From 2bc529bf7d9fa18d85c06b34063ff5b3a8cfacd9 Mon Sep 17 00:00:00 2001 From: Konrad Trifunovic Date: Wed, 25 Nov 2009 06:29:01 +0100 Subject: [PATCH] graphite-interchange.c (build_partial_difference): New. 2009-11-04 Konrad Trifunovic * 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. From-SVN: r154634 --- gcc/ChangeLog.graphite | 7 ++ gcc/graphite-interchange.c | 134 ++++++++++++++++++++++++++----------- 2 files changed, 103 insertions(+), 38 deletions(-) diff --git a/gcc/ChangeLog.graphite b/gcc/ChangeLog.graphite index eec4f010782..468d3f59135 100644 --- a/gcc/ChangeLog.graphite +++ b/gcc/ChangeLog.graphite @@ -1,3 +1,10 @@ +2009-11-04 Konrad Trifunovic + + * 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 * graphite-clast-to-gimple.c (gloog): Free if_region, diff --git a/gcc/graphite-interchange.c b/gcc/graphite-interchange.c index 6ac7fca84df..42a0b1dac7f 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);