#include "graphite.h"
#include "graphite-poly.h"
-/* Returns the subscript dimension defined by CSTR in PDR. */
+/* Builds a linear expression, of dimension DIM, representing PDR's
+ memory access:
-static ppl_dimension_type
-compute_subscript (poly_dr_p pdr, ppl_const_Constraint_t cstr)
-{
- graphite_dim_t i;
- ppl_Linear_Expression_t expr;
- ppl_Coefficient_t coef;
- Value val;
+ L = r_{n}*r_{n-1}*...*r_{1}*s_{0} + ... + r_{n}*s_{n-1} + s_{n}.
- value_init (val);
- ppl_new_Coefficient (&coef);
+ For an array A[10][20] with two subscript locations s0 and s1, the
+ linear memory access is 20 * s0 + s1: a stride of 1 in subscript s0
+ corresponds to a memory stride of 20.
- for (i = 0; i < pdr_nb_subscripts (pdr); i++)
- {
- ppl_dimension_type sub_dim = pdr_subscript_dim (pdr, i);
+ OFFSET is a number of dimensions to prepend before the
+ subscript dimensions: s_0, s_1, ..., s_n.
- ppl_new_Linear_Expression_from_Constraint (&expr, cstr);
- ppl_Linear_Expression_coefficient (expr, sub_dim, coef);
- ppl_delete_Linear_Expression (expr);
- ppl_Coefficient_to_mpz_t (coef, val);
+ Thus, the final linear expression has the following format:
+ 0 .. 0_{offset} | 0 .. 0_{nit} | 0 .. 0_{gd} | 0 | c_0 c_1 ... c_n
+ where the expression itself is:
+ c_0 * s_0 + c_1 * s_1 + ... c_n * s_n. */
- if (value_notzero_p (val))
- {
- gcc_assert (value_one_p (val)
- || value_mone_p (val));
+static ppl_Linear_Expression_t
+build_linearized_memory_access (ppl_dimension_type offset, poly_dr_p pdr)
+{
+ ppl_Linear_Expression_t res;
+ ppl_Linear_Expression_t le;
+ ppl_dimension_type i;
+ ppl_dimension_type first = pdr_subscript_dim (pdr, 0);
+ ppl_dimension_type last = pdr_subscript_dim (pdr, PDR_NB_SUBSCRIPTS (pdr));
+ mpz_t size, sub_size;
+ graphite_dim_t dim = offset + pdr_dim (pdr);
+
+ ppl_new_Linear_Expression_with_dimension (&res, dim);
+
+ mpz_init (size);
+ mpz_set_si (size, 1);
+ mpz_init (sub_size);
+ mpz_set_si (sub_size, 1);
+
+ for (i = last - 1; i >= first; i--)
+ {
+ ppl_set_coef_gmp (res, i + offset, size);
- value_clear (val);
- ppl_delete_Coefficient (coef);
- return sub_dim;
- }
+ ppl_new_Linear_Expression_with_dimension (&le, dim - offset);
+ ppl_set_coef (le, i, 1);
+ ppl_max_for_le_pointset (PDR_ACCESSES (pdr), le, sub_size);
+ mpz_mul (size, size, sub_size);
+ ppl_delete_Linear_Expression (le);
}
- gcc_unreachable ();
- return 0;
+ mpz_clear (sub_size);
+ mpz_clear (size);
+ return res;
}
+/* Builds a partial difference equations and inserts them
+ into pointset powerset polyhedron P. Polyhedron is assumed
+ to have the format: T|I|T'|I'|G|S|S'|l1|l2.
+
+ TIME_DEPTH is the time dimension w.r.t. which we are
+ differentiating.
+ OFFSET represents the number of dimensions between
+ columns t_{time_depth} and t'_{time_depth}.
+ DIM_SCTR is the number of scattering dimensions. It is
+ essentially the dimensionality of the T vector.
+
+ The following equations are inserted into the polyhedron P:
+ | t_1 = t_1'
+ | ...
+ | t_{time_depth-1} = t'_{time_depth-1}
+ | t_{time_depth} = t'_{time_depth} + 1
+ | t_{time_depth+1} = t'_{time_depth + 1}
+ | ...
+ | t_{dim_sctr} = t'_{dim_sctr}. */
+
static void
-compute_array_size_cstr (ppl_dimension_type sub_dim, Value res,
- ppl_const_Constraint_t cstr)
+build_partial_difference (ppl_Pointset_Powerset_C_Polyhedron_t *p,
+ ppl_dimension_type time_depth,
+ ppl_dimension_type offset,
+ ppl_dimension_type dim_sctr)
{
- ppl_Linear_Expression_t expr;
- ppl_Coefficient_t coef;
- Value val;
+ ppl_Constraint_t new_cstr;
+ ppl_Linear_Expression_t le;
+ ppl_dimension_type i;
+ ppl_dimension_type dim;
+ ppl_Pointset_Powerset_C_Polyhedron_t temp;
+
+ /* Add the equality: t_{time_depth} = t'_{time_depth} + 1.
