_node;
+ TREE_VEC_ELT (*overlaps_a, 1) = integer_zero_node;
+ *overlaps_b = integer_zero_node;
+ if (xz_p)
+ {
+ TREE_VEC_ELT (*overlaps_a, 0) =
+ chrec_fold_plus (integer_type_node, TREE_VEC_ELT (*overlaps_a, 0),
+ overlaps_a_xz);
+ *overlaps_b =
+ chrec_fold_plus (integer_type_node, *overlaps_b, overlaps_b_xz);
+ *last_conflicts = last_conflicts_xz;
+ }
+ if (yz_p)
+ {
+ TREE_VEC_ELT (*overlaps_a, 1) =
+ chrec_fold_plus (integer_type_node, TREE_VEC_ELT (*overlaps_a, 1),
+ overlaps_a_yz);
+ *overlaps_b =
+ chrec_fold_plus (integer_type_node, *overlaps_b, overlaps_b_yz);
+ *last_conflicts = last_conflicts_yz;
+ }
+ if (xyz_p)
+ {
+ TREE_VEC_ELT (*overlaps_a, 0) =
+ chrec_fold_plus (integer_type_node, TREE_VEC_ELT (*overlaps_a, 0),
+ overlaps_a_xyz);
+ TREE_VEC_ELT (*overlaps_a, 1) =
+ chrec_fold_plus (integer_type_node, TREE_VEC_ELT (*overlaps_a, 1),
+ overlaps_a_xyz);
+ *overlaps_b =
+ chrec_fold_plus (integer_type_node, *overlaps_b, overlaps_b_xyz);
+ *last_conflicts = last_conflicts_xyz;
+ }
+ }
+ else
+ {
+ *overlaps_a = integer_zero_node;
+ *overlaps_b = integer_zero_node;
+ *last_conflicts = integer_zero_node;
+ }
}
/* Determines the overlapping elements due to accesses CHREC_A and
analyze_subscript_affine_affine (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
- tree left_a, left_b, right_a, right_b;
-
+ unsigned nb_vars_a, nb_vars_b, dim;
+ int init_a, init_b, gamma, gcd_alpha_beta;
+ int tau1, tau2;
+ lambda_matrix A, U, S;
+
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(analyze_subscript_affine_affine \n");
For answering to the question: "Is there a dependence?" we have
to prove that there exists a solution to the Diophantine
equation, and that the solution is in the iteration domain,
- ie. the solution is positive or zero, and that the solution
+ i.e. the solution is positive or zero, and that the solution
happens before the upper bound loop.nb_iterations. Otherwise
there is no dependence. This function outputs a description of
the iterations that hold the intersections. */
- left_a = CHREC_LEFT (chrec_a);
- left_b = CHREC_LEFT (chrec_b);
- right_a = CHREC_RIGHT (chrec_a);
- right_b = CHREC_RIGHT (chrec_b);
- if (chrec_zerop (chrec_fold_minus (integer_type_node, left_a, left_b)))
- {
- /* The first element accessed twice is on the first
- iteration. */
- *overlaps_a = build_polynomial_chrec
- (CHREC_VARIABLE (chrec_b), integer_zero_node, integer_one_node);
- *overlaps_b = build_polynomial_chrec
- (CHREC_VARIABLE (chrec_a), integer_zero_node, integer_one_node);
- }
-
- else if (TREE_CODE (left_a) == INTEGER_CST
- && TREE_CODE (left_b) == INTEGER_CST
- && TREE_CODE (right_a) == INTEGER_CST
- && TREE_CODE (right_b) == INTEGER_CST
-
- /* Both functions should have the same evolution sign. */
- && ((tree_int_cst_sgn (right_a) > 0
- && tree_int_cst_sgn (right_b) > 0)
- || (tree_int_cst_sgn (right_a) < 0
- && tree_int_cst_sgn (right_b) < 0)))
+ nb_vars_a = nb_vars_in_chrec (chrec_a);
+ nb_vars_b = nb_vars_in_chrec (chrec_b);
+
+ dim = nb_vars_a + nb_vars_b;
+ U = lambda_matrix_new (dim, dim);
+ A = lambda_matrix_new (dim, 1);
+ S = lambda_matrix_new (dim, 1);
+
+ init_a = initialize_matrix_A (A, chrec_a, 0, 1);
+ init_b = initialize_matrix_A (A, chrec_b, nb_vars_a, -1);
+ gamma = init_b - init_a;
+
+ /* Don't do all the hard work of solving the Diophantine equation
+ when we already know the solution: for example,
+ | {3, +, 1}_1
+ | {3, +, 4}_2
+ | gamma = 3 - 3 = 0.
+ Then the first overlap occurs during the first iterations:
+ | {3, +, 1}_1 ({0, +, 4}_x) = {3, +, 4}_2 ({0, +, 1}_x)
+ */
+ if (gamma == 0)
{
- /* Here we have to solve the Diophantine equation. Reference
- book: "Loop Transformations for Restructuring Compilers - The
- Foundations" by Utpal Banerjee, pages 59-80.
-
- ALPHA * X0 = BETA * Y0 + GAMMA.
-
- with:
- ALPHA = RIGHT_A
- BETA = RIGHT_B
- GAMMA = LEFT_B - LEFT_A
- CHREC_A = {LEFT_A, +, RIGHT_A}
- CHREC_B = {LEFT_B, +, RIGHT_B}
-
- The Diophantine equation has a solution if and only if gcd
- (ALPHA, BETA) divides GAMMA. This is commonly known under
- the name of the "gcd-test".
