/* Vectorizer Copyright (C) 2003-2015 Free Software Foundation, Inc. Contributed by Dorit Naishlos 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 . */ /* Loop and basic block vectorizer. This file contains drivers for the three vectorizers: (1) loop vectorizer (inter-iteration parallelism), (2) loop-aware SLP (intra-iteration parallelism) (invoked by the loop vectorizer) (3) BB vectorizer (out-of-loops), aka SLP The rest of the vectorizer's code is organized as follows: - tree-vect-loop.c - loop specific parts such as reductions, etc. These are used by drivers (1) and (2). - tree-vect-loop-manip.c - vectorizer's loop control-flow utilities, used by drivers (1) and (2). - tree-vect-slp.c - BB vectorization specific analysis and transformation, used by drivers (2) and (3). - tree-vect-stmts.c - statements analysis and transformation (used by all). - tree-vect-data-refs.c - vectorizer specific data-refs analysis and manipulations (used by all). - tree-vect-patterns.c - vectorizable code patterns detector (used by all) Here's a poor attempt at illustrating that: tree-vectorizer.c: loop_vect() loop_aware_slp() slp_vect() | / \ / | / \ / tree-vect-loop.c tree-vect-slp.c | \ \ / / | | \ \/ / | | \ /\ / | | \ / \ / | tree-vect-stmts.c tree-vect-data-refs.c \ / tree-vect-patterns.c */ #include "config.h" #include "system.h" #include "coretypes.h" #include "dumpfile.h" #include "backend.h" #include "predict.h" #include "tree.h" #include "gimple.h" #include "hard-reg-set.h" #include "ssa.h" #include "alias.h" #include "fold-const.h" #include "stor-layout.h" #include "tree-pretty-print.h" #include "internal-fn.h" #include "gimple-iterator.h" #include "gimple-walk.h" #include "cgraph.h" #include "tree-ssa-loop-manip.h" #include "tree-cfg.h" #include "cfgloop.h" #include "tree-vectorizer.h" #include "tree-pass.h" #include "tree-ssa-propagate.h" #include "dbgcnt.h" #include "gimple-fold.h" #include "tree-scalar-evolution.h" /* Loop or bb location. */ source_location vect_location; /* Vector mapping GIMPLE stmt to stmt_vec_info. */ vec stmt_vec_info_vec; /* For mapping simduid to vectorization factor. */ struct simduid_to_vf : free_ptr_hash { unsigned int simduid; int vf; /* hash_table support. */ static inline hashval_t hash (const simduid_to_vf *); static inline int equal (const simduid_to_vf *, const simduid_to_vf *); }; inline hashval_t simduid_to_vf::hash (const simduid_to_vf *p) { return p->simduid; } inline int simduid_to_vf::equal (const simduid_to_vf *p1, const simduid_to_vf *p2) { return p1->simduid == p2->simduid; } /* This hash maps the OMP simd array to the corresponding simduid used to index into it. Like thus, _7 = GOMP_SIMD_LANE (simduid.0) ... ... D.1737[_7] = stuff; This hash maps from the OMP simd array (D.1737[]) to DECL_UID of simduid.0. */ struct simd_array_to_simduid : free_ptr_hash { tree decl; unsigned int simduid; /* hash_table support. */ static inline hashval_t hash (const simd_array_to_simduid *); static inline int equal (const simd_array_to_simduid *, const simd_array_to_simduid *); }; inline hashval_t simd_array_to_simduid::hash (const simd_array_to_simduid *p) { return DECL_UID (p->decl); } inline int simd_array_to_simduid::equal (const simd_array_to_simduid *p1, const simd_array_to_simduid *p2) { return p1->decl == p2->decl; } /* Fold IFN_GOMP_SIMD_LANE, IFN_GOMP_SIMD_VF and IFN_GOMP_SIMD_LAST_LANE into their corresponding constants. */ static void adjust_simduid_builtins (hash_table *htab) { basic_block bb; FOR_EACH_BB_FN (bb, cfun) { gimple_stmt_iterator i; for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) { unsigned int vf = 1; enum internal_fn ifn; gimple stmt = gsi_stmt (i); tree t; if (!is_gimple_call (stmt) || !gimple_call_internal_p (stmt)) continue; ifn = gimple_call_internal_fn (stmt); switch (ifn) { case IFN_GOMP_SIMD_LANE: case IFN_GOMP_SIMD_VF: case IFN_GOMP_SIMD_LAST_LANE: break; default: continue; } tree arg = gimple_call_arg (stmt, 0); gcc_assert (arg != NULL_TREE); gcc_assert (TREE_CODE (arg) == SSA_NAME); simduid_to_vf *p = NULL, data; data.simduid = DECL_UID (SSA_NAME_VAR (arg)); if (htab) { p = htab->find (&data); if (p) vf = p->vf; } switch (ifn) { case IFN_GOMP_SIMD_VF: t = build_int_cst (unsigned_type_node, vf); break; case IFN_GOMP_SIMD_LANE: t = build_int_cst (unsigned_type_node, 0); break; case IFN_GOMP_SIMD_LAST_LANE: t = gimple_call_arg (stmt, 1); break; default: gcc_unreachable (); } update_call_from_tree (&i, t); } } } /* Helper structure for note_simd_array_uses. */ struct note_simd_array_uses_struct { hash_table **htab; unsigned int simduid; }; /* Callback for note_simd_array_uses, called through walk_gimple_op. */ static tree note_simd_array_uses_cb (tree *tp, int *walk_subtrees, void *data) { struct walk_stmt_info *wi = (struct walk_stmt_info *) data; struct note_simd_array_uses_struct *ns = (struct note_simd_array_uses_struct *) wi->info; if (TYPE_P (*tp)) *walk_subtrees = 0; else if (VAR_P (*tp) && lookup_attribute ("omp simd array", DECL_ATTRIBUTES (*tp)) && DECL_CONTEXT (*tp) == current_function_decl) { simd_array_to_simduid data; if (!*ns->htab) *ns->htab = new hash_table (15); data.decl = *tp; data.simduid = ns->simduid; simd_array_to_simduid **slot = (*ns->htab)->find_slot (&data, INSERT); if (*slot == NULL) { simd_array_to_simduid *p = XNEW (simd_array_to_simduid); *p = data; *slot = p; } else if ((*slot)->simduid != ns->simduid) (*slot)->simduid = -1U; *walk_subtrees = 0; } return NULL_TREE; } /* Find "omp simd array" temporaries and map them to corresponding simduid. */ static void note_simd_array_uses (hash_table **htab) { basic_block bb; gimple_stmt_iterator gsi; struct walk_stmt_info wi; struct note_simd_array_uses_struct ns; memset (&wi, 0, sizeof (wi)); wi.info = &ns; ns.htab = htab; FOR_EACH_BB_FN (bb, cfun) for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { gimple stmt = gsi_stmt (gsi); if (!is_gimple_call (stmt) || !gimple_call_internal_p (stmt)) continue; switch (gimple_call_internal_fn (stmt)) { case IFN_GOMP_SIMD_LANE: case IFN_GOMP_SIMD_VF: case IFN_GOMP_SIMD_LAST_LANE: break; default: continue; } tree lhs = gimple_call_lhs (stmt); if (lhs == NULL_TREE) continue; imm_use_iterator use_iter; gimple use_stmt; ns.simduid = DECL_UID (SSA_NAME_VAR (gimple_call_arg (stmt, 0))); FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, lhs) if (!is_gimple_debug (use_stmt)) walk_gimple_op (use_stmt, note_simd_array_uses_cb, &wi); } } /* Shrink arrays with "omp simd array" attribute to the corresponding vectorization factor. */ static void shrink_simd_arrays (hash_table *simd_array_to_simduid_htab, hash_table *simduid_to_vf_htab) { for (hash_table::iterator iter = simd_array_to_simduid_htab->begin (); iter != simd_array_to_simduid_htab->end (); ++iter) if ((*iter)->simduid != -1U) { tree decl = (*iter)->decl; int vf = 1; if (simduid_to_vf_htab) { simduid_to_vf *p = NULL, data; data.simduid = (*iter)->simduid; p = simduid_to_vf_htab->find (&data); if (p) vf = p->vf; } tree atype = build_array_type_nelts (TREE_TYPE (TREE_TYPE (decl)), vf); TREE_TYPE (decl) = atype; relayout_decl (decl); } delete simd_array_to_simduid_htab; } /* A helper function to free data refs. */ void vect_destroy_datarefs (loop_vec_info loop_vinfo, bb_vec_info bb_vinfo) { vec datarefs; struct data_reference *dr; unsigned int i; if (loop_vinfo) datarefs = LOOP_VINFO_DATAREFS (loop_vinfo); else datarefs = BB_VINFO_DATAREFS (bb_vinfo); FOR_EACH_VEC_ELT (datarefs, i, dr) if (dr->aux) { free (dr->aux); dr->aux = NULL; } free_data_refs (datarefs); } /* If LOOP has been versioned during ifcvt, return the internal call guarding it. */ static gimple vect_loop_vectorized_call (struct loop *loop) { basic_block bb = loop_preheader_edge (loop)->src; gimple g; do { g = last_stmt (bb); if (g) break; if (!single_pred_p (bb)) break; bb = single_pred (bb); } while (1); if (g && gimple_code (g) == GIMPLE_COND) { gimple_stmt_iterator gsi = gsi_for_stmt (g); gsi_prev (&gsi); if (!gsi_end_p (gsi)) { g = gsi_stmt (gsi); if (is_gimple_call (g) && gimple_call_internal_p (g) && gimple_call_internal_fn (g) == IFN_LOOP_VECTORIZED && (tree_to_shwi (gimple_call_arg (g, 0)) == loop->num || tree_to_shwi (gimple_call_arg (g, 1)) == loop->num)) return g; } } return NULL; } /* Fold LOOP_VECTORIZED internal call G to VALUE and update any immediate uses of it's LHS. */ static void fold_loop_vectorized_call (gimple g, tree value) { tree lhs = gimple_call_lhs (g); use_operand_p use_p; imm_use_iterator iter; gimple use_stmt; gimple_stmt_iterator gsi = gsi_for_stmt (g); update_call_from_tree (&gsi, value); FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) { FOR_EACH_IMM_USE_ON_STMT (use_p, iter) SET_USE (use_p, value); update_stmt (use_stmt); } } /* Set the uids of all the statements in basic blocks inside loop represented by LOOP_VINFO. LOOP_VECTORIZED_CALL is the internal call guarding the loop which has been if converted. */ static void set_uid_loop_bbs (loop_vec_info loop_vinfo, gimple loop_vectorized_call) { tree arg = gimple_call_arg (loop_vectorized_call, 1); basic_block *bbs; unsigned int i; struct loop *scalar_loop = get_loop (cfun, tree_to_shwi (arg)); LOOP_VINFO_SCALAR_LOOP (loop_vinfo) = scalar_loop; gcc_checking_assert (vect_loop_vectorized_call (LOOP_VINFO_SCALAR_LOOP (loop_vinfo)) == loop_vectorized_call); bbs = get_loop_body (scalar_loop); for (i = 0; i < scalar_loop->num_nodes; i++) { basic_block bb = bbs[i]; gimple_stmt_iterator gsi; for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { gimple phi = gsi_stmt (gsi); gimple_set_uid (phi, 0); } for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { gimple stmt = gsi_stmt (gsi); gimple_set_uid (stmt, 0); } } free (bbs); } /* Function vectorize_loops. Entry point to loop vectorization phase. */ unsigned vectorize_loops (void) { unsigned int i; unsigned int num_vectorized_loops = 0; unsigned int vect_loops_num; struct loop *loop; hash_table *simduid_to_vf_htab = NULL; hash_table *simd_array_to_simduid_htab = NULL; bool any_ifcvt_loops = false; unsigned ret = 0; vect_loops_num = number_of_loops (cfun); /* Bail out if there are no loops. */ if (vect_loops_num <= 1) return 0; if (cfun->has_simduid_loops) note_simd_array_uses (&simd_array_to_simduid_htab); init_stmt_vec_info_vec (); /* ----------- Analyze loops. ----------- */ /* If some loop was duplicated, it gets bigger number than all previously defined loops. This fact allows us to run only over initial loops skipping newly generated ones. */ FOR_EACH_LOOP (loop, 0) if (loop->dont_vectorize) any_ifcvt_loops = true; else if ((flag_tree_loop_vectorize && optimize_loop_nest_for_speed_p (loop)) || loop->force_vectorize) { loop_vec_info loop_vinfo; vect_location = find_loop_location (loop); if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOCATION && dump_enabled_p ()) dump_printf (MSG_NOTE, "\nAnalyzing loop at %s:%d\n", LOCATION_FILE (vect_location), LOCATION_LINE (vect_location)); loop_vinfo = vect_analyze_loop (loop); loop->aux = loop_vinfo; if (!loop_vinfo || !LOOP_VINFO_VECTORIZABLE_P (loop_vinfo)) continue; if (!dbg_cnt (vect_loop)) break; gimple loop_vectorized_call = vect_loop_vectorized_call (loop); if (loop_vectorized_call) set_uid_loop_bbs (loop_vinfo, loop_vectorized_call); if (LOCATION_LOCUS (vect_location) != UNKNOWN_LOCATION && dump_enabled_p ()) dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location, "loop vectorized\n"); vect_transform_loop (loop_vinfo); num_vectorized_loops++; /* Now that the loop has been vectorized, allow it to be unrolled etc. */ loop->force_vectorize = false; if (loop->simduid) { simduid_to_vf *simduid_to_vf_data = XNEW (simduid_to_vf); if (!simduid_to_vf_htab) simduid_to_vf_htab = new hash_table (15); simduid_to_vf_data->simduid = DECL_UID (loop->simduid); simduid_to_vf_data->vf = loop_vinfo->vectorization_factor; *simduid_to_vf_htab->find_slot (simduid_to_vf_data, INSERT) = simduid_to_vf_data; } if (loop_vectorized_call) { fold_loop_vectorized_call (loop_vectorized_call, boolean_true_node); ret |= TODO_cleanup_cfg; } } vect_location = UNKNOWN_LOCATION; statistics_counter_event (cfun, "Vectorized loops", num_vectorized_loops); if (dump_enabled_p () || (num_vectorized_loops > 0 && dump_enabled_p ())) dump_printf_loc (MSG_NOTE, vect_location, "vectorized %u loops in function.\n", num_vectorized_loops); /* ----------- Finalize. ----------- */ if (any_ifcvt_loops) for (i = 1; i < vect_loops_num; i++) { loop = get_loop (cfun, i); if (loop && loop->dont_vectorize) { gimple g = vect_loop_vectorized_call (loop); if (g) { fold_loop_vectorized_call (g, boolean_false_node); ret |= TODO_cleanup_cfg; } } } for (i = 1; i < vect_loops_num; i++) { loop_vec_info loop_vinfo; loop = get_loop (cfun, i); if (!loop) continue; loop_vinfo = (loop_vec_info) loop->aux; destroy_loop_vec_info (loop_vinfo, true); loop->aux = NULL; } free_stmt_vec_info_vec (); /* Fold IFN_GOMP_SIMD_{VF,LANE,LAST_LANE} builtins. */ if (cfun->has_simduid_loops) adjust_simduid_builtins (simduid_to_vf_htab); /* Shrink any "omp array simd" temporary arrays to the actual vectorization factors. */ if (simd_array_to_simduid_htab) shrink_simd_arrays (simd_array_to_simduid_htab, simduid_to_vf_htab); delete simduid_to_vf_htab; cfun->has_simduid_loops = false; if (num_vectorized_loops > 0) { /* If we vectorized any loop only virtual SSA form needs to be updated. ??? Also while we try hard to update loop-closed SSA form we fail to properly do this in some corner-cases (see PR56286). */ rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa_only_virtuals); return TODO_cleanup_cfg; } return ret; } /* Entry point to the simduid cleanup pass. */ namespace { const pass_data pass_data_simduid_cleanup = { GIMPLE_PASS, /* type */ "simduid", /* name */ OPTGROUP_NONE, /* optinfo_flags */ TV_NONE, /* tv_id */ ( PROP_ssa | PROP_cfg ), /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0, /* todo_flags_finish */ }; class pass_simduid_cleanup : public gimple_opt_pass { public: pass_simduid_cleanup (gcc::context *ctxt) : gimple_opt_pass (pass_data_simduid_cleanup, ctxt) {} /* opt_pass methods: */ opt_pass * clone () { return new pass_simduid_cleanup (m_ctxt); } virtual bool gate (function *fun) { return fun->has_simduid_loops; } virtual unsigned int execute (function *); }; // class pass_simduid_cleanup unsigned int pass_simduid_cleanup::execute (function *fun) { hash_table *simd_array_to_simduid_htab = NULL; note_simd_array_uses (&simd_array_to_simduid_htab); /* Fold IFN_GOMP_SIMD_{VF,LANE,LAST_LANE} builtins. */ adjust_simduid_builtins (NULL); /* Shrink any "omp array simd" temporary arrays to the actual vectorization factors. */ if (simd_array_to_simduid_htab) shrink_simd_arrays (simd_array_to_simduid_htab, NULL); fun->has_simduid_loops = false; return 0; } } // anon namespace gimple_opt_pass * make_pass_simduid_cleanup (gcc::context *ctxt) { return new pass_simduid_cleanup (ctxt); } /* Entry point to basic block SLP phase. */ namespace { const pass_data pass_data_slp_vectorize = { GIMPLE_PASS, /* type */ "slp", /* name */ OPTGROUP_LOOP | OPTGROUP_VEC, /* optinfo_flags */ TV_TREE_SLP_VECTORIZATION, /* tv_id */ ( PROP_ssa | PROP_cfg ), /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ TODO_update_ssa, /* todo_flags_finish */ }; class pass_slp_vectorize : public gimple_opt_pass { public: pass_slp_vectorize (gcc::context *ctxt) : gimple_opt_pass (pass_data_slp_vectorize, ctxt) {} /* opt_pass methods: */ opt_pass * clone () { return new pass_slp_vectorize (m_ctxt); } virtual bool gate (function *) { return flag_tree_slp_vectorize != 0; } virtual unsigned int execute (function *); }; // class pass_slp_vectorize unsigned int pass_slp_vectorize::execute (function *fun) { basic_block bb; bool in_loop_pipeline = scev_initialized_p (); if (!in_loop_pipeline) { loop_optimizer_init (LOOPS_NORMAL); scev_initialize (); } init_stmt_vec_info_vec (); FOR_EACH_BB_FN (bb, fun) { vect_location = find_bb_location (bb); if (vect_slp_analyze_bb (bb)) { if (!dbg_cnt (vect_slp)) break; vect_slp_transform_bb (bb); if (dump_enabled_p ()) dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location, "basic block vectorized\n"); } } free_stmt_vec_info_vec (); if (!in_loop_pipeline) { scev_finalize (); loop_optimizer_finalize (); } return 0; } } // anon namespace gimple_opt_pass * make_pass_slp_vectorize (gcc::context *ctxt) { return new pass_slp_vectorize (ctxt); } /* Increase alignment of global arrays to improve vectorization potential. TODO: - Consider also structs that have an array field. - Use ipa analysis to prune arrays that can't be vectorized? This should involve global alignment analysis and in the future also array padding. */ static unsigned int increase_alignment (void) { varpool_node *vnode; vect_location = UNKNOWN_LOCATION; /* Increase the alignment of all global arrays for vectorization. */ FOR_EACH_DEFINED_VARIABLE (vnode) { tree vectype, decl = vnode->decl; tree t; unsigned int alignment; t = TREE_TYPE (decl); if (TREE_CODE (t) != ARRAY_TYPE) continue; vectype = get_vectype_for_scalar_type (strip_array_types (t)); if (!vectype) continue; alignment = TYPE_ALIGN (vectype); if (DECL_ALIGN (decl) >= alignment) continue; if (vect_can_force_dr_alignment_p (decl, alignment)) { vnode->increase_alignment (TYPE_ALIGN (vectype)); dump_printf (MSG_NOTE, "Increasing alignment of decl: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, decl); dump_printf (MSG_NOTE, "\n"); } } return 0; } namespace { const pass_data pass_data_ipa_increase_alignment = { SIMPLE_IPA_PASS, /* type */ "increase_alignment", /* name */ OPTGROUP_LOOP | OPTGROUP_VEC, /* optinfo_flags */ TV_IPA_OPT, /* tv_id */ 0, /* properties_required */ 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ 0, /* todo_flags_finish */ }; class pass_ipa_increase_alignment : public simple_ipa_opt_pass { public: pass_ipa_increase_alignment (gcc::context *ctxt) : simple_ipa_opt_pass (pass_data_ipa_increase_alignment, ctxt) {} /* opt_pass methods: */ virtual bool gate (function *) { return flag_section_anchors && flag_tree_loop_vectorize; } virtual unsigned int execute (function *) { return increase_alignment (); } }; // class pass_ipa_increase_alignment } // anon namespace simple_ipa_opt_pass * make_pass_ipa_increase_alignment (gcc::context *ctxt) { return new pass_ipa_increase_alignment (ctxt); }