+ This is the core part of this alogrithm, since this
+ constraint asks for the memory access stride (difference)
+ between two consecutive points in time dimensions. */
+
+ ppl_Pointset_Powerset_C_Polyhedron_space_dimension (*p, &dim);
+ ppl_new_Linear_Expression_with_dimension (&le, dim);
+ ppl_set_coef (le, time_depth, 1);
+ ppl_set_coef (le, time_depth + offset, -1);
+ ppl_set_inhomogeneous (le, 1);
+ ppl_new_Constraint (&new_cstr, le, PPL_CONSTRAINT_TYPE_EQUAL);
+ ppl_Pointset_Powerset_C_Polyhedron_add_constraint (*p, new_cstr);
+ ppl_delete_Linear_Expression (le);
+ ppl_delete_Constraint (new_cstr);
+
+ /* Add equalities:
+ | t1 = t1'
+ | ...
+ | t_{time_depth-1} = t'_{time_depth-1}
+ | t_{time_depth+1} = t'_{time_depth+1}
+ | ...
+ | t_{dim_sctr} = t'_{dim_sctr}
+
+ This means that all the time dimensions are equal except for
+ time_depth, where the constraint is t_{depth} = t'_{depth} + 1
+ step. More to this: we should be carefull not to add equalities
+ to the 'coupled' dimensions, which happens when the one dimension
+ is stripmined dimension, and the other dimension corresponds
+ to the point loop inside stripmined dimension. */
+
+ ppl_new_Pointset_Powerset_C_Polyhedron_from_Pointset_Powerset_C_Polyhedron (&temp, *p);
+
+ for (i = 0; i < dim_sctr; i++)
+ if (i != time_depth)
+ {
+ ppl_new_Linear_Expression_with_dimension (&le, dim);
+ ppl_set_coef (le, i, 1);
+ ppl_set_coef (le, i + offset, -1);
+ ppl_new_Constraint (&new_cstr, le, PPL_CONSTRAINT_TYPE_EQUAL);
+ ppl_Pointset_Powerset_C_Polyhedron_add_constraint (temp, new_cstr);
+
+ if (ppl_Pointset_Powerset_C_Polyhedron_is_empty (temp))
+ {
+ ppl_delete_Pointset_Powerset_C_Polyhedron (temp);
+ ppl_new_Pointset_Powerset_C_Polyhedron_from_Pointset_Powerset_C_Polyhedron (&temp, *p);
+ }
+ else
+ ppl_Pointset_Powerset_C_Polyhedron_add_constraint (*p, new_cstr);
+ ppl_delete_Linear_Expression (le);
+ ppl_delete_Constraint (new_cstr);
+ }
+
+ ppl_delete_Pointset_Powerset_C_Polyhedron (temp);
+}
- value_init (val);
- ppl_new_Coefficient (&coef);
- ppl_new_Linear_Expression_from_Constraint (&expr, cstr);
- ppl_Linear_Expression_coefficient (expr, sub_dim, coef);
- ppl_Coefficient_to_mpz_t (coef, val);
- value_set_si (res, 0);
+/* Set STRIDE to the stride of PDR in memory by advancing by one in
+ the loop at DEPTH. */
- if (value_notzero_p (val))
+static void
+pdr_stride_in_loop (mpz_t stride, graphite_dim_t depth, poly_dr_p pdr)
+{
+ ppl_dimension_type time_depth;
+ ppl_Linear_Expression_t le, lma;
+ ppl_Constraint_t new_cstr;
+ ppl_dimension_type i, *map;
+ ppl_Pointset_Powerset_C_Polyhedron_t p1, p2, sctr;
+ graphite_dim_t nb_subscripts = PDR_NB_SUBSCRIPTS (pdr) + 1;
+ poly_bb_p pbb = PDR_PBB (pdr);
+ ppl_dimension_type offset = pbb_nb_scattering_transform (pbb)
+ + pbb_nb_local_vars (pbb)
+ + pbb_dim_iter_domain (pbb);
+ ppl_dimension_type offsetg = offset + pbb_nb_params (pbb);
+ ppl_dimension_type dim_sctr = pbb_nb_scattering_transform (pbb)
+ + pbb_nb_local_vars (pbb);
+ ppl_dimension_type dim_L1 = offset + offsetg + 2 * nb_subscripts;
+ ppl_dimension_type dim_L2 = offset + offsetg + 2 * nb_subscripts + 1;
+ ppl_dimension_type new_dim = offset + offsetg + 2 * nb_subscripts + 2;
+
+ /* The resulting polyhedron should have the following format:
+ T|I|T'|I'|G|S|S'|l1|l2
+ where:
+ | T = t_1..t_{dim_sctr}
+ | I = i_1..i_{dim_iter_domain}
+ | T'= t'_1..t'_{dim_sctr}
+ | I'= i'_1..i'_{dim_iter_domain}
+ | G = g_1..g_{nb_params}
+ | S = s_1..s_{nb_subscripts}
+ | S'= s'_1..s'_{nb_subscripts}
+ | l1 and l2 are scalars.
