| /* A scheduling optimizer for Graphite |
| Copyright (C) 2012-2017 Free Software Foundation, Inc. |
| Contributed by Tobias Grosser <tobias@grosser.es>. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3, or (at your option) |
| any later version. |
| |
| GCC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #define USES_ISL |
| |
| #include "config.h" |
| |
| #ifdef HAVE_isl |
| |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "cfghooks.h" |
| #include "tree.h" |
| #include "gimple.h" |
| #include "fold-const.h" |
| #include "gimple-iterator.h" |
| #include "tree-ssa-loop.h" |
| #include "cfgloop.h" |
| #include "tree-data-ref.h" |
| #include "params.h" |
| #include "dumpfile.h" |
| #include "tree-vectorizer.h" |
| #include "graphite.h" |
| |
| |
| /* get_schedule_for_node_st - Improve schedule for the schedule node. |
| Only Simple loop tiling is considered. */ |
| |
| static __isl_give isl_schedule_node * |
| get_schedule_for_node_st (__isl_take isl_schedule_node *node, void *user) |
| { |
| if (user) |
| return node; |
| |
| if (isl_schedule_node_get_type (node) != isl_schedule_node_band |
| || isl_schedule_node_n_children (node) != 1) |
| return node; |
| |
| isl_space *space = isl_schedule_node_band_get_space (node); |
| unsigned dims = isl_space_dim (space, isl_dim_set); |
| isl_schedule_node *child = isl_schedule_node_get_child (node, 0); |
| isl_schedule_node_type type = isl_schedule_node_get_type (child); |
| isl_space_free (space); |
| isl_schedule_node_free (child); |
| |
| if (type != isl_schedule_node_leaf) |
| return node; |
| |
| long tile_size = PARAM_VALUE (PARAM_LOOP_BLOCK_TILE_SIZE); |
| if (dims <= 1 |
| || tile_size == 0 |
| || !isl_schedule_node_band_get_permutable (node)) |
| { |
| if (dump_file && dump_flags) |
| fprintf (dump_file, "not tiled\n"); |
| return node; |
| } |
| |
| /* Tile loops. */ |
| space = isl_schedule_node_band_get_space (node); |
| isl_multi_val *sizes = isl_multi_val_zero (space); |
| isl_ctx *ctx = isl_schedule_node_get_ctx (node); |
| |
| for (unsigned i = 0; i < dims; i++) |
| { |
| sizes = isl_multi_val_set_val (sizes, i, |
| isl_val_int_from_si (ctx, tile_size)); |
| if (dump_file && dump_flags) |
| fprintf (dump_file, "tiled by %ld\n", tile_size); |
| } |
| |
| node = isl_schedule_node_band_tile (node, sizes); |
| node = isl_schedule_node_child (node, 0); |
| |
| return node; |
| } |
| |
| static isl_union_set * |
| scop_get_domains (scop_p scop) |
| { |
| int i; |
| poly_bb_p pbb; |
| isl_space *space = isl_set_get_space (scop->param_context); |
| isl_union_set *res = isl_union_set_empty (space); |
| |
| FOR_EACH_VEC_ELT (scop->pbbs, i, pbb) |
| res = isl_union_set_add_set (res, isl_set_copy (pbb->domain)); |
| |
| return res; |
| } |
| |
| /* Compute the schedule for SCOP based on its parameters, domain and set of |
| constraints. Then apply the schedule to SCOP. */ |
| |
| static bool |
| optimize_isl (scop_p scop) |
| { |
| int old_err = isl_options_get_on_error (scop->isl_context); |
| int old_max_operations = isl_ctx_get_max_operations (scop->isl_context); |
| int max_operations = PARAM_VALUE (PARAM_MAX_ISL_OPERATIONS); |
| if (max_operations) |
| isl_ctx_set_max_operations (scop->isl_context, max_operations); |
| isl_options_set_on_error (scop->isl_context, ISL_ON_ERROR_CONTINUE); |
| |
| isl_union_set *domain = scop_get_domains (scop); |
| |
| /* Simplify the dependences on the domain. */ |
| scop_get_dependences (scop); |
| isl_union_map *dependences |
| = isl_union_map_gist_domain (isl_union_map_copy (scop->dependence), |
| isl_union_set_copy (domain)); |
| isl_union_map *validity |
| = isl_union_map_gist_range (dependences, isl_union_set_copy (domain)); |
| |
