/* Loop Vectorization Copyright (C) 2003-2015 Free Software Foundation, Inc. Contributed by Dorit Naishlos and Ira Rosen 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 . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "dumpfile.h" #include "backend.h" #include "cfghooks.h" #include "tree.h" #include "gimple.h" #include "rtl.h" #include "ssa.h" #include "alias.h" #include "fold-const.h" #include "stor-layout.h" #include "cfganal.h" #include "gimple-pretty-print.h" #include "internal-fn.h" #include "gimplify.h" #include "gimple-iterator.h" #include "gimplify-me.h" #include "tree-ssa-loop-ivopts.h" #include "tree-ssa-loop-manip.h" #include "tree-ssa-loop-niter.h" #include "tree-pass.h" #include "cfgloop.h" #include "flags.h" #include "insn-codes.h" #include "optabs-tree.h" #include "params.h" #include "diagnostic-core.h" #include "tree-chrec.h" #include "tree-scalar-evolution.h" #include "tree-vectorizer.h" #include "target.h" #include "gimple-fold.h" /* Loop Vectorization Pass. This pass tries to vectorize loops. For example, the vectorizer transforms the following simple loop: short a[N]; short b[N]; short c[N]; int i; for (i=0; inum_nodes; unsigned int vectorization_factor = 0; tree scalar_type; gphi *phi; tree vectype; unsigned int nunits; stmt_vec_info stmt_info; int i; HOST_WIDE_INT dummy; gimple *stmt, *pattern_stmt = NULL; gimple_seq pattern_def_seq = NULL; gimple_stmt_iterator pattern_def_si = gsi_none (); bool analyze_pattern_stmt = false; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== vect_determine_vectorization_factor ===\n"); for (i = 0; i < nbbs; i++) { basic_block bb = bbs[i]; for (gphi_iterator si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) { phi = si.phi (); stmt_info = vinfo_for_stmt (phi); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "==> examining phi: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, phi, 0); dump_printf (MSG_NOTE, "\n"); } gcc_assert (stmt_info); if (STMT_VINFO_RELEVANT_P (stmt_info)) { gcc_assert (!STMT_VINFO_VECTYPE (stmt_info)); scalar_type = TREE_TYPE (PHI_RESULT (phi)); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "get vectype for scalar type: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, scalar_type); dump_printf (MSG_NOTE, "\n"); } vectype = get_vectype_for_scalar_type (scalar_type); if (!vectype) { if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: unsupported " "data-type "); dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, scalar_type); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return false; } STMT_VINFO_VECTYPE (stmt_info) = vectype; if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "vectype: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, vectype); dump_printf (MSG_NOTE, "\n"); } nunits = TYPE_VECTOR_SUBPARTS (vectype); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "nunits = %d\n", nunits); if (!vectorization_factor || (nunits > vectorization_factor)) vectorization_factor = nunits; } } for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si) || analyze_pattern_stmt;) { tree vf_vectype; if (analyze_pattern_stmt) stmt = pattern_stmt; else stmt = gsi_stmt (si); stmt_info = vinfo_for_stmt (stmt); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "==> examining statement: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, stmt, 0); dump_printf (MSG_NOTE, "\n"); } gcc_assert (stmt_info); /* Skip stmts which do not need to be vectorized. */ if ((!STMT_VINFO_RELEVANT_P (stmt_info) && !STMT_VINFO_LIVE_P (stmt_info)) || gimple_clobber_p (stmt)) { if (STMT_VINFO_IN_PATTERN_P (stmt_info) && (pattern_stmt = STMT_VINFO_RELATED_STMT (stmt_info)) && (STMT_VINFO_RELEVANT_P (vinfo_for_stmt (pattern_stmt)) || STMT_VINFO_LIVE_P (vinfo_for_stmt (pattern_stmt)))) { stmt = pattern_stmt; stmt_info = vinfo_for_stmt (pattern_stmt); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "==> examining pattern statement: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, stmt, 0); dump_printf (MSG_NOTE, "\n"); } } else { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "skip.\n"); gsi_next (&si); continue; } } else if (STMT_VINFO_IN_PATTERN_P (stmt_info) && (pattern_stmt = STMT_VINFO_RELATED_STMT (stmt_info)) && (STMT_VINFO_RELEVANT_P (vinfo_for_stmt (pattern_stmt)) || STMT_VINFO_LIVE_P (vinfo_for_stmt (pattern_stmt)))) analyze_pattern_stmt = true; /* If a pattern statement has def stmts, analyze them too. */ if (is_pattern_stmt_p (stmt_info)) { if (pattern_def_seq == NULL) { pattern_def_seq = STMT_VINFO_PATTERN_DEF_SEQ (stmt_info); pattern_def_si = gsi_start (pattern_def_seq); } else if (!gsi_end_p (pattern_def_si)) gsi_next (&pattern_def_si); if (pattern_def_seq != NULL) { gimple *pattern_def_stmt = NULL; stmt_vec_info pattern_def_stmt_info = NULL; while (!gsi_end_p (pattern_def_si)) { pattern_def_stmt = gsi_stmt (pattern_def_si); pattern_def_stmt_info = vinfo_for_stmt (pattern_def_stmt); if (STMT_VINFO_RELEVANT_P (pattern_def_stmt_info) || STMT_VINFO_LIVE_P (pattern_def_stmt_info)) break; gsi_next (&pattern_def_si); } if (!gsi_end_p (pattern_def_si)) { if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "==> examining pattern def stmt: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, pattern_def_stmt, 0); dump_printf (MSG_NOTE, "\n"); } stmt = pattern_def_stmt; stmt_info = pattern_def_stmt_info; } else { pattern_def_si = gsi_none (); analyze_pattern_stmt = false; } } else analyze_pattern_stmt = false; } if (gimple_get_lhs (stmt) == NULL_TREE /* MASK_STORE has no lhs, but is ok. */ && (!is_gimple_call (stmt) || !gimple_call_internal_p (stmt) || gimple_call_internal_fn (stmt) != IFN_MASK_STORE)) { if (is_gimple_call (stmt)) { /* Ignore calls with no lhs. These must be calls to #pragma omp simd functions, and what vectorization factor it really needs can't be determined until vectorizable_simd_clone_call. */ if (!analyze_pattern_stmt && gsi_end_p (pattern_def_si)) { pattern_def_seq = NULL; gsi_next (&si); } continue; } if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: irregular stmt."); dump_gimple_stmt (MSG_MISSED_OPTIMIZATION, TDF_SLIM, stmt, 0); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return false; } if (VECTOR_MODE_P (TYPE_MODE (gimple_expr_type (stmt)))) { if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: vector stmt in loop:"); dump_gimple_stmt (MSG_MISSED_OPTIMIZATION, TDF_SLIM, stmt, 0); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return false; } if (STMT_VINFO_VECTYPE (stmt_info)) { /* The only case when a vectype had been already set is for stmts that contain a dataref, or for "pattern-stmts" (stmts generated by the vectorizer to represent/replace a certain idiom). */ gcc_assert (STMT_VINFO_DATA_REF (stmt_info) || is_pattern_stmt_p (stmt_info) || !gsi_end_p (pattern_def_si)); vectype = STMT_VINFO_VECTYPE (stmt_info); } else { gcc_assert (!STMT_VINFO_DATA_REF (stmt_info)); if (is_gimple_call (stmt) && gimple_call_internal_p (stmt) && gimple_call_internal_fn (stmt) == IFN_MASK_STORE) scalar_type = TREE_TYPE (gimple_call_arg (stmt, 3)); else scalar_type = TREE_TYPE (gimple_get_lhs (stmt)); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "get vectype for scalar type: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, scalar_type); dump_printf (MSG_NOTE, "\n"); } vectype = get_vectype_for_scalar_type (scalar_type); if (!vectype) { if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: unsupported " "data-type "); dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, scalar_type); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return false; } STMT_VINFO_VECTYPE (stmt_info) = vectype; if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "vectype: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, vectype); dump_printf (MSG_NOTE, "\n"); } } /* The vectorization factor is according to the smallest scalar type (or the largest vector size, but we only support one vector size per loop). */ scalar_type = vect_get_smallest_scalar_type (stmt, &dummy, &dummy); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "get vectype for scalar type: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, scalar_type); dump_printf (MSG_NOTE, "\n"); } vf_vectype = get_vectype_for_scalar_type (scalar_type); if (!vf_vectype) { if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: unsupported data-type "); dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, scalar_type); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return false; } if ((GET_MODE_SIZE (TYPE_MODE (vectype)) != GET_MODE_SIZE (TYPE_MODE (vf_vectype)))) { if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: different sized vector " "types in statement, "); dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, vectype); dump_printf (MSG_MISSED_OPTIMIZATION, " and "); dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, vf_vectype); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return false; } if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "vectype: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, vf_vectype); dump_printf (MSG_NOTE, "\n"); } nunits = TYPE_VECTOR_SUBPARTS (vf_vectype); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "nunits = %d\n", nunits); if (!vectorization_factor || (nunits > vectorization_factor)) vectorization_factor = nunits; if (!analyze_pattern_stmt && gsi_end_p (pattern_def_si)) { pattern_def_seq = NULL; gsi_next (&si); } } } /* TODO: Analyze cost. Decide if worth while to vectorize. */ if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "vectorization factor = %d\n", vectorization_factor); if (vectorization_factor <= 1) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: unsupported data-type\n"); return false; } LOOP_VINFO_VECT_FACTOR (loop_vinfo) = vectorization_factor; return true; } /* Function vect_is_simple_iv_evolution. FORNOW: A simple evolution of an induction variables in the loop is considered a polynomial evolution. */ static bool vect_is_simple_iv_evolution (unsigned loop_nb, tree access_fn, tree * init, tree * step) { tree init_expr; tree step_expr; tree evolution_part = evolution_part_in_loop_num (access_fn, loop_nb); basic_block bb; /* When there is no evolution in this loop, the evolution function is not "simple". */ if (evolution_part == NULL_TREE) return false; /* When the evolution is a polynomial of degree >= 2 the evolution function is not "simple". */ if (tree_is_chrec (evolution_part)) return false; step_expr = evolution_part; init_expr = unshare_expr (initial_condition_in_loop_num (access_fn, loop_nb)); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "step: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, step_expr); dump_printf (MSG_NOTE, ", init: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, init_expr); dump_printf (MSG_NOTE, "\n"); } *init = init_expr; *step = step_expr; if (TREE_CODE (step_expr) != INTEGER_CST && (TREE_CODE (step_expr) != SSA_NAME || ((bb = gimple_bb (SSA_NAME_DEF_STMT (step_expr))) && flow_bb_inside_loop_p (get_loop (cfun, loop_nb), bb)) || (!INTEGRAL_TYPE_P (TREE_TYPE (step_expr)) && (!SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr)) || !flag_associative_math))) && (TREE_CODE (step_expr) != REAL_CST || !flag_associative_math)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "step unknown.\n"); return false; } return true; } /* Function vect_analyze_scalar_cycles_1. Examine the cross iteration def-use cycles of scalar variables in LOOP. LOOP_VINFO represents the loop that is now being considered for vectorization (can be LOOP, or an outer-loop enclosing LOOP). */ static void vect_analyze_scalar_cycles_1 (loop_vec_info loop_vinfo, struct loop *loop) { basic_block bb = loop->header; tree init, step; auto_vec worklist; gphi_iterator gsi; bool double_reduc; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== vect_analyze_scalar_cycles ===\n"); /* First - identify all inductions. Reduction detection assumes that all the inductions have been identified, therefore, this order must not be changed. */ for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { gphi *phi = gsi.phi (); tree access_fn = NULL; tree def = PHI_RESULT (phi); stmt_vec_info stmt_vinfo = vinfo_for_stmt (phi); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "Analyze phi: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, phi, 0); dump_printf (MSG_NOTE, "\n"); } /* Skip virtual phi's. The data dependences that are associated with virtual defs/uses (i.e., memory accesses) are analyzed elsewhere. */ if (virtual_operand_p (def)) continue; STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_unknown_def_type; /* Analyze the evolution function. */ access_fn = analyze_scalar_evolution (loop, def); if (access_fn) { STRIP_NOPS (access_fn); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "Access function of PHI: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, access_fn); dump_printf (MSG_NOTE, "\n"); } STMT_VINFO_LOOP_PHI_EVOLUTION_PART (stmt_vinfo) = evolution_part_in_loop_num (access_fn, loop->num); } if (!access_fn || !vect_is_simple_iv_evolution (loop->num, access_fn, &init, &step) || (LOOP_VINFO_LOOP (loop_vinfo) != loop && TREE_CODE (step) != INTEGER_CST)) { worklist.safe_push (phi); continue; } gcc_assert (STMT_VINFO_LOOP_PHI_EVOLUTION_PART (stmt_vinfo) != NULL_TREE); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Detected induction.\n"); STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_induction_def; } /* Second - identify all reductions and nested cycles. */ while (worklist.length () > 0) { gimple *phi = worklist.pop (); tree def = PHI_RESULT (phi); stmt_vec_info stmt_vinfo = vinfo_for_stmt (phi); gimple *reduc_stmt; bool nested_cycle; if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "Analyze phi: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, phi, 0); dump_printf (MSG_NOTE, "\n"); } gcc_assert (!virtual_operand_p (def) && STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_unknown_def_type); nested_cycle = (loop != LOOP_VINFO_LOOP (loop_vinfo)); reduc_stmt = vect_force_simple_reduction (loop_vinfo, phi, !nested_cycle, &double_reduc, false); if (reduc_stmt) { if (double_reduc) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Detected double reduction.\n"); STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_double_reduction_def; STMT_VINFO_DEF_TYPE (vinfo_for_stmt (reduc_stmt)) = vect_double_reduction_def; } else { if (nested_cycle) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Detected vectorizable nested cycle.\n"); STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_nested_cycle; STMT_VINFO_DEF_TYPE (vinfo_for_stmt (reduc_stmt)) = vect_nested_cycle; } else { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Detected reduction.\n"); STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_reduction_def; STMT_VINFO_DEF_TYPE (vinfo_for_stmt (reduc_stmt)) = vect_reduction_def; /* Store the reduction cycles for possible vectorization in loop-aware SLP. */ LOOP_VINFO_REDUCTIONS (loop_vinfo).safe_push (reduc_stmt); } } } else if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "Unknown def-use cycle pattern.\n"); } } /* Function vect_analyze_scalar_cycles. Examine the cross iteration def-use cycles of scalar variables, by analyzing the loop-header PHIs of scalar variables. Classify each cycle as one of the following: invariant, induction, reduction, unknown. We do that for the loop represented by LOOP_VINFO, and also to its inner-loop, if exists. Examples for scalar cycles: Example1: reduction: loop1: for (i=0; iinner) vect_analyze_scalar_cycles_1 (loop_vinfo, loop->inner); } /* Transfer group and reduction information from STMT to its pattern stmt. */ static void vect_fixup_reduc_chain (gimple *stmt) { gimple *firstp = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (stmt)); gimple *stmtp; gcc_assert (!GROUP_FIRST_ELEMENT (vinfo_for_stmt (firstp)) && GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt))); GROUP_SIZE (vinfo_for_stmt (firstp)) = GROUP_SIZE (vinfo_for_stmt (stmt)); do { stmtp = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (stmt)); GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmtp)) = firstp; stmt = GROUP_NEXT_ELEMENT (vinfo_for_stmt (stmt)); if (stmt) GROUP_NEXT_ELEMENT (vinfo_for_stmt (stmtp)) = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (stmt)); } while (stmt); STMT_VINFO_DEF_TYPE (vinfo_for_stmt (stmtp)) = vect_reduction_def; } /* Fixup scalar cycles that now have their stmts detected as patterns. */ static void vect_fixup_scalar_cycles_with_patterns (loop_vec_info loop_vinfo) { gimple *first; unsigned i; FOR_EACH_VEC_ELT (LOOP_VINFO_REDUCTION_CHAINS (loop_vinfo), i, first) if (STMT_VINFO_IN_PATTERN_P (vinfo_for_stmt (first))) { vect_fixup_reduc_chain (first); LOOP_VINFO_REDUCTION_CHAINS (loop_vinfo)[i] = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (first)); } } /* Function vect_get_loop_niters. Determine how many iterations the loop is executed and place it in NUMBER_OF_ITERATIONS. Place the number of latch iterations in NUMBER_OF_ITERATIONSM1. Return the loop exit condition. */ static gcond * vect_get_loop_niters (struct loop *loop, tree *number_of_iterations, tree *number_of_iterationsm1) { tree niters; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== get_loop_niters ===\n"); niters = number_of_latch_executions (loop); *number_of_iterationsm1 = niters; /* We want the number of loop header executions which is the number of latch executions plus one. ??? For UINT_MAX latch executions this number overflows to zero for loops like do { n++; } while (n != 0); */ if (niters && !chrec_contains_undetermined (niters)) niters = fold_build2 (PLUS_EXPR, TREE_TYPE (niters), unshare_expr (niters), build_int_cst (TREE_TYPE (niters), 1)); *number_of_iterations = niters; return get_loop_exit_condition (loop); } /* Function bb_in_loop_p Used as predicate for dfs order traversal of the loop bbs. */ static bool bb_in_loop_p (const_basic_block bb, const void *data) { const struct loop *const loop = (const struct loop *)data; if (flow_bb_inside_loop_p (loop, bb)) return true; return false; } /* Function new_loop_vec_info. Create and initialize a new loop_vec_info struct for LOOP, as well as stmt_vec_info structs for all the stmts in LOOP. */ static loop_vec_info new_loop_vec_info (struct loop *loop) { loop_vec_info res; basic_block *bbs; gimple_stmt_iterator si; unsigned int i, nbbs; res = (loop_vec_info) xcalloc (1, sizeof (struct _loop_vec_info)); res->kind = vec_info::loop; LOOP_VINFO_LOOP (res) = loop; bbs = get_loop_body (loop); /* Create/Update stmt_info for all stmts in the loop. */ for (i = 0; i < loop->num_nodes; i++) { basic_block bb = bbs[i]; for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) { gimple *phi = gsi_stmt (si); gimple_set_uid (phi, 0); set_vinfo_for_stmt (phi, new_stmt_vec_info (phi, res)); } for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) { gimple *stmt = gsi_stmt (si); gimple_set_uid (stmt, 0); set_vinfo_for_stmt (stmt, new_stmt_vec_info (stmt, res)); } } /* CHECKME: We want to visit all BBs before their successors (except for latch blocks, for which this assertion wouldn't hold). In the simple case of the loop forms we allow, a dfs order of the BBs would the same as reversed postorder traversal, so we are safe. */ free (bbs); bbs = XCNEWVEC (basic_block, loop->num_nodes); nbbs = dfs_enumerate_from (loop->header, 0, bb_in_loop_p, bbs, loop->num_nodes, loop); gcc_assert (nbbs == loop->num_nodes); LOOP_VINFO_BBS (res) = bbs; LOOP_VINFO_NITERSM1 (res) = NULL; LOOP_VINFO_NITERS (res) = NULL; LOOP_VINFO_NITERS_UNCHANGED (res) = NULL; LOOP_VINFO_COST_MODEL_THRESHOLD (res) = 0; LOOP_VINFO_VECTORIZABLE_P (res) = 0; LOOP_VINFO_PEELING_FOR_ALIGNMENT (res) = 0; LOOP_VINFO_VECT_FACTOR (res) = 0; LOOP_VINFO_LOOP_NEST (res) = vNULL; LOOP_VINFO_DATAREFS (res) = vNULL; LOOP_VINFO_DDRS (res) = vNULL; LOOP_VINFO_UNALIGNED_DR (res) = NULL; LOOP_VINFO_MAY_MISALIGN_STMTS (res) = vNULL; LOOP_VINFO_MAY_ALIAS_DDRS (res) = vNULL; LOOP_VINFO_GROUPED_STORES (res) = vNULL; LOOP_VINFO_REDUCTIONS (res) = vNULL; LOOP_VINFO_REDUCTION_CHAINS (res) = vNULL; LOOP_VINFO_SLP_INSTANCES (res) = vNULL; LOOP_VINFO_SLP_UNROLLING_FACTOR (res) = 1; LOOP_VINFO_TARGET_COST_DATA (res) = init_cost (loop); LOOP_VINFO_PEELING_FOR_GAPS (res) = false; LOOP_VINFO_PEELING_FOR_NITER (res) = false; LOOP_VINFO_OPERANDS_SWAPPED (res) = false; return res; } /* Function destroy_loop_vec_info. Free LOOP_VINFO struct, as well as all the stmt_vec_info structs of all the stmts in the loop. */ void destroy_loop_vec_info (loop_vec_info loop_vinfo, bool clean_stmts) { struct loop *loop; basic_block *bbs; int nbbs; gimple_stmt_iterator si; int j; vec slp_instances; slp_instance instance; bool swapped; if (!loop_vinfo) return; loop = LOOP_VINFO_LOOP (loop_vinfo); bbs = LOOP_VINFO_BBS (loop_vinfo); nbbs = clean_stmts ? loop->num_nodes : 0; swapped = LOOP_VINFO_OPERANDS_SWAPPED (loop_vinfo); for (j = 0; j < nbbs; j++) { basic_block bb = bbs[j]; for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) free_stmt_vec_info (gsi_stmt (si)); for (si = gsi_start_bb (bb); !gsi_end_p (si); ) { gimple *stmt = gsi_stmt (si); /* We may have broken canonical form by moving a