+
+ Some invariants:
+ offset = dim_sctr + dim_iter_domain + nb_local_vars
+ offsetg = dim_sctr + dim_iter_domain + nb_local_vars + nb_params. */
+
+ /* Construct the T|I|0|0|G|0|0|0|0 part. */
+ {
+ ppl_new_Pointset_Powerset_C_Polyhedron_from_C_Polyhedron
+ (&sctr, PBB_TRANSFORMED_SCATTERING (pbb));
+ ppl_Pointset_Powerset_C_Polyhedron_add_space_dimensions_and_embed
+ (sctr, 2 * nb_subscripts + 2);
+ ppl_insert_dimensions_pointset (sctr, offset, offset);
+ }
+
+ /* Construct the 0|I|0|0|G|S|0|0|0 part. */
+ {
+ ppl_new_Pointset_Powerset_C_Polyhedron_from_Pointset_Powerset_C_Polyhedron
+ (&p1, PDR_ACCESSES (pdr));
+ ppl_Pointset_Powerset_C_Polyhedron_add_space_dimensions_and_embed
+ (p1, nb_subscripts + 2);
+ ppl_insert_dimensions_pointset (p1, 0, dim_sctr);
+ ppl_insert_dimensions_pointset (p1, offset, offset);
+ }
+
+ /* Construct the 0|0|0|0|0|S|0|l1|0 part. */
+ {
+ lma = build_linearized_memory_access (offset + dim_sctr, pdr);
+ ppl_set_coef (lma, dim_L1, -1);
+ ppl_new_Constraint (&new_cstr, lma, PPL_CONSTRAINT_TYPE_EQUAL);
+ ppl_Pointset_Powerset_C_Polyhedron_add_constraint (p1, new_cstr);
+ ppl_delete_Linear_Expression (lma);
+ ppl_delete_Constraint (new_cstr);
+ }
+
+ /* Now intersect all the parts to get the polyhedron P1:
+ T|I|0|0|G|0|0|0 |0
+ 0|I|0|0|G|S|0|0 |0
+ 0|0|0|0|0|S|0|l1|0
+ ------------------
+ T|I|0|0|G|S|0|l1|0. */
+
+ ppl_Pointset_Powerset_C_Polyhedron_intersection_assign (p1, sctr);
+ ppl_delete_Pointset_Powerset_C_Polyhedron (sctr);
+
+ /* Build P2, which would have the following form:
+ 0|0|T'|I'|G|0|S'|0|l2
+
+ P2 is built, by remapping the P1 polyhedron:
+ T|I|0|0|G|S|0|l1|0
+
+ using the following mapping:
+ T->T'
+ I->I'
+ S->S'
+ l1->l2. */
+ {
+ ppl_new_Pointset_Powerset_C_Polyhedron_from_Pointset_Powerset_C_Polyhedron
+ (&p2, p1);
+
+ map = ppl_new_id_map (new_dim);
+
+ /* TI -> T'I'. */
+ for (i = 0; i < offset; i++)
+ ppl_interchange (map, i, i + offset);
+
+ /* l1 -> l2. */
+ ppl_interchange (map, dim_L1, dim_L2);
+
+ /* S -> S'. */
+ for (i = 0; i < nb_subscripts; i++)
+ ppl_interchange (map, offset + offsetg + i,
+ offset + offsetg + nb_subscripts + i);
+
+ ppl_Pointset_Powerset_C_Polyhedron_map_space_dimensions (p2, map, new_dim);
+ free (map);
+ }
+
+ time_depth = psct_dynamic_dim (pbb, depth);
+
+ /* P1 = P1 inter P2. */
+ ppl_Pointset_Powerset_C_Polyhedron_intersection_assign (p1, p2);
+ build_partial_difference (&p1, time_depth, offset, dim_sctr);
+
+ /* Maximise the expression L2 - L1. */
+ {
+ ppl_new_Linear_Expression_with_dimension (&le, new_dim);
+ ppl_set_coef (le, dim_L2, 1);
+ ppl_set_coef (le, dim_L1, -1);
+ ppl_max_for_le_pointset (p1, le, stride);
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- gcc_assert (value_one_p (val) || value_mone_p (val));
- ppl_Linear_Expression_inhomogeneous_term (expr, coef);
- ppl_Coefficient_to_mpz_t (coef, res);
- value_absolute (res, res);
+ char *str;
+ void (*gmp_free) (void *, size_t);
+
+ fprintf (dump_file, "\nStride in BB_%d, DR_%d, depth %d:",
