diff --git a/gcc/ChangeLog.graphite b/gcc/ChangeLog.graphite
index eec4f010782854b8657276276f4848f0df5dc104..468d3f59135a66c29041029f98773ef7d7c65232 100644
--- a/gcc/ChangeLog.graphite
+++ b/gcc/ChangeLog.graphite
@@ -1,3 +1,10 @@
+2009-11-04 Konrad Trifunovic <konrad.trifunovic@inria.fr>
+
+ * graphite-interchange.c (build_partial_difference): New.
+ (memory_stride_in_loop): Refactored the computation of
+ equality constraints into build_partial_difference function.
+ Added support for debugging stride computations.
+
2009-11-03 Sebastian Pop <sebastian.pop@amd.com>
* graphite-clast-to-gimple.c (gloog): Free if_region,
diff --git a/gcc/graphite-interchange.c b/gcc/graphite-interchange.c
index 6ac7fca84df204543f50ee5c638d6a5605294074..42a0b1dac7f27968ea21317fabcbd47b13eb8c55 100644
--- a/gcc/graphite-interchange.c
+++ b/gcc/graphite-interchange.c
@@ -104,6 +104,94 @@ build_linearized_memory_access (ppl_dimension_type offset, poly_dr_p pdr)
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
+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_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);
+}
+
+
/* Set STRIDE to the stride of PDR in memory by advancing by one in
time dimension DEPTH. */
@@ -215,48 +303,11 @@ memory_stride_in_loop (Value stride, graphite_dim_t depth, poly_dr_p pdr)
free (map);
}
- /* Add equalities:
- | t1 = t1'
- | ...
- | t_{depth-1} = t'_{depth-1}
- | t_{depth+1} = t'_{depth+1}
- | ...
- | t_{dim_sctr} = t'_{dim_sctr}
-
- This means that all the time dimensions are equal except for
- depth, where we will add t_{depth} = t'_{depth} + 1 in the next
- step. */
-
time_depth = psct_dynamic_dim (pbb, depth);
- for (i = 0; i < dim_sctr; i++)
- if (i != time_depth)
- {
- ppl_new_Linear_Expression_with_dimension (&le, new_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 (p2, new_cstr);
- ppl_delete_Linear_Expression (le);
- ppl_delete_Constraint (new_cstr);
- }
-
- /* Add equality : t_{depth} = t'_{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_new_Linear_Expression_with_dimension (&le, new_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 (p2, new_cstr);
- ppl_delete_Linear_Expression (le);
- ppl_delete_Constraint (new_cstr);
- }
/* 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. */
{
@@ -266,6 +317,13 @@ memory_stride_in_loop (Value stride, graphite_dim_t depth, poly_dr_p pdr)
ppl_max_for_le_pointset (p1, le, stride);
}
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "\nStride in BB_%d, DR_%d, depth %d:",
+ pbb_index (pbb), PDR_ID (pdr), (int) depth);
+ value_print (dump_file, " %s ", stride);
+ }
+
ppl_delete_Pointset_Powerset_C_Polyhedron (p1);
ppl_delete_Pointset_Powerset_C_Polyhedron (p2);
ppl_delete_Linear_Expression (le);