constant into RHS1 of a commutative op. Fix such occurrences. */ if (swapped && is_gimple_assign (stmt)) { enum tree_code code = gimple_assign_rhs_code (stmt); if ((code == PLUS_EXPR || code == POINTER_PLUS_EXPR || code == MULT_EXPR) && CONSTANT_CLASS_P (gimple_assign_rhs1 (stmt))) swap_ssa_operands (stmt, gimple_assign_rhs1_ptr (stmt), gimple_assign_rhs2_ptr (stmt)); } /* Free stmt_vec_info. */ free_stmt_vec_info (stmt); gsi_next (&si); } } free (LOOP_VINFO_BBS (loop_vinfo)); vect_destroy_datarefs (loop_vinfo); free_dependence_relations (LOOP_VINFO_DDRS (loop_vinfo)); LOOP_VINFO_LOOP_NEST (loop_vinfo).release (); LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo).release (); LOOP_VINFO_MAY_ALIAS_DDRS (loop_vinfo).release (); slp_instances = LOOP_VINFO_SLP_INSTANCES (loop_vinfo); FOR_EACH_VEC_ELT (slp_instances, j, instance) vect_free_slp_instance (instance); LOOP_VINFO_SLP_INSTANCES (loop_vinfo).release (); LOOP_VINFO_GROUPED_STORES (loop_vinfo).release (); LOOP_VINFO_REDUCTIONS (loop_vinfo).release (); LOOP_VINFO_REDUCTION_CHAINS (loop_vinfo).release (); destroy_cost_data (LOOP_VINFO_TARGET_COST_DATA (loop_vinfo)); loop_vinfo->scalar_cost_vec.release (); free (loop_vinfo); loop->aux = NULL; } /* Calculate the cost of one scalar iteration of the loop. */ static void vect_compute_single_scalar_iteration_cost (loop_vec_info loop_vinfo) { struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); int nbbs = loop->num_nodes, factor, scalar_single_iter_cost = 0; int innerloop_iters, i; /* Count statements in scalar loop. Using this as scalar cost for a single iteration for now. TODO: Add outer loop support. TODO: Consider assigning different costs to different scalar statements. */ /* FORNOW. */ innerloop_iters = 1; if (loop->inner) innerloop_iters = 50; /* FIXME */ for (i = 0; i < nbbs; i++) { gimple_stmt_iterator si; basic_block bb = bbs[i]; if (bb->loop_father == loop->inner) factor = innerloop_iters; else factor = 1; for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) { gimple *stmt = gsi_stmt (si); stmt_vec_info stmt_info = vinfo_for_stmt (stmt); if (!is_gimple_assign (stmt) && !is_gimple_call (stmt)) continue; /* Skip stmts that are not vectorized inside the loop. */ if (stmt_info && !STMT_VINFO_RELEVANT_P (stmt_info) && (!STMT_VINFO_LIVE_P (stmt_info) || !VECTORIZABLE_CYCLE_DEF (STMT_VINFO_DEF_TYPE (stmt_info))) && !STMT_VINFO_IN_PATTERN_P (stmt_info)) continue; vect_cost_for_stmt kind; if (STMT_VINFO_DATA_REF (vinfo_for_stmt (stmt))) { if (DR_IS_READ (STMT_VINFO_DATA_REF (vinfo_for_stmt (stmt)))) kind = scalar_load; else kind = scalar_store; } else kind = scalar_stmt; scalar_single_iter_cost += record_stmt_cost (&LOOP_VINFO_SCALAR_ITERATION_COST (loop_vinfo), factor, kind, NULL, 0, vect_prologue); } } LOOP_VINFO_SINGLE_SCALAR_ITERATION_COST (loop_vinfo) = scalar_single_iter_cost; } /* Function vect_analyze_loop_form_1. Verify that certain CFG restrictions hold, including: - the loop has a pre-header - the loop has a single entry and exit - the loop exit condition is simple enough, and the number of iterations can be analyzed (a countable loop). */ bool vect_analyze_loop_form_1 (struct loop *loop, gcond **loop_cond, tree *number_of_iterationsm1, tree *number_of_iterations, gcond **inner_loop_cond) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== vect_analyze_loop_form ===\n"); /* Different restrictions apply when we are considering an inner-most loop, vs. an outer (nested) loop. (FORNOW. May want to relax some of these restrictions in the future). */ if (!loop->inner) { /* Inner-most loop. We currently require that the number of BBs is exactly 2 (the header and latch). Vectorizable inner-most loops look like this: (pre-header) | header <--------+ | | | | +--> latch --+ | (exit-bb) */ if (loop->num_nodes != 2) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: control flow in loop.\n"); return false; } if (empty_block_p (loop->header)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: empty loop.\n"); return false; } } else { struct loop *innerloop = loop->inner; edge entryedge; /* Nested loop. We currently require that the loop is doubly-nested, contains a single inner loop, and the number of BBs is exactly 5. Vectorizable outer-loops look like this: (pre-header) | header <---+ | | inner-loop | | | tail ------+ | (exit-bb) The inner-loop has the properties expected of inner-most loops as described above. */ if ((loop->inner)->inner || (loop->inner)->next) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: multiple nested loops.\n"); return false; } if (loop->num_nodes != 5) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: control flow in loop.\n"); return false; } entryedge = loop_preheader_edge (innerloop); if (entryedge->src != loop->header || !single_exit (innerloop) || single_exit (innerloop)->dest != EDGE_PRED (loop->latch, 0)->src) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: unsupported outerloop form.\n"); return false; } /* Analyze the inner-loop. */ tree inner_niterm1, inner_niter; if (! vect_analyze_loop_form_1 (loop->inner, inner_loop_cond, &inner_niterm1, &inner_niter, NULL)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: Bad inner loop.\n"); return false; } if (!expr_invariant_in_loop_p (loop, inner_niter)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: inner-loop count not" " invariant.\n"); return false; } if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Considering outer-loop vectorization.\n"); } if (!single_exit (loop) || EDGE_COUNT (loop->header->preds) != 2) { if (dump_enabled_p ()) { if (!single_exit (loop)) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: multiple exits.\n"); else if (EDGE_COUNT (loop->header->preds) != 2) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: too many incoming edges.\n"); } return false; } /* We assume that the loop exit condition is at the end of the loop. i.e, that the loop is represented as a do-while (with a proper if-guard before the loop if needed), where the loop header contains all the executable statements, and the latch is empty. */ if (!empty_block_p (loop->latch) || !gimple_seq_empty_p (phi_nodes (loop->latch))) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: latch block not empty.\n"); return false; } /* Make sure there exists a single-predecessor exit bb: */ if (!single_pred_p (single_exit (loop)->dest)) { edge e = single_exit (loop); if (!(e->flags & EDGE_ABNORMAL)) { split_loop_exit_edge (e); if (dump_enabled_p ()) dump_printf (MSG_NOTE, "split exit edge.\n"); } else { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: abnormal loop exit edge.\n"); return false; } } *loop_cond = vect_get_loop_niters (loop, number_of_iterations, number_of_iterationsm1); if (!*loop_cond) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: complicated exit condition.\n"); return false; } if (!*number_of_iterations || chrec_contains_undetermined (*number_of_iterations)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: number of iterations cannot be " "computed.\n"); return false; } if (integer_zerop (*number_of_iterations)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: number of iterations = 0.\n"); return false; } return true; } /* Analyze LOOP form and return a loop_vec_info if it is of suitable form. */ loop_vec_info vect_analyze_loop_form (struct loop *loop) { tree number_of_iterations, number_of_iterationsm1; gcond *loop_cond, *inner_loop_cond = NULL; if (! vect_analyze_loop_form_1 (loop, &loop_cond, &number_of_iterationsm1, &number_of_iterations, &inner_loop_cond)) return NULL; loop_vec_info loop_vinfo = new_loop_vec_info (loop); LOOP_VINFO_NITERSM1 (loop_vinfo) = number_of_iterationsm1; LOOP_VINFO_NITERS (loop_vinfo) = number_of_iterations; LOOP_VINFO_NITERS_UNCHANGED (loop_vinfo) = number_of_iterations; if (!LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)) { if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "Symbolic number of iterations is "); dump_generic_expr (MSG_NOTE, TDF_DETAILS, number_of_iterations); dump_printf (MSG_NOTE, "\n"); } } STMT_VINFO_TYPE (vinfo_for_stmt (loop_cond)) = loop_exit_ctrl_vec_info_type; if (inner_loop_cond) STMT_VINFO_TYPE (vinfo_for_stmt (inner_loop_cond)) = loop_exit_ctrl_vec_info_type; gcc_assert (!loop->aux); loop->aux = loop_vinfo; return loop_vinfo; } /* Scan the loop stmts and dependent on whether there are any (non-)SLP statements update the vectorization factor. */ static void vect_update_vf_for_slp (loop_vec_info loop_vinfo) { struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); int nbbs = loop->num_nodes; unsigned int vectorization_factor; int i; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== vect_update_vf_for_slp ===\n"); vectorization_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo); gcc_assert (vectorization_factor != 0); /* If all the stmts in the loop can be SLPed, we perform only SLP, and vectorization factor of the loop is the unrolling factor required by the SLP instances. If that unrolling factor is 1, we say, that we perform pure SLP on loop - cross iteration parallelism is not exploited. */ bool only_slp_in_loop = true; for (i = 0; i < nbbs; i++) { basic_block bb = bbs[i]; for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) { gimple *stmt = gsi_stmt (si); stmt_vec_info stmt_info = vinfo_for_stmt (stmt); if (STMT_VINFO_IN_PATTERN_P (stmt_info) && STMT_VINFO_RELATED_STMT (stmt_info)) { stmt = STMT_VINFO_RELATED_STMT (stmt_info); stmt_info = vinfo_for_stmt (stmt); } if ((STMT_VINFO_RELEVANT_P (stmt_info) || VECTORIZABLE_CYCLE_DEF (STMT_VINFO_DEF_TYPE (stmt_info))) && !PURE_SLP_STMT (stmt_info)) /* STMT needs both SLP and loop-based vectorization. */ only_slp_in_loop = false; } } if (only_slp_in_loop) vectorization_factor = LOOP_VINFO_SLP_UNROLLING_FACTOR (loop_vinfo); else vectorization_factor = least_common_multiple (vectorization_factor, LOOP_VINFO_SLP_UNROLLING_FACTOR (loop_vinfo)); LOOP_VINFO_VECT_FACTOR (loop_vinfo) = vectorization_factor; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Updating vectorization factor to %d\n", vectorization_factor); } /* Function vect_analyze_loop_operations. Scan the loop stmts and make sure they are all vectorizable. */ static bool vect_analyze_loop_operations (loop_vec_info loop_vinfo) { struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); int nbbs = loop->num_nodes; int i; stmt_vec_info stmt_info; bool need_to_vectorize = false; bool ok; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== vect_analyze_loop_operations ===\n"); for (i = 0; i < nbbs; i++) { basic_block bb = bbs[i]; for (gphi_iterator si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) { gphi *phi = si.phi (); ok = true; stmt_info = vinfo_for_stmt (phi); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "examining phi: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, phi, 0); dump_printf (MSG_NOTE, "\n"); } if (virtual_operand_p (gimple_phi_result (phi))) continue; /* Inner-loop loop-closed exit phi in outer-loop vectorization (i.e., a phi in the tail of the outer-loop). */ if (! is_loop_header_bb_p (bb)) { /* FORNOW: we currently don't support the case that these phis are not used in the outerloop (unless it is double reduction, i.e., this phi is vect_reduction_def), cause this case requires to actually do something here. */ if ((!STMT_VINFO_RELEVANT_P (stmt_info) || STMT_VINFO_LIVE_P (stmt_info)) && STMT_VINFO_DEF_TYPE (stmt_info) != vect_double_reduction_def) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "Unsupported loop-closed phi in " "outer-loop.\n"); return false; } /* If PHI is used in the outer loop, we check that its operand is defined in the inner loop. */ if (STMT_VINFO_RELEVANT_P (stmt_info)) { tree phi_op; gimple *op_def_stmt; if (gimple_phi_num_args (phi) != 1) return false; phi_op = PHI_ARG_DEF (phi, 0); if (TREE_CODE (phi_op) != SSA_NAME) return false; op_def_stmt = SSA_NAME_DEF_STMT (phi_op); if (gimple_nop_p (op_def_stmt) || !flow_bb_inside_loop_p (loop, gimple_bb (op_def_stmt)) || !vinfo_for_stmt (op_def_stmt)) return false; if (STMT_VINFO_RELEVANT (vinfo_for_stmt (op_def_stmt)) != vect_used_in_outer && STMT_VINFO_RELEVANT (vinfo_for_stmt (op_def_stmt)) != vect_used_in_outer_by_reduction) return false; } continue; } gcc_assert (stmt_info); if (STMT_VINFO_LIVE_P (stmt_info)) { /* FORNOW: not yet supported. */ if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: value used after loop.\n"); return false; } if (STMT_VINFO_RELEVANT (stmt_info) == vect_used_in_scope && STMT_VINFO_DEF_TYPE (stmt_info) != vect_induction_def) { /* A scalar-dependence cycle that we don't support. */ if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: scalar dependence cycle.\n"); return false; } if (STMT_VINFO_RELEVANT_P (stmt_info)) { need_to_vectorize = true; if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_induction_def) ok = vectorizable_induction (phi, NULL, NULL); } if (!ok) { if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: relevant phi not " "supported: "); dump_gimple_stmt (MSG_MISSED_OPTIMIZATION, TDF_SLIM, phi, 0); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return false; } } for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) { gimple *stmt = gsi_stmt (si); if (!gimple_clobber_p (stmt) && !vect_analyze_stmt (stmt, &need_to_vectorize, NULL)) return false; } } /* bbs */ /* All operations in the loop are either irrelevant (deal with loop control, or dead), or only used outside the loop and can be moved out of the loop (e.g. invariants, inductions). The loop can be optimized away by scalar optimizations. We're better off not touching this loop. */ if (!need_to_vectorize) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "All the computation can be taken out of the loop.\n"); if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: redundant loop. no profit to " "vectorize.\n"); return false; } return true; } /* Function vect_analyze_loop_2. Apply a set of analyses on LOOP, and create a loop_vec_info struct for it. The different analyses will record information in the loop_vec_info struct. */ static bool vect_analyze_loop_2 (loop_vec_info loop_vinfo) { bool ok; int max_vf = MAX_VECTORIZATION_FACTOR; int min_vf = 2; unsigned int n_stmts = 0; /* Find all data references in the loop (which correspond to vdefs/vuses) and analyze their evolution in the loop. Also adjust the minimal vectorization factor according to the loads and stores. FORNOW: Handle only simple, array references, which alignment can be forced, and aligned pointer-references. */ ok = vect_analyze_data_refs (loop_vinfo, &min_vf, &n_stmts); if (!ok) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "bad data references.\n"); return false; } /* Classify all cross-iteration scalar data-flow cycles. Cross-iteration cycles caused by virtual phis are analyzed separately. */ vect_analyze_scalar_cycles (loop_vinfo); vect_pattern_recog (loop_vinfo); vect_fixup_scalar_cycles_with_patterns (loop_vinfo); /* Analyze the access patterns of the data-refs in the loop (consecutive, complex, etc.). FORNOW: Only handle consecutive access pattern. */ ok = vect_analyze_data_ref_accesses (loop_vinfo); if (!ok) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "bad data access.\n"); return false; } /* Data-flow analysis to detect stmts that do not need to be vectorized. */ ok = vect_mark_stmts_to_be_vectorized (loop_vinfo); if (!ok) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "unexpected pattern.\n"); return false; } /* Analyze data dependences between the data-refs in the loop and adjust the maximum vectorization factor according to the dependences. FORNOW: fail at the first data dependence that we encounter. */ ok = vect_analyze_data_ref_dependences (loop_vinfo, &max_vf); if (!ok || max_vf < min_vf) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "bad data dependence.\n"); return false; } ok = vect_determine_vectorization_factor (loop_vinfo); if (!ok) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "can't determine vectorization factor.\n"); return false; } if (max_vf < LOOP_VINFO_VECT_FACTOR (loop_vinfo)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "bad data dependence.\n"); return false; } /* Check the SLP opportunities in the loop, analyze and build SLP trees. */ ok = vect_analyze_slp (loop_vinfo, n_stmts); if (!ok) return false; /* If there are any SLP instances mark them as pure_slp. */ bool slp = vect_make_slp_decision (loop_vinfo); if (slp) { /* Find stmts that need to be both vectorized and SLPed. */ vect_detect_hybrid_slp (loop_vinfo); /* Update the vectorization factor based on the SLP decision. */ vect_update_vf_for_slp (loop_vinfo); } /* Now the vectorization factor is final. */ unsigned vectorization_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo); gcc_assert (vectorization_factor != 0); if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) && dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "vectorization_factor = %d, niters = " HOST_WIDE_INT_PRINT_DEC "\n", vectorization_factor, LOOP_VINFO_INT_NITERS (loop_vinfo)); HOST_WIDE_INT max_niter = max_stmt_executions_int (LOOP_VINFO_LOOP (loop_vinfo)); if ((LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) && (LOOP_VINFO_INT_NITERS (loop_vinfo) < vectorization_factor)) || (max_niter != -1 && (unsigned HOST_WIDE_INT) max_niter < vectorization_factor)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: iteration count too small.\n"); if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: iteration count smaller than " "vectorization factor.\n"); return false; } /* Analyze the alignment of the data-refs in the loop. Fail if a data reference is found that cannot be vectorized. */ ok = vect_analyze_data_refs_alignment (loop_vinfo); if (!ok) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "bad data alignment.\n"); return false; } /* Prune the list of ddrs to be tested at run-time by versioning for alias. It is important to call pruning after vect_analyze_data_ref_accesses, since we use grouping information gathered by interleaving analysis. */ ok = vect_prune_runtime_alias_test_list (loop_vinfo); if (!ok) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "number of versioning for alias " "run-time tests exceeds %d " "(--param vect-max-version-for-alias-checks)\n", PARAM_VALUE (PARAM_VECT_MAX_VERSION_FOR_ALIAS_CHECKS)); return false; } /* Compute the scalar iteration cost. */ vect_compute_single_scalar_iteration_cost (loop_vinfo); /* This pass will decide on using loop versioning and/or loop peeling in order to enhance the alignment of data references in the loop. */ ok = vect_enhance_data_refs_alignment (loop_vinfo); if (!ok) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "bad data alignment.\n"); return false; } if (slp) { /* Analyze operations in the SLP instances. Note this may remove unsupported SLP instances which makes the above SLP kind detection invalid. */ unsigned old_size = LOOP_VINFO_SLP_INSTANCES (loop_vinfo).length (); vect_slp_analyze_operations (LOOP_VINFO_SLP_INSTANCES (loop_vinfo), LOOP_VINFO_TARGET_COST_DATA (loop_vinfo)); if (LOOP_VINFO_SLP_INSTANCES (loop_vinfo).length () != old_size) return false; } /* Scan all the remaining operations in the loop that are not subject to SLP and make sure they are vectorizable. */ ok = vect_analyze_loop_operations (loop_vinfo); if (!ok) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "bad operation or unsupported loop bound.\n"); return false; } /* Analyze cost. Decide if worth while to vectorize. */ int min_profitable_estimate, min_profitable_iters; vect_estimate_min_profitable_iters (loop_vinfo, &min_profitable_iters, &min_profitable_estimate); if (min_profitable_iters < 0) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: vectorization not profitable.\n"); if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: vector version will never be " "profitable.\n"); return false; } int min_scalar_loop_bound = ((PARAM_VALUE (PARAM_MIN_VECT_LOOP_BOUND) * vectorization_factor) - 1); /* Use the cost model only if it is more conservative than user specified threshold. */ unsigned th = (unsigned) min_scalar_loop_bound; if (min_profitable_iters && (!min_scalar_loop_bound || min_profitable_iters > min_scalar_loop_bound)) th = (unsigned) min_profitable_iters; LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo) = th; if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) && LOOP_VINFO_INT_NITERS (loop_vinfo) <= th) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: vectorization not profitable.\n"); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "not vectorized: iteration count smaller than user " "specified loop bound parameter or minimum profitable " "iterations (whichever is more conservative).\n"); return false; } HOST_WIDE_INT estimated_niter = estimated_stmt_executions_int (LOOP_VINFO_LOOP (loop_vinfo)); if (estimated_niter != -1 && ((unsigned HOST_WIDE_INT) estimated_niter <= MAX (th, (unsigned)min_profitable_estimate))) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: estimated iteration count too " "small.\n"); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "not vectorized: estimated iteration count smaller " "than specified loop bound parameter or minimum " "profitable iterations (whichever is more " "conservative).