+ pbb_index (pbb), PDR_ID (pdr), (int) depth);
+ str = mpz_get_str (0, 10, stride);
+ fprintf (dump_file, " %s ", str);
+ mp_get_memory_functions (NULL, NULL, &gmp_free);
+ (*gmp_free) (str, strlen (str) + 1);
}
- value_clear (val);
- ppl_delete_Coefficient (coef);
- ppl_delete_Linear_Expression (expr);
+ ppl_delete_Pointset_Powerset_C_Polyhedron (p1);
+ ppl_delete_Pointset_Powerset_C_Polyhedron (p2);
+ ppl_delete_Linear_Expression (le);
}
-/* Returns in ARRAY_SIZE the size in bytes of the array PDR for the
- subscript at dimension SUB_DIM. */
+
+/* Sets STRIDES to the sum of all the strides of the data references
+ accessed in LOOP at DEPTH. */
static void
-compute_array_size_poly (poly_dr_p pdr, ppl_dimension_type sub_dim, Value array_size,
- ppl_const_Polyhedron_t ph)
+memory_strides_in_loop_1 (lst_p loop, graphite_dim_t depth, mpz_t strides)
{
- ppl_const_Constraint_System_t pcs;
- ppl_Constraint_System_const_iterator_t cit, cend;
- ppl_const_Constraint_t cstr;
- Value val;
- Value res;
+ int i, j;
+ lst_p l;
+ poly_dr_p pdr;
+ mpz_t s, n;
- if (sub_dim >= pdr_subscript_dim (pdr, pdr_nb_subscripts (pdr)))
+ mpz_init (s);
+ mpz_init (n);
+
+ for (j = 0; VEC_iterate (lst_p, LST_SEQ (loop), j, l); j++)
+ if (LST_LOOP_P (l))
+ memory_strides_in_loop_1 (l, depth, strides);
+ else
+ for (i = 0; VEC_iterate (poly_dr_p, PBB_DRS (LST_PBB (l)), i, pdr); i++)
+ {
+ pdr_stride_in_loop (s, depth, pdr);
+ mpz_set_si (n, PDR_NB_REFS (pdr));
+ mpz_mul (s, s, n);
+ mpz_add (strides, strides, s);
+ }
+
+ mpz_clear (s);
+ mpz_clear (n);
+}
+
+/* Sets STRIDES to the sum of all the strides of the data references
+ accessed in LOOP at DEPTH. */
+
+static void
+memory_strides_in_loop (lst_p loop, graphite_dim_t depth, mpz_t strides)
+{
+ if (mpz_cmp_si (loop->memory_strides, -1) == 0)
{
- value_set_si (array_size, 1);
- return;
+ mpz_set_si (strides, 0);
+ memory_strides_in_loop_1 (loop, depth, strides);
}
+ else
+ mpz_set (strides, loop->memory_strides);
+}
- value_init (val);
- value_init (res);
+/* Return true when the interchange of loops LOOP1 and LOOP2 is
+ profitable.
+
+ Example:
+
+ | int a[100][100];
+ |
+ | int
+ | foo (int N)
+ | {
+ | int j;
+ | int i;
+ |
+ | for (i = 0; i < N; i++)
+ | for (j = 0; j < N; j++)
+ | a[j][2 * i] += 1;
+ |
+ | return a[N][12];
+ | }
+
+ The data access A[j][i] is described like this:
+
+ | i j N a s0 s1 1
+ | 0 0 0 1 0 0 -5 = 0
+ | 0 -1 0 0 1 0 0 = 0
+ |-2 0 0 0 0 1 0 = 0
+ | 0 0 0 0 1 0 0 >= 0
+ | 0 0 0 0 0 1 0 >= 0
+ | 0 0 0 0 -1 0 100 >= 0
+ | 0 0 0 0 0 -1 100 >= 0
+
+ The linearized memory access L to A[100][100] is:
+
+ | i j N a s0 s1 1
+ | 0 0 0 0 100 1 0
+
+ TODO: the shown format is not valid as it does not show the fact
+ that the iteration domain "i j" is transformed using the scattering.
+
+ Next, to measure the impact of iterating once in loop "i", we build
+ a maximization problem: first, we add to DR accesses the dimensions
+ k, s2, s3, L1 = 100 * s0 + s1, L2, and D1: this is the polyhedron P1.
+ L1 and L2 are the linearized memory access functions.
