| /* Gimple Represented as Polyhedra. |
| Copyright (C) 2006-2021 Free Software Foundation, Inc. |
| Contributed by Sebastian Pop <sebastian.pop@inria.fr>. |
| |
| 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/>. */ |
| |
| /* This pass converts GIMPLE to GRAPHITE, performs some loop |
| transformations and then converts the resulting representation back |
| to GIMPLE. |
| |
| An early description of this pass can be found in the GCC Summit'06 |
| paper "GRAPHITE: Polyhedral Analyses and Optimizations for GCC". |
| The wiki page http://gcc.gnu.org/wiki/Graphite contains pointers to |
| the related work. */ |
| |
| #define INCLUDE_ISL |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "diagnostic-core.h" |
| #include "cfgloop.h" |
| #include "tree-pass.h" |
| #include "pretty-print.h" |
| #include "cfganal.h" |
| |
| #ifdef HAVE_isl |
| #include "cfghooks.h" |
| #include "tree.h" |
| #include "gimple.h" |
| #include "ssa.h" |
| #include "fold-const.h" |
| #include "gimple-iterator.h" |
| #include "tree-cfg.h" |
| #include "tree-ssa-loop.h" |
| #include "tree-data-ref.h" |
| #include "tree-scalar-evolution.h" |
| #include "dbgcnt.h" |
| #include "tree-parloops.h" |
| #include "tree-cfgcleanup.h" |
| #include "tree-vectorizer.h" |
| #include "tree-ssa-loop-manip.h" |
| #include "tree-ssa.h" |
| #include "tree-into-ssa.h" |
| #include "graphite.h" |
| |
| /* Print global statistics to FILE. */ |
| |
| static void |
| print_global_statistics (FILE* file) |
| { |
| long n_bbs = 0; |
| long n_loops = 0; |
| long n_stmts = 0; |
| long n_conditions = 0; |
| profile_count n_p_bbs = profile_count::zero (); |
| profile_count n_p_loops = profile_count::zero (); |
| profile_count n_p_stmts = profile_count::zero (); |
| profile_count n_p_conditions = profile_count::zero (); |
| |
| basic_block bb; |
| |
| FOR_ALL_BB_FN (bb, cfun) |
| { |
| gimple_stmt_iterator psi; |
| |
| n_bbs++; |
| if (bb->count.initialized_p ()) |
| n_p_bbs += bb->count; |
| |
| /* Ignore artificial surrounding loop. */ |
| if (bb == bb->loop_father->header |
| && bb->index != 0) |
| { |
| n_loops++; |
| n_p_loops += bb->count; |
| } |
| |
| if (EDGE_COUNT (bb->succs) > 1) |
| { |
| n_conditions++; |
| if (bb->count.initialized_p ()) |
| n_p_conditions += bb->count; |
| } |
| |
| for (psi = gsi_start_bb (bb); !gsi_end_p (psi); gsi_next (&psi)) |
| { |
| n_stmts++; |
| if (bb->count.initialized_p ()) |
| n_p_stmts += bb->count; |
| } |
| } |
| |
| fprintf (file, "\nGlobal statistics ("); |
| fprintf (file, "BBS:%ld, ", n_bbs); |
| fprintf (file, "LOOPS:%ld, ", n_loops); |
| fprintf (file, "CONDITIONS:%ld, ", n_conditions); |
| fprintf (file, "STMTS:%ld)\n", n_stmts); |
| fprintf (file, "Global profiling statistics ("); |
| fprintf (file, "BBS:"); |
| n_p_bbs.dump (file); |
| fprintf (file, ", LOOPS:"); |
| n_p_loops.dump (file); |
| fprintf (file, ", CONDITIONS:"); |
| n_p_conditions.dump (file); |
| fprintf (file, ", STMTS:"); |
| n_p_stmts.dump (file); |
| fprintf (file, ")\n\n"); |
| } |
| |
| /* Print statistics for SCOP to FILE. */ |
| |
| static void |
| print_graphite_scop_statistics (FILE* file, scop_p scop) |
| { |
| long n_bbs = 0; |
| long n_loops = 0; |
| long n_stmts = 0; |
| long n_conditions = 0; |
| profile_count n_p_bbs = profile_count::zero (); |
| profile_count n_p_loops = profile_count::zero (); |