\n"); return false; } /* Decide whether we need to create an epilogue loop to handle remaining scalar iterations. */ th = ((LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo) + 1) / LOOP_VINFO_VECT_FACTOR (loop_vinfo)) * LOOP_VINFO_VECT_FACTOR (loop_vinfo); if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) && LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) > 0) { if (ctz_hwi (LOOP_VINFO_INT_NITERS (loop_vinfo) - LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo)) < exact_log2 (LOOP_VINFO_VECT_FACTOR (loop_vinfo))) LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo) = true; } else if (LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) || (tree_ctz (LOOP_VINFO_NITERS (loop_vinfo)) < (unsigned)exact_log2 (LOOP_VINFO_VECT_FACTOR (loop_vinfo)) /* In case of versioning, check if the maximum number of iterations is greater than th. If they are identical, the epilogue is unnecessary. */ && ((!LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo) && !LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo)) || (unsigned HOST_WIDE_INT) max_niter > th))) LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo) = true; /* If an epilogue loop is required make sure we can create one. */ if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) || LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo)) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "epilog loop required\n"); if (!vect_can_advance_ivs_p (loop_vinfo) || !slpeel_can_duplicate_loop_p (LOOP_VINFO_LOOP (loop_vinfo), single_exit (LOOP_VINFO_LOOP (loop_vinfo)))) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not vectorized: can't create required " "epilog loop\n"); return false; } } gcc_assert (vectorization_factor == (unsigned)LOOP_VINFO_VECT_FACTOR (loop_vinfo)); return true; } /* Function vect_analyze_loop. Apply a set of analyses on LOOP, and create a loop_vec_info struct for it. The different analyses will record information in the loop_vec_info struct. */ loop_vec_info vect_analyze_loop (struct loop *loop) { loop_vec_info loop_vinfo; unsigned int vector_sizes; /* Autodetect first vector size we try. */ current_vector_size = 0; vector_sizes = targetm.vectorize.autovectorize_vector_sizes (); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "===== analyze_loop_nest =====\n"); if (loop_outer (loop) && loop_vec_info_for_loop (loop_outer (loop)) && LOOP_VINFO_VECTORIZABLE_P (loop_vec_info_for_loop (loop_outer (loop)))) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "outer-loop already vectorized.\n"); return NULL; } while (1) { /* Check the CFG characteristics of the loop (nesting, entry/exit). */ loop_vinfo = vect_analyze_loop_form (loop); if (!loop_vinfo) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "bad loop form.\n"); return NULL; } if (vect_analyze_loop_2 (loop_vinfo)) { LOOP_VINFO_VECTORIZABLE_P (loop_vinfo) = 1; return loop_vinfo; } destroy_loop_vec_info (loop_vinfo, true); vector_sizes &= ~current_vector_size; if (vector_sizes == 0 || current_vector_size == 0) return NULL; /* Try the next biggest vector size. */ current_vector_size = 1 << floor_log2 (vector_sizes); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "***** Re-trying analysis with " "vector size %d\n", current_vector_size); } } /* Function reduction_code_for_scalar_code Input: CODE - tree_code of a reduction operations. Output: REDUC_CODE - the corresponding tree-code to be used to reduce the vector of partial results into a single scalar result, or ERROR_MARK if the operation is a supported reduction operation, but does not have such a tree-code. Return FALSE if CODE currently cannot be vectorized as reduction. */ static bool reduction_code_for_scalar_code (enum tree_code code, enum tree_code *reduc_code) { switch (code) { case MAX_EXPR: *reduc_code = REDUC_MAX_EXPR; return true; case MIN_EXPR: *reduc_code = REDUC_MIN_EXPR; return true; case PLUS_EXPR: *reduc_code = REDUC_PLUS_EXPR; return true; case MULT_EXPR: case MINUS_EXPR: case BIT_IOR_EXPR: case BIT_XOR_EXPR: case BIT_AND_EXPR: *reduc_code = ERROR_MARK; return true; default: return false; } } /* Error reporting helper for vect_is_simple_reduction below. GIMPLE statement STMT is printed with a message MSG. */ static void report_vect_op (int msg_type, gimple *stmt, const char *msg) { dump_printf_loc (msg_type, vect_location, "%s", msg); dump_gimple_stmt (msg_type, TDF_SLIM, stmt, 0); dump_printf (msg_type, "\n"); } /* Detect SLP reduction of the form: #a1 = phi a2 = operation (a1) a3 = operation (a2) a4 = operation (a3) a5 = operation (a4) #a = phi PHI is the reduction phi node (#a1 = phi above) FIRST_STMT is the first reduction stmt in the chain (a2 = operation (a1)). Return TRUE if a reduction chain was detected. */ static bool vect_is_slp_reduction (loop_vec_info loop_info, gimple *phi, gimple *first_stmt) { struct loop *loop = (gimple_bb (phi))->loop_father; struct loop *vect_loop = LOOP_VINFO_LOOP (loop_info); enum tree_code code; gimple *current_stmt = NULL, *loop_use_stmt = NULL, *first, *next_stmt; stmt_vec_info use_stmt_info, current_stmt_info; tree lhs; imm_use_iterator imm_iter; use_operand_p use_p; int nloop_uses, size = 0, n_out_of_loop_uses; bool found = false; if (loop != vect_loop) return false; lhs = PHI_RESULT (phi); code = gimple_assign_rhs_code (first_stmt); while (1) { nloop_uses = 0; n_out_of_loop_uses = 0; FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs) { gimple *use_stmt = USE_STMT (use_p); if (is_gimple_debug (use_stmt)) continue; /* Check if we got back to the reduction phi. */ if (use_stmt == phi) { loop_use_stmt = use_stmt; found = true; break; } if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt))) { loop_use_stmt = use_stmt; nloop_uses++; } else n_out_of_loop_uses++; /* There are can be either a single use in the loop or two uses in phi nodes. */ if (nloop_uses > 1 || (n_out_of_loop_uses && nloop_uses)) return false; } if (found) break; /* We reached a statement with no loop uses. */ if (nloop_uses == 0) return false; /* This is a loop exit phi, and we haven't reached the reduction phi. */ if (gimple_code (loop_use_stmt) == GIMPLE_PHI) return false; if (!is_gimple_assign (loop_use_stmt) || code != gimple_assign_rhs_code (loop_use_stmt) || !flow_bb_inside_loop_p (loop, gimple_bb (loop_use_stmt))) return false; /* Insert USE_STMT into reduction chain. */ use_stmt_info = vinfo_for_stmt (loop_use_stmt); if (current_stmt) { current_stmt_info = vinfo_for_stmt (current_stmt); GROUP_NEXT_ELEMENT (current_stmt_info) = loop_use_stmt; GROUP_FIRST_ELEMENT (use_stmt_info) = GROUP_FIRST_ELEMENT (current_stmt_info); } else GROUP_FIRST_ELEMENT (use_stmt_info) = loop_use_stmt; lhs = gimple_assign_lhs (loop_use_stmt); current_stmt = loop_use_stmt; size++; } if (!found || loop_use_stmt != phi || size < 2) return false; /* Swap the operands, if needed, to make the reduction operand be the second operand. */ lhs = PHI_RESULT (phi); next_stmt = GROUP_FIRST_ELEMENT (vinfo_for_stmt (current_stmt)); while (next_stmt) { if (gimple_assign_rhs2 (next_stmt) == lhs) { tree op = gimple_assign_rhs1 (next_stmt); gimple *def_stmt = NULL; if (TREE_CODE (op) == SSA_NAME) def_stmt = SSA_NAME_DEF_STMT (op); /* Check that the other def is either defined in the loop ("vect_internal_def"), or it's an induction (defined by a loop-header phi-node). */ if (def_stmt && gimple_bb (def_stmt) && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt)) && (is_gimple_assign (def_stmt) || is_gimple_call (def_stmt) || STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def_stmt)) == vect_induction_def || (gimple_code (def_stmt) == GIMPLE_PHI && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def_stmt)) == vect_internal_def && !is_loop_header_bb_p (gimple_bb (def_stmt))))) { lhs = gimple_assign_lhs (next_stmt); next_stmt = GROUP_NEXT_ELEMENT (vinfo_for_stmt (next_stmt)); continue; } return false; } else { tree op = gimple_assign_rhs2 (next_stmt); gimple *def_stmt = NULL; if (TREE_CODE (op) == SSA_NAME) def_stmt = SSA_NAME_DEF_STMT (op); /* Check that the other def is either defined in the loop ("vect_internal_def"), or it's an induction (defined by a loop-header phi-node). */ if (def_stmt && gimple_bb (def_stmt) && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt)) && (is_gimple_assign (def_stmt) || is_gimple_call (def_stmt) || STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def_stmt)) == vect_induction_def || (gimple_code (def_stmt) == GIMPLE_PHI && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def_stmt)) == vect_internal_def && !is_loop_header_bb_p (gimple_bb (def_stmt))))) { if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "swapping oprnds: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, next_stmt, 0); dump_printf (MSG_NOTE, "\n"); } swap_ssa_operands (next_stmt, gimple_assign_rhs1_ptr (next_stmt), gimple_assign_rhs2_ptr (next_stmt)); update_stmt (next_stmt); if (CONSTANT_CLASS_P (gimple_assign_rhs1 (next_stmt))) LOOP_VINFO_OPERANDS_SWAPPED (loop_info) = true; } else return false; } lhs = gimple_assign_lhs (next_stmt); next_stmt = GROUP_NEXT_ELEMENT (vinfo_for_stmt (next_stmt)); } /* Save the chain for further analysis in SLP detection. */ first = GROUP_FIRST_ELEMENT (vinfo_for_stmt (current_stmt)); LOOP_VINFO_REDUCTION_CHAINS (loop_info).safe_push (first); GROUP_SIZE (vinfo_for_stmt (first)) = size; return true; } /* Function vect_is_simple_reduction_1 (1) Detect a cross-iteration def-use cycle that represents a simple reduction computation. We look for the following pattern: loop_header: a1 = phi < a0, a2 > a3 = ... a2 = operation (a3, a1) or a3 = ... loop_header: a1 = phi < a0, a2 > a2 = operation (a3, a1) such that: 1. operation is commutative and associative and it is safe to change the order of the computation (if CHECK_REDUCTION is true) 2. no uses for a2 in the loop (a2 is used out of the loop) 3. no uses of a1 in the loop besides the reduction operation 4. no uses of a1 outside the loop. Conditions 1,4 are tested here. Conditions 2,3 are tested in vect_mark_stmts_to_be_vectorized. (2) Detect a cross-iteration def-use cycle in nested loops, i.e., nested cycles, if CHECK_REDUCTION is false. (3) Detect cycles of phi nodes in outer-loop vectorization, i.e., double reductions: a1 = phi < a0, a2 > inner loop (def of a3) a2 = phi < a3 > (4) Detect condition expressions, ie: for (int i = 0; i < N; i++) if (a[i] < val) ret_val = a[i]; If MODIFY is true it tries also to rework the code in-place to enable detection of more reduction patterns. For the time being we rewrite "res -= RHS" into "rhs += -RHS" when it seems worthwhile. */ static gimple * vect_is_simple_reduction_1 (loop_vec_info loop_info, gimple *phi, bool check_reduction, bool *double_reduc, bool modify, bool need_wrapping_integral_overflow, enum vect_reduction_type *v_reduc_type) { struct loop *loop = (gimple_bb (phi))->loop_father; struct loop *vect_loop = LOOP_VINFO_LOOP (loop_info); edge latch_e = loop_latch_edge (loop); tree loop_arg = PHI_ARG_DEF_FROM_EDGE (phi, latch_e); gimple *def_stmt, *def1 = NULL, *def2 = NULL; enum tree_code orig_code, code; tree op1, op2, op3 = NULL_TREE, op4 = NULL_TREE; tree type; int nloop_uses; tree name; imm_use_iterator imm_iter; use_operand_p use_p; bool phi_def; *double_reduc = false; *v_reduc_type = TREE_CODE_REDUCTION; /* If CHECK_REDUCTION is true, we assume inner-most loop vectorization, otherwise, we assume outer loop vectorization. */ gcc_assert ((check_reduction && loop == vect_loop) || (!check_reduction && flow_loop_nested_p (vect_loop, loop))); name = PHI_RESULT (phi); /* ??? If there are no uses of the PHI result the inner loop reduction won't be detected as possibly double-reduction by vectorizable_reduction because that tries to walk the PHI arg from the preheader edge which can be constant. See PR60382. */ if (has_zero_uses (name)) return NULL; nloop_uses = 0; FOR_EACH_IMM_USE_FAST (use_p, imm_iter, name) { gimple *use_stmt = USE_STMT (use_p); if (is_gimple_debug (use_stmt)) continue; if (!flow_bb_inside_loop_p (loop, gimple_bb (use_stmt))) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "intermediate value used outside loop.\n"); return NULL; } nloop_uses++; if (nloop_uses > 1) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "reduction used in loop.\n"); return NULL; } } if (TREE_CODE (loop_arg) != SSA_NAME) { if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "reduction: not ssa_name: "); dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, loop_arg); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return NULL; } def_stmt = SSA_NAME_DEF_STMT (loop_arg); if (!def_stmt) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "reduction: no def_stmt.\n"); return NULL; } if (!is_gimple_assign (def_stmt) && gimple_code (def_stmt) != GIMPLE_PHI) { if (dump_enabled_p ()) { dump_gimple_stmt (MSG_NOTE, TDF_SLIM, def_stmt, 0); dump_printf (MSG_NOTE, "\n"); } return NULL; } if (is_gimple_assign (def_stmt)) { name = gimple_assign_lhs (def_stmt); phi_def = false; } else { name = PHI_RESULT (def_stmt); phi_def = true; } nloop_uses = 0; FOR_EACH_IMM_USE_FAST (use_p, imm_iter, name) { gimple *use_stmt = USE_STMT (use_p); if (is_gimple_debug (use_stmt)) continue; if (flow_bb_inside_loop_p (loop, gimple_bb (use_stmt))) nloop_uses++; if (nloop_uses > 1) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "reduction used in loop.\n"); return NULL; } } /* If DEF_STMT is a phi node itself, we expect it to have a single argument defined in the inner loop. */ if (phi_def) { op1 = PHI_ARG_DEF (def_stmt, 0); if (gimple_phi_num_args (def_stmt) != 1 || TREE_CODE (op1) != SSA_NAME) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "unsupported phi node definition.\n"); return NULL; } def1 = SSA_NAME_DEF_STMT (op1); if (gimple_bb (def1) && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt)) && loop->inner && flow_bb_inside_loop_p (loop->inner, gimple_bb (def1)) && is_gimple_assign (def1)) { if (dump_enabled_p ()) report_vect_op (MSG_NOTE, def_stmt, "detected double reduction: "); *double_reduc = true; return def_stmt; } return NULL; } code = orig_code = gimple_assign_rhs_code (def_stmt); /* We can handle "res -= x[i]", which is non-associative by simply rewriting this into "res += -x[i]". Avoid changing gimple instruction for the first simple tests and only do this if we're allowed to change code at all. */ if (code == MINUS_EXPR && modify && (op1 = gimple_assign_rhs1 (def_stmt)) && TREE_CODE (op1) == SSA_NAME && SSA_NAME_DEF_STMT (op1) == phi) code = PLUS_EXPR; if (check_reduction) { if (code == COND_EXPR) *v_reduc_type = COND_REDUCTION; else if (!commutative_tree_code (code) || !associative_tree_code (code)) { if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: not commutative/associative: "); return NULL; } } if (get_gimple_rhs_class (code) != GIMPLE_BINARY_RHS) { if (code != COND_EXPR) { if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: not binary operation: "); return NULL; } op3 = gimple_assign_rhs1 (def_stmt); if (COMPARISON_CLASS_P (op3)) { op4 = TREE_OPERAND (op3, 1); op3 = TREE_OPERAND (op3, 0); } op1 = gimple_assign_rhs2 (def_stmt); op2 = gimple_assign_rhs3 (def_stmt); if (TREE_CODE (op1) != SSA_NAME && TREE_CODE (op2) != SSA_NAME) { if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: uses not ssa_names: "); return NULL; } } else { op1 = gimple_assign_rhs1 (def_stmt); op2 = gimple_assign_rhs2 (def_stmt); if (TREE_CODE (op1) != SSA_NAME && TREE_CODE (op2) != SSA_NAME) { if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: uses not ssa_names: "); return NULL; } } type = TREE_TYPE (gimple_assign_lhs (def_stmt)); if ((TREE_CODE (op1) == SSA_NAME && !types_compatible_p (type,TREE_TYPE (op1))) || (TREE_CODE (op2) == SSA_NAME && !types_compatible_p (type, TREE_TYPE (op2))) || (op3 && TREE_CODE (op3) == SSA_NAME && !types_compatible_p (type, TREE_TYPE (op3))) || (op4 && TREE_CODE (op4) == SSA_NAME && !types_compatible_p (type, TREE_TYPE (op4)))) { if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "reduction: multiple types: operation type: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, type); dump_printf (MSG_NOTE, ", operands types: "); dump_generic_expr (MSG_NOTE, TDF_SLIM, TREE_TYPE (op1)); dump_printf (MSG_NOTE, ","); dump_generic_expr (MSG_NOTE, TDF_SLIM, TREE_TYPE (op2)); if (op3) { dump_printf (MSG_NOTE, ","); dump_generic_expr (MSG_NOTE, TDF_SLIM, TREE_TYPE (op3)); } if (op4) { dump_printf (MSG_NOTE, ","); dump_generic_expr (MSG_NOTE, TDF_SLIM, TREE_TYPE (op4)); } dump_printf (MSG_NOTE, "\n"); } return NULL; } /* Check that it's ok to change the order of the computation. Generally, when vectorizing a reduction we change the order of the computation. This may change the behavior of the program in some cases, so we need to check that this is ok. One exception is when vectorizing an outer-loop: the inner-loop is executed sequentially, and therefore vectorizing reductions in the inner-loop during outer-loop vectorization is safe. */ if (*v_reduc_type != COND_REDUCTION) { /* CHECKME: check for !flag_finite_math_only too? */ if (SCALAR_FLOAT_TYPE_P (type) && !flag_associative_math && check_reduction) { /* Changing the order of operations changes the semantics. */ if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: unsafe fp math optimization: "); return NULL; } else if (INTEGRAL_TYPE_P (type) && check_reduction) { if (!operation_no_trapping_overflow (type, code)) { /* Changing the order of operations changes the semantics. */ if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: unsafe int math optimization" " (overflow traps): "); return NULL; } if (need_wrapping_integral_overflow && !TYPE_OVERFLOW_WRAPS (type) && operation_can_overflow (code)) { /* Changing the order of operations changes the semantics. */ if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: unsafe int math optimization" " (overflow doesn't wrap): "); return NULL; } } else if (SAT_FIXED_POINT_TYPE_P (type) && check_reduction) { /* Changing the order of operations changes the semantics. */ if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: unsafe fixed-point math optimization: "); return NULL; } } /* If we detected "res -= x[i]" earlier, rewrite it into "res += -x[i]" now. If this turns out to be useless reassoc will clean it up again. */ if (orig_code == MINUS_EXPR) { tree rhs = gimple_assign_rhs2 (def_stmt); tree negrhs = make_ssa_name (TREE_TYPE (rhs)); gimple *negate_stmt = gimple_build_assign (negrhs, NEGATE_EXPR, rhs); gimple_stmt_iterator gsi = gsi_for_stmt (def_stmt); set_vinfo_for_stmt (negate_stmt, new_stmt_vec_info (negate_stmt, loop_info)); gsi_insert_before (&gsi, negate_stmt, GSI_NEW_STMT); gimple_assign_set_rhs2 (def_stmt, negrhs); gimple_assign_set_rhs_code (def_stmt, PLUS_EXPR); update_stmt (def_stmt); } /* Reduction is safe. We're dealing with one of the following: 1) integer arithmetic and no trapv 2) floating point arithmetic, and special flags permit this optimization 3) nested cycle (i.e., outer loop vectorization). */ if (TREE_CODE (op1) == SSA_NAME) def1 = SSA_NAME_DEF_STMT (op1); if (TREE_CODE (op2) == SSA_NAME) def2 = SSA_NAME_DEF_STMT (op2); if (code != COND_EXPR && ((!def1 || gimple_nop_p (def1)) && (!def2 || gimple_nop_p (def2)))) { if (dump_enabled_p ()) report_vect_op (MSG_NOTE, def_stmt, "reduction: no defs for operands: "); return NULL; } /* Check that one def is the reduction def, defined by PHI, the other def is either defined in the loop ("vect_internal_def"), or it's an induction (defined by a loop-header phi-node). */ if (def2 && def2 == phi && (code == COND_EXPR || !def1 || gimple_nop_p (def1) || !flow_bb_inside_loop_p (loop, gimple_bb (def1)) || (def1 && flow_bb_inside_loop_p (loop, gimple_bb (def1)) && (is_gimple_assign (def1) || is_gimple_call (def1) || STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def1)) == vect_induction_def || (gimple_code (def1) == GIMPLE_PHI && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def1)) == vect_internal_def && !is_loop_header_bb_p (gimple_bb (def1))))))) { if (dump_enabled_p ()) report_vect_op (MSG_NOTE, def_stmt, "detected reduction: "); return def_stmt; } if (def1 && def1 == phi && (code == COND_EXPR || !def2 || gimple_nop_p (def2) || !flow_bb_inside_loop_p (loop, gimple_bb (def2)) || (def2 && flow_bb_inside_loop_p (loop, gimple_bb (def2)) && (is_gimple_assign (def2) || is_gimple_call (def2) || STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def2)) == vect_induction_def || (gimple_code (def2) == GIMPLE_PHI && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def2)) == vect_internal_def && !is_loop_header_bb_p (gimple_bb (def2))))))) { if (check_reduction) { if (code == COND_EXPR) { /* No current known use where this case would be useful. */ if (dump_enabled_p ()) report_vect_op (MSG_NOTE, def_stmt, "detected reduction: cannot currently swap " "operands for cond_expr"); return NULL; } /* Swap operands (just for simplicity - so that the rest of the code can assume that the reduction variable is always the last (second) argument). */ if (dump_enabled_p ()) report_vect_op (MSG_NOTE, def_stmt, "detected reduction: need to swap operands: "); swap_ssa_operands (def_stmt, gimple_assign_rhs1_ptr (def_stmt), gimple_assign_rhs2_ptr (def_stmt)); if (CONSTANT_CLASS_P (gimple_assign_rhs1 (def_stmt))) LOOP_VINFO_OPERANDS_SWAPPED (loop_info) = true; } else { if (dump_enabled_p ()) report_vect_op (MSG_NOTE, def_stmt, "detected reduction: "); } return def_stmt; } /* Try to find SLP reduction chain. */ if (check_reduction && code != COND_EXPR && vect_is_slp_reduction (loop_info, phi, def_stmt)) { if (dump_enabled_p ()) report_vect_op (MSG_NOTE, def_stmt, "reduction: detected reduction chain: "); return def_stmt; } if (dump_enabled_p ()) report_vect_op (MSG_MISSED_OPTIMIZATION, def_stmt, "reduction: unknown pattern: "); return NULL; } /* Wrapper around vect_is_simple_reduction_1, that won't modify code in-place. Arguments as there. */ static gimple * vect_is_simple_reduction (loop_vec_info loop_info, gimple *phi, bool check_reduction, bool *double_reduc, bool need_wrapping_integral_overflow, enum vect_reduction_type *v_reduc_type) { return vect_is_simple_reduction_1 (loop_info, phi, check_reduction, double_reduc, false, need_wrapping_integral_overflow, v_reduc_type); } /* Wrapper around vect_is_simple_reduction_1, which will modify code in-place if it enables detection of more reductions. Arguments as there. */ gimple * vect_force_simple_reduction (loop_vec_info loop_info, gimple *phi, bool check_reduction, bool *double_reduc, bool need_wrapping_integral_overflow) { enum vect_reduction_type v_reduc_type; return vect_is_simple_reduction_1 (loop_info, phi, check_reduction, double_reduc, true, need_wrapping_integral_overflow, &v_reduc_type); } /* Calculate cost of peeling the loop PEEL_ITERS_PROLOGUE times. */ int vect_get_known_peeling_cost (loop_vec_info loop_vinfo, int peel_iters_prologue, int *peel_iters_epilogue, stmt_vector_for_cost *scalar_cost_vec, stmt_vector_for_cost *prologue_cost_vec, stmt_vector_for_cost *epilogue_cost_vec) { int retval = 0; int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); if (!LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)) { *peel_iters_epilogue = vf/2; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "cost model: epilogue peel iters set to vf/2 " "because loop iterations are unknown .