+
+ | i j N a s0 s1 k s2 s3 L1 L2 D1 1
+ | 0 0 0 1 0 0 0 0 0 0 0 0 -5 = 0 alias = 5
+ | 0 -1 0 0 1 0 0 0 0 0 0 0 0 = 0 s0 = j
+ |-2 0 0 0 0 1 0 0 0 0 0 0 0 = 0 s1 = 2 * i
+ | 0 0 0 0 1 0 0 0 0 0 0 0 0 >= 0
+ | 0 0 0 0 0 1 0 0 0 0 0 0 0 >= 0
+ | 0 0 0 0 -1 0 0 0 0 0 0 0 100 >= 0
+ | 0 0 0 0 0 -1 0 0 0 0 0 0 100 >= 0
+ | 0 0 0 0 100 1 0 0 0 -1 0 0 0 = 0 L1 = 100 * s0 + s1
+
+ Then, we generate the polyhedron P2 by interchanging the dimensions
+ (s0, s2), (s1, s3), (L1, L2), (k, i)
+
+ | i j N a s0 s1 k s2 s3 L1 L2 D1 1
+ | 0 0 0 1 0 0 0 0 0 0 0 0 -5 = 0 alias = 5
+ | 0 -1 0 0 0 0 0 1 0 0 0 0 0 = 0 s2 = j
+ | 0 0 0 0 0 0 -2 0 1 0 0 0 0 = 0 s3 = 2 * k
+ | 0 0 0 0 0 0 0 1 0 0 0 0 0 >= 0
+ | 0 0 0 0 0 0 0 0 1 0 0 0 0 >= 0
+ | 0 0 0 0 0 0 0 -1 0 0 0 0 100 >= 0
+ | 0 0 0 0 0 0 0 0 -1 0 0 0 100 >= 0
+ | 0 0 0 0 0 0 0 100 1 0 -1 0 0 = 0 L2 = 100 * s2 + s3
+
+ then we add to P2 the equality k = i + 1:
+
+ |-1 0 0 0 0 0 1 0 0 0 0 0 -1 = 0 k = i + 1
+
+ and finally we maximize the expression "D1 = max (P1 inter P2, L2 - L1)".
+
+ Similarly, to determine the impact of one iteration on loop "j", we
+ interchange (k, j), we add "k = j + 1", and we compute D2 the
+ maximal value of the difference.
+
+ Finally, the profitability test is D1 < D2: if in the outer loop
+ the strides are smaller than in the inner loop, then it is
+ profitable to interchange the loops at DEPTH1 and DEPTH2. */
- value_set_si (res, 0);
+static bool
+lst_interchange_profitable_p (lst_p loop1, lst_p loop2)
+{
+ mpz_t d1, d2;
+ bool res;
- ppl_Polyhedron_get_constraints (ph, &pcs);
- ppl_new_Constraint_System_const_iterator (&cit);
- ppl_new_Constraint_System_const_iterator (&cend);
-
- for (ppl_Constraint_System_begin (pcs, cit),
- ppl_Constraint_System_end (pcs, cend);
- !ppl_Constraint_System_const_iterator_equal_test (cit, cend);
- ppl_Constraint_System_const_iterator_increment (cit))
- {
- ppl_Constraint_System_const_iterator_dereference (cit, &cstr);
+ gcc_assert (loop1 && loop2
+ && LST_LOOP_P (loop1) && LST_LOOP_P (loop2)
+ && lst_depth (loop1) < lst_depth (loop2));
- if (ppl_Constraint_type (cstr) == PPL_CONSTRAINT_TYPE_EQUAL)
- continue;
+ mpz_init (d1);
+ mpz_init (d2);
- compute_array_size_cstr (sub_dim, val, cstr);
- value_max (res, res, val);
- }
+ memory_strides_in_loop (loop1, lst_depth (loop1), d1);
+ memory_strides_in_loop (loop2, lst_depth (loop2), d2);
- compute_array_size_poly (pdr, sub_dim + 1, val, ph);
- value_multiply (array_size, res, val);
+ res = value_lt (d1, d2);
- value_clear (res);
- value_clear (val);
+ mpz_clear (d1);
+ mpz_clear (d2);
+
+ return res;
}
-/* Initializes ARRAY_SIZE, the size in bytes of the array for the
- subscript at dimension SUB_DIM in PDR. */
+/* Interchanges the loops at DEPTH1 and DEPTH2 of the original
+ scattering and assigns the resulting polyhedron to the transformed
+ scattering. */
static void
-compute_array_size (poly_dr_p pdr, ppl_dimension_type sub_dim, Value array_size)
+pbb_interchange_loop_depths (graphite_dim_t depth1, graphite_dim_t depth2,
+ poly_bb_p pbb)
{
- ppl_Pointset_Powerset_C_Polyhedron_t data_container = PDR_DATA_CONTAINER (pdr);
- ppl_Pointset_Powerset_C_Polyhedron_iterator_t it, end;
- Value val;
-
- value_set_si (array_size, 1);
- if (sub_dim >= pdr_subscript_dim (pdr, pdr_nb_subscripts (pdr)))
- return;
+ ppl_dimension_type i, dim;
+ ppl_dimension_type *map;
+ ppl_Polyhedron_t poly = PBB_TRANSFORMED_SCATTERING (pbb);
+ ppl_dimension_type dim1 = psct_dynamic_dim (pbb, depth1);
+ ppl_dimension_type dim2 = psct_dynamic_dim (pbb, depth2);
- value_init (val);
- ppl_new_Pointset_Powerset_C_Polyhedron_iterator (&it);
- ppl_new_Pointset_Powerset_C_Polyhedron_iterator (&end);
+ ppl_Polyhedron_space_dimension (poly, &dim);
+ map = (ppl_dimension_type *) XNEWVEC (ppl_dimension_type, dim);
- for (ppl_Pointset_Powerset_C_Polyhedron_iterator_begin (data_container, it),