| profile_count n_p_stmts = profile_count::zero (); |
| profile_count n_p_conditions = profile_count::zero (); |
| |
| basic_block bb; |
| |
| FOR_ALL_BB_FN (bb, cfun) |
| { |
| gimple_stmt_iterator psi; |
| loop_p loop = bb->loop_father; |
| |
| if (!bb_in_sese_p (bb, scop->scop_info->region)) |
| continue; |
| |
| n_bbs++; |
| if (bb->count.initialized_p ()) |
| n_p_bbs += bb->count; |
| |
| if (EDGE_COUNT (bb->succs) > 1) |
| { |
| n_conditions++; |
| n_p_conditions += bb->count; |
| } |
| |
| for (psi = gsi_start_bb (bb); !gsi_end_p (psi); gsi_next (&psi)) |
| { |
| n_stmts++; |
| n_p_stmts += bb->count; |
| } |
| |
| if (loop->header == bb && loop_in_sese_p (loop, scop->scop_info->region)) |
| { |
| n_loops++; |
| n_p_loops += bb->count; |
| } |
| } |
| |
| fprintf (file, "\nFunction Name: %s\n", current_function_name ()); |
| |
| edge scop_begin = scop->scop_info->region.entry; |
| edge scop_end = scop->scop_info->region.exit; |
| |
| fprintf (file, "\nSCoP (entry_edge (bb_%d, bb_%d), ", |
| scop_begin->src->index, scop_begin->dest->index); |
| fprintf (file, "exit_edge (bb_%d, bb_%d))", |
| scop_end->src->index, scop_end->dest->index); |
| |
| fprintf (file, "\nSCoP statistics ("); |
| fprintf (file, "BBS:%ld, ", n_bbs); |
| fprintf (file, "LOOPS:%ld, ", n_loops); |
| fprintf (file, "CONDITIONS:%ld, ", n_conditions); |
| fprintf (file, "STMTS:%ld)\n", n_stmts); |
| fprintf (file, "SCoP profiling statistics ("); |
| fprintf (file, "BBS:"); |
| n_p_bbs.dump (file); |
| fprintf (file, ", LOOPS:"); |
| n_p_loops.dump (file); |
| fprintf (file, ", CONDITIONS:"); |
| n_p_conditions.dump (file); |
| fprintf (file, ", STMTS:"); |
| n_p_stmts.dump (file); |
| fprintf (file, ")\n\n"); |
| } |
| |
| /* Print statistics for SCOPS to FILE. */ |
| |
| static void |
| print_graphite_statistics (FILE* file, vec<scop_p> scops) |
| { |
| int i; |
| scop_p scop; |
| |
| FOR_EACH_VEC_ELT (scops, i, scop) |
| print_graphite_scop_statistics (file, scop); |
| } |
| |
| struct seir_cache_key |
| { |
| hashval_t hash; |
| int entry_dest; |
| int exit_src; |
| int loop_num; |
| tree expr; |
| }; |
| |
| struct sese_scev_hash : typed_noop_remove <seir_cache_key> |
| { |
| typedef seir_cache_key value_type; |
| typedef seir_cache_key compare_type; |
| static hashval_t hash (const seir_cache_key &key) { return key.hash; } |
| static bool |
| equal (const seir_cache_key &key1, const seir_cache_key &key2) |
| { |
| return (key1.hash == key2.hash |
| && key1.entry_dest == key2.entry_dest |
| && key1.exit_src == key2.exit_src |
| && key1.loop_num == key2.loop_num |
| && operand_equal_p (key1.expr, key2.expr, 0)); |
| } |
| static void mark_deleted (seir_cache_key &key) { key.expr = NULL_TREE; } |
| static const bool empty_zero_p = false; |
| static void mark_empty (seir_cache_key &key) { key.entry_dest = 0; } |
| static bool is_deleted (const seir_cache_key &key) { return !key.expr; } |
| static bool is_empty (const seir_cache_key &key) { return key.entry_dest == 0; } |
| }; |
| |
| static hash_map<sese_scev_hash, tree> *seir_cache; |
| |
| /* Same as scalar_evolution_in_region but caches results so we avoid |
| re-computing evolutions during transform phase. */ |
| |
| tree |
| cached_scalar_evolution_in_region (const sese_l ®ion, loop_p loop, |
| tree expr) |
| { |
| seir_cache_key key; |