\n"); /* If peeled iterations are known but number of scalar loop iterations are unknown, count a taken branch per peeled loop. */ retval = record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken, NULL, 0, vect_prologue); retval = record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken, NULL, 0, vect_epilogue); } else { int niters = LOOP_VINFO_INT_NITERS (loop_vinfo); peel_iters_prologue = niters < peel_iters_prologue ? niters : peel_iters_prologue; *peel_iters_epilogue = (niters - peel_iters_prologue) % vf; /* If we need to peel for gaps, but no peeling is required, we have to peel VF iterations. */ if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) && !*peel_iters_epilogue) *peel_iters_epilogue = vf; } stmt_info_for_cost *si; int j; if (peel_iters_prologue) FOR_EACH_VEC_ELT (*scalar_cost_vec, j, si) retval += record_stmt_cost (prologue_cost_vec, si->count * peel_iters_prologue, si->kind, NULL, si->misalign, vect_prologue); if (*peel_iters_epilogue) FOR_EACH_VEC_ELT (*scalar_cost_vec, j, si) retval += record_stmt_cost (epilogue_cost_vec, si->count * *peel_iters_epilogue, si->kind, NULL, si->misalign, vect_epilogue); return retval; } /* Function vect_estimate_min_profitable_iters Return the number of iterations required for the vector version of the loop to be profitable relative to the cost of the scalar version of the loop. */ static void vect_estimate_min_profitable_iters (loop_vec_info loop_vinfo, int *ret_min_profitable_niters, int *ret_min_profitable_estimate) { int min_profitable_iters; int min_profitable_estimate; int peel_iters_prologue; int peel_iters_epilogue; unsigned vec_inside_cost = 0; int vec_outside_cost = 0; unsigned vec_prologue_cost = 0; unsigned vec_epilogue_cost = 0; int scalar_single_iter_cost = 0; int scalar_outside_cost = 0; int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); int npeel = LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo); void *target_cost_data = LOOP_VINFO_TARGET_COST_DATA (loop_vinfo); /* Cost model disabled. */ if (unlimited_cost_model (LOOP_VINFO_LOOP (loop_vinfo))) { dump_printf_loc (MSG_NOTE, vect_location, "cost model disabled.\n"); *ret_min_profitable_niters = 0; *ret_min_profitable_estimate = 0; return; } /* Requires loop versioning tests to handle misalignment. */ if (LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo)) { /* FIXME: Make cost depend on complexity of individual check. */ unsigned len = LOOP_VINFO_MAY_MISALIGN_STMTS (loop_vinfo).length (); (void) add_stmt_cost (target_cost_data, len, vector_stmt, NULL, 0, vect_prologue); dump_printf (MSG_NOTE, "cost model: Adding cost of checks for loop " "versioning to treat misalignment.\n"); } /* Requires loop versioning with alias checks. */ if (LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo)) { /* FIXME: Make cost depend on complexity of individual check. */ unsigned len = LOOP_VINFO_COMP_ALIAS_DDRS (loop_vinfo).length (); (void) add_stmt_cost (target_cost_data, len, vector_stmt, NULL, 0, vect_prologue); dump_printf (MSG_NOTE, "cost model: Adding cost of checks for loop " "versioning aliasing.\n"); } if (LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo) || LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo)) (void) add_stmt_cost (target_cost_data, 1, cond_branch_taken, NULL, 0, vect_prologue); /* Count statements in scalar loop. Using this as scalar cost for a single iteration for now. TODO: Add outer loop support. TODO: Consider assigning different costs to different scalar statements. */ scalar_single_iter_cost = LOOP_VINFO_SINGLE_SCALAR_ITERATION_COST (loop_vinfo); /* Add additional cost for the peeled instructions in prologue and epilogue loop. FORNOW: If we don't know the value of peel_iters for prologue or epilogue at compile-time - we assume it's vf/2 (the worst would be vf-1). TODO: Build an expression that represents peel_iters for prologue and epilogue to be used in a run-time test. */ if (npeel < 0) { peel_iters_prologue = vf/2; dump_printf (MSG_NOTE, "cost model: " "prologue peel iters set to vf/2.\n"); /* If peeling for alignment is unknown, loop bound of main loop becomes unknown. */ peel_iters_epilogue = vf/2; dump_printf (MSG_NOTE, "cost model: " "epilogue peel iters set to vf/2 because " "peeling for alignment is unknown.\n"); /* If peeled iterations are unknown, count a taken branch and a not taken branch per peeled loop. Even if scalar loop iterations are known, vector iterations are not known since peeled prologue iterations are not known. Hence guards remain the same. */ (void) add_stmt_cost (target_cost_data, 1, cond_branch_taken, NULL, 0, vect_prologue); (void) add_stmt_cost (target_cost_data, 1, cond_branch_not_taken, NULL, 0, vect_prologue); (void) add_stmt_cost (target_cost_data, 1, cond_branch_taken, NULL, 0, vect_epilogue); (void) add_stmt_cost (target_cost_data, 1, cond_branch_not_taken, NULL, 0, vect_epilogue); stmt_info_for_cost *si; int j; FOR_EACH_VEC_ELT (LOOP_VINFO_SCALAR_ITERATION_COST (loop_vinfo), j, si) { struct _stmt_vec_info *stmt_info = si->stmt ? vinfo_for_stmt (si->stmt) : NULL; (void) add_stmt_cost (target_cost_data, si->count * peel_iters_prologue, si->kind, stmt_info, si->misalign, vect_prologue); (void) add_stmt_cost (target_cost_data, si->count * peel_iters_epilogue, si->kind, stmt_info, si->misalign, vect_epilogue); } } else { stmt_vector_for_cost prologue_cost_vec, epilogue_cost_vec; stmt_info_for_cost *si; int j; void *data = LOOP_VINFO_TARGET_COST_DATA (loop_vinfo); prologue_cost_vec.create (2); epilogue_cost_vec.create (2); peel_iters_prologue = npeel; (void) vect_get_known_peeling_cost (loop_vinfo, peel_iters_prologue, &peel_iters_epilogue, &LOOP_VINFO_SCALAR_ITERATION_COST (loop_vinfo), &prologue_cost_vec, &epilogue_cost_vec); FOR_EACH_VEC_ELT (prologue_cost_vec, j, si) { struct _stmt_vec_info *stmt_info = si->stmt ? vinfo_for_stmt (si->stmt) : NULL; (void) add_stmt_cost (data, si->count, si->kind, stmt_info, si->misalign, vect_prologue); } FOR_EACH_VEC_ELT (epilogue_cost_vec, j, si) { struct _stmt_vec_info *stmt_info = si->stmt ? vinfo_for_stmt (si->stmt) : NULL; (void) add_stmt_cost (data, si->count, si->kind, stmt_info, si->misalign, vect_epilogue); } prologue_cost_vec.release (); epilogue_cost_vec.release (); } /* FORNOW: The scalar outside cost is incremented in one of the following ways: 1. The vectorizer checks for alignment and aliasing and generates a condition that allows dynamic vectorization. A cost model check is ANDED with the versioning condition. Hence scalar code path now has the added cost of the versioning check. if (cost > th & versioning_check) jmp to vector code Hence run-time scalar is incremented by not-taken branch cost. 2. The vectorizer then checks if a prologue is required. If the cost model check was not done before during versioning, it has to be done before the prologue check. if (cost <= th) prologue = scalar_iters if (prologue == 0) jmp to vector code else execute prologue if (prologue == num_iters) go to exit Hence the run-time scalar cost is incremented by a taken branch, plus a not-taken branch, plus a taken branch cost. 3. The vectorizer then checks if an epilogue is required. If the cost model check was not done before during prologue check, it has to be done with the epilogue check. if (prologue == 0) jmp to vector code else execute prologue if (prologue == num_iters) go to exit vector code: if ((cost <= th) | (scalar_iters-prologue-epilogue == 0)) jmp to epilogue Hence the run-time scalar cost should be incremented by 2 taken branches. TODO: The back end may reorder the BBS's differently and reverse conditions/branch directions. Change the estimates below to something more reasonable. */ /* If the number of iterations is known and we do not do versioning, we can decide whether to vectorize at compile time. Hence the scalar version do not carry cost model guard costs. */ if (!LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo) || LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo) || LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo)) { /* Cost model check occurs at versioning. */ if (LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo) || LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo)) scalar_outside_cost += vect_get_stmt_cost (cond_branch_not_taken); else { /* Cost model check occurs at prologue generation. */ if (LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo) < 0) scalar_outside_cost += 2 * vect_get_stmt_cost (cond_branch_taken) + vect_get_stmt_cost (cond_branch_not_taken); /* Cost model check occurs at epilogue generation. */ else scalar_outside_cost += 2 * vect_get_stmt_cost (cond_branch_taken); } } /* Complete the target-specific cost calculations. */ finish_cost (LOOP_VINFO_TARGET_COST_DATA (loop_vinfo), &vec_prologue_cost, &vec_inside_cost, &vec_epilogue_cost); vec_outside_cost = (int)(vec_prologue_cost + vec_epilogue_cost); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "Cost model analysis: \n"); dump_printf (MSG_NOTE, " Vector inside of loop cost: %d\n", vec_inside_cost); dump_printf (MSG_NOTE, " Vector prologue cost: %d\n", vec_prologue_cost); dump_printf (MSG_NOTE, " Vector epilogue cost: %d\n", vec_epilogue_cost); dump_printf (MSG_NOTE, " Scalar iteration cost: %d\n", scalar_single_iter_cost); dump_printf (MSG_NOTE, " Scalar outside cost: %d\n", scalar_outside_cost); dump_printf (MSG_NOTE, " Vector outside cost: %d\n", vec_outside_cost); dump_printf (MSG_NOTE, " prologue iterations: %d\n", peel_iters_prologue); dump_printf (MSG_NOTE, " epilogue iterations: %d\n", peel_iters_epilogue); } /* Calculate number of iterations required to make the vector version profitable, relative to the loop bodies only. The following condition must hold true: SIC * niters + SOC > VIC * ((niters-PL_ITERS-EP_ITERS)/VF) + VOC where SIC = scalar iteration cost, VIC = vector iteration cost, VOC = vector outside cost, VF = vectorization factor, PL_ITERS = prologue iterations, EP_ITERS= epilogue iterations SOC = scalar outside cost for run time cost model check. */ if ((scalar_single_iter_cost * vf) > (int) vec_inside_cost) { if (vec_outside_cost <= 0) min_profitable_iters = 1; else { min_profitable_iters = ((vec_outside_cost - scalar_outside_cost) * vf - vec_inside_cost * peel_iters_prologue - vec_inside_cost * peel_iters_epilogue) / ((scalar_single_iter_cost * vf) - vec_inside_cost); if ((scalar_single_iter_cost * vf * min_profitable_iters) <= (((int) vec_inside_cost * min_profitable_iters) + (((int) vec_outside_cost - scalar_outside_cost) * vf))) min_profitable_iters++; } } /* vector version will never be profitable. */ else { if (LOOP_VINFO_LOOP (loop_vinfo)->force_vectorize) warning_at (vect_location, OPT_Wopenmp_simd, "vectorization " "did not happen for a simd loop"); if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "cost model: the vector iteration cost = %d " "divided by the scalar iteration cost = %d " "is greater or equal to the vectorization factor = %d" ".\n", vec_inside_cost, scalar_single_iter_cost, vf); *ret_min_profitable_niters = -1; *ret_min_profitable_estimate = -1; return; } dump_printf (MSG_NOTE, " Calculated minimum iters for profitability: %d\n", min_profitable_iters); min_profitable_iters = min_profitable_iters < vf ? vf : min_profitable_iters; /* Because the condition we create is: if (niters <= min_profitable_iters) then skip the vectorized loop. */ min_profitable_iters--; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, " Runtime profitability threshold = %d\n", min_profitable_iters); *ret_min_profitable_niters = min_profitable_iters; /* Calculate number of iterations required to make the vector version profitable, relative to the loop bodies only. Non-vectorized variant is SIC * niters and it must win over vector variant on the expected loop trip count. The following condition must hold true: SIC * niters > VIC * ((niters-PL_ITERS-EP_ITERS)/VF) + VOC + SOC */ if (vec_outside_cost <= 0) min_profitable_estimate = 1; else { min_profitable_estimate = ((vec_outside_cost + scalar_outside_cost) * vf - vec_inside_cost * peel_iters_prologue - vec_inside_cost * peel_iters_epilogue) / ((scalar_single_iter_cost * vf) - vec_inside_cost); } min_profitable_estimate --; min_profitable_estimate = MAX (min_profitable_estimate, min_profitable_iters); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, " Static estimate profitability threshold = %d\n", min_profitable_iters); *ret_min_profitable_estimate = min_profitable_estimate; } /* Writes into SEL a mask for a vec_perm, equivalent to a vec_shr by OFFSET vector elements (not bits) for a vector of mode MODE. */ static void calc_vec_perm_mask_for_shift (enum machine_mode mode, unsigned int offset, unsigned char *sel) { unsigned int i, nelt = GET_MODE_NUNITS (mode); for (i = 0; i < nelt; i++) sel[i] = (i + offset) & (2*nelt - 1); } /* Checks whether the target supports whole-vector shifts for vectors of mode MODE. This is the case if _either_ the platform handles vec_shr_optab, _or_ it supports vec_perm_const with masks for all necessary shift amounts. */ static bool have_whole_vector_shift (enum machine_mode mode) { if (optab_handler (vec_shr_optab, mode) != CODE_FOR_nothing) return true; if (direct_optab_handler (vec_perm_const_optab, mode) == CODE_FOR_nothing) return false; unsigned int i, nelt = GET_MODE_NUNITS (mode); unsigned char *sel = XALLOCAVEC (unsigned char, nelt); for (i = nelt/2; i >= 1; i/=2) { calc_vec_perm_mask_for_shift (mode, i, sel); if (!can_vec_perm_p (mode, false, sel)) return false; } return true; } /* Return the reduction operand (with index REDUC_INDEX) of STMT. */ static tree get_reduction_op (gimple *stmt, int reduc_index) { switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt))) { case GIMPLE_SINGLE_RHS: gcc_assert (TREE_OPERAND_LENGTH (gimple_assign_rhs1 (stmt)) == ternary_op); return TREE_OPERAND (gimple_assign_rhs1 (stmt), reduc_index); case GIMPLE_UNARY_RHS: return gimple_assign_rhs1 (stmt); case GIMPLE_BINARY_RHS: return (reduc_index ? gimple_assign_rhs2 (stmt) : gimple_assign_rhs1 (stmt)); case GIMPLE_TERNARY_RHS: return gimple_op (stmt, reduc_index + 1); default: gcc_unreachable (); } } /* TODO: Close dependency between vect_model_*_cost and vectorizable_* functions. Design better to avoid maintenance issues. */ /* Function vect_model_reduction_cost. Models cost for a reduction operation, including the vector ops generated within the strip-mine loop, the initial definition before the loop, and the epilogue code that must be generated. */ static bool vect_model_reduction_cost (stmt_vec_info stmt_info, enum tree_code reduc_code, int ncopies, int reduc_index) { int prologue_cost = 0, epilogue_cost = 0; enum tree_code code; optab optab; tree vectype; gimple *stmt, *orig_stmt; tree reduction_op; machine_mode mode; loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); struct loop *loop = NULL; void *target_cost_data; if (loop_vinfo) { loop = LOOP_VINFO_LOOP (loop_vinfo); target_cost_data = LOOP_VINFO_TARGET_COST_DATA (loop_vinfo); } else target_cost_data = BB_VINFO_TARGET_COST_DATA (STMT_VINFO_BB_VINFO (stmt_info)); /* Condition reductions generate two reductions in the loop. */ if (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == COND_REDUCTION) ncopies *= 2; /* Cost of reduction op inside loop. */ unsigned inside_cost = add_stmt_cost (target_cost_data, ncopies, vector_stmt, stmt_info, 0, vect_body); stmt = STMT_VINFO_STMT (stmt_info); reduction_op = get_reduction_op (stmt, reduc_index); vectype = get_vectype_for_scalar_type (TREE_TYPE (reduction_op)); if (!vectype) { if (dump_enabled_p ()) { dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "unsupported data-type "); dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, TREE_TYPE (reduction_op)); dump_printf (MSG_MISSED_OPTIMIZATION, "\n"); } return false; } mode = TYPE_MODE (vectype); orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info); if (!orig_stmt) orig_stmt = STMT_VINFO_STMT (stmt_info); code = gimple_assign_rhs_code (orig_stmt); /* Add in cost for initial definition. For cond reduction we have four vectors: initial index, step, initial result of the data reduction, initial value of the index reduction. */ int prologue_stmts = STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == COND_REDUCTION ? 4 : 1; prologue_cost += add_stmt_cost (target_cost_data, prologue_stmts, scalar_to_vec, stmt_info, 0, vect_prologue); /* Determine cost of epilogue code. We have a reduction operator that will reduce the vector in one statement. Also requires scalar extract. */ if (!loop || !nested_in_vect_loop_p (loop, orig_stmt)) { if (reduc_code != ERROR_MARK) { if (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == COND_REDUCTION) { /* An EQ stmt and an COND_EXPR stmt. */ epilogue_cost += add_stmt_cost (target_cost_data, 2, vector_stmt, stmt_info, 0, vect_epilogue); /* Reduction of the max index and a reduction of the found values. */ epilogue_cost += add_stmt_cost (target_cost_data, 2, vec_to_scalar, stmt_info, 0, vect_epilogue); /* A broadcast of the max value. */ epilogue_cost += add_stmt_cost (target_cost_data, 1, scalar_to_vec, stmt_info, 0, vect_epilogue); } else { epilogue_cost += add_stmt_cost (target_cost_data, 1, vector_stmt, stmt_info, 0, vect_epilogue); epilogue_cost += add_stmt_cost (target_cost_data, 1, vec_to_scalar, stmt_info, 0, vect_epilogue); } } else { int vec_size_in_bits = tree_to_uhwi (TYPE_SIZE (vectype)); tree bitsize = TYPE_SIZE (TREE_TYPE (gimple_assign_lhs (orig_stmt))); int element_bitsize = tree_to_uhwi (bitsize); int nelements = vec_size_in_bits / element_bitsize; optab = optab_for_tree_code (code, vectype, optab_default); /* We have a whole vector shift available. */ if (VECTOR_MODE_P (mode) && optab_handler (optab, mode) != CODE_FOR_nothing && have_whole_vector_shift (mode)) { /* Final reduction via vector shifts and the reduction operator. Also requires scalar extract. */ epilogue_cost += add_stmt_cost (target_cost_data, exact_log2 (nelements) * 2, vector_stmt, stmt_info, 0, vect_epilogue); epilogue_cost += add_stmt_cost (target_cost_data, 1, vec_to_scalar, stmt_info, 0, vect_epilogue); } else /* Use extracts and reduction op for final reduction. For N elements, we have N extracts and N-1 reduction ops. */ epilogue_cost += add_stmt_cost (target_cost_data, nelements + nelements - 1, vector_stmt, stmt_info, 0, vect_epilogue); } } if (dump_enabled_p ()) dump_printf (MSG_NOTE, "vect_model_reduction_cost: inside_cost = %d, " "prologue_cost = %d, epilogue_cost = %d .\n", inside_cost, prologue_cost, epilogue_cost); return true; } /* Function vect_model_induction_cost. Models cost for induction operations. */ static void vect_model_induction_cost (stmt_vec_info stmt_info, int ncopies) { loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); void *target_cost_data = LOOP_VINFO_TARGET_COST_DATA (loop_vinfo); unsigned inside_cost, prologue_cost; /* loop cost for vec_loop. */ inside_cost = add_stmt_cost (target_cost_data, ncopies, vector_stmt, stmt_info, 0, vect_body); /* prologue cost for vec_init and vec_step. */ prologue_cost = add_stmt_cost (target_cost_data, 2, scalar_to_vec, stmt_info, 0, vect_prologue); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "vect_model_induction_cost: inside_cost = %d, " "prologue_cost = %d .