- */
- tree alpha, beta, gamma;
- tree la, lb;
- tree gcd_alpha_beta;
- tree u11, u12, u21, u22;
-
- /* Both alpha and beta have to be integer_type_node. The gcd
- function does not work correctly otherwise. */
- alpha = copy_node (right_a);
- beta = copy_node (right_b);
- la = copy_node (left_a);
- lb = copy_node (left_b);
- TREE_TYPE (alpha) = integer_type_node;
- TREE_TYPE (beta) = integer_type_node;
- TREE_TYPE (la) = integer_type_node;
- TREE_TYPE (lb) = integer_type_node;
-
- gamma = fold (build (MINUS_EXPR, integer_type_node, lb, la));
-
- /* FIXME: Use lambda_*_Hermite for implementing Bezout. */
- gcd_alpha_beta = tree_fold_bezout
- (alpha,
- fold (build (MULT_EXPR, integer_type_node, beta,
- integer_minus_one_node)),
- &u11, &u12,
- &u21, &u22);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
+ if (nb_vars_a == 1 && nb_vars_b == 1)
{
- fprintf (dump_file, " (alpha = ");
- print_generic_expr (dump_file, alpha, 0);
- fprintf (dump_file, ")\n (beta = ");
- print_generic_expr (dump_file, beta, 0);
- fprintf (dump_file, ")\n (gamma = ");
- print_generic_expr (dump_file, gamma, 0);
- fprintf (dump_file, ")\n (gcd_alpha_beta = ");
- print_generic_expr (dump_file, gcd_alpha_beta, 0);
- fprintf (dump_file, ")\n");
+ int step_a, step_b;
+ int niter, niter_a, niter_b;
+ tree numiter_a, numiter_b;
+
+ numiter_a = number_of_iterations_in_loop
+ (current_loops->parray[CHREC_VARIABLE (chrec_a)]);
+ numiter_b = number_of_iterations_in_loop
+ (current_loops->parray[CHREC_VARIABLE (chrec_b)]);
+
+ if (TREE_CODE (numiter_a) != INTEGER_CST)
+ numiter_a = current_loops->parray[CHREC_VARIABLE (chrec_a)]
+ ->estimated_nb_iterations;
+ if (TREE_CODE (numiter_b) != INTEGER_CST)
+ numiter_b = current_loops->parray[CHREC_VARIABLE (chrec_b)]
+ ->estimated_nb_iterations;
+ if (numiter_a == NULL_TREE || numiter_b == NULL_TREE)
+ {
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
+ return;
+ }
+
+ niter_a = int_cst_value (numiter_a);
+ niter_b = int_cst_value (numiter_b);
+ niter = MIN (niter_a, niter_b);
+
+ step_a = int_cst_value (CHREC_RIGHT (chrec_a));
+ step_b = int_cst_value (CHREC_RIGHT (chrec_b));
+
+ compute_overlap_steps_for_affine_univar (niter, step_a, step_b,
+ overlaps_a, overlaps_b,
+ last_conflicts, 1);
}
-
- /* The classic "gcd-test". */
- if (!tree_fold_divides_p (integer_type_node, gcd_alpha_beta, gamma))
+
+ else if (nb_vars_a == 2 && nb_vars_b == 1)
+ compute_overlap_steps_for_affine_1_2
+ (chrec_a, chrec_b, overlaps_a, overlaps_b, last_conflicts);
+
+ else if (nb_vars_a == 1 && nb_vars_b == 2)
+ compute_overlap_steps_for_affine_1_2
+ (chrec_b, chrec_a, overlaps_b, overlaps_a, last_conflicts);
+
+ else
{
- /* The "gcd-test" has determined that there is no integer
- solution, ie. there is no dependence. */
- *overlaps_a = chrec_known;
- *overlaps_b = chrec_known;
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
-
- else
+ return;
+ }
+
+ /* U.A = S */
+ lambda_matrix_right_hermite (A, dim, 1, S, U);
+
+ if (S[0][0] < 0)
+ {
+ S[0][0] *= -1;
+ lambda_matrix_row_negate (U, dim, 0);
+ }
+ gcd_alpha_beta = S[0][0];
+
+ /* The classic "gcd-test". */
+ if (!int_divides_p (gcd_alpha_beta, gamma))
+ {
+ /* The "gcd-test" has determined that there is no integer
+ solution, i.e. there is no dependence. */
+ *overlaps_a = chrec_known;
+ *overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
+ }
+
+ /* Both access functions are univariate. This includes SIV and MIV cases. */
+ else if (nb_vars_a == 1 && nb_vars_b == 1)
+ {
+ /* Both functions should have the same evolution sign. */
+ if (((A[0][0] > 0 && -A[1][0] > 0)
+ || (A[0][0] < 0 && -A[1][0] < 0)))
{
/* The solutions are given by:
|
- | [GAMMA/GCD_ALPHA_BETA t].[u11 u12] = [X]
- | [u21 u22] [Y]
-
+ | [GAMMA/GCD_ALPHA_BETA t].[u11 u12] = [x0]
+ | [u21 u22] [y0]
+
For a given integer t. Using the following variables,
-
+
| i0 = u11 * gamma / gcd_alpha_beta
| j0 = u12 * gamma / gcd_alpha_beta
| i1 = u21
| j1 = u22
-
+
the solutions are:
-
- | x = i0 + i1 * t,
- | y = j0 + j1 * t. */
-
- tree i0, j0, i1, j1, t;
- tree gamma_gcd;
-
+
+ | x0 = i0 + i1 * t,
+ | y0 = j0 + j1 * t. */
+
+ int i0, j0, i1, j1;
+
/* X0 and Y0 are the first iterations for which there is a
dependence. X0, Y0 are two solutions of the Diophantine
equation: chrec_a (X0) = chrec_b (Y0). */
- tree x0, y0;
-
- /* Exact div because in this case gcd_alpha_beta divides
- gamma. */
- gamma_gcd = fold (build (EXACT_DIV_EXPR, integer_type_node, gamma,
- gcd_alpha_beta));
- i0 = fold (build (MULT_EXPR, integer_type_node, u11, gamma_gcd));
- j0 = fold (build (MULT_EXPR, integer_type_node, u12, gamma_gcd));
- i1 = u21;
- j1 = u22;
-
- if ((tree_int_cst_sgn (i1) == 0
- && tree_int_cst_sgn (i0) < 0)
- || (tree_int_cst_sgn (j1) == 0
- && tree_int_cst_sgn (j0) < 0))
+ int x0, y0;
+ int niter, niter_a, niter_b;
+ tree numiter_a, numiter_b;
+
+ numiter_a = number_of_iterations_in_loop
+ (current_loops->parray[CHREC_VARIABLE (chrec_a)]);
+ numiter_b = number_of_iterations_in_loop
+ (current_loops->parray[CHREC_VARIABLE (chrec_b)]);
+
+ if (TREE_CODE (numiter_a) != INTEGER_CST)
+ numiter_a = current_loops->parray[CHREC_VARIABLE (chrec_a)]
+ ->estimated_nb_iterations;
+ if (TREE_CODE (numiter_b) != INTEGER_CST)
+ numiter_b = current_loops->parray[CHREC_VARIABLE (chrec_b)]
+ ->estimated_nb_iterations;
+ if (numiter_a == NULL_TREE || numiter_b == NULL_TREE)
+ {
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
+ return;
+ }
+
+ niter_a = int_cst_value (numiter_a);
+ niter_b = int_cst_value (numiter_b);
+ niter = MIN (niter_a, niter_b);
+
+ i0 = U[0][0] * gamma / gcd_alpha_beta;
+ j0 = U[0][1] * gamma / gcd_alpha_beta;
+ i1 = U[1][0];
+ j1 = U[1][1];
+
+ if ((i1 == 0 && i0 < 0)
+ || (j1 == 0 && j0 < 0))
{
/* There is no solution.
