1 /* Interchange heuristics and transform for loop interchange on
2 polyhedral representation.
4 Copyright (C) 2009 Free Software Foundation, Inc.
5 Contributed by Sebastian Pop <sebastian.pop@amd.com> and
6 Harsha Jagasia <harsha.jagasia@amd.com>.
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.h"
31 #include "basic-block.h"
32 #include "diagnostic.h"
33 #include "tree-flow.h"
35 #include "tree-dump.h"
38 #include "tree-chrec.h"
39 #include "tree-data-ref.h"
40 #include "tree-scalar-evolution.h"
41 #include "tree-pass.h"
43 #include "value-prof.h"
44 #include "pointer-set.h"
49 #include "cloog/cloog.h"
52 #include "graphite-ppl.h"
54 #include "graphite-poly.h"
56 /* Computes ACCESS_STRIDES, the sum of all the strides of PDR at
60 gather_access_strides (poly_dr_p pdr ATTRIBUTE_UNUSED,
61 graphite_dim_t loop_depth ATTRIBUTE_UNUSED,
62 Value access_strides ATTRIBUTE_UNUSED)
67 /* Returns true when it is profitable to interchange loop at depth1
68 and loop at depth2 with depth1 < depth2 for the polyhedral black
72 pbb_interchange_profitable_p (graphite_dim_t depth1, graphite_dim_t depth2, poly_bb_p pbb)
76 Value access_strides1, access_strides2;
79 gcc_assert (depth1 < depth2);
81 value_init (access_strides1);
82 value_init (access_strides2);
84 value_set_si (access_strides1, 0);
85 value_set_si (access_strides2, 0);
87 for (i = 0; VEC_iterate (poly_dr_p, PBB_DRS (pbb), i, pdr); i++)
89 gather_access_strides (pdr, depth1, access_strides1);
90 gather_access_strides (pdr, depth2, access_strides2);
93 res = value_lt (access_strides1, access_strides2);
95 value_clear (access_strides1);
96 value_clear (access_strides2);
101 /* Interchanges the loops at DEPTH1 and DEPTH2 of the original
102 scattering and assigns the resulting polyhedron to the transformed
106 pbb_interchange_loop_depths (graphite_dim_t depth1, graphite_dim_t depth2, poly_bb_p pbb)
108 ppl_dimension_type i, dim;
109 ppl_dimension_type *map;
110 ppl_Polyhedron_t poly = PBB_TRANSFORMED_SCATTERING (pbb);
111 ppl_dimension_type dim1 = psct_iterator_dim (pbb, depth1);
112 ppl_dimension_type dim2 = psct_iterator_dim (pbb, depth2);
114 ppl_Polyhedron_space_dimension (poly, &dim);
115 map = (ppl_dimension_type *) XNEWVEC (ppl_dimension_type, dim);
117 for (i = 0; i < dim; i++)
123 ppl_Polyhedron_map_space_dimensions (poly, map, dim);
127 /* Interchanges all the loop depths that are considered profitable for PBB. */
130 pbb_do_interchange (poly_bb_p pbb, scop_p scop)
133 bool transform_done = false;
135 for (i = 0; i < pbb_dim_iter_domain (pbb); i++)
136 for (j = i + 1; j < pbb_dim_iter_domain (pbb); j++)
137 if (pbb_interchange_profitable_p (i, j, pbb))
139 pbb_interchange_loop_depths (i, j, pbb);
141 if (graphite_legal_transform (scop))
143 transform_done = true;
145 if (dump_file && (dump_flags & TDF_DETAILS))
147 "PBB %d: loops at depths %d and %d will be interchanged.\n",
148 GBB_BB (PBB_BLACK_BOX (pbb))->index, (int) i, (int) j);
151 /* Undo the transform. */
152 pbb_interchange_loop_depths (j, i, pbb);
155 return transform_done;
158 /* Interchanges all the loop depths that are considered profitable for SCOP. */
161 scop_do_interchange (scop_p scop)
165 bool transform_done = false;
167 store_scattering (scop);
169 for (i = 0; VEC_iterate (poly_bb_p, SCOP_BBS (scop), i, pbb); i++)
170 transform_done |= pbb_do_interchange (pbb, scop);
175 if (!graphite_legal_transform (scop))
177 restore_scattering (scop);
181 return transform_done;