\n", inside_cost, prologue_cost); } /* Function get_initial_def_for_induction Input: STMT - a stmt that performs an induction operation in the loop. IV_PHI - the initial value of the induction variable Output: Return a vector variable, initialized with the first VF values of the induction variable. E.g., for an iv with IV_PHI='X' and evolution S, for a vector of 4 units, we want to return: [X, X + S, X + 2*S, X + 3*S]. */ static tree get_initial_def_for_induction (gimple *iv_phi) { stmt_vec_info stmt_vinfo = vinfo_for_stmt (iv_phi); loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_vinfo); struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); tree vectype; int nunits; edge pe = loop_preheader_edge (loop); struct loop *iv_loop; basic_block new_bb; tree new_vec, vec_init, vec_step, t; tree new_name; gimple *new_stmt; gphi *induction_phi; tree induc_def, vec_def, vec_dest; tree init_expr, step_expr; int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); int i; int ncopies; tree expr; stmt_vec_info phi_info = vinfo_for_stmt (iv_phi); bool nested_in_vect_loop = false; gimple_seq stmts; imm_use_iterator imm_iter; use_operand_p use_p; gimple *exit_phi; edge latch_e; tree loop_arg; gimple_stmt_iterator si; basic_block bb = gimple_bb (iv_phi); tree stepvectype; tree resvectype; /* Is phi in an inner-loop, while vectorizing an enclosing outer-loop? */ if (nested_in_vect_loop_p (loop, iv_phi)) { nested_in_vect_loop = true; iv_loop = loop->inner; } else iv_loop = loop; gcc_assert (iv_loop == (gimple_bb (iv_phi))->loop_father); latch_e = loop_latch_edge (iv_loop); loop_arg = PHI_ARG_DEF_FROM_EDGE (iv_phi, latch_e); step_expr = STMT_VINFO_LOOP_PHI_EVOLUTION_PART (phi_info); gcc_assert (step_expr != NULL_TREE); pe = loop_preheader_edge (iv_loop); init_expr = PHI_ARG_DEF_FROM_EDGE (iv_phi, loop_preheader_edge (iv_loop)); vectype = get_vectype_for_scalar_type (TREE_TYPE (init_expr)); resvectype = get_vectype_for_scalar_type (TREE_TYPE (PHI_RESULT (iv_phi))); gcc_assert (vectype); nunits = TYPE_VECTOR_SUBPARTS (vectype); ncopies = vf / nunits; gcc_assert (phi_info); gcc_assert (ncopies >= 1); /* Convert the step to the desired type. */ stmts = NULL; step_expr = gimple_convert (&stmts, TREE_TYPE (vectype), step_expr); if (stmts) { new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts); gcc_assert (!new_bb); } /* Find the first insertion point in the BB. */ si = gsi_after_labels (bb); /* Create the vector that holds the initial_value of the induction. */ if (nested_in_vect_loop) { /* iv_loop is nested in the loop to be vectorized. init_expr had already been created during vectorization of previous stmts. We obtain it from the STMT_VINFO_VEC_STMT of the defining stmt. */ vec_init = vect_get_vec_def_for_operand (init_expr, iv_phi); /* If the initial value is not of proper type, convert it. */ if (!useless_type_conversion_p (vectype, TREE_TYPE (vec_init))) { new_stmt = gimple_build_assign (vect_get_new_ssa_name (vectype, vect_simple_var, "vec_iv_"), VIEW_CONVERT_EXPR, build1 (VIEW_CONVERT_EXPR, vectype, vec_init)); vec_init = gimple_assign_lhs (new_stmt); new_bb = gsi_insert_on_edge_immediate (loop_preheader_edge (iv_loop), new_stmt); gcc_assert (!new_bb); set_vinfo_for_stmt (new_stmt, new_stmt_vec_info (new_stmt, loop_vinfo)); } } else { vec *v; /* iv_loop is the loop to be vectorized. Create: vec_init = [X, X+S, X+2*S, X+3*S] (S = step_expr, X = init_expr) */ stmts = NULL; new_name = gimple_convert (&stmts, TREE_TYPE (vectype), init_expr); vec_alloc (v, nunits); bool constant_p = is_gimple_min_invariant (new_name); CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, new_name); for (i = 1; i < nunits; i++) { /* Create: new_name_i = new_name + step_expr */ new_name = gimple_build (&stmts, PLUS_EXPR, TREE_TYPE (new_name), new_name, step_expr); if (!is_gimple_min_invariant (new_name)) constant_p = false; CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, new_name); } if (stmts) { new_bb = gsi_insert_seq_on_edge_immediate (pe, stmts); gcc_assert (!new_bb); } /* Create a vector from [new_name_0, new_name_1, ..., new_name_nunits-1] */ if (constant_p) new_vec = build_vector_from_ctor (vectype, v); else new_vec = build_constructor (vectype, v); vec_init = vect_init_vector (iv_phi, new_vec, vectype, NULL); } /* Create the vector that holds the step of the induction. */ if (nested_in_vect_loop) /* iv_loop is nested in the loop to be vectorized. Generate: vec_step = [S, S, S, S] */ new_name = step_expr; else { /* iv_loop is the loop to be vectorized. Generate: vec_step = [VF*S, VF*S, VF*S, VF*S] */ if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr))) { expr = build_int_cst (integer_type_node, vf); expr = fold_convert (TREE_TYPE (step_expr), expr); } else expr = build_int_cst (TREE_TYPE (step_expr), vf); new_name = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr), expr, step_expr); if (TREE_CODE (step_expr) == SSA_NAME) new_name = vect_init_vector (iv_phi, new_name, TREE_TYPE (step_expr), NULL); } t = unshare_expr (new_name); gcc_assert (CONSTANT_CLASS_P (new_name) || TREE_CODE (new_name) == SSA_NAME); stepvectype = get_vectype_for_scalar_type (TREE_TYPE (new_name)); gcc_assert (stepvectype); new_vec = build_vector_from_val (stepvectype, t); vec_step = vect_init_vector (iv_phi, new_vec, stepvectype, NULL); /* Create the following def-use cycle: loop prolog: vec_init = ... vec_step = ... loop: vec_iv = PHI ... STMT ... vec_loop = vec_iv + vec_step; */ /* Create the induction-phi that defines the induction-operand. */ vec_dest = vect_get_new_vect_var (vectype, vect_simple_var, "vec_iv_"); induction_phi = create_phi_node (vec_dest, iv_loop->header); set_vinfo_for_stmt (induction_phi, new_stmt_vec_info (induction_phi, loop_vinfo)); induc_def = PHI_RESULT (induction_phi); /* Create the iv update inside the loop */ new_stmt = gimple_build_assign (vec_dest, PLUS_EXPR, induc_def, vec_step); vec_def = make_ssa_name (vec_dest, new_stmt); gimple_assign_set_lhs (new_stmt, vec_def); gsi_insert_before (&si, new_stmt, GSI_SAME_STMT); set_vinfo_for_stmt (new_stmt, new_stmt_vec_info (new_stmt, loop_vinfo)); /* Set the arguments of the phi node: */ add_phi_arg (induction_phi, vec_init, pe, UNKNOWN_LOCATION); add_phi_arg (induction_phi, vec_def, loop_latch_edge (iv_loop), UNKNOWN_LOCATION); /* In case that vectorization factor (VF) is bigger than the number of elements that we can fit in a vectype (nunits), we have to generate more than one vector stmt - i.e - we need to "unroll" the vector stmt by a factor VF/nunits. For more details see documentation in vectorizable_operation. */ if (ncopies > 1) { stmt_vec_info prev_stmt_vinfo; /* FORNOW. This restriction should be relaxed. */ gcc_assert (!nested_in_vect_loop); /* Create the vector that holds the step of the induction. */ if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (step_expr))) { expr = build_int_cst (integer_type_node, nunits); expr = fold_convert (TREE_TYPE (step_expr), expr); } else expr = build_int_cst (TREE_TYPE (step_expr), nunits); new_name = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr), expr, step_expr); if (TREE_CODE (step_expr) == SSA_NAME) new_name = vect_init_vector (iv_phi, new_name, TREE_TYPE (step_expr), NULL); t = unshare_expr (new_name); gcc_assert (CONSTANT_CLASS_P (new_name) || TREE_CODE (new_name) == SSA_NAME); new_vec = build_vector_from_val (stepvectype, t); vec_step = vect_init_vector (iv_phi, new_vec, stepvectype, NULL); vec_def = induc_def; prev_stmt_vinfo = vinfo_for_stmt (induction_phi); for (i = 1; i < ncopies; i++) { /* vec_i = vec_prev + vec_step */ new_stmt = gimple_build_assign (vec_dest, PLUS_EXPR, vec_def, vec_step); vec_def = make_ssa_name (vec_dest, new_stmt); gimple_assign_set_lhs (new_stmt, vec_def); gsi_insert_before (&si, new_stmt, GSI_SAME_STMT); if (!useless_type_conversion_p (resvectype, vectype)) { new_stmt = gimple_build_assign (vect_get_new_vect_var (resvectype, vect_simple_var, "vec_iv_"), VIEW_CONVERT_EXPR, build1 (VIEW_CONVERT_EXPR, resvectype, gimple_assign_lhs (new_stmt))); gimple_assign_set_lhs (new_stmt, make_ssa_name (gimple_assign_lhs (new_stmt), new_stmt)); gsi_insert_before (&si, new_stmt, GSI_SAME_STMT); } set_vinfo_for_stmt (new_stmt, new_stmt_vec_info (new_stmt, loop_vinfo)); STMT_VINFO_RELATED_STMT (prev_stmt_vinfo) = new_stmt; prev_stmt_vinfo = vinfo_for_stmt (new_stmt); } } if (nested_in_vect_loop) { /* Find the loop-closed exit-phi of the induction, and record the final vector of induction results: */ exit_phi = NULL; FOR_EACH_IMM_USE_FAST (use_p, imm_iter, loop_arg) { gimple *use_stmt = USE_STMT (use_p); if (is_gimple_debug (use_stmt)) continue; if (!flow_bb_inside_loop_p (iv_loop, gimple_bb (use_stmt))) { exit_phi = use_stmt; break; } } if (exit_phi) { stmt_vec_info stmt_vinfo = vinfo_for_stmt (exit_phi); /* FORNOW. Currently not supporting the case that an inner-loop induction is not used in the outer-loop (i.e. only outside the outer-loop). */ gcc_assert (STMT_VINFO_RELEVANT_P (stmt_vinfo) && !STMT_VINFO_LIVE_P (stmt_vinfo)); STMT_VINFO_VEC_STMT (stmt_vinfo) = new_stmt; if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "vector of inductions after inner-loop:"); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, new_stmt, 0); dump_printf (MSG_NOTE, "\n"); } } } if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "transform induction: created def-use cycle: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, induction_phi, 0); dump_printf (MSG_NOTE, "\n"); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, SSA_NAME_DEF_STMT (vec_def), 0); dump_printf (MSG_NOTE, "\n"); } STMT_VINFO_VEC_STMT (phi_info) = induction_phi; if (!useless_type_conversion_p (resvectype, vectype)) { new_stmt = gimple_build_assign (vect_get_new_vect_var (resvectype, vect_simple_var, "vec_iv_"), VIEW_CONVERT_EXPR, build1 (VIEW_CONVERT_EXPR, resvectype, induc_def)); induc_def = make_ssa_name (gimple_assign_lhs (new_stmt), new_stmt); gimple_assign_set_lhs (new_stmt, induc_def); si = gsi_after_labels (bb); gsi_insert_before (&si, new_stmt, GSI_SAME_STMT); set_vinfo_for_stmt (new_stmt, new_stmt_vec_info (new_stmt, loop_vinfo)); STMT_VINFO_RELATED_STMT (vinfo_for_stmt (new_stmt)) = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (induction_phi)); } return induc_def; } /* Function get_initial_def_for_reduction Input: STMT - a stmt that performs a reduction operation in the loop. INIT_VAL - the initial value of the reduction variable Output: ADJUSTMENT_DEF - a tree that holds a value to be added to the final result of the reduction (used for adjusting the epilog - see below). Return a vector variable, initialized according to the operation that STMT performs. This vector will be used as the initial value of the vector of partial results. Option1 (adjust in epilog): Initialize the vector as follows: add/bit or/xor: [0,0,...,0,0] mult/bit and: [1,1,...,1,1] min/max/cond_expr: [init_val,init_val,..,init_val,init_val] and when necessary (e.g. add/mult case) let the caller know that it needs to adjust the result by init_val. Option2: Initialize the vector as follows: add/bit or/xor: [init_val,0,0,...,0] mult/bit and: [init_val,1,1,...,1] min/max/cond_expr: [init_val,init_val,...,init_val] and no adjustments are needed. For example, for the following code: s = init_val; for (i=0;iloop_father); /* In case of double reduction we only create a vector variable to be put in the reduction phi node. The actual statement creation is done in vect_create_epilog_for_reduction. */ if (adjustment_def && nested_in_vect_loop && TREE_CODE (init_val) == SSA_NAME && (def_stmt = SSA_NAME_DEF_STMT (init_val)) && gimple_code (def_stmt) == GIMPLE_PHI && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt)) && vinfo_for_stmt (def_stmt) && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def_stmt)) == vect_double_reduction_def) { *adjustment_def = NULL; return vect_create_destination_var (init_val, vectype); } if (TREE_CONSTANT (init_val)) { if (SCALAR_FLOAT_TYPE_P (scalar_type)) init_value = build_real (scalar_type, TREE_REAL_CST (init_val)); else init_value = build_int_cst (scalar_type, TREE_INT_CST_LOW (init_val)); } else init_value = init_val; switch (code) { case WIDEN_SUM_EXPR: case DOT_PROD_EXPR: case SAD_EXPR: case PLUS_EXPR: case MINUS_EXPR: case BIT_IOR_EXPR: case BIT_XOR_EXPR: case MULT_EXPR: case BIT_AND_EXPR: /* ADJUSMENT_DEF is NULL when called from vect_create_epilog_for_reduction to vectorize double reduction. */ if (adjustment_def) { if (nested_in_vect_loop) *adjustment_def = vect_get_vec_def_for_operand (init_val, stmt); else *adjustment_def = init_val; } if (code == MULT_EXPR) { real_init_val = dconst1; int_init_val = 1; } if (code == BIT_AND_EXPR) int_init_val = -1; if (SCALAR_FLOAT_TYPE_P (scalar_type)) def_for_init = build_real (scalar_type, real_init_val); else def_for_init = build_int_cst (scalar_type, int_init_val); /* Create a vector of '0' or '1' except the first element. */ elts = XALLOCAVEC (tree, nunits); for (i = nunits - 2; i >= 0; --i) elts[i + 1] = def_for_init; /* Option1: the first element is '0' or '1' as well. */ if (adjustment_def) { elts[0] = def_for_init; init_def = build_vector (vectype, elts); break; } /* Option2: the first element is INIT_VAL. */ elts[0] = init_val; if (TREE_CONSTANT (init_val)) init_def = build_vector (vectype, elts); else { vec *v; vec_alloc (v, nunits); CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, init_val); for (i = 1; i < nunits; ++i) CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, elts[i]); init_def = build_constructor (vectype, v); } break; case MIN_EXPR: case MAX_EXPR: case COND_EXPR: if (adjustment_def) { *adjustment_def = NULL_TREE; if (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_vinfo) != COND_REDUCTION) { init_def = vect_get_vec_def_for_operand (init_val, stmt); break; } } init_def = build_vector_from_val (vectype, init_value); break; default: gcc_unreachable (); } return init_def; } /* Function vect_create_epilog_for_reduction Create code at the loop-epilog to finalize the result of a reduction computation. VECT_DEFS is list of vector of partial results, i.e., the lhs's of vector reduction statements. STMT is the scalar reduction stmt that is being vectorized. NCOPIES is > 1 in case the vectorization factor (VF) is bigger than the number of elements that we can fit in a vectype (nunits). In this case we have to generate more than one vector stmt - i.e - we need to "unroll" the vector stmt by a factor VF/nunits. For more details see documentation in vectorizable_operation. REDUC_CODE is the tree-code for the epilog reduction. REDUCTION_PHIS is a list of the phi-nodes that carry the reduction computation. REDUC_INDEX is the index of the operand in the right hand side of the statement that is defined by REDUCTION_PHI. DOUBLE_REDUC is TRUE if double reduction phi nodes should be handled. SLP_NODE is an SLP node containing a group of reduction statements. The first one in this group is STMT. INDUCTION_INDEX is the index of the loop for condition reductions. Otherwise it is undefined. This function: 1. Creates the reduction def-use cycles: sets the arguments for REDUCTION_PHIS: The loop-entry argument is the vectorized initial-value of the reduction. The loop-latch argument is taken from VECT_DEFS - the vector of partial sums. 2. "Reduces" each vector of partial results VECT_DEFS into a single result, by applying the operation specified by REDUC_CODE if available, or by other means (whole-vector shifts or a scalar loop). The function also creates a new phi node at the loop exit to preserve loop-closed form, as illustrated below. The flow at the entry to this function: loop: vec_def = phi # REDUCTION_PHI VECT_DEF = vector_stmt # vectorized form of STMT s_loop = scalar_stmt # (scalar) STMT loop_exit: s_out0 = phi # (scalar) EXIT_PHI use use The above is transformed by this function into: loop: vec_def = phi # REDUCTION_PHI VECT_DEF = vector_stmt # vectorized form of STMT s_loop = scalar_stmt # (scalar) STMT loop_exit: s_out0 = phi # (scalar) EXIT_PHI v_out1 = phi # NEW_EXIT_PHI v_out2 = reduce s_out3 = extract_field s_out4 = adjust_result use use */ static void vect_create_epilog_for_reduction (vec vect_defs, gimple *stmt, int ncopies, enum tree_code reduc_code, vec reduction_phis, int reduc_index, bool double_reduc, slp_tree slp_node, tree induction_index) { stmt_vec_info stmt_info = vinfo_for_stmt (stmt); stmt_vec_info prev_phi_info; tree vectype; machine_mode mode; loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo), *outer_loop = NULL; basic_block exit_bb; tree scalar_dest; tree scalar_type; gimple *new_phi = NULL, *phi; gimple_stmt_iterator exit_gsi; tree vec_dest; tree new_temp = NULL_TREE, new_dest, new_name, new_scalar_dest; gimple *epilog_stmt = NULL; enum tree_code code = gimple_assign_rhs_code (stmt); gimple *exit_phi; tree bitsize; tree adjustment_def = NULL; tree vec_initial_def = NULL; tree reduction_op, expr, def; tree orig_name, scalar_result; imm_use_iterator imm_iter, phi_imm_iter; use_operand_p use_p, phi_use_p; gimple *use_stmt, *orig_stmt, *reduction_phi = NULL; bool nested_in_vect_loop = false; auto_vec new_phis; auto_vec inner_phis; enum vect_def_type dt = vect_unknown_def_type; int j, i; auto_vec scalar_results; unsigned int group_size = 1, k, ratio; auto_vec vec_initial_defs; auto_vec phis; bool slp_reduc = false; tree new_phi_result; gimple *inner_phi = NULL; if (slp_node) group_size = SLP_TREE_SCALAR_STMTS (slp_node).length (); if (nested_in_vect_loop_p (loop, stmt)) { outer_loop = loop; loop = loop->inner; nested_in_vect_loop = true; gcc_assert (!slp_node); } reduction_op = get_reduction_op (stmt, reduc_index); vectype = get_vectype_for_scalar_type (TREE_TYPE (reduction_op)); gcc_assert (vectype); mode = TYPE_MODE (vectype); /* 1. Create the reduction def-use cycle: Set the arguments of REDUCTION_PHIS, i.e., transform loop: vec_def = phi # REDUCTION_PHI VECT_DEF = vector_stmt # vectorized form of STMT ... into: loop: vec_def = phi # REDUCTION_PHI VECT_DEF = vector_stmt # vectorized form of STMT ... (in case of SLP, do it for all the phis). */ /* Get the loop-entry arguments. */ if (slp_node) vect_get_vec_defs (reduction_op, NULL_TREE, stmt, &vec_initial_defs, NULL, slp_node, reduc_index); else { /* Get at the scalar def before the loop, that defines the initial value of the reduction variable. */ gimple *def_stmt = SSA_NAME_DEF_STMT (reduction_op); tree op = PHI_ARG_DEF_FROM_EDGE (def_stmt, loop_preheader_edge (loop)); vec_initial_defs.create (1); vec_initial_def = get_initial_def_for_reduction (stmt, op, &adjustment_def); vec_initial_defs.quick_push (vec_initial_def); } /* Set phi nodes arguments. */ FOR_EACH_VEC_ELT (reduction_phis, i, phi) { tree vec_init_def, def; gimple_seq stmts; vec_init_def = force_gimple_operand (vec_initial_defs[i], &stmts, true, NULL_TREE); gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts); def = vect_defs[i]; for (j = 0; j < ncopies; j++) { /* Set the loop-entry arg of the reduction-phi. */ add_phi_arg (as_a (phi), vec_init_def, loop_preheader_edge (loop), UNKNOWN_LOCATION); /* Set the loop-latch arg for the reduction-phi. */ if (j > 0) def = vect_get_vec_def_for_stmt_copy (vect_unknown_def_type, def); add_phi_arg (as_a (phi), def, loop_latch_edge (loop), UNKNOWN_LOCATION); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "transform reduction: created def-use cycle: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, phi, 0); dump_printf (MSG_NOTE, "\n"); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, SSA_NAME_DEF_STMT (def), 0); dump_printf (MSG_NOTE, "\n"); } phi = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (phi)); } } /* 2. Create epilog code. The reduction epilog code operates across the elements of the vector of partial results computed by the vectorized loop. The reduction epilog code consists of: step 1: compute the scalar result in a vector (v_out2) step 2: extract the scalar result (s_out3) from the vector (v_out2) step 3: adjust the scalar result (s_out3) if needed. Step 1 can be accomplished using one the following three schemes: (scheme 1) using reduc_code, if available. (scheme 2) using whole-vector shifts, if available. (scheme 3) using a scalar loop. In this case steps 1+2 above are combined. The overall epilog code looks like this: s_out0 = phi # original EXIT_PHI v_out1 = phi # NEW_EXIT_PHI v_out2 = reduce # step 1 s_out3 = extract_field # step 2 s_out4 = adjust_result # step 3 (step 3 is optional, and steps 1 and 2 may be combined). Lastly, the uses of s_out0 are replaced by s_out4. */ /* 2.1 Create new loop-exit-phis to preserve loop-closed form: v_out1 = phi Store them in NEW_PHIS. */ exit_bb = single_exit (loop)->dest; prev_phi_info = NULL; new_phis.create (vect_defs.length ()); FOR_EACH_VEC_ELT (vect_defs, i, def) { for (j = 0; j < ncopies; j++) { tree new_def = copy_ssa_name (def); phi = create_phi_node (new_def, exit_bb); set_vinfo_for_stmt (phi, new_stmt_vec_info (phi, loop_vinfo)); if (j == 0) new_phis.quick_push (phi); else { def = vect_get_vec_def_for_stmt_copy (dt, def); STMT_VINFO_RELATED_STMT (prev_phi_info) = phi; } SET_PHI_ARG_DEF (phi, single_exit (loop)->dest_idx, def); prev_phi_info = vinfo_for_stmt (phi); } } /* The epilogue is created for the outer-loop, i.e., for the loop being vectorized. Create exit phis for the outer loop. */ if (double_reduc) { loop = outer_loop; exit_bb = single_exit (loop)->dest; inner_phis.create (vect_defs.length ()); FOR_EACH_VEC_ELT (new_phis, i, phi) { tree new_result = copy_ssa_name (PHI_RESULT (phi)); gphi *outer_phi = create_phi_node (new_result, exit_bb); SET_PHI_ARG_DEF (outer_phi, single_exit (loop)->dest_idx, PHI_RESULT (phi)); set_vinfo_for_stmt (outer_phi, new_stmt_vec_info (outer_phi, loop_vinfo)); inner_phis.quick_push (phi); new_phis[i] = outer_phi; prev_phi_info = vinfo_for_stmt (outer_phi); while (STMT_VINFO_RELATED_STMT (vinfo_for_stmt (phi))) { phi = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (phi)); new_result = copy_ssa_name (PHI_RESULT (phi)); outer_phi = create_phi_node (new_result, exit_bb); SET_PHI_ARG_DEF (outer_phi, single_exit (loop)->dest_idx, PHI_RESULT (phi)); set_vinfo_for_stmt (outer_phi, new_stmt_vec_info (outer_phi, loop_vinfo)); STMT_VINFO_RELATED_STMT (prev_phi_info) = outer_phi; prev_phi_info = vinfo_for_stmt (outer_phi); } } } exit_gsi = gsi_after_labels (exit_bb); /* 2.2 Get the relevant tree-code to use in the epilog for schemes 2,3 (i.e. when reduc_code is not available) and in the final adjustment code (if needed). Also get the original scalar reduction variable as defined in the loop. In case STMT is a "pattern-stmt" (i.e. - it represents a reduction pattern), the tree-code and scalar-def are taken from the original stmt that the pattern-stmt (STMT) replaces. Otherwise (it is a regular reduction) - the tree-code and scalar-def are taken from STMT. */ orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info); if (!orig_stmt) { /* Regular reduction */ orig_stmt = stmt; } else { /* Reduction pattern */ stmt_vec_info stmt_vinfo = vinfo_for_stmt (orig_stmt); gcc_assert (STMT_VINFO_IN_PATTERN_P (stmt_vinfo)); gcc_assert (STMT_VINFO_RELATED_STMT (stmt_vinfo) == stmt); } code = gimple_assign_rhs_code (orig_stmt); /* For MINUS_EXPR the initial vector is [init_val,0,...,0], therefore, partial results are added and not subtracted. */ if (code == MINUS_EXPR) code = PLUS_EXPR; scalar_dest = gimple_assign_lhs (orig_stmt); scalar_type = TREE_TYPE (scalar_dest); scalar_results.create (group_size); new_scalar_dest = vect_create_destination_var (scalar_dest, NULL); bitsize = TYPE_SIZE (scalar_type); /* In case this is a reduction in an inner-loop while vectorizing an outer loop - we don't need to extract a single scalar result at the end of the inner-loop (unless it is double reduction, i.e., the use of reduction is outside the outer-loop). The final vector of partial results will be used in the vectorized outer-loop, or reduced to a scalar result at the end of the outer-loop. */ if (nested_in_vect_loop && !double_reduc) goto vect_finalize_reduction; /* SLP reduction without reduction chain, e.g., # a1 = phi # b1 = phi a2 = operation (a1) b2 = operation (b1) */ slp_reduc = (slp_node && !GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt))); /* In case of reduction chain, e.g., # a1 = phi a2 = operation (a1) a3 = operation (a2), we may end up with more than one vector result. Here we reduce them to one vector. */ if (GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt))) { tree first_vect = PHI_RESULT (new_phis[0]); tree tmp; gassign *new_vec_stmt = NULL; vec_dest = vect_create_destination_var (scalar_dest, vectype); for (k = 1; k < new_phis.length (); k++) { gimple *next_phi = new_phis[k]; tree second_vect = PHI_RESULT (next_phi); tmp = build2 (code, vectype, first_vect, second_vect); new_vec_stmt = gimple_build_assign (vec_dest, tmp); first_vect = make_ssa_name (vec_dest, new_vec_stmt); gimple_assign_set_lhs (new_vec_stmt, first_vect); gsi_insert_before (&exit_gsi, new_vec_stmt, GSI_SAME_STMT); } new_phi_result = first_vect; if (new_vec_stmt) { new_phis.truncate (0); new_phis.safe_push (new_vec_stmt); } } else new_phi_result = PHI_RESULT (new_phis[0]); if (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == COND_REDUCTION) { /* For condition reductions, we have a vector (NEW_PHI_RESULT) containing various data values where the condition matched and another vector (INDUCTION_INDEX) containing all the indexes of those matches. We need to extract the last matching index (which will be the index with highest value) and use this to index into the data vector. For the case where there were no matches, the data vector will contain all default values and the index vector will be all zeros. */ /* Get various versions of the type of the vector of indexes. */ tree index_vec_type = TREE_TYPE (induction_index); gcc_checking_assert (TYPE_UNSIGNED (index_vec_type)); tree index_vec_type_signed = signed_type_for (index_vec_type); tree index_scalar_type = TREE_TYPE (index_vec_type); /* Get an unsigned integer version of the type of the data vector. */ int scalar_precision = GET_MODE_PRECISION (TYPE_MODE (scalar_type)); tree scalar_type_unsigned = make_unsigned_type (scalar_precision); tree vectype_unsigned = build_vector_type (scalar_type_unsigned, TYPE_VECTOR_SUBPARTS (vectype)); /* First we need to create a vector (ZERO_VEC) of zeros and another vector (MAX_INDEX_VEC) filled with the last matching index, which we can create using a MAX reduction and then expanding. In the case where the loop never made any matches, the max index will be zero. */ /* Vector of {0, 0, 0,...}. */ tree zero_vec = make_ssa_name (vectype); tree zero_vec_rhs = build_zero_cst (vectype); gimple *zero_vec_stmt = gimple_build_assign (zero_vec, zero_vec_rhs); gsi_insert_before (&exit_gsi, zero_vec_stmt, GSI_SAME_STMT); /* Find maximum value from the vector of found indexes. */ tree max_index = make_ssa_name (index_scalar_type); gimple *max_index_stmt = gimple_build_assign (max_index, REDUC_MAX_EXPR, induction_index); gsi_insert_before (&exit_gsi, max_index_stmt, GSI_SAME_STMT); /* Vector of {max_index, max_index, max_index,...}. */ tree max_index_vec = make_ssa_name (index_vec_type); tree max_index_vec_rhs = build_vector_from_val (index_vec_type, max_index); gimple *max_index_vec_stmt = gimple_build_assign (max_index_vec, max_index_vec_rhs); gsi_insert_before (&exit_gsi, max_index_vec_stmt, GSI_SAME_STMT); /* Next we compare the new vector (MAX_INDEX_VEC) full of max indexes with the vector (INDUCTION_INDEX) of found indexes, choosing values from the data vector (NEW_PHI_RESULT) for matches, 0 (ZERO_VEC) otherwise. Only one value should match, resulting in a vector (VEC_COND) with one data value and the rest zeros. In the case where the loop never made any matches, every index will match, resulting in a vector with all data values (which will all be the default value). */ /* Compare the max index vector to the vector of found indexes to find the position of the max value. */ tree vec_compare = make_ssa_name (index_vec_type_signed); gimple *vec_compare_stmt = gimple_build_assign (vec_compare, EQ_EXPR, induction_index, max_index_vec); gsi_insert_before (&exit_gsi, vec_compare_stmt, GSI_SAME_STMT); /* Use the compare to choose either values from the data vector or zero. */ tree vec_cond = make_ssa_name (vectype); gimple *vec_cond_stmt = gimple_build_assign (vec_cond, VEC_COND_EXPR, vec_compare, new_phi_result, zero_vec); gsi_insert_before (&exit_gsi, vec_cond_stmt, GSI_SAME_STMT); /* Finally we need to extract the data value from the vector (VEC_COND) into a scalar (MATCHED_DATA_REDUC). Logically we want to do a OR reduction, but because this doesn't exist, we can use a MAX reduction instead. The data value might be signed or a float so we need to cast it first. In the case where the loop never made any matches, the data values are all identical, and so will reduce down correctly. */ /* Make the matched data values unsigned. */ tree vec_cond_cast = make_ssa_name (vectype_unsigned); tree vec_cond_cast_rhs = build1 (VIEW_CONVERT_EXPR, vectype_unsigned, vec_cond); gimple *vec_cond_cast_stmt = gimple_build_assign (vec_cond_cast, VIEW_CONVERT_EXPR, vec_cond_cast_rhs); gsi_insert_before (&exit_gsi, vec_cond_cast_stmt, GSI_SAME_STMT); /* Reduce down to a scalar value. */ tree data_reduc = make_ssa_name (scalar_type_unsigned); optab ot = optab_for_tree_code (REDUC_MAX_EXPR, vectype_unsigned, optab_default); gcc_assert (optab_handler (ot, TYPE_MODE (vectype_unsigned)) != CODE_FOR_nothing); gimple *data_reduc_stmt = gimple_build_assign (data_reduc, REDUC_MAX_EXPR, vec_cond_cast); gsi_insert_before (&exit_gsi, data_reduc_stmt, GSI_SAME_STMT); /* Convert the reduced value back to the result type and set as the result. */ tree data_reduc_cast = build1 (VIEW_CONVERT_EXPR, scalar_type, data_reduc); epilog_stmt = gimple_build_assign (new_scalar_dest, data_reduc_cast); new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_temp); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); scalar_results.safe_push (new_temp); } /* 2.3 Create the reduction code, using one of the three schemes described above. In SLP we simply need to extract all the elements from the vector (without reducing them), so we use scalar shifts. */ else if (reduc_code != ERROR_MARK && !slp_reduc) { tree tmp; tree vec_elem_type; /*** Case 1: Create: v_out2 = reduc_expr */ if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Reduce using direct vector reduction.\n"); vec_elem_type = TREE_TYPE (TREE_TYPE (new_phi_result)); if (!useless_type_conversion_p (scalar_type, vec_elem_type)) { tree tmp_dest = vect_create_destination_var (scalar_dest, vec_elem_type); tmp = build1 (reduc_code, vec_elem_type, new_phi_result); epilog_stmt = gimple_build_assign (tmp_dest, tmp); new_temp = make_ssa_name (tmp_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_temp); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); tmp = build1 (NOP_EXPR, scalar_type, new_temp); } else tmp = build1 (reduc_code, scalar_type, new_phi_result); epilog_stmt = gimple_build_assign (new_scalar_dest, tmp); new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_temp); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); scalar_results.safe_push (new_temp); } else { bool reduce_with_shift = have_whole_vector_shift (mode); int element_bitsize = tree_to_uhwi (bitsize); int vec_size_in_bits = tree_to_uhwi (TYPE_SIZE (vectype)); tree vec_temp; /* Regardless of whether we have a whole vector shift, if we're emulating the operation via tree-vect-generic, we don't want to use it. Only the first round of the reduction is likely to still be profitable via emulation. */ /* ??? It might be better to emit a reduction tree code here, so that tree-vect-generic can expand the first round via bit tricks. */ if (!VECTOR_MODE_P (mode)) reduce_with_shift = false; else { optab optab = optab_for_tree_code (code, vectype, optab_default); if (optab_handler (optab, mode) == CODE_FOR_nothing) reduce_with_shift = false; } if (reduce_with_shift && !slp_reduc) { int nelements = vec_size_in_bits / element_bitsize; unsigned char *sel = XALLOCAVEC (unsigned char, nelements); int elt_offset; tree zero_vec = build_zero_cst (vectype); /*** Case 2: Create: for (offset = nelements/2; offset >= 1; offset/=2) { Create: va' = vec_shift Create: va = vop } */ tree rhs; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Reduce using vector shifts\n"); vec_dest = vect_create_destination_var (scalar_dest, vectype); new_temp = new_phi_result; for (elt_offset = nelements / 2; elt_offset >= 1; elt_offset /= 2) { calc_vec_perm_mask_for_shift (mode, elt_offset, sel); tree mask = vect_gen_perm_mask_any (vectype, sel); epilog_stmt = gimple_build_assign (vec_dest, VEC_PERM_EXPR, new_temp, zero_vec, mask); new_name = make_ssa_name (vec_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_name); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); epilog_stmt = gimple_build_assign (vec_dest, code, new_name, new_temp); new_temp = make_ssa_name (vec_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_temp); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); } /* 2.4 Extract the final scalar result. Create: s_out3 = extract_field */ if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "extract scalar result\n"); rhs = build3 (BIT_FIELD_REF, scalar_type, new_temp, bitsize, bitsize_zero_node); epilog_stmt = gimple_build_assign (new_scalar_dest, rhs); new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_temp); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); scalar_results.safe_push (new_temp); } else { /*** Case 3: Create: s = extract_field for (offset = element_size; offset < vector_size; offset += element_size;) { Create: s' = extract_field Create: s = op // For non SLP cases } */ if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Reduce using scalar code.\n"); vec_size_in_bits = tree_to_uhwi (TYPE_SIZE (vectype)); FOR_EACH_VEC_ELT (new_phis, i, new_phi) { int bit_offset; if (gimple_code (new_phi) == GIMPLE_PHI) vec_temp = PHI_RESULT (new_phi); else vec_temp = gimple_assign_lhs (new_phi); tree rhs = build3 (BIT_FIELD_REF, scalar_type, vec_temp, bitsize, bitsize_zero_node); epilog_stmt = gimple_build_assign (new_scalar_dest, rhs); new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_temp); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); /* In SLP we don't need to apply reduction operation, so we just collect s' values in SCALAR_RESULTS. */ if (slp_reduc) scalar_results.safe_push (new_temp); for (bit_offset = element_bitsize; bit_offset < vec_size_in_bits; bit_offset += element_bitsize) { tree bitpos = bitsize_int (bit_offset); tree rhs = build3 (BIT_FIELD_REF, scalar_type, vec_temp, bitsize, bitpos); epilog_stmt = gimple_build_assign (new_scalar_dest, rhs); new_name = make_ssa_name (new_scalar_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_name); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); if (slp_reduc) { /* In SLP we don't need to apply reduction operation, so we just collect s' values in SCALAR_RESULTS. */ new_temp = new_name; scalar_results.safe_push (new_name); } else { epilog_stmt = gimple_build_assign (new_scalar_dest, code, new_name, new_temp); new_temp = make_ssa_name (new_scalar_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_temp); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); } } } /* The only case where we need to reduce scalar results in SLP, is unrolling. If the size of SCALAR_RESULTS is greater than GROUP_SIZE, we reduce them combining elements modulo GROUP_SIZE. */ if (slp_reduc) { tree res, first_res, new_res; gimple *new_stmt; /* Reduce multiple scalar results in case of SLP unrolling. */ for (j = group_size; scalar_results.iterate (j, &res); j++) { first_res = scalar_results[j % group_size]; new_stmt = gimple_build_assign (new_scalar_dest, code, first_res, res); new_res = make_ssa_name (new_scalar_dest, new_stmt); gimple_assign_set_lhs (new_stmt, new_res); gsi_insert_before (&exit_gsi, new_stmt, GSI_SAME_STMT); scalar_results[j % group_size] = new_res; } } else /* Not SLP - we have one scalar to keep in SCALAR_RESULTS. */ scalar_results.safe_push (new_temp); } } vect_finalize_reduction: if (double_reduc) loop = loop->inner; /* 2.5 Adjust the final result by the initial value of the reduction variable. (When such adjustment is not needed, then 'adjustment_def' is zero). For example, if code is PLUS we create: new_temp = loop_exit_def + adjustment_def */ if (adjustment_def) { gcc_assert (!slp_reduc); if (nested_in_vect_loop) { new_phi = new_phis[0]; gcc_assert (TREE_CODE (TREE_TYPE (adjustment_def)) == VECTOR_TYPE); expr = build2 (code, vectype, PHI_RESULT (new_phi), adjustment_def); new_dest = vect_create_destination_var (scalar_dest, vectype); } else { new_temp = scalar_results[0]; gcc_assert (TREE_CODE (TREE_TYPE (adjustment_def)) != VECTOR_TYPE); expr = build2 (code, scalar_type, new_temp, adjustment_def); new_dest = vect_create_destination_var (scalar_dest, scalar_type); } epilog_stmt = gimple_build_assign (new_dest, expr); new_temp = make_ssa_name (new_dest, epilog_stmt); gimple_assign_set_lhs (epilog_stmt, new_temp); gsi_insert_before (&exit_gsi, epilog_stmt, GSI_SAME_STMT); if (nested_in_vect_loop) { set_vinfo_for_stmt (epilog_stmt, new_stmt_vec_info (epilog_stmt, loop_vinfo)); STMT_VINFO_RELATED_STMT (vinfo_for_stmt (epilog_stmt)) = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (new_phi)); if (!double_reduc) scalar_results.quick_push (new_temp); else scalar_results[0] = new_temp; } else scalar_results[0] = new_temp; new_phis[0] = epilog_stmt; } /* 2.6 Handle the loop-exit phis. Replace the uses of scalar loop-exit phis with new adjusted scalar results, i.e., replace use with use . Transform: loop_exit: s_out0 = phi # (scalar) EXIT_PHI v_out1 = phi # NEW_EXIT_PHI v_out2 = reduce s_out3 = extract_field s_out4 = adjust_result use use into: loop_exit: s_out0 = phi # (scalar) EXIT_PHI v_out1 = phi # NEW_EXIT_PHI v_out2 = reduce s_out3 = extract_field s_out4 = adjust_result use use */ /* In SLP reduction chain we reduce vector results into one vector if necessary, hence we set here GROUP_SIZE to 1. SCALAR_DEST is the LHS of the last stmt in the reduction chain, since we are looking for the loop exit phi node. */ if (GROUP_FIRST_ELEMENT (vinfo_for_stmt (stmt))) { gimple *dest_stmt = SLP_TREE_SCALAR_STMTS (slp_node)[group_size - 1]; /* Handle reduction patterns. */ if (STMT_VINFO_RELATED_STMT (vinfo_for_stmt (dest_stmt))) dest_stmt = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (dest_stmt)); scalar_dest = gimple_assign_lhs (dest_stmt); group_size = 1; } /* In SLP we may have several statements in NEW_PHIS and REDUCTION_PHIS (in case that GROUP_SIZE is greater than vectorization factor). Therefore, we need to match SCALAR_RESULTS with corresponding statements. The first (GROUP_SIZE / number of new vector stmts) scalar results correspond to the first vector stmt, etc. (RATIO is equal to (GROUP_SIZE / number of new vector stmts)). */ if (group_size > new_phis.length ()) { ratio = group_size / new_phis.length (); gcc_assert (!