FIXME: The case "i0 > nb_iterations, j0 > nb_iterations"
upper bound of the iteration domain. */
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
- }
-
+ *last_conflicts = integer_zero_node;
+ }
+
else
{
- if (tree_int_cst_sgn (i1) > 0)
+ if (i1 > 0)
{
- t = fold
- (build (CEIL_DIV_EXPR, integer_type_node,
- fold (build (MULT_EXPR, integer_type_node, i0,
- integer_minus_one_node)),
- i1));
-
- if (tree_int_cst_sgn (j1) > 0)
+ tau1 = CEIL (-i0, i1);
+ tau2 = FLOOR_DIV (niter - i0, i1);
+
+ if (j1 > 0)
{
- t = fold
- (build (MAX_EXPR, integer_type_node, t,
- fold (build (CEIL_DIV_EXPR, integer_type_node,
- fold (build
- (MULT_EXPR,
- integer_type_node, j0,
- integer_minus_one_node)),
- j1))));
-
- x0 = fold
- (build (PLUS_EXPR, integer_type_node, i0,
- fold (build
- (MULT_EXPR, integer_type_node, i1, t))));
- y0 = fold
- (build (PLUS_EXPR, integer_type_node, j0,
- fold (build
- (MULT_EXPR, integer_type_node, j1, t))));
-
- *overlaps_a = build_polynomial_chrec
- (CHREC_VARIABLE (chrec_b), x0, u21);
- *overlaps_b = build_polynomial_chrec
- (CHREC_VARIABLE (chrec_a), y0, u22);
+ int last_conflict, min_multiple;
+ tau1 = MAX (tau1, CEIL (-j0, j1));
+ tau2 = MIN (tau2, FLOOR_DIV (niter - j0, j1));
+
+ x0 = i1 * tau1 + i0;
+ y0 = j1 * tau1 + j0;
+
+ /* At this point (x0, y0) is one of the
+ solutions to the Diophantine equation. The
+ next step has to compute the smallest
+ positive solution: the first conflicts. */
+ min_multiple = MIN (x0 / i1, y0 / j1);
+ x0 -= i1 * min_multiple;
+ y0 -= j1 * min_multiple;
+
+ tau1 = (x0 - i0)/i1;
+ last_conflict = tau2 - tau1;
+
+ *overlaps_a = build_polynomial_chrec
+ (1,
+ build_int_cst (NULL_TREE, x0),
+ build_int_cst (NULL_TREE, i1));
+ *overlaps_b = build_polynomial_chrec
+ (1,
+ build_int_cst (NULL_TREE, y0),
+ build_int_cst (NULL_TREE, j1));
+ *last_conflicts = build_int_cst (NULL_TREE, last_conflict);
}
else
{
/* FIXME: For the moment, the upper bound of the
- iteration domain for j is not checked. */
+ iteration domain for j is not checked. */
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
}
-
+
else
{
/* FIXME: For the moment, the upper bound of the
- iteration domain for i is not checked. */
+ iteration domain for i is not checked. */
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
}
}
+ else
+ {
+ *overlaps_a = chrec_dont_know;
+ *overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
+ }
}
-
+
else
{
- /* For the moment, "don't know". */
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
-
+
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, " (overlaps_a = ");
analyze_siv_subscript (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(analyze_siv_subscript \n");
if (evolution_function_is_constant_p (chrec_a)
&& evolution_function_is_affine_p (chrec_b))
analyze_siv_subscript_cst_affine (chrec_a, chrec_b,
- overlaps_a, overlaps_b);
+ overlaps_a, overlaps_b, last_conflicts);
else if (evolution_function_is_affine_p (chrec_a)
&& evolution_function_is_constant_p (chrec_b))
- analyze_siv_subscript_affine_cst (chrec_a, chrec_b,
- overlaps_a, overlaps_b);
+ analyze_siv_subscript_cst_affine (chrec_b, chrec_a,
+ overlaps_b, overlaps_a, last_conflicts);
else if (evolution_function_is_affine_p (chrec_a)
- && evolution_function_is_affine_p (chrec_b)
- && (CHREC_VARIABLE (chrec_a) == CHREC_VARIABLE (chrec_b)))
+ && evolution_function_is_affine_p (chrec_b))
analyze_subscript_affine_affine (chrec_a, chrec_b,
- overlaps_a, overlaps_b);
+ overlaps_a, overlaps_b, last_conflicts);
else
{
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
if (dump_file && (dump_flags & TDF_DETAILS))
analyze_miv_subscript (tree chrec_a,
tree chrec_b,
tree *overlaps_a,
- tree *overlaps_b)
+ tree *overlaps_b,
+ tree *last_conflicts)
{
/* FIXME: This is a MIV subscript, not yet handled.