- ppl_Pointset_Powerset_C_Polyhedron_iterator_end (data_container, end);
- !ppl_Pointset_Powerset_C_Polyhedron_iterator_equal_test (it, end);
- ppl_Pointset_Powerset_C_Polyhedron_iterator_increment (it))
- {
- ppl_const_Polyhedron_t ph;
+ for (i = 0; i < dim; i++)
+ map[i] = i;
- ppl_Pointset_Powerset_C_Polyhedron_iterator_dereference (it, &ph);
- compute_array_size_poly (pdr, sub_dim, val, ph);
- value_max (array_size, array_size, val);
- }
+ map[dim1] = dim2;
+ map[dim2] = dim1;
- value_clear (val);
- ppl_delete_Pointset_Powerset_C_Polyhedron_iterator (it);
- ppl_delete_Pointset_Powerset_C_Polyhedron_iterator (end);
+ ppl_Polyhedron_map_space_dimensions (poly, map, dim);
+ free (map);
}
-/* Computes ACCESS_STRIDES, the sum of all the strides of PDR at
- LOOP_DEPTH. */
+/* Apply the interchange of loops at depths DEPTH1 and DEPTH2 to all
+ the statements below LST. */
static void
-gather_access_strides_poly (poly_dr_p pdr, ppl_const_Polyhedron_t ph,
- ppl_dimension_type loop_dim, Value res)
+lst_apply_interchange (lst_p lst, int depth1, int depth2)
{
- ppl_const_Constraint_System_t pcs;
- ppl_Constraint_System_const_iterator_t cit, cend;
- ppl_const_Constraint_t cstr;
- ppl_Linear_Expression_t expr;
- ppl_Coefficient_t coef;
- Value stride;
- Value array_size;
-
- value_init (array_size);
- value_init (stride);
- ppl_new_Coefficient (&coef);
- value_set_si (res, 0);
-
- ppl_Polyhedron_get_constraints (ph, &pcs);
- ppl_new_Constraint_System_const_iterator (&cit);
- ppl_new_Constraint_System_const_iterator (&cend);
-
- for (ppl_Constraint_System_begin (pcs, cit),
- ppl_Constraint_System_end (pcs, cend);
- !ppl_Constraint_System_const_iterator_equal_test (cit, cend);
- ppl_Constraint_System_const_iterator_increment (cit))
+ if (!lst)
+ return;
+
+ if (LST_LOOP_P (lst))
{
- ppl_Constraint_System_const_iterator_dereference (cit, &cstr);
- ppl_new_Linear_Expression_from_Constraint (&expr, cstr);
- ppl_Linear_Expression_coefficient (expr, loop_dim, coef);
- ppl_delete_Linear_Expression (expr);
- ppl_Coefficient_to_mpz_t (coef, stride);
-
- if (value_zero_p (stride))
- continue;
-
- value_absolute (stride, stride);
- compute_array_size (pdr, compute_subscript (pdr, cstr), array_size);
- value_multiply (stride, stride, array_size);
- value_addto (res, res, stride);
+ int i;
+ lst_p l;
+
+ for (i = 0; VEC_iterate (lst_p, LST_SEQ (lst), i, l); i++)
+ lst_apply_interchange (l, depth1, depth2);
}
+ else
+ pbb_interchange_loop_depths (depth1, depth2, LST_PBB (lst));
+}
+
+/* Return true when the nest starting at LOOP1 and ending on LOOP2 is
+ perfect: i.e. there are no sequence of statements. */
- value_clear (array_size);
- value_clear (stride);
- ppl_delete_Coefficient (coef);
- ppl_delete_Constraint_System_const_iterator (cit);
- ppl_delete_Constraint_System_const_iterator (cend);
+static bool
+lst_perfectly_nested_p (lst_p loop1, lst_p loop2)
+{
+ if (loop1 == loop2)
+ return true;
+
+ if (!LST_LOOP_P (loop1))
+ return false;
+
+ return VEC_length (lst_p, LST_SEQ (loop1)) == 1
+ && lst_perfectly_nested_p (VEC_index (lst_p, LST_SEQ (loop1), 0), loop2);
}
-/* Computes ACCESS_STRIDES, the sum of all the strides of PDR at
- LOOP_DEPTH. */
+/* Transform the loop nest between LOOP1 and LOOP2 into a perfect
+ nest. To continue the naming tradition, this function is called
+ after perfect_nestify. NEST is set to the perfectly nested loop
+ that is created. BEFORE/AFTER are set to the loops distributed
+ before/after the loop NEST. */
static void
-gather_access_strides (poly_dr_p pdr, graphite_dim_t loop_depth,
- Value access_strides)
+lst_perfect_nestify (lst_p loop1, lst_p loop2, lst_p *before,
+ lst_p *nest, lst_p *after)
{
- ppl_dimension_type loop_dim = pdr_iterator_dim (pdr, loop_depth);
+ poly_bb_p first, last;
- ppl_Pointset_Powerset_C_Polyhedron_t accesses = PDR_ACCESSES (pdr);