| key.entry_dest = region.entry->dest->index; |
| key.exit_src = region.exit->src->index; |
| key.loop_num = loop->num; |
| key.expr = expr; |
| inchash::hash hstate (0); |
| hstate.add_int (key.entry_dest); |
| hstate.add_int (key.exit_src); |
| hstate.add_int (key.loop_num); |
| inchash::add_expr (key.expr, hstate); |
| key.hash = hstate.end (); |
| |
| bool existed; |
| tree &chrec = seir_cache->get_or_insert (key, &existed); |
| if (!existed) |
| chrec = scalar_evolution_in_region (region, loop, expr); |
| return chrec; |
| } |
| |
| /* Deletes all scops in SCOPS. */ |
| |
| static void |
| free_scops (vec<scop_p> scops) |
| { |
| int i; |
| scop_p scop; |
| |
| FOR_EACH_VEC_ELT (scops, i, scop) |
| free_scop (scop); |
| |
| scops.release (); |
| } |
| |
| /* Transforms LOOP to the canonical loop closed SSA form. */ |
| |
| static void |
| canonicalize_loop_closed_ssa (loop_p loop, edge e) |
| { |
| basic_block bb; |
| gphi_iterator psi; |
| |
| bb = e->dest; |
| |
| /* Make the loop-close PHI node BB contain only PHIs and have a |
| single predecessor. */ |
| if (single_pred_p (bb)) |
| { |
| e = split_block_after_labels (bb); |
| bb = e->src; |
| } |
| else |
| { |
| basic_block close = split_edge (e); |
| e = single_succ_edge (close); |
| for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) |
| { |
| gphi *phi = psi.phi (); |
| use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e); |
| tree arg = USE_FROM_PTR (use_p); |
| |
| /* Only add close phi nodes for SSA_NAMEs defined in LOOP. */ |
| if (TREE_CODE (arg) != SSA_NAME |
| || SSA_NAME_IS_DEFAULT_DEF (arg) |
| || ! flow_bb_inside_loop_p (loop, |
| gimple_bb (SSA_NAME_DEF_STMT (arg)))) |
| continue; |
| |
| tree res = copy_ssa_name (arg); |
| gphi *close_phi = create_phi_node (res, close); |
| add_phi_arg (close_phi, arg, gimple_phi_arg_edge (close_phi, 0), |
| UNKNOWN_LOCATION); |
| SET_USE (use_p, res); |
| } |
| bb = close; |
| } |
| |
| /* Eliminate duplicates. This relies on processing loops from |
| innermost to outer. */ |
| for (psi = gsi_start_phis (bb); !gsi_end_p (psi); gsi_next (&psi)) |
| { |
| gphi_iterator gsi = psi; |
| gphi *phi = psi.phi (); |
| |
| /* At this point, PHI should be a close phi in normal form. */ |
| gcc_assert (gimple_phi_num_args (phi) == 1); |
| |
| /* Iterate over the next phis and remove duplicates. */ |
| gsi_next (&gsi); |
| while (!gsi_end_p (gsi)) |
| if (gimple_phi_arg_def (phi, 0) == gimple_phi_arg_def (gsi.phi (), 0)) |
| { |
| replace_uses_by (gimple_phi_result (gsi.phi ()), |
| gimple_phi_result (phi)); |
| remove_phi_node (&gsi, true); |
| } |
| else |
| gsi_next (&gsi); |
| } |
| } |
| |
| /* Converts the current loop closed SSA form to a canonical form |
| expected by the Graphite code generation. |
| |
| The loop closed SSA form has the following invariant: a variable |
| defined in a loop that is used outside the loop appears only in the |
| phi nodes in the destination of the loop exit. These phi nodes are |
| called close phi nodes. |
| |
| The canonical loop closed SSA form contains the extra invariants: |
| |
| - when the loop contains only one exit, the close phi nodes contain |
| only one argument. That implies that the basic block that contains |
| the close phi nodes has only one predecessor, that is a basic block |
| in the loop. |
| |