Example: (A[{1, +, 1}_1] vs. A[{1, +, 1}_2]) that comes from
in the same order. */
*overlaps_a = integer_zero_node;
*overlaps_b = integer_zero_node;
+ *last_conflicts = number_of_iterations_in_loop
+ (current_loops->parray[CHREC_VARIABLE (chrec_a)]);
}
else if (evolution_function_is_constant_p (difference)
consequently there are no overlapping elements. */
*overlaps_a = chrec_known;
*overlaps_b = chrec_known;
+ *last_conflicts = integer_zero_node;
}
- else if (evolution_function_is_univariate_p (chrec_a)
- && evolution_function_is_univariate_p (chrec_b))
+ else if (evolution_function_is_affine_multivariate_p (chrec_a)
+ && evolution_function_is_affine_multivariate_p (chrec_b))
{
/* testsuite/.../ssa-chrec-35.c
{0, +, 1}_2 vs. {0, +, 1}_3
the overlapping elements are respectively located at iterations:
- {0, +, 1}_3 and {0, +, 1}_2.
+ {0, +, 1}_x and {0, +, 1}_x,
+ in other words, we have the equality:
+ {0, +, 1}_2 ({0, +, 1}_x) = {0, +, 1}_3 ({0, +, 1}_x)
+
+ Other examples:
+ {{0, +, 1}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y) =
+ {0, +, 1}_1 ({{0, +, 1}_x, +, 2}_y)
+
+ {{0, +, 2}_1, +, 3}_2 ({0, +, 1}_y, {0, +, 1}_x) =
+ {{0, +, 3}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y)
*/
- if (evolution_function_is_affine_p (chrec_a)
- && evolution_function_is_affine_p (chrec_b))
- analyze_subscript_affine_affine (chrec_a, chrec_b,
- overlaps_a, overlaps_b);
- else
- {
- *overlaps_a = chrec_dont_know;
- *overlaps_b = chrec_dont_know;
- }
+ analyze_subscript_affine_affine (chrec_a, chrec_b,
+ overlaps_a, overlaps_b, last_conflicts);
}
else
/* When the analysis is too difficult, answer "don't know". */
*overlaps_a = chrec_dont_know;
*overlaps_b = chrec_dont_know;
+ *last_conflicts = chrec_dont_know;
}
if (dump_file && (dump_flags & TDF_DETAILS))
analyze_overlapping_iterations (tree chrec_a,
tree chrec_b,
tree *overlap_iterations_a,
- tree *overlap_iterations_b)
+ tree *overlap_iterations_b,
+ tree *last_conflicts)
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
else if (ziv_subscript_p (chrec_a, chrec_b))
analyze_ziv_subscript (chrec_a, chrec_b,
- overlap_iterations_a, overlap_iterations_b);
+ overlap_iterations_a, overlap_iterations_b,
+ last_conflicts);
else if (siv_subscript_p (chrec_a, chrec_b))
analyze_siv_subscript (chrec_a, chrec_b,
- overlap_iterations_a, overlap_iterations_b);
+ overlap_iterations_a, overlap_iterations_b,
+ last_conflicts);
else
analyze_miv_subscript (chrec_a, chrec_b,
- overlap_iterations_a, overlap_iterations_b);
+ overlap_iterations_a, overlap_iterations_b,
+ last_conflicts);
if (dump_file && (dump_flags & TDF_DETAILS))
{
unsigned int i;
struct data_reference *dra = DDR_A (ddr);
struct data_reference *drb = DDR_B (ddr);
+ tree last_conflicts;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "(subscript_dependence_tester \n");
analyze_overlapping_iterations (DR_ACCESS_FN (dra, i),
DR_ACCESS_FN (drb, i),
- &overlaps_a, &overlaps_b);
+ &overlaps_a, &overlaps_b,
+ &last_conflicts);
if (chrec_contains_undetermined (overlaps_a)
|| chrec_contains_undetermined (overlaps_b))
{
SUB_CONFLICTS_IN_A (subscript) = overlaps_a;
SUB_CONFLICTS_IN_B (subscript) = overlaps_b;
+ SUB_LAST_CONFLICT (subscript) = last_conflicts;
}
}
DDR is the data dependence relation to build a vector from.
NB_LOOPS is the total number of loops we are considering.
- FIRST_LOOP is the loop->num of the first loop. */
+ FIRST_LOOP_DEPTH is the loop->depth of the first loop in the analyzed
+ loop nest.
+ Return FALSE if the dependence relation is outside of the loop nest
+ starting at FIRST_LOOP_DEPTH.