- ppl_Pointset_Powerset_C_Polyhedron_iterator_t it, end;
- Value res;
+ gcc_assert (loop1 && loop2
+ && loop1 != loop2
+ && LST_LOOP_P (loop1) && LST_LOOP_P (loop2));
- value_init (res);
- ppl_new_Pointset_Powerset_C_Polyhedron_iterator (&it);
- ppl_new_Pointset_Powerset_C_Polyhedron_iterator (&end);
+ first = LST_PBB (lst_find_first_pbb (loop2));
+ last = LST_PBB (lst_find_last_pbb (loop2));
- for (ppl_Pointset_Powerset_C_Polyhedron_iterator_begin (accesses, it),
- ppl_Pointset_Powerset_C_Polyhedron_iterator_end (accesses, end);
- !ppl_Pointset_Powerset_C_Polyhedron_iterator_equal_test (it, end);
- ppl_Pointset_Powerset_C_Polyhedron_iterator_increment (it))
- {
- ppl_const_Polyhedron_t ph;
+ *before = copy_lst (loop1);
+ *nest = copy_lst (loop1);
+ *after = copy_lst (loop1);
- ppl_Pointset_Powerset_C_Polyhedron_iterator_dereference (it, &ph);
- gather_access_strides_poly (pdr, ph, loop_dim, res);
- value_addto (access_strides, access_strides, res);
- }
+ lst_remove_all_before_including_pbb (*before, first, false);
+ lst_remove_all_before_including_pbb (*after, last, true);
- value_clear (res);
- ppl_delete_Pointset_Powerset_C_Polyhedron_iterator (it);
- ppl_delete_Pointset_Powerset_C_Polyhedron_iterator (end);
+ lst_remove_all_before_excluding_pbb (*nest, first, true);
+ lst_remove_all_before_excluding_pbb (*nest, last, false);
+
+ if (lst_empty_p (*before))
+ {
+ free_lst (*before);
+ *before = NULL;
+ }
+ if (lst_empty_p (*after))
+ {
+ free_lst (*after);
+ *after = NULL;
+ }
+ if (lst_empty_p (*nest))
+ {
+ free_lst (*nest);
+ *nest = NULL;
+ }
}
-/* Returns true when it is profitable to interchange loop at depth1
- and loop at depth2 with depth1 < depth2 for the polyhedral black
- box PBB. */
+/* Try to interchange LOOP1 with LOOP2 for all the statements of the
+ body of LOOP2. LOOP1 contains LOOP2. Return true if it did the
+ interchange. */
static bool
-pbb_interchange_profitable_p (graphite_dim_t depth1, graphite_dim_t depth2, poly_bb_p pbb)
+lst_try_interchange_loops (scop_p scop, lst_p loop1, lst_p loop2)
{
- int i;
- poly_dr_p pdr;
- Value access_strides1, access_strides2;
- bool res;
+ int depth1 = lst_depth (loop1);
+ int depth2 = lst_depth (loop2);
+ lst_p transformed;
- gcc_assert (depth1 < depth2);
+ lst_p before = NULL, nest = NULL, after = NULL;
+
+ if (!lst_interchange_profitable_p (loop1, loop2))
+ return false;
- value_init (access_strides1);
- value_init (access_strides2);
+ if (!lst_perfectly_nested_p (loop1, loop2))
+ lst_perfect_nestify (loop1, loop2, &before, &nest, &after);
- value_set_si (access_strides1, 0);
- value_set_si (access_strides2, 0);
+ lst_apply_interchange (loop2, depth1, depth2);
- for (i = 0; VEC_iterate (poly_dr_p, PBB_DRS (pbb), i, pdr); i++)
+ /* Sync the transformed LST information and the PBB scatterings
+ before using the scatterings in the data dependence analysis. */
+ if (before || nest || after)
{
- gather_access_strides (pdr, depth1, access_strides1);
- gather_access_strides (pdr, depth2, access_strides2);
+ transformed = lst_substitute_3 (SCOP_TRANSFORMED_SCHEDULE (scop), loop1,
+ before, nest, after);
+ lst_update_scattering (transformed);
+ free_lst (transformed);
}
- res = value_lt (access_strides1, access_strides2);
+ if (graphite_legal_transform (scop))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Loops at depths %d and %d will be interchanged.\n",
+ depth1, depth2);
- value_clear (access_strides1);
- value_clear (access_strides2);
+ /* Transform the SCOP_TRANSFORMED_SCHEDULE of the SCOP. */
+ lst_insert_in_sequence (before, loop1, true);
+ lst_insert_in_sequence (after, loop1, false);
- return res;
+ if (nest)
+ {
+ lst_replace (loop1, nest);
+ free_lst (loop1);
+ }
+
+ return true;
+ }
+
+ /* Undo the transform. */
+ free_lst (before);
+ free_lst (nest);
+ free_lst (after);
+ lst_apply_interchange (loop2, depth2, depth1);