| /* FIXME: proximity should not be validity. */ |
| isl_union_map *proximity = isl_union_map_copy (validity); |
| |
| isl_schedule_constraints *sc = isl_schedule_constraints_on_domain (domain); |
| sc = isl_schedule_constraints_set_proximity (sc, proximity); |
| sc = isl_schedule_constraints_set_validity (sc, isl_union_map_copy (validity)); |
| sc = isl_schedule_constraints_set_coincidence (sc, validity); |
| |
| isl_options_set_schedule_serialize_sccs (scop->isl_context, 0); |
| isl_options_set_schedule_maximize_band_depth (scop->isl_context, 1); |
| isl_options_set_schedule_max_constant_term (scop->isl_context, 20); |
| isl_options_set_schedule_max_coefficient (scop->isl_context, 20); |
| isl_options_set_tile_scale_tile_loops (scop->isl_context, 0); |
| /* Generate loop upper bounds that consist of the current loop iterator, an |
| operator (< or <=) and an expression not involving the iterator. If this |
| option is not set, then the current loop iterator may appear several times |
| in the upper bound. See the isl manual for more details. */ |
| isl_options_set_ast_build_atomic_upper_bound (scop->isl_context, 1); |
| |
| scop->transformed_schedule = isl_schedule_constraints_compute_schedule (sc); |
| scop->transformed_schedule = |
| isl_schedule_map_schedule_node_bottom_up (scop->transformed_schedule, |
| get_schedule_for_node_st, NULL); |
| |
| isl_options_set_on_error (scop->isl_context, old_err); |
| isl_ctx_reset_operations (scop->isl_context); |
| isl_ctx_set_max_operations (scop->isl_context, old_max_operations); |
| if (!scop->transformed_schedule |
| || isl_ctx_last_error (scop->isl_context) != isl_error_none) |
| { |
| location_t loc = find_loop_location |
| (scop->scop_info->region.entry->dest->loop_father); |
| if (isl_ctx_last_error (scop->isl_context) == isl_error_quota) |
| dump_printf_loc (MSG_MISSED_OPTIMIZATION, loc, |
| "loop nest not optimized, optimization timed out " |
| "after %d operations [--param max-isl-operations]\n", |
| max_operations); |
| else |
| dump_printf_loc (MSG_MISSED_OPTIMIZATION, loc, |
| "loop nest not optimized, ISL signalled an error\n"); |
| return false; |
| } |
| |
| gcc_assert (scop->original_schedule); |
| isl_union_map *original = isl_schedule_get_map (scop->original_schedule); |
| isl_union_map *transformed = isl_schedule_get_map (scop->transformed_schedule); |
| bool same_schedule = isl_union_map_is_equal (original, transformed); |
| isl_union_map_free (original); |
| isl_union_map_free (transformed); |
| |
| if (same_schedule) |
| { |
| location_t loc = find_loop_location |
| (scop->scop_info->region.entry->dest->loop_father); |
| dump_printf_loc (MSG_NOTE, loc, |
| "loop nest not optimized, optimized schedule is " |
| "identical to original schedule\n"); |
| if (dump_file) |
| print_schedule_ast (dump_file, scop->original_schedule, scop); |
| isl_schedule_free (scop->transformed_schedule); |
| scop->transformed_schedule = isl_schedule_copy (scop->original_schedule); |
| return flag_graphite_identity || flag_loop_parallelize_all; |
| } |
| |
| return true; |
| } |
| |
| /* Apply graphite transformations to all the basic blocks of SCOP. */ |
| |
| bool |
| apply_poly_transforms (scop_p scop) |
| { |
| if (flag_loop_nest_optimize) |
| return optimize_isl (scop); |
| |
| if (!flag_graphite_identity && !flag_loop_parallelize_all) |
| return false; |
| |
| /* Generate code even if we did not apply any real transformation. |
| This also allows to check the performance for the identity |
| transformation: GIMPLE -> GRAPHITE -> GIMPLE. */ |
| gcc_assert (scop->original_schedule); |
| scop->transformed_schedule = isl_schedule_copy (scop->original_schedule); |
| return true; |
| } |
| |
| #endif /* HAVE_isl */ |