+ Return TRUE otherwise. */
-static void
+bool
build_classic_dist_vector (struct data_dependence_relation *ddr,
- int nb_loops, unsigned int first_loop)
+ int nb_loops, int first_loop_depth)
{
unsigned i;
lambda_vector dist_v, init_v;
lambda_vector_clear (init_v, nb_loops);
if (DDR_ARE_DEPENDENT (ddr) != NULL_TREE)
- return;
+ return true;
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
{
+ tree access_fn_a, access_fn_b;
struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
- return;
+ {
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
+ access_fn_a = DR_ACCESS_FN (DDR_A (ddr), i);
+ access_fn_b = DR_ACCESS_FN (DDR_B (ddr), i);
- if (TREE_CODE (SUB_CONFLICTS_IN_A (subscript)) == POLYNOMIAL_CHREC)
+ if (TREE_CODE (access_fn_a) == POLYNOMIAL_CHREC
+ && TREE_CODE (access_fn_b) == POLYNOMIAL_CHREC)
{
- int dist;
- int loop_nb;
- loop_nb = CHREC_VARIABLE (SUB_CONFLICTS_IN_A (subscript));
- loop_nb -= first_loop;
+ int dist, loop_nb, loop_depth;
+ int loop_nb_a = CHREC_VARIABLE (access_fn_a);
+ int loop_nb_b = CHREC_VARIABLE (access_fn_b);
+ struct loop *loop_a = current_loops->parray[loop_nb_a];
+ struct loop *loop_b = current_loops->parray[loop_nb_b];
+
+ /* If the loop for either variable is at a lower depth than
+ the first_loop's depth, then we can't possibly have a
+ dependency at this level of the loop. */
+
+ if (loop_a->depth < first_loop_depth
+ || loop_b->depth < first_loop_depth)
+ return false;
+
+ if (loop_nb_a != loop_nb_b
+ && !flow_loop_nested_p (loop_a, loop_b)
+ && !flow_loop_nested_p (loop_b, loop_a))
+ {
+ /* Example: when there are two consecutive loops,
+
+ | loop_1
+ | A[{0, +, 1}_1]
+ | endloop_1
+ | loop_2
+ | A[{0, +, 1}_2]
+ | endloop_2
+
+ the dependence relation cannot be captured by the
+ distance abstraction. */
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
+ /* The dependence is carried by the outermost loop. Example:
+ | loop_1
+ | A[{4, +, 1}_1]
+ | loop_2
+ | A[{5, +, 1}_2]
+ | endloop_2
+ | endloop_1
+ In this case, the dependence is carried by loop_1. */
+ loop_nb = loop_nb_a < loop_nb_b ? loop_nb_a : loop_nb_b;
+ loop_depth = current_loops->parray[loop_nb]->depth - first_loop_depth;
+
/* If the loop number is still greater than the number of
loops we've been asked to analyze, or negative,
something is borked. */
- if (loop_nb < 0 || loop_nb >= nb_loops)
- abort ();
+ gcc_assert (loop_depth >= 0);
+ gcc_assert (loop_depth < nb_loops);
+ if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
+ {
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
dist = int_cst_value (SUB_DISTANCE (subscript));
/* This is the subscript coupling test.
| ... = T[i][i]
| endloop
There is no dependence. */
- if (init_v[loop_nb] != 0
- && dist_v[loop_nb] != dist)
+ if (init_v[loop_depth] != 0
+ && dist_v[loop_depth] != dist)
{
finalize_ddr_dependent (ddr, chrec_known);
- return;
+ return true;
}
- dist_v[loop_nb] = dist;
- init_v[loop_nb] = 1;
+ dist_v[loop_depth] = dist;
+ init_v[loop_depth] = 1;
}
}
struct loop *lca, *loop_a, *loop_b;
struct data_reference *a = DDR_A (ddr);
struct data_reference *b = DDR_B (ddr);
- int lca_nb;
+ int lca_depth;
loop_a = loop_containing_stmt (DR_STMT (a));
loop_b = loop_containing_stmt (DR_STMT (b));
/* Get the common ancestor loop. */
lca = find_common_loop (loop_a, loop_b);
- lca_nb = lca->num;
- lca_nb -= first_loop;
- if (lca_nb < 0 || lca_nb >= nb_loops)
- abort ();
+ lca_depth = lca->depth;
+ lca_depth -= first_loop_depth;
+ gcc_assert (lca_depth >= 0);
+ gcc_assert (lca_depth < nb_loops);
+
/* For each outer loop where init_v is not set, the accesses are
in dependence of distance 1 in the loop. */
if (lca != loop_a
&& lca != loop_b
- && init_v[lca_nb] == 0)
- dist_v[lca_nb] = 1;
+ && init_v[lca_depth] == 0)
+ dist_v[lca_depth] = 1;
lca = lca->outer;
if (lca)
{
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
while (lca->depth != 0)
{
- if (lca_nb < 0 || lca_nb >= nb_loops)
- abort ();
- if (init_v[lca_nb] == 0)
- dist_v[lca_nb] = 1;
+ /* If we're considering just a sub-nest, then don't record
+ any information on the outer loops. */
+ if (lca_depth < 0)
+ break;
+
+ gcc_assert (lca_depth < nb_loops);
+
+ if (init_v[lca_depth] == 0)
+ dist_v[lca_depth] = 1;
lca = lca->outer;
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
}
}
}
DDR_DIST_VECT (ddr) = dist_v;
+ DDR_SIZE_VECT (ddr) = nb_loops;
+ return true;
}
/* Compute the classic per loop direction vector.
DDR is the data dependence relation to build a vector from.
NB_LOOPS is the total number of loops we are considering.
- FIRST_LOOP is the loop->num of the first loop. */
+ FIRST_LOOP_DEPTH is the loop->depth of the first loop in the analyzed
+ loop nest.
+ Return FALSE if the dependence relation is outside of the loop nest
+ at FIRST_LOOP_DEPTH.