(group_size % new_phis.length ())); } else ratio = 1; for (k = 0; k < group_size; k++) { if (k % ratio == 0) { epilog_stmt = new_phis[k / ratio]; reduction_phi = reduction_phis[k / ratio]; if (double_reduc) inner_phi = inner_phis[k / ratio]; } if (slp_reduc) { gimple *current_stmt = SLP_TREE_SCALAR_STMTS (slp_node)[k]; orig_stmt = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (current_stmt)); /* SLP statements can't participate in patterns. */ gcc_assert (!orig_stmt); scalar_dest = gimple_assign_lhs (current_stmt); } phis.create (3); /* Find the loop-closed-use at the loop exit of the original scalar result. (The reduction result is expected to have two immediate uses - one at the latch block, and one at the loop exit). */ FOR_EACH_IMM_USE_FAST (use_p, imm_iter, scalar_dest) if (!flow_bb_inside_loop_p (loop, gimple_bb (USE_STMT (use_p))) && !is_gimple_debug (USE_STMT (use_p))) phis.safe_push (USE_STMT (use_p)); /* While we expect to have found an exit_phi because of loop-closed-ssa form we can end up without one if the scalar cycle is dead. */ FOR_EACH_VEC_ELT (phis, i, exit_phi) { if (outer_loop) { stmt_vec_info exit_phi_vinfo = vinfo_for_stmt (exit_phi); gphi *vect_phi; /* FORNOW. Currently not supporting the case that an inner-loop reduction is not used in the outer-loop (but only outside the outer-loop), unless it is double reduction. */ gcc_assert ((STMT_VINFO_RELEVANT_P (exit_phi_vinfo) && !STMT_VINFO_LIVE_P (exit_phi_vinfo)) || double_reduc); if (double_reduc) STMT_VINFO_VEC_STMT (exit_phi_vinfo) = inner_phi; else STMT_VINFO_VEC_STMT (exit_phi_vinfo) = epilog_stmt; if (!double_reduc || STMT_VINFO_DEF_TYPE (exit_phi_vinfo) != vect_double_reduction_def) continue; /* Handle double reduction: stmt1: s1 = phi - double reduction phi (outer loop) stmt2: s3 = phi - (regular) reduc phi (inner loop) stmt3: s4 = use (s3) - (regular) reduc stmt (inner loop) stmt4: s2 = phi - double reduction stmt (outer loop) At that point the regular reduction (stmt2 and stmt3) is already vectorized, as well as the exit phi node, stmt4. Here we vectorize the phi node of double reduction, stmt1, and update all relevant statements. */ /* Go through all the uses of s2 to find double reduction phi node, i.e., stmt1 above. */ orig_name = PHI_RESULT (exit_phi); FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, orig_name) { stmt_vec_info use_stmt_vinfo; stmt_vec_info new_phi_vinfo; tree vect_phi_init, preheader_arg, vect_phi_res, init_def; basic_block bb = gimple_bb (use_stmt); gimple *use; /* Check that USE_STMT is really double reduction phi node. */ if (gimple_code (use_stmt) != GIMPLE_PHI || gimple_phi_num_args (use_stmt) != 2 || bb->loop_father != outer_loop) continue; use_stmt_vinfo = vinfo_for_stmt (use_stmt); if (!use_stmt_vinfo || STMT_VINFO_DEF_TYPE (use_stmt_vinfo) != vect_double_reduction_def) continue; /* Create vector phi node for double reduction: vs1 = phi vs1 was created previously in this function by a call to vect_get_vec_def_for_operand and is stored in vec_initial_def; vs2 is defined by INNER_PHI, the vectorized EXIT_PHI; vs0 is created here. */ /* Create vector phi node. */ vect_phi = create_phi_node (vec_initial_def, bb); new_phi_vinfo = new_stmt_vec_info (vect_phi, loop_vec_info_for_loop (outer_loop)); set_vinfo_for_stmt (vect_phi, new_phi_vinfo); /* Create vs0 - initial def of the double reduction phi. */ preheader_arg = PHI_ARG_DEF_FROM_EDGE (use_stmt, loop_preheader_edge (outer_loop)); init_def = get_initial_def_for_reduction (stmt, preheader_arg, NULL); vect_phi_init = vect_init_vector (use_stmt, init_def, vectype, NULL); /* Update phi node arguments with vs0 and vs2. */ add_phi_arg (vect_phi, vect_phi_init, loop_preheader_edge (outer_loop), UNKNOWN_LOCATION); add_phi_arg (vect_phi, PHI_RESULT (inner_phi), loop_latch_edge (outer_loop), UNKNOWN_LOCATION); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "created double reduction phi node: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, vect_phi, 0); dump_printf (MSG_NOTE, "\n"); } vect_phi_res = PHI_RESULT (vect_phi); /* Replace the use, i.e., set the correct vs1 in the regular reduction phi node. FORNOW, NCOPIES is always 1, so the loop is redundant. */ use = reduction_phi; for (j = 0; j < ncopies; j++) { edge pr_edge = loop_preheader_edge (loop); SET_PHI_ARG_DEF (use, pr_edge->dest_idx, vect_phi_res); use = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (use)); } } } } phis.release (); if (nested_in_vect_loop) { if (double_reduc) loop = outer_loop; else continue; } phis.create (3); /* Find the loop-closed-use at the loop exit of the original scalar result. (The reduction result is expected to have two immediate uses, one at the latch block, and one at the loop exit). For double reductions we are looking for exit phis of the outer loop. */ FOR_EACH_IMM_USE_FAST (use_p, imm_iter, scalar_dest) { if (!flow_bb_inside_loop_p (loop, gimple_bb (USE_STMT (use_p)))) { if (!is_gimple_debug (USE_STMT (use_p))) phis.safe_push (USE_STMT (use_p)); } else { if (double_reduc && gimple_code (USE_STMT (use_p)) == GIMPLE_PHI) { tree phi_res = PHI_RESULT (USE_STMT (use_p)); FOR_EACH_IMM_USE_FAST (phi_use_p, phi_imm_iter, phi_res) { if (!flow_bb_inside_loop_p (loop, gimple_bb (USE_STMT (phi_use_p))) && !is_gimple_debug (USE_STMT (phi_use_p))) phis.safe_push (USE_STMT (phi_use_p)); } } } } FOR_EACH_VEC_ELT (phis, i, exit_phi) { /* Replace the uses: */ orig_name = PHI_RESULT (exit_phi); scalar_result = scalar_results[k]; FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, orig_name) FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) SET_USE (use_p, scalar_result); } phis.release (); } } /* Function vectorizable_reduction. Check if STMT performs a reduction operation that can be vectorized. If VEC_STMT is also passed, vectorize the STMT: create a vectorized stmt to replace it, put it in VEC_STMT, and insert it at GSI. Return FALSE if not a vectorizable STMT, TRUE otherwise. This function also handles reduction idioms (patterns) that have been recognized in advance during vect_pattern_recog. In this case, STMT may be of this form: X = pattern_expr (arg0, arg1, ..., X) and it's STMT_VINFO_RELATED_STMT points to the last stmt in the original sequence that had been detected and replaced by the pattern-stmt (STMT). This function also handles reduction of condition expressions, for example: for (int i = 0; i < N; i++) if (a[i] < value) last = a[i]; This is handled by vectorising the loop and creating an additional vector containing the loop indexes for which "a[i] < value" was true. In the function epilogue this is reduced to a single max value and then used to index into the vector of results. In some cases of reduction patterns, the type of the reduction variable X is different than the type of the other arguments of STMT. In such cases, the vectype that is used when transforming STMT into a vector stmt is different than the vectype that is used to determine the vectorization factor, because it consists of a different number of elements than the actual number of elements that are being operated upon in parallel. For example, consider an accumulation of shorts into an int accumulator. On some targets it's possible to vectorize this pattern operating on 8 shorts at a time (hence, the vectype for purposes of determining the vectorization factor should be V8HI); on the other hand, the vectype that is used to create the vector form is actually V4SI (the type of the result). Upon entry to this function, STMT_VINFO_VECTYPE records the vectype that indicates what is the actual level of parallelism (V8HI in the example), so that the right vectorization factor would be derived. This vectype corresponds to the type of arguments to the reduction stmt, and should *NOT* be used to create the vectorized stmt. The right vectype for the vectorized stmt is obtained from the type of the result X: get_vectype_for_scalar_type (TREE_TYPE (X)) This means that, contrary to "regular" reductions (or "regular" stmts in general), the following equation: STMT_VINFO_VECTYPE == get_vectype_for_scalar_type (TREE_TYPE (X)) does *NOT* necessarily hold for reduction patterns. */ bool vectorizable_reduction (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt, slp_tree slp_node) { tree vec_dest; tree scalar_dest; tree loop_vec_def0 = NULL_TREE, loop_vec_def1 = NULL_TREE; stmt_vec_info stmt_info = vinfo_for_stmt (stmt); tree vectype_out = STMT_VINFO_VECTYPE (stmt_info); tree vectype_in = NULL_TREE; loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); enum tree_code code, orig_code, epilog_reduc_code; machine_mode vec_mode; int op_type; optab optab, reduc_optab; tree new_temp = NULL_TREE; gimple *def_stmt; enum vect_def_type dt; gphi *new_phi = NULL; tree scalar_type; bool is_simple_use; gimple *orig_stmt; stmt_vec_info orig_stmt_info; tree expr = NULL_TREE; int i; int ncopies; int epilog_copies; stmt_vec_info prev_stmt_info, prev_phi_info; bool single_defuse_cycle = false; tree reduc_def = NULL_TREE; gimple *new_stmt = NULL; int j; tree ops[3]; bool nested_cycle = false, found_nested_cycle_def = false; gimple *reduc_def_stmt = NULL; bool double_reduc = false, dummy; basic_block def_bb; struct loop * def_stmt_loop, *outer_loop = NULL; tree def_arg; gimple *def_arg_stmt; auto_vec vec_oprnds0; auto_vec vec_oprnds1; auto_vec vect_defs; auto_vec phis; int vec_num; tree def0, def1, tem, op0, op1 = NULL_TREE; bool first_p = true; tree cr_index_scalar_type = NULL_TREE, cr_index_vector_type = NULL_TREE; /* In case of reduction chain we switch to the first stmt in the chain, but we don't update STMT_INFO, since only the last stmt is marked as reduction and has reduction properties. */ if (GROUP_FIRST_ELEMENT (stmt_info) && GROUP_FIRST_ELEMENT (stmt_info) != stmt) { stmt = GROUP_FIRST_ELEMENT (stmt_info); first_p = false; } if (nested_in_vect_loop_p (loop, stmt)) { outer_loop = loop; loop = loop->inner; nested_cycle = true; } /* 1. Is vectorizable reduction? */ /* Not supportable if the reduction variable is used in the loop, unless it's a reduction chain. */ if (STMT_VINFO_RELEVANT (stmt_info) > vect_used_in_outer && !GROUP_FIRST_ELEMENT (stmt_info)) return false; /* Reductions that are not used even in an enclosing outer-loop, are expected to be "live" (used out of the loop). */ if (STMT_VINFO_RELEVANT (stmt_info) == vect_unused_in_scope && !STMT_VINFO_LIVE_P (stmt_info)) return false; /* Make sure it was already recognized as a reduction computation. */ if (STMT_VINFO_DEF_TYPE (vinfo_for_stmt (stmt)) != vect_reduction_def && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (stmt)) != vect_nested_cycle) return false; /* 2. Has this been recognized as a reduction pattern? Check if STMT represents a pattern that has been recognized in earlier analysis stages. For stmts that represent a pattern, the STMT_VINFO_RELATED_STMT field records the last stmt in the original sequence that constitutes the pattern. */ orig_stmt = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (stmt)); if (orig_stmt) { orig_stmt_info = vinfo_for_stmt (orig_stmt); gcc_assert (STMT_VINFO_IN_PATTERN_P (orig_stmt_info)); gcc_assert (!STMT_VINFO_IN_PATTERN_P (stmt_info)); } /* 3. Check the operands of the operation. The first operands are defined inside the loop body. The last operand is the reduction variable, which is defined by the loop-header-phi. */ gcc_assert (is_gimple_assign (stmt)); /* Flatten RHS. */ switch (get_gimple_rhs_class (gimple_assign_rhs_code (stmt))) { case GIMPLE_SINGLE_RHS: op_type = TREE_OPERAND_LENGTH (gimple_assign_rhs1 (stmt)); if (op_type == ternary_op) { tree rhs = gimple_assign_rhs1 (stmt); ops[0] = TREE_OPERAND (rhs, 0); ops[1] = TREE_OPERAND (rhs, 1); ops[2] = TREE_OPERAND (rhs, 2); code = TREE_CODE (rhs); } else return false; break; case GIMPLE_BINARY_RHS: code = gimple_assign_rhs_code (stmt); op_type = TREE_CODE_LENGTH (code); gcc_assert (op_type == binary_op); ops[0] = gimple_assign_rhs1 (stmt); ops[1] = gimple_assign_rhs2 (stmt); break; case GIMPLE_TERNARY_RHS: code = gimple_assign_rhs_code (stmt); op_type = TREE_CODE_LENGTH (code); gcc_assert (op_type == ternary_op); ops[0] = gimple_assign_rhs1 (stmt); ops[1] = gimple_assign_rhs2 (stmt); ops[2] = gimple_assign_rhs3 (stmt); break; case GIMPLE_UNARY_RHS: return false; default: gcc_unreachable (); } /* The default is that the reduction variable is the last in statement. */ int reduc_index = op_type - 1; if (code == COND_EXPR && slp_node) return false; scalar_dest = gimple_assign_lhs (stmt); scalar_type = TREE_TYPE (scalar_dest); if (!POINTER_TYPE_P (scalar_type) && !INTEGRAL_TYPE_P (scalar_type) && !SCALAR_FLOAT_TYPE_P (scalar_type)) return false; /* Do not try to vectorize bit-precision reductions. */ if ((TYPE_PRECISION (scalar_type) != GET_MODE_PRECISION (TYPE_MODE (scalar_type)))) return false; /* All uses but the last are expected to be defined in the loop. The last use is the reduction variable. In case of nested cycle this assumption is not true: we use reduc_index to record the index of the reduction variable. */ for (i = 0; i < op_type - 1; i++) { /* The condition of COND_EXPR is checked in vectorizable_condition(). */ if (i == 0 && code == COND_EXPR) continue; is_simple_use = vect_is_simple_use (ops[i], loop_vinfo, &def_stmt, &dt, &tem); if (!vectype_in) vectype_in = tem; gcc_assert (is_simple_use); if (dt != vect_internal_def && dt != vect_external_def && dt != vect_constant_def && dt != vect_induction_def && !(dt == vect_nested_cycle && nested_cycle)) return false; if (dt == vect_nested_cycle) { found_nested_cycle_def = true; reduc_def_stmt = def_stmt; reduc_index = i; } } is_simple_use = vect_is_simple_use (ops[i], loop_vinfo, &def_stmt, &dt, &tem); if (!vectype_in) vectype_in = tem; gcc_assert (is_simple_use); if (!found_nested_cycle_def) reduc_def_stmt = def_stmt; if (reduc_def_stmt && gimple_code (reduc_def_stmt) != GIMPLE_PHI) return false; if (!(dt == vect_reduction_def || dt == vect_nested_cycle || ((dt == vect_internal_def || dt == vect_external_def || dt == vect_constant_def || dt == vect_induction_def) && nested_cycle && found_nested_cycle_def))) { /* For pattern recognized stmts, orig_stmt might be a reduction, but some helper statements for the pattern might not, or might be COND_EXPRs with reduction uses in the condition. */ gcc_assert (orig_stmt); return false; } gimple *tmp = vect_is_simple_reduction (loop_vinfo, reduc_def_stmt, !nested_cycle, &dummy, false, &STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info)); if (orig_stmt) gcc_assert (tmp == orig_stmt || GROUP_FIRST_ELEMENT (vinfo_for_stmt (tmp)) == orig_stmt); else /* We changed STMT to be the first stmt in reduction chain, hence we check that in this case the first element in the chain is STMT. */ gcc_assert (stmt == tmp || GROUP_FIRST_ELEMENT (vinfo_for_stmt (tmp)) == stmt); if (STMT_VINFO_LIVE_P (vinfo_for_stmt (reduc_def_stmt))) return false; if (slp_node || PURE_SLP_STMT (stmt_info)) ncopies = 1; else ncopies = (LOOP_VINFO_VECT_FACTOR (loop_vinfo) / TYPE_VECTOR_SUBPARTS (vectype_in)); gcc_assert (ncopies >= 1); vec_mode = TYPE_MODE (vectype_in); if (code == COND_EXPR) { /* Only call during the analysis stage, otherwise we'll lose STMT_VINFO_TYPE. */ if (!vec_stmt && !vectorizable_condition (stmt, gsi, NULL, ops[reduc_index], 0, NULL)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "unsupported condition in reduction\n"); return false; } } else { /* 4. Supportable by target? */ if (code == LSHIFT_EXPR || code == RSHIFT_EXPR || code == LROTATE_EXPR || code == RROTATE_EXPR) { /* Shifts and rotates are only supported by vectorizable_shifts, not vectorizable_reduction. */ if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "unsupported shift or rotation.\n"); return false; } /* 4.1. check support for the operation in the loop */ optab = optab_for_tree_code (code, vectype_in, optab_default); if (!optab) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "no optab.\n"); return false; } if (optab_handler (optab, vec_mode) == CODE_FOR_nothing) { if (dump_enabled_p ()) dump_printf (MSG_NOTE, "op not supported by target.\n"); if (GET_MODE_SIZE (vec_mode) != UNITS_PER_WORD || LOOP_VINFO_VECT_FACTOR (loop_vinfo) < vect_min_worthwhile_factor (code)) return false; if (dump_enabled_p ()) dump_printf (MSG_NOTE, "proceeding using word mode.\n"); } /* Worthwhile without SIMD support? */ if (!VECTOR_MODE_P (TYPE_MODE (vectype_in)) && LOOP_VINFO_VECT_FACTOR (loop_vinfo) < vect_min_worthwhile_factor (code)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "not worthwhile without SIMD support.\n"); return false; } } /* 4.2. Check support for the epilog operation. If STMT represents a reduction pattern, then the type of the reduction variable may be different than the type of the rest of the arguments. For example, consider the case of accumulation of shorts into an int accumulator; The original code: S1: int_a = (int) short_a; orig_stmt-> S2: int_acc = plus ; was replaced with: STMT: int_acc = widen_sum This means that: 1. The tree-code that is used to create the vector operation in the epilog code (that reduces the partial results) is not the tree-code of STMT, but is rather the tree-code of the original stmt from the pattern that STMT is replacing. I.e, in the example above we want to use 'widen_sum' in the loop, but 'plus' in the epilog. 2. The type (mode) we use to check available target support for the vector operation to be created in the *epilog*, is determined by the type of the reduction variable (in the example above we'd check this: optab_handler (plus_optab, vect_int_mode])). However the type (mode) we use to check available target support for the vector operation to be created *inside the loop*, is determined by the type of the other arguments to STMT (in the example we'd check this: optab_handler (widen_sum_optab, vect_short_mode)). This is contrary to "regular" reductions, in which the types of all the arguments are the same as the type of the reduction variable. For "regular" reductions we can therefore use the same vector type (and also the same tree-code) when generating the epilog code and when generating the code inside the loop. */ if (orig_stmt) { /* This is a reduction pattern: get the vectype from the type of the reduction variable, and get the tree-code from orig_stmt. */ orig_code = gimple_assign_rhs_code (orig_stmt); gcc_assert (vectype_out); vec_mode = TYPE_MODE (vectype_out); } else { /* Regular reduction: use the same vectype and tree-code as used for the vector code inside the loop can be used for the epilog code. */ orig_code = code; } if (nested_cycle) { def_bb = gimple_bb (reduc_def_stmt); def_stmt_loop = def_bb->loop_father; def_arg = PHI_ARG_DEF_FROM_EDGE (reduc_def_stmt, loop_preheader_edge (def_stmt_loop)); if (TREE_CODE (def_arg) == SSA_NAME && (def_arg_stmt = SSA_NAME_DEF_STMT (def_arg)) && gimple_code (def_arg_stmt) == GIMPLE_PHI && flow_bb_inside_loop_p (outer_loop, gimple_bb (def_arg_stmt)) && vinfo_for_stmt (def_arg_stmt) && STMT_VINFO_DEF_TYPE (vinfo_for_stmt (def_arg_stmt)) == vect_double_reduction_def) double_reduc = true; } epilog_reduc_code = ERROR_MARK; if (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == TREE_CODE_REDUCTION) { if (reduction_code_for_scalar_code (orig_code, &epilog_reduc_code)) { reduc_optab = optab_for_tree_code (epilog_reduc_code, vectype_out, optab_default); if (!reduc_optab) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "no optab for reduction.\n"); epilog_reduc_code = ERROR_MARK; } else if (optab_handler (reduc_optab, vec_mode) == CODE_FOR_nothing) { optab = scalar_reduc_to_vector (reduc_optab, vectype_out); if (optab_handler (optab, vec_mode) == CODE_FOR_nothing) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "reduc op not supported by target.\n"); epilog_reduc_code = ERROR_MARK; } } } else { if (!nested_cycle || double_reduc) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "no reduc code for scalar code.\n"); return false; } } } else { int scalar_precision = GET_MODE_PRECISION (TYPE_MODE (scalar_type)); cr_index_scalar_type = make_unsigned_type (scalar_precision); cr_index_vector_type = build_vector_type (cr_index_scalar_type, TYPE_VECTOR_SUBPARTS (vectype_out)); epilog_reduc_code = REDUC_MAX_EXPR; optab = optab_for_tree_code (REDUC_MAX_EXPR, cr_index_vector_type, optab_default); if (optab_handler (optab, TYPE_MODE (cr_index_vector_type)) == CODE_FOR_nothing) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "reduc max op not supported by target.\n"); return false; } } if ((double_reduc || STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == COND_REDUCTION) && ncopies > 1) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "multiple types in double reduction or condition " "reduction.\n"); return false; } /* In case of widenning multiplication by a constant, we update the type of the constant to be the type of the other operand. We check that the constant fits the type in the pattern recognition pass. */ if (code == DOT_PROD_EXPR && !types_compatible_p (TREE_TYPE (ops[0]), TREE_TYPE (ops[1]))) { if (TREE_CODE (ops[0]) == INTEGER_CST) ops[0] = fold_convert (TREE_TYPE (ops[1]), ops[0]); else if (TREE_CODE (ops[1]) == INTEGER_CST) ops[1] = fold_convert (TREE_TYPE (ops[0]), ops[1]); else { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "invalid types in dot-prod\n"); return false; } } if (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == COND_REDUCTION) { widest_int ni; if (! max_loop_iterations (loop, &ni)) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "loop count not known, cannot create cond " "reduction.\n"); return false; } /* Convert backedges to iterations. */ ni += 1; /* The additional index will be the same type as the condition. Check that the loop can fit into this less one (because we'll use up the zero slot for when there are no matches). */ tree max_index = TYPE_MAX_VALUE (cr_index_scalar_type); if (wi::geu_p (ni, wi::to_widest (max_index))) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "loop size is greater than data size.\n"); return false; } } if (!vec_stmt) /* transformation not required. */ { if (first_p && !vect_model_reduction_cost (stmt_info, epilog_reduc_code, ncopies, reduc_index)) return false; STMT_VINFO_TYPE (stmt_info) = reduc_vec_info_type; return true; } /** Transform. **/ if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "transform reduction.