+ return false;
}
-/* Interchanges the loops at DEPTH1 and DEPTH2 of the original
- scattering and assigns the resulting polyhedron to the transformed
- scattering. */
+/* Selects the inner loop in LST_SEQ (INNER_FATHER) to be interchanged
+ with the loop OUTER in LST_SEQ (OUTER_FATHER). */
-static void
-pbb_interchange_loop_depths (graphite_dim_t depth1, graphite_dim_t depth2, poly_bb_p pbb)
+static bool
+lst_interchange_select_inner (scop_p scop, lst_p outer_father, int outer,
+ lst_p inner_father)
{
- ppl_dimension_type i, dim;
- ppl_dimension_type *map;
- ppl_Polyhedron_t poly = PBB_TRANSFORMED_SCATTERING (pbb);
- ppl_dimension_type dim1 = psct_iterator_dim (pbb, depth1);
- ppl_dimension_type dim2 = psct_iterator_dim (pbb, depth2);
+ int inner;
+ lst_p loop1, loop2;
- ppl_Polyhedron_space_dimension (poly, &dim);
- map = (ppl_dimension_type *) XNEWVEC (ppl_dimension_type, dim);
+ gcc_assert (outer_father
+ && LST_LOOP_P (outer_father)
+ && LST_LOOP_P (VEC_index (lst_p, LST_SEQ (outer_father), outer))
+ && inner_father
+ && LST_LOOP_P (inner_father));
- for (i = 0; i < dim; i++)
- map[i] = i;
+ loop1 = VEC_index (lst_p, LST_SEQ (outer_father), outer);
- map[dim1] = dim2;
- map[dim2] = dim1;
+ for (inner = 0; VEC_iterate (lst_p, LST_SEQ (inner_father), inner, loop2); inner++)
+ if (LST_LOOP_P (loop2)
+ && (lst_try_interchange_loops (scop, loop1, loop2)
+ || lst_interchange_select_inner (scop, outer_father, outer, loop2)))
+ return true;
- ppl_Polyhedron_map_space_dimensions (poly, map, dim);
- free (map);
+ return false;
}
-/* Interchanges all the loop depths that are considered profitable for PBB. */
+/* Interchanges all the loops of LOOP and the loops of its body that
+ are considered profitable to interchange. Return true if it did
+ interchanged some loops. OUTER is the index in LST_SEQ (LOOP) that
+ points to the next outer loop to be considered for interchange. */
static bool
-pbb_do_interchange (poly_bb_p pbb, scop_p scop)
+lst_interchange_select_outer (scop_p scop, lst_p loop, int outer)
{
- graphite_dim_t i, j;
- bool transform_done = false;
+ lst_p l;
+ bool res = false;
+ int i = 0;
+ lst_p father;
- for (i = 0; i < pbb_dim_iter_domain (pbb); i++)
- for (j = i + 1; j < pbb_dim_iter_domain (pbb); j++)
- if (pbb_interchange_profitable_p (i, j, pbb))
+ if (!loop || !LST_LOOP_P (loop))
+ return false;
+
+ father = LST_LOOP_FATHER (loop);
+ if (father)
+ {
+ while (lst_interchange_select_inner (scop, father, outer, loop))
{
- pbb_interchange_loop_depths (i, j, pbb);
-
- if (graphite_legal_transform (scop))
- {
- transform_done = true;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file,
- "PBB %d: loops at depths %d and %d will be interchanged.\n",
- GBB_BB (PBB_BLACK_BOX (pbb))->index, (int) i, (int) j);
- }
- else
- /* Undo the transform. */
- pbb_interchange_loop_depths (j, i, pbb);
+ res = true;
+ loop = VEC_index (lst_p, LST_SEQ (father), outer);
}
+ }
+
+ if (LST_LOOP_P (loop))
+ for (i = 0; VEC_iterate (lst_p, LST_SEQ (loop), i, l); i++)
+ if (LST_LOOP_P (l))
+ res |= lst_interchange_select_outer (scop, l, i);
- return transform_done;
+ return res;
}
/* Interchanges all the loop depths that are considered profitable for SCOP. */
bool
scop_do_interchange (scop_p scop)
{
- int i;
- poly_bb_p pbb;
- bool transform_done = false;
-
- store_scattering (scop);
+ bool res = lst_interchange_select_outer
+ (scop, SCOP_TRANSFORMED_SCHEDULE (scop), 0);
- for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
- transform_done |= pbb_do_interchange (pbb, scop);
+ lst_update_scattering (SCOP_TRANSFORMED_SCHEDULE (scop));
- if (!transform_done)
- return false;
-
- if (!graphite_legal_transform (scop))
- {
- restore_scattering (scop);
- return false;
- }
-
- return transform_done;
+ return res;
}
+
#endif
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