+ Return TRUE otherwise. */
-static void
+static bool
build_classic_dir_vector (struct data_dependence_relation *ddr,
- int nb_loops, unsigned int first_loop)
+ int nb_loops, int first_loop_depth)
{
unsigned i;
lambda_vector dir_v, init_v;
lambda_vector_clear (init_v, nb_loops);
if (DDR_ARE_DEPENDENT (ddr) != NULL_TREE)
- return;
+ return true;
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
{
+ tree access_fn_a, access_fn_b;
struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
- if (TREE_CODE (SUB_CONFLICTS_IN_A (subscript)) == POLYNOMIAL_CHREC
- && TREE_CODE (SUB_CONFLICTS_IN_B (subscript)) == POLYNOMIAL_CHREC)
+ if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
{
- int loop_nb;
-
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
+ access_fn_a = DR_ACCESS_FN (DDR_A (ddr), i);
+ access_fn_b = DR_ACCESS_FN (DDR_B (ddr), i);
+ if (TREE_CODE (access_fn_a) == POLYNOMIAL_CHREC
+ && TREE_CODE (access_fn_b) == POLYNOMIAL_CHREC)
+ {
+ int dist, loop_nb, loop_depth;
enum data_dependence_direction dir = dir_star;
- loop_nb = CHREC_VARIABLE (SUB_CONFLICTS_IN_A (subscript));
- loop_nb -= first_loop;
+ int loop_nb_a = CHREC_VARIABLE (access_fn_a);
+ int loop_nb_b = CHREC_VARIABLE (access_fn_b);
+ struct loop *loop_a = current_loops->parray[loop_nb_a];
+ struct loop *loop_b = current_loops->parray[loop_nb_b];
+
+ /* If the loop for either variable is at a lower depth than
+ the first_loop's depth, then we can't possibly have a
+ dependency at this level of the loop. */
+
+ if (loop_a->depth < first_loop_depth
+ || loop_b->depth < first_loop_depth)
+ return false;
+
+ if (loop_nb_a != loop_nb_b
+ && !flow_loop_nested_p (loop_a, loop_b)
+ && !flow_loop_nested_p (loop_b, loop_a))
+ {
+ /* Example: when there are two consecutive loops,
+
+ | loop_1
+ | A[{0, +, 1}_1]
+ | endloop_1
+ | loop_2
+ | A[{0, +, 1}_2]
+ | endloop_2
+
+ the dependence relation cannot be captured by the
+ distance abstraction. */
+ non_affine_dependence_relation (ddr);
+ return true;
+ }
+
+ /* The dependence is carried by the outermost loop. Example:
+ | loop_1
+ | A[{4, +, 1}_1]
+ | loop_2
+ | A[{5, +, 1}_2]
+ | endloop_2
+ | endloop_1
+ In this case, the dependence is carried by loop_1. */
+ loop_nb = loop_nb_a < loop_nb_b ? loop_nb_a : loop_nb_b;
+ loop_depth = current_loops->parray[loop_nb]->depth - first_loop_depth;
/* If the loop number is still greater than the number of
loops we've been asked to analyze, or negative,
something is borked. */
- if (loop_nb < 0 || loop_nb >= nb_loops)
- abort ();
+ gcc_assert (loop_depth >= 0);
+ gcc_assert (loop_depth < nb_loops);
+
if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
{
-
- }
- else
- {
- int dist = int_cst_value (SUB_DISTANCE (subscript));
-
- if (dist == 0)
- dir = dir_equal;
- else if (dist > 0)
- dir = dir_positive;
- else if (dist < 0)
- dir = dir_negative;
+ non_affine_dependence_relation (ddr);
+ return true;
}
+
+ dist = int_cst_value (SUB_DISTANCE (subscript));
+
+ if (dist == 0)
+ dir = dir_equal;
+ else if (dist > 0)
+ dir = dir_positive;
+ else if (dist < 0)
+ dir = dir_negative;
/* This is the subscript coupling test.
| loop i = 0, N, 1
| ... = T[i][i]
| endloop
There is no dependence. */
- if (init_v[loop_nb] != 0
+ if (init_v[loop_depth] != 0
&& dir != dir_star
- && (enum data_dependence_direction) dir_v[loop_nb] != dir
- && (enum data_dependence_direction) dir_v[loop_nb] != dir_star)
+ && (enum data_dependence_direction) dir_v[loop_depth] != dir
+ && (enum data_dependence_direction) dir_v[loop_depth] != dir_star)
{
finalize_ddr_dependent (ddr, chrec_known);
- return;
+ return true;
}
- dir_v[loop_nb] = dir;
- init_v[loop_nb] = 1;
+ dir_v[loop_depth] = dir;
+ init_v[loop_depth] = 1;
}
}
struct loop *lca, *loop_a, *loop_b;
struct data_reference *a = DDR_A (ddr);
struct data_reference *b = DDR_B (ddr);
- int lca_nb;
+ int lca_depth;
loop_a = loop_containing_stmt (DR_STMT (a));
loop_b = loop_containing_stmt (DR_STMT (b));
/* Get the common ancestor loop. */
lca = find_common_loop (loop_a, loop_b);
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
+
+ gcc_assert (lca_depth >= 0);
+ gcc_assert (lca_depth < nb_loops);
- if (lca_nb < 0 || lca_nb >= nb_loops)
- abort ();
/* For each outer loop where init_v is not set, the accesses are
in dependence of distance 1 in the loop. */
if (lca != loop_a
&& lca != loop_b
- && init_v[lca_nb] == 0)
- dir_v[lca_nb] = dir_positive;
+ && init_v[lca_depth] == 0)
+ dir_v[lca_depth] = dir_positive;
lca = lca->outer;
if (lca)
{
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
while (lca->depth != 0)
{
- if (lca_nb < 0 || lca_nb >= nb_loops)
- abort ();
- if (init_v[lca_nb] == 0)
- dir_v[lca_nb] = dir_positive;
+ /* If we're considering just a sub-nest, then don't record
+ any information on the outer loops. */
+ if (lca_depth < 0)
+ break;
+
+ gcc_assert (lca_depth < nb_loops);
+
+ if (init_v[lca_depth] == 0)
+ dir_v[lca_depth] = dir_positive;
lca = lca->outer;
- lca_nb = lca->num - first_loop;
+ lca_depth = lca->depth - first_loop_depth;
}
}
}
DDR_DIR_VECT (ddr) = dir_v;
+ DDR_SIZE_VECT (ddr) = nb_loops;
+ return true;
}
/* Returns true when all the access functions of A are affine or
access_functions_are_affine_or_constant_p (struct data_reference *a)
{
unsigned int i;
- varray_type fns = DR_ACCESS_FNS (a);
+ VEC(tree,heap) **fns = &DR_ACCESS_FNS (a);
+ tree t;
- for (i = 0; i < VARRAY_ACTIVE_SIZE (fns); i++)
- if (!evolution_function_is_constant_p (VARRAY_TREE (fns, i))
- && !evolution_function_is_affine_multivariate_p (VARRAY_TREE (fns, i)))
+ for (i = 0; VEC_iterate (tree, *fns, i, t); i++)
+ if (!evolution_function_is_constant_p (t)
+ && !evolution_function_is_affine_multivariate_p (t))
return false;
return true;
fprintf (dump_file, ")\n");
}
+
+typedef struct data_dependence_relation *ddr_p;
+DEF_VEC_P(ddr_p);
+DEF_VEC_ALLOC_P(ddr_p,heap);
+
/* Compute a subset of the data dependence relation graph. Don't
compute read-read relations, and avoid the computation of the
- opposite relation, ie. when AB has been computed, don't compute BA.