| - the basic block containing the close phi nodes does not contain |
| other statements. |
| |
| - there exist only one phi node per definition in the loop. |
| |
| In addition to that we also make sure that loop exit edges are |
| first in the successor edge vector. This is to make RPO order |
| as computed by pre_and_rev_post_order_compute be consistent with |
| what initial schedule generation expects. |
| */ |
| |
| static void |
| canonicalize_loop_form (void) |
| { |
| loop_p loop; |
| FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
| { |
| edge e = single_exit (loop); |
| if (!e || (e->flags & (EDGE_COMPLEX|EDGE_FAKE))) |
| continue; |
| |
| canonicalize_loop_closed_ssa (loop, e); |
| |
| /* If the exit is not first in the edge vector make it so. */ |
| if (e != EDGE_SUCC (e->src, 0)) |
| { |
| unsigned ei; |
| for (ei = 0; EDGE_SUCC (e->src, ei) != e; ++ei) |
| ; |
| std::swap (EDGE_SUCC (e->src, ei), EDGE_SUCC (e->src, 0)); |
| } |
| } |
| |
| /* We can end up releasing duplicate exit PHIs and also introduce |
| additional copies so the cached information isn't correct anymore. */ |
| scev_reset (); |
| |
| checking_verify_loop_closed_ssa (true); |
| } |
| |
| isl_ctx *the_isl_ctx; |
| |
| /* Perform a set of linear transforms on the loops of the current |
| function. */ |
| |
| void |
| graphite_transform_loops (void) |
| { |
| int i; |
| scop_p scop; |
| bool changed = false; |
| vec<scop_p> scops = vNULL; |
| isl_ctx *ctx; |
| |
| /* If a function is parallel it was most probably already run through graphite |
| once. No need to run again. */ |
| if (parallelized_function_p (cfun->decl)) |
| return; |
| |
| calculate_dominance_info (CDI_DOMINATORS); |
| |
| /* We rely on post-dominators during merging of SESE regions so those |
| have to be meaningful. */ |
| connect_infinite_loops_to_exit (); |
| |
| ctx = isl_ctx_alloc (); |
| isl_options_set_on_error (ctx, ISL_ON_ERROR_ABORT); |
| the_isl_ctx = ctx; |
| |
| sort_sibling_loops (cfun); |
| canonicalize_loop_form (); |
| |
| /* Print the loop structure. */ |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| print_loops (dump_file, 2); |
| print_loops (dump_file, 3); |
| } |
| |
| seir_cache = new hash_map<sese_scev_hash, tree>; |
| |
| calculate_dominance_info (CDI_POST_DOMINATORS); |
| build_scops (&scops); |
| free_dominance_info (CDI_POST_DOMINATORS); |
| |
| /* Remove the fake exits before transform given they are not reflected |
| in loop structures we end up verifying. */ |
| remove_fake_exit_edges (); |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| print_graphite_statistics (dump_file, scops); |
| print_global_statistics (dump_file); |
| } |
| |
| FOR_EACH_VEC_ELT (scops, i, scop) |
| if (dbg_cnt (graphite_scop)) |
| { |
| scop->isl_context = ctx; |
| if (!build_poly_scop (scop)) |
| continue; |
| |
| if (!apply_poly_transforms (scop)) |
| continue; |
| |
| changed = true; |
| if (graphite_regenerate_ast_isl (scop) |
| && dump_enabled_p ()) |
| { |
| dump_user_location_t loc = find_loop_location |
| (scops[i]->scop_info->region.entry->dest->loop_father); |
| dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, loc, |
| "loop nest optimized\n"); |
| } |
| } |
| |
| delete seir_cache; |
| seir_cache = NULL; |
| |
| if (changed) |
| { |
| mark_virtual_operands_for_renaming (cfun); |