+ opposite relation, i.e. when AB has been computed, don't compute BA.
DATAREFS contains a list of data references, and the result is set
in DEPENDENCE_RELATIONS. */
static void
compute_all_dependences (varray_type datarefs,
- varray_type *dependence_relations)
+ VEC(ddr_p,heap) **dependence_relations)
{
unsigned int i, j, N;
a = VARRAY_GENERIC_PTR (datarefs, i);
b = VARRAY_GENERIC_PTR (datarefs, j);
-
ddr = initialize_data_dependence_relation (a, b);
- VARRAY_PUSH_GENERIC_PTR (*dependence_relations, ddr);
+ VEC_safe_push (ddr_p, heap, *dependence_relations, ddr);
compute_affine_dependence (ddr);
- compute_distance_vector (ddr);
+ compute_subscript_distance (ddr);
}
}
DATAREFS. Returns chrec_dont_know when failing to analyze a
difficult case, returns NULL_TREE otherwise.
- FIXME: This is a "dumb" walker over all the trees in the loop body.
- Find another technique that avoids this costly walk. This is
- acceptable for the moment, since this function is used only for
- debugging purposes. */
+ TODO: This function should be made smarter so that it can handle address
+ arithmetic as if they were array accesses, etc. */
-static tree
+tree
find_data_references_in_loop (struct loop *loop, varray_type *datarefs)
{
- basic_block bb;
+ basic_block bb, *bbs;
+ unsigned int i;
block_stmt_iterator bsi;
-
- FOR_EACH_BB (bb)
+
+ bbs = get_loop_body (loop);
+
+ for (i = 0; i < loop->num_nodes; i++)
{
- if (!flow_bb_inside_loop_p (loop, bb))
- continue;
-
+ bb = bbs[i];
+
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
tree stmt = bsi_stmt (bsi);
- stmt_ann_t ann = stmt_ann (stmt);
- if (TREE_CODE (stmt) != MODIFY_EXPR)
- continue;
+ /* ASM_EXPR and CALL_EXPR may embed arbitrary side effects.
+ Calls have side-effects, except those to const or pure
+ functions. */
+ if ((TREE_CODE (stmt) == CALL_EXPR
+ && !(call_expr_flags (stmt) & (ECF_CONST | ECF_PURE)))
+ || (TREE_CODE (stmt) == ASM_EXPR
+ && ASM_VOLATILE_P (stmt)))
+ goto insert_dont_know_node;
- if (!VUSE_OPS (ann)
- && !V_MUST_DEF_OPS (ann)
- && !V_MAY_DEF_OPS (ann))
+ if (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
continue;
- /* In the GIMPLE representation, a modify expression
- contains a single load or store to memory. */
- if (TREE_CODE (TREE_OPERAND (stmt, 0)) == ARRAY_REF)
- VARRAY_PUSH_GENERIC_PTR
- (*datarefs, analyze_array (stmt, TREE_OPERAND (stmt, 0),
- false));
+ switch (TREE_CODE (stmt))
+ {
+ case MODIFY_EXPR:
+ if (TREE_CODE (TREE_OPERAND (stmt, 0)) == ARRAY_REF)
+ VARRAY_PUSH_GENERIC_PTR
+ (*datarefs, analyze_array (stmt, TREE_OPERAND (stmt, 0),
+ false));
+
+ if (TREE_CODE (TREE_OPERAND (stmt, 1)) == ARRAY_REF)
+ VARRAY_PUSH_GENERIC_PTR
+ (*datarefs, analyze_array (stmt, TREE_OPERAND (stmt, 1),
+ true));
+
+ if (TREE_CODE (TREE_OPERAND (stmt, 0)) != ARRAY_REF
+ && TREE_CODE (TREE_OPERAND (stmt, 1)) != ARRAY_REF)
+ goto insert_dont_know_node;
+
+ break;
+
+ case CALL_EXPR:
+ {
+ tree args;
+ bool one_inserted = false;
+
+ for (args = TREE_OPERAND (stmt, 1); args; args = TREE_CHAIN (args))
+ if (TREE_CODE (TREE_VALUE (args)) == ARRAY_REF)
+ {
+ VARRAY_PUSH_GENERIC_PTR
+ (*datarefs, analyze_array (stmt, TREE_VALUE (args), true));
+ one_inserted = true;
+ }
+
+ if (!one_inserted)
+ goto insert_dont_know_node;
- else if (TREE_CODE (TREE_OPERAND (stmt, 1)) == ARRAY_REF)
- VARRAY_PUSH_GENERIC_PTR
- (*datarefs, analyze_array (stmt, TREE_OPERAND (stmt, 1),
- true));
+ break;
+ }
- else
- return chrec_dont_know;
+ default:
+ {
+ struct data_reference *res;
+
+ insert_dont_know_node:;
+ res = xmalloc (sizeof (struct data_reference));
+ DR_STMT (res) = NULL_TREE;
+ DR_REF (res) = NULL_TREE;
+ DR_ACCESS_FNS (res) = NULL;
+ DR_BASE_NAME (res) = NULL;
+ DR_IS_READ (res) = false;
+ VARRAY_PUSH_GENERIC_PTR (*datarefs, res);
+
+ free (bbs);
+ return chrec_dont_know;
+ }
+ }
+
+ /* When there are no defs in the loop, the loop is parallel. */
+ if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_DEFS))
+ bb->loop_father->parallel_p = false;
}
+
+ if (bb->loop_father->estimated_nb_iterations == NULL_TREE)
+ compute_estimated_nb_iterations (bb->loop_father);
}
+ free (bbs);
+
return NULL_TREE;
}
varray_type *dependence_relations)
{
unsigned int i;
+ VEC(ddr_p,heap) *allrelations;
+ struct data_dependence_relation *ddr;
/* If one of the data references is not computable, give up without
spending time to compute other dependences. */
chrec_dont_know. */
ddr = initialize_data_dependence_relation (NULL, NULL);
VARRAY_PUSH_GENERIC_PTR (*dependence_relations, ddr);
- build_classic_dist_vector (ddr, nb_loops, loop->num);
- build_classic_dir_vector (ddr, nb_loops, loop->num);
+ build_classic_dist_vector (ddr, nb_loops, loop->depth);
+ build_classic_dir_vector (ddr, nb_loops, loop->depth);
return;
}
- compute_all_dependences (*datarefs, dependence_relations);
+ allrelations = NULL;
+ compute_all_dependences (*datarefs, &allrelations);
- for (i = 0; i < VARRAY_ACTIVE_SIZE (*dependence_relations); i++)
+ for (i = 0; VEC_iterate (ddr_p, allrelations, i, ddr); i++)
{
- struct data_dependence_relation *ddr;
- ddr = VARRAY_GENERIC_PTR (*dependence_relations, i);
- build_classic_dist_vector (ddr, nb_loops, loop->num);
- build_classic_dir_vector (ddr, nb_loops, loop->num);
+ if (build_classic_dist_vector (ddr, nb_loops, loop->depth))
+ {
+ VARRAY_PUSH_GENERIC_PTR (*dependence_relations, ddr);
+ build_classic_dir_vector (ddr, nb_loops, loop->depth);
+ }
}
}
{
dump_data_dependence_relations (dump_file, dependence_relations);
fprintf (dump_file, "\n\n");
- }
- /* Don't dump distances in order to avoid to update the
- testsuite. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- for (i = 0; i < VARRAY_ACTIVE_SIZE (dependence_relations); i++)
- {
- struct data_dependence_relation *ddr =
- (struct data_dependence_relation *)
- VARRAY_GENERIC_PTR (dependence_relations, i);
- if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
- {
- fprintf (dump_file, "DISTANCE_V (");
- print_lambda_vector (dump_file, DDR_DIST_VECT (ddr), loops->num);
- fprintf (dump_file, ")\n");
- fprintf (dump_file, "DIRECTION_V (");
- print_lambda_vector (dump_file, DDR_DIR_VECT (ddr), loops->num);
- fprintf (dump_file, ")\n");
- }
- }
- fprintf (dump_file, "\n\n");
- }
-
- if (dump_file && (dump_flags & TDF_STATS))
- {
- unsigned nb_top_relations = 0;
- unsigned nb_bot_relations = 0;
- unsigned nb_basename_differ = 0;
- unsigned nb_chrec_relations = 0;
+ if (dump_flags & TDF_DETAILS)
+ dump_dist_dir_vectors (dump_file, dependence_relations);
- for (i = 0; i < VARRAY_ACTIVE_SIZE (dependence_relations); i++)
+ if (dump_flags & TDF_STATS)
{
- struct data_dependence_relation *ddr;
- ddr = VARRAY_GENERIC_PTR (dependence_relations, i);
+ unsigned nb_top_relations = 0;
+ unsigned nb_bot_relations = 0;
+ unsigned nb_basename_differ = 0;
+ unsigned nb_chrec_relations = 0;
+
+ for (i = 0; i < VARRAY_ACTIVE_SIZE (dependence_relations); i++)
+ {
+ struct data_dependence_relation *ddr;
+ ddr = VARRAY_GENERIC_PTR (dependence_relations, i);
- if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (ddr)))
- nb_top_relations++;
+ if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (ddr)))
+ nb_top_relations++;
- else if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
- {
- struct data_reference *a = DDR_A (ddr);
- struct data_reference *b = DDR_B (ddr);
- bool differ_p;
+ else if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
+ {
+ struct data_reference *a = DDR_A (ddr);
+ struct data_reference *b = DDR_B (ddr);
+ bool differ_p;
- if (DR_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b)
- || (array_base_name_differ_p (a, b, &differ_p) && differ_p))
- nb_basename_differ++;
- else
- nb_bot_relations++;
- }
+ if (DR_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b)
+ || (array_base_name_differ_p (a, b, &differ_p) && differ_p))
+ nb_basename_differ++;
+ else
+ nb_bot_relations++;
+ }
- else
- nb_chrec_relations++;
- }
+ else
+ nb_chrec_relations++;
+ }
- gather_stats_on_scev_database ();
+ gather_stats_on_scev_database ();
+ }
}
free_dependence_relations (dependence_relations);
{
struct data_reference *dr = (struct data_reference *)
VARRAY_GENERIC_PTR (datarefs, i);
- if (dr && DR_ACCESS_FNS (dr))
- varray_clear (DR_ACCESS_FNS (dr));
+ if (dr)
+ {
+ VEC_free (tree, heap, DR_ACCESS_FNS (dr));
+ free (dr);
+ }
}
varray_clear (datarefs);
}
+
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