| update_ssa (TODO_update_ssa); |
| checking_verify_ssa (true, true); |
| rewrite_into_loop_closed_ssa (NULL, 0); |
| scev_reset (); |
| checking_verify_loop_structure (); |
| } |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| loop_p loop; |
| int num_no_dependency = 0; |
| |
| FOR_EACH_LOOP (loop, 0) |
| if (loop->can_be_parallel) |
| num_no_dependency++; |
| |
| fprintf (dump_file, "%d loops carried no dependency.\n", |
| num_no_dependency); |
| } |
| |
| free_scops (scops); |
| the_isl_ctx = NULL; |
| isl_ctx_free (ctx); |
| |
| if (changed) |
| { |
| cleanup_tree_cfg (); |
| profile_status_for_fn (cfun) = PROFILE_ABSENT; |
| release_recorded_exits (cfun); |
| tree_estimate_probability (false); |
| } |
| } |
| |
| #else /* If isl is not available: #ifndef HAVE_isl. */ |
| |
| static void |
| graphite_transform_loops (void) |
| { |
| sorry ("Graphite loop optimizations cannot be used (isl is not available)."); |
| } |
| |
| #endif |
| |
| |
| static unsigned int |
| graphite_transforms (struct function *fun) |
| { |
| if (number_of_loops (fun) <= 1) |
| return 0; |
| |
| graphite_transform_loops (); |
| |
| return 0; |
| } |
| |
| static bool |
| gate_graphite_transforms (void) |
| { |
| /* Enable -fgraphite pass if any one of the graphite optimization flags |
| is turned on. */ |
| if (flag_graphite_identity |
| || flag_loop_parallelize_all |
| || flag_loop_nest_optimize) |
| flag_graphite = 1; |
| |
| return flag_graphite != 0; |
| } |
| |
| namespace { |
| |
| const pass_data pass_data_graphite = |
| { |
| GIMPLE_PASS, /* type */ |
| "graphite0", /* name */ |
| OPTGROUP_LOOP, /* optinfo_flags */ |
| TV_GRAPHITE, /* tv_id */ |
| ( PROP_cfg | PROP_ssa ), /* properties_required */ |
| 0, /* properties_provided */ |
| 0, /* properties_destroyed */ |
| 0, /* todo_flags_start */ |
| 0, /* todo_flags_finish */ |
| }; |
| |
| class pass_graphite : public gimple_opt_pass |
| { |
| public: |
| pass_graphite (gcc::context *ctxt) |
| : gimple_opt_pass (pass_data_graphite, ctxt) |
| {} |
| |
| /* opt_pass methods: */ |
| virtual bool gate (function *) { return gate_graphite_transforms (); } |
| |
| }; // class pass_graphite |
| |
| } // anon namespace |
| |
| gimple_opt_pass * |
| make_pass_graphite (gcc::context *ctxt) |
| { |
| return new pass_graphite (ctxt); |
| } |
| |
| namespace { |
| |
| const pass_data pass_data_graphite_transforms = |
| { |
| GIMPLE_PASS, /* type */ |
| "graphite", /* name */ |
| OPTGROUP_LOOP, /* optinfo_flags */ |
| TV_GRAPHITE_TRANSFORMS, /* tv_id */ |
| ( PROP_cfg | PROP_ssa ), /* properties_required */ |
| 0, /* properties_provided */ |
| 0, /* properties_destroyed */ |
| 0, /* todo_flags_start */ |
| 0, /* todo_flags_finish */ |
| }; |
| |
| class pass_graphite_transforms : public gimple_opt_pass |
| { |
| public: |
| pass_graphite_transforms (gcc::context *ctxt) |
| : gimple_opt_pass (pass_data_graphite_transforms, ctxt) |
| {} |
| |
| /* opt_pass methods: */ |
| virtual bool gate (function *) { return gate_graphite_transforms (); } |
| virtual unsigned int execute (function *fun) { return graphite_transforms (fun); } |
| |
| }; // class pass_graphite_transforms |
| |
| } // anon namespace |
| |
| gimple_opt_pass * |
| make_pass_graphite_transforms (gcc::context *ctxt) |
| { |
| return new pass_graphite_transforms (ctxt); |
| } |
| |
| |