\n"); /* FORNOW: Multiple types are not supported for condition. */ if (code == COND_EXPR) gcc_assert (ncopies == 1); /* Create the destination vector */ vec_dest = vect_create_destination_var (scalar_dest, vectype_out); /* In case the vectorization factor (VF) is bigger than the number of elements that we can fit in a vectype (nunits), we have to generate more than one vector stmt - i.e - we need to "unroll" the vector stmt by a factor VF/nunits. For more details see documentation in vectorizable_operation. */ /* If the reduction is used in an outer loop we need to generate VF intermediate results, like so (e.g. for ncopies=2): r0 = phi (init, r0) r1 = phi (init, r1) r0 = x0 + r0; r1 = x1 + r1; (i.e. we generate VF results in 2 registers). In this case we have a separate def-use cycle for each copy, and therefore for each copy we get the vector def for the reduction variable from the respective phi node created for this copy. Otherwise (the reduction is unused in the loop nest), we can combine together intermediate results, like so (e.g. for ncopies=2): r = phi (init, r) r = x0 + r; r = x1 + r; (i.e. we generate VF/2 results in a single register). In this case for each copy we get the vector def for the reduction variable from the vectorized reduction operation generated in the previous iteration. */ if (STMT_VINFO_RELEVANT (stmt_info) == vect_unused_in_scope) { single_defuse_cycle = true; epilog_copies = 1; } else epilog_copies = ncopies; prev_stmt_info = NULL; prev_phi_info = NULL; if (slp_node) vec_num = SLP_TREE_NUMBER_OF_VEC_STMTS (slp_node); else { vec_num = 1; vec_oprnds0.create (1); if (op_type == ternary_op) vec_oprnds1.create (1); } phis.create (vec_num); vect_defs.create (vec_num); if (!slp_node) vect_defs.quick_push (NULL_TREE); for (j = 0; j < ncopies; j++) { if (j == 0 || !single_defuse_cycle) { for (i = 0; i < vec_num; i++) { /* Create the reduction-phi that defines the reduction operand. */ new_phi = create_phi_node (vec_dest, loop->header); set_vinfo_for_stmt (new_phi, new_stmt_vec_info (new_phi, loop_vinfo)); if (j == 0 || slp_node) phis.quick_push (new_phi); } } if (code == COND_EXPR) { gcc_assert (!slp_node); vectorizable_condition (stmt, gsi, vec_stmt, PHI_RESULT (phis[0]), reduc_index, NULL); /* Multiple types are not supported for condition. */ break; } /* Handle uses. */ if (j == 0) { op0 = ops[!reduc_index]; if (op_type == ternary_op) { if (reduc_index == 0) op1 = ops[2]; else op1 = ops[1]; } if (slp_node) vect_get_vec_defs (op0, op1, stmt, &vec_oprnds0, &vec_oprnds1, slp_node, -1); else { loop_vec_def0 = vect_get_vec_def_for_operand (ops[!reduc_index], stmt); vec_oprnds0.quick_push (loop_vec_def0); if (op_type == ternary_op) { loop_vec_def1 = vect_get_vec_def_for_operand (op1, stmt); vec_oprnds1.quick_push (loop_vec_def1); } } } else { if (!slp_node) { enum vect_def_type dt; gimple *dummy_stmt; vect_is_simple_use (ops[!reduc_index], loop_vinfo, &dummy_stmt, &dt); loop_vec_def0 = vect_get_vec_def_for_stmt_copy (dt, loop_vec_def0); vec_oprnds0[0] = loop_vec_def0; if (op_type == ternary_op) { vect_is_simple_use (op1, loop_vinfo, &dummy_stmt, &dt); loop_vec_def1 = vect_get_vec_def_for_stmt_copy (dt, loop_vec_def1); vec_oprnds1[0] = loop_vec_def1; } } if (single_defuse_cycle) reduc_def = gimple_assign_lhs (new_stmt); STMT_VINFO_RELATED_STMT (prev_phi_info) = new_phi; } FOR_EACH_VEC_ELT (vec_oprnds0, i, def0) { if (slp_node) reduc_def = PHI_RESULT (phis[i]); else { if (!single_defuse_cycle || j == 0) reduc_def = PHI_RESULT (new_phi); } def1 = ((op_type == ternary_op) ? vec_oprnds1[i] : NULL); if (op_type == binary_op) { if (reduc_index == 0) expr = build2 (code, vectype_out, reduc_def, def0); else expr = build2 (code, vectype_out, def0, reduc_def); } else { if (reduc_index == 0) expr = build3 (code, vectype_out, reduc_def, def0, def1); else { if (reduc_index == 1) expr = build3 (code, vectype_out, def0, reduc_def, def1); else expr = build3 (code, vectype_out, def0, def1, reduc_def); } } new_stmt = gimple_build_assign (vec_dest, expr); new_temp = make_ssa_name (vec_dest, new_stmt); gimple_assign_set_lhs (new_stmt, new_temp); vect_finish_stmt_generation (stmt, new_stmt, gsi); if (slp_node) { SLP_TREE_VEC_STMTS (slp_node).quick_push (new_stmt); vect_defs.quick_push (new_temp); } else vect_defs[0] = new_temp; } if (slp_node) continue; if (j == 0) STMT_VINFO_VEC_STMT (stmt_info) = *vec_stmt = new_stmt; else STMT_VINFO_RELATED_STMT (prev_stmt_info) = new_stmt; prev_stmt_info = vinfo_for_stmt (new_stmt); prev_phi_info = vinfo_for_stmt (new_phi); } tree indx_before_incr, indx_after_incr, cond_name = NULL; /* Finalize the reduction-phi (set its arguments) and create the epilog reduction code. */ if ((!single_defuse_cycle || code == COND_EXPR) && !slp_node) { new_temp = gimple_assign_lhs (*vec_stmt); vect_defs[0] = new_temp; /* For cond reductions we want to create a new vector (INDEX_COND_EXPR) which is updated with the current index of the loop for every match of the original loop's cond_expr (VEC_STMT). This results in a vector containing the last time the condition passed for that vector lane. The first match will be a 1 to allow 0 to be used for non-matching indexes. If there are no matches at all then the vector will be all zeroes. */ if (STMT_VINFO_VEC_REDUCTION_TYPE (stmt_info) == COND_REDUCTION) { int nunits_out = TYPE_VECTOR_SUBPARTS (vectype_out); int k; gcc_assert (gimple_assign_rhs_code (*vec_stmt) == VEC_COND_EXPR); /* First we create a simple vector induction variable which starts with the values {1,2,3,...} (SERIES_VECT) and increments by the vector size (STEP). */ /* Create a {1,2,3,...} vector. */ tree *vtemp = XALLOCAVEC (tree, nunits_out); for (k = 0; k < nunits_out; ++k) vtemp[k] = build_int_cst (cr_index_scalar_type, k + 1); tree series_vect = build_vector (cr_index_vector_type, vtemp); /* Create a vector of the step value. */ tree step = build_int_cst (cr_index_scalar_type, nunits_out); tree vec_step = build_vector_from_val (cr_index_vector_type, step); /* Create an induction variable. */ gimple_stmt_iterator incr_gsi; bool insert_after; standard_iv_increment_position (loop, &incr_gsi, &insert_after); create_iv (series_vect, vec_step, NULL_TREE, loop, &incr_gsi, insert_after, &indx_before_incr, &indx_after_incr); /* Next create a new phi node vector (NEW_PHI_TREE) which starts filled with zeros (VEC_ZERO). */ /* Create a vector of 0s. */ tree zero = build_zero_cst (cr_index_scalar_type); tree vec_zero = build_vector_from_val (cr_index_vector_type, zero); /* Create a vector phi node. */ tree new_phi_tree = make_ssa_name (cr_index_vector_type); new_phi = create_phi_node (new_phi_tree, loop->header); set_vinfo_for_stmt (new_phi, new_stmt_vec_info (new_phi, loop_vinfo)); add_phi_arg (new_phi, vec_zero, loop_preheader_edge (loop), UNKNOWN_LOCATION); /* Now take the condition from the loops original cond_expr (VEC_STMT) and produce a new cond_expr (INDEX_COND_EXPR) which for every match uses values from the induction variable (INDEX_BEFORE_INCR) otherwise uses values from the phi node (NEW_PHI_TREE). Finally, we update the phi (NEW_PHI_TREE) to take the value of the new cond_expr (INDEX_COND_EXPR). */ /* Turn the condition from vec_stmt into an ssa name. */ gimple_stmt_iterator vec_stmt_gsi = gsi_for_stmt (*vec_stmt); tree ccompare = gimple_assign_rhs1 (*vec_stmt); tree ccompare_name = make_ssa_name (TREE_TYPE (ccompare)); gimple *ccompare_stmt = gimple_build_assign (ccompare_name, ccompare); gsi_insert_before (&vec_stmt_gsi, ccompare_stmt, GSI_SAME_STMT); gimple_assign_set_rhs1 (*vec_stmt, ccompare_name); update_stmt (*vec_stmt); /* Create a conditional, where the condition is taken from vec_stmt (CCOMPARE_NAME), then is the induction index (INDEX_BEFORE_INCR) and else is the phi (NEW_PHI_TREE). */ tree index_cond_expr = build3 (VEC_COND_EXPR, cr_index_vector_type, ccompare_name, indx_before_incr, new_phi_tree); cond_name = make_ssa_name (cr_index_vector_type); gimple *index_condition = gimple_build_assign (cond_name, index_cond_expr); gsi_insert_before (&incr_gsi, index_condition, GSI_SAME_STMT); stmt_vec_info index_vec_info = new_stmt_vec_info (index_condition, loop_vinfo); STMT_VINFO_VECTYPE (index_vec_info) = cr_index_vector_type; set_vinfo_for_stmt (index_condition, index_vec_info); /* Update the phi with the vec cond. */ add_phi_arg (new_phi, cond_name, loop_latch_edge (loop), UNKNOWN_LOCATION); } } vect_create_epilog_for_reduction (vect_defs, stmt, epilog_copies, epilog_reduc_code, phis, reduc_index, double_reduc, slp_node, cond_name); return true; } /* Function vect_min_worthwhile_factor. For a loop where we could vectorize the operation indicated by CODE, return the minimum vectorization factor that makes it worthwhile to use generic vectors. */ int vect_min_worthwhile_factor (enum tree_code code) { switch (code) { case PLUS_EXPR: case MINUS_EXPR: case NEGATE_EXPR: return 4; case BIT_AND_EXPR: case BIT_IOR_EXPR: case BIT_XOR_EXPR: case BIT_NOT_EXPR: return 2; default: return INT_MAX; } } /* Function vectorizable_induction Check if PHI performs an induction computation that can be vectorized. If VEC_STMT is also passed, vectorize the induction PHI: create a vectorized phi to replace it, put it in VEC_STMT, and add it to the same basic block. Return FALSE if not a vectorizable STMT, TRUE otherwise. */ bool vectorizable_induction (gimple *phi, gimple_stmt_iterator *gsi ATTRIBUTE_UNUSED, gimple **vec_stmt) { stmt_vec_info stmt_info = vinfo_for_stmt (phi); tree vectype = STMT_VINFO_VECTYPE (stmt_info); loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); int nunits = TYPE_VECTOR_SUBPARTS (vectype); int ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits; tree vec_def; gcc_assert (ncopies >= 1); /* FORNOW. These restrictions should be relaxed. */ if (nested_in_vect_loop_p (loop, phi)) { imm_use_iterator imm_iter; use_operand_p use_p; gimple *exit_phi; edge latch_e; tree loop_arg; if (ncopies > 1) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "multiple types in nested loop.\n"); return false; } exit_phi = NULL; latch_e = loop_latch_edge (loop->inner); loop_arg = PHI_ARG_DEF_FROM_EDGE (phi, latch_e); FOR_EACH_IMM_USE_FAST (use_p, imm_iter, loop_arg) { gimple *use_stmt = USE_STMT (use_p); if (is_gimple_debug (use_stmt)) continue; if (!flow_bb_inside_loop_p (loop->inner, gimple_bb (use_stmt))) { exit_phi = use_stmt; break; } } if (exit_phi) { stmt_vec_info exit_phi_vinfo = vinfo_for_stmt (exit_phi); if (!(STMT_VINFO_RELEVANT_P (exit_phi_vinfo) && !STMT_VINFO_LIVE_P (exit_phi_vinfo))) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "inner-loop induction only used outside " "of the outer vectorized loop.\n"); return false; } } } if (!STMT_VINFO_RELEVANT_P (stmt_info)) return false; /* FORNOW: SLP not supported. */ if (STMT_SLP_TYPE (stmt_info)) return false; gcc_assert (STMT_VINFO_DEF_TYPE (stmt_info) == vect_induction_def); if (gimple_code (phi) != GIMPLE_PHI) return false; if (!vec_stmt) /* transformation not required. */ { STMT_VINFO_TYPE (stmt_info) = induc_vec_info_type; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== vectorizable_induction ===\n"); vect_model_induction_cost (stmt_info, ncopies); return true; } /** Transform. **/ if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "transform induction phi.\n"); vec_def = get_initial_def_for_induction (phi); *vec_stmt = SSA_NAME_DEF_STMT (vec_def); return true; } /* Function vectorizable_live_operation. STMT computes a value that is used outside the loop. Check if it can be supported. */ bool vectorizable_live_operation (gimple *stmt, gimple_stmt_iterator *gsi ATTRIBUTE_UNUSED, gimple **vec_stmt) { stmt_vec_info stmt_info = vinfo_for_stmt (stmt); loop_vec_info loop_vinfo = STMT_VINFO_LOOP_VINFO (stmt_info); struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); int i; int op_type; tree op; gimple *def_stmt; enum vect_def_type dt; enum tree_code code; enum gimple_rhs_class rhs_class; gcc_assert (STMT_VINFO_LIVE_P (stmt_info)); if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def) return false; if (!is_gimple_assign (stmt)) { if (gimple_call_internal_p (stmt) && gimple_call_internal_fn (stmt) == IFN_GOMP_SIMD_LANE && gimple_call_lhs (stmt) && loop->simduid && TREE_CODE (gimple_call_arg (stmt, 0)) == SSA_NAME && loop->simduid == SSA_NAME_VAR (gimple_call_arg (stmt, 0))) { edge e = single_exit (loop); basic_block merge_bb = e->dest; imm_use_iterator imm_iter; use_operand_p use_p; tree lhs = gimple_call_lhs (stmt); FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs) { gimple *use_stmt = USE_STMT (use_p); if (gimple_code (use_stmt) == GIMPLE_PHI && gimple_bb (use_stmt) == merge_bb) { if (vec_stmt) { tree vfm1 = build_int_cst (unsigned_type_node, loop_vinfo->vectorization_factor - 1); SET_PHI_ARG_DEF (use_stmt, e->dest_idx, vfm1); } return true; } } } return false; } if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME) return false; /* FORNOW. CHECKME. */ if (nested_in_vect_loop_p (loop, stmt)) return false; code = gimple_assign_rhs_code (stmt); op_type = TREE_CODE_LENGTH (code); rhs_class = get_gimple_rhs_class (code); gcc_assert (rhs_class != GIMPLE_UNARY_RHS || op_type == unary_op); gcc_assert (rhs_class != GIMPLE_BINARY_RHS || op_type == binary_op); /* FORNOW: support only if all uses are invariant. This means that the scalar operations can remain in place, unvectorized. The original last scalar value that they compute will be used. */ for (i = 0; i < op_type; i++) { if (rhs_class == GIMPLE_SINGLE_RHS) op = TREE_OPERAND (gimple_op (stmt, 1), i); else op = gimple_op (stmt, i + 1); if (op && !vect_is_simple_use (op, loop_vinfo, &def_stmt, &dt)) { if (dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, "use not simple.\n"); return false; } if (dt != vect_external_def && dt != vect_constant_def) return false; } /* No transformation is required for the cases we currently support. */ return true; } /* Kill any debug uses outside LOOP of SSA names defined in STMT. */ static void vect_loop_kill_debug_uses (struct loop *loop, gimple *stmt) { ssa_op_iter op_iter; imm_use_iterator imm_iter; def_operand_p def_p; gimple *ustmt; FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF) { FOR_EACH_IMM_USE_STMT (ustmt, imm_iter, DEF_FROM_PTR (def_p)) { basic_block bb; if (!is_gimple_debug (ustmt)) continue; bb = gimple_bb (ustmt); if (!flow_bb_inside_loop_p (loop, bb)) { if (gimple_debug_bind_p (ustmt)) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "killing debug use\n"); gimple_debug_bind_reset_value (ustmt); update_stmt (ustmt); } else gcc_unreachable (); } } } } /* This function builds ni_name = number of iterations. Statements are emitted on the loop preheader edge. */ static tree vect_build_loop_niters (loop_vec_info loop_vinfo) { tree ni = unshare_expr (LOOP_VINFO_NITERS (loop_vinfo)); if (TREE_CODE (ni) == INTEGER_CST) return ni; else { tree ni_name, var; gimple_seq stmts = NULL; edge pe = loop_preheader_edge (LOOP_VINFO_LOOP (loop_vinfo)); var = create_tmp_var (TREE_TYPE (ni), "niters"); ni_name = force_gimple_operand (ni, &stmts, false, var); if (stmts) gsi_insert_seq_on_edge_immediate (pe, stmts); return ni_name; } } /* This function generates the following statements: ni_name = number of iterations loop executes ratio = ni_name / vf ratio_mult_vf_name = ratio * vf and places them on the loop preheader edge. */ static void vect_generate_tmps_on_preheader (loop_vec_info loop_vinfo, tree ni_name, tree *ratio_mult_vf_name_ptr, tree *ratio_name_ptr) { tree ni_minus_gap_name; tree var; tree ratio_name; tree ratio_mult_vf_name; int vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); edge pe = loop_preheader_edge (LOOP_VINFO_LOOP (loop_vinfo)); tree log_vf; log_vf = build_int_cst (TREE_TYPE (ni_name), exact_log2 (vf)); /* If epilogue loop is required because of data accesses with gaps, we subtract one iteration from the total number of iterations here for correct calculation of RATIO. */ if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)) { ni_minus_gap_name = fold_build2 (MINUS_EXPR, TREE_TYPE (ni_name), ni_name, build_one_cst (TREE_TYPE (ni_name))); if (!is_gimple_val (ni_minus_gap_name)) { var = create_tmp_var (TREE_TYPE (ni_name), "ni_gap"); gimple *stmts = NULL; ni_minus_gap_name = force_gimple_operand (ni_minus_gap_name, &stmts, true, var); gsi_insert_seq_on_edge_immediate (pe, stmts); } } else ni_minus_gap_name = ni_name; /* Create: ratio = ni >> log2(vf) */ /* ??? As we have ni == number of latch executions + 1, ni could have overflown to zero. So avoid computing ratio based on ni but compute it using the fact that we know ratio will be at least one, thus via (ni - vf) >> log2(vf) + 1. */ ratio_name = fold_build2 (PLUS_EXPR, TREE_TYPE (ni_name), fold_build2 (RSHIFT_EXPR, TREE_TYPE (ni_name), fold_build2 (MINUS_EXPR, TREE_TYPE (ni_name), ni_minus_gap_name, build_int_cst (TREE_TYPE (ni_name), vf)), log_vf), build_int_cst (TREE_TYPE (ni_name), 1)); if (!is_gimple_val (ratio_name)) { var = create_tmp_var (TREE_TYPE (ni_name), "bnd"); gimple *stmts = NULL; ratio_name = force_gimple_operand (ratio_name, &stmts, true, var); gsi_insert_seq_on_edge_immediate (pe, stmts); } *ratio_name_ptr = ratio_name; /* Create: ratio_mult_vf = ratio << log2 (vf). */ if (ratio_mult_vf_name_ptr) { ratio_mult_vf_name = fold_build2 (LSHIFT_EXPR, TREE_TYPE (ratio_name), ratio_name, log_vf); if (!is_gimple_val (ratio_mult_vf_name)) { var = create_tmp_var (TREE_TYPE (ni_name), "ratio_mult_vf"); gimple *stmts = NULL; ratio_mult_vf_name = force_gimple_operand (ratio_mult_vf_name, &stmts, true, var); gsi_insert_seq_on_edge_immediate (pe, stmts); } *ratio_mult_vf_name_ptr = ratio_mult_vf_name; } return; } /* Function vect_transform_loop. The analysis phase has determined that the loop is vectorizable. Vectorize the loop - created vectorized stmts to replace the scalar stmts in the loop, and update the loop exit condition. */ void vect_transform_loop (loop_vec_info loop_vinfo) { struct loop *loop = LOOP_VINFO_LOOP (loop_vinfo); basic_block *bbs = LOOP_VINFO_BBS (loop_vinfo); int nbbs = loop->num_nodes; int i; tree ratio = NULL; int vectorization_factor = LOOP_VINFO_VECT_FACTOR (loop_vinfo); bool grouped_store; bool slp_scheduled = false; gimple *stmt, *pattern_stmt; gimple_seq pattern_def_seq = NULL; gimple_stmt_iterator pattern_def_si = gsi_none (); bool transform_pattern_stmt = false; bool check_profitability = false; int th; /* Record number of iterations before we started tampering with the profile. */ gcov_type expected_iterations = expected_loop_iterations_unbounded (loop); if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== vec_transform_loop ===\n"); /* If profile is inprecise, we have chance to fix it up. */ if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)) expected_iterations = LOOP_VINFO_INT_NITERS (loop_vinfo); /* Use the more conservative vectorization threshold. If the number of iterations is constant assume the cost check has been performed by our caller. If the threshold makes all loops profitable that run at least the vectorization factor number of times checking is pointless, too. */ th = LOOP_VINFO_COST_MODEL_THRESHOLD (loop_vinfo); if (th >= LOOP_VINFO_VECT_FACTOR (loop_vinfo) - 1 && !LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "Profitability threshold is %d loop iterations.\n", th); check_profitability = true; } /* Version the loop first, if required, so the profitability check comes first. */ if (LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT (loop_vinfo) || LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo)) { vect_loop_versioning (loop_vinfo, th, check_profitability); check_profitability = false; } tree ni_name = vect_build_loop_niters (loop_vinfo); LOOP_VINFO_NITERS_UNCHANGED (loop_vinfo) = ni_name; /* Peel the loop if there are data refs with unknown alignment. Only one data ref with unknown store is allowed. */ if (LOOP_VINFO_PEELING_FOR_ALIGNMENT (loop_vinfo)) { vect_do_peeling_for_alignment (loop_vinfo, ni_name, th, check_profitability); check_profitability = false; /* The above adjusts LOOP_VINFO_NITERS, so cause ni_name to be re-computed. */ ni_name = NULL_TREE; } /* If the loop has a symbolic number of iterations 'n' (i.e. it's not a compile time constant), or it is a constant that doesn't divide by the vectorization factor, then an epilog loop needs to be created. We therefore duplicate the loop: the original loop will be vectorized, and will compute the first (n/VF) iterations. The second copy of the loop will remain scalar and will compute the remaining (n%VF) iterations. (VF is the vectorization factor). */ if (LOOP_VINFO_PEELING_FOR_NITER (loop_vinfo) || LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo)) { tree ratio_mult_vf; if (!ni_name) ni_name = vect_build_loop_niters (loop_vinfo); vect_generate_tmps_on_preheader (loop_vinfo, ni_name, &ratio_mult_vf, &ratio); vect_do_peeling_for_loop_bound (loop_vinfo, ni_name, ratio_mult_vf, th, check_profitability); } else if (LOOP_VINFO_NITERS_KNOWN_P (loop_vinfo)) ratio = build_int_cst (TREE_TYPE (LOOP_VINFO_NITERS (loop_vinfo)), LOOP_VINFO_INT_NITERS (loop_vinfo) / vectorization_factor); else { if (!ni_name) ni_name = vect_build_loop_niters (loop_vinfo); vect_generate_tmps_on_preheader (loop_vinfo, ni_name, NULL, &ratio); } /* 1) Make sure the loop header has exactly two entries 2) Make sure we have a preheader basic block. */ gcc_assert (EDGE_COUNT (loop->header->preds) == 2); split_edge (loop_preheader_edge (loop)); /* FORNOW: the vectorizer supports only loops which body consist of one basic block (header + empty latch). When the vectorizer will support more involved loop forms, the order by which the BBs are traversed need to be reconsidered. */ for (i = 0; i < nbbs; i++) { basic_block bb = bbs[i]; stmt_vec_info stmt_info; for (gphi_iterator si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) { gphi *phi = si.phi (); if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "------>vectorizing phi: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, phi, 0); dump_printf (MSG_NOTE, "\n"); } stmt_info = vinfo_for_stmt (phi); if (!stmt_info) continue; if (MAY_HAVE_DEBUG_STMTS && !STMT_VINFO_LIVE_P (stmt_info)) vect_loop_kill_debug_uses (loop, phi); if (!STMT_VINFO_RELEVANT_P (stmt_info) && !STMT_VINFO_LIVE_P (stmt_info)) continue; if (STMT_VINFO_VECTYPE (stmt_info) && (TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info)) != (unsigned HOST_WIDE_INT) vectorization_factor) && dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "multiple-types.\n"); if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_induction_def) { if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "transform phi.\n"); vect_transform_stmt (phi, NULL, NULL, NULL, NULL); } } pattern_stmt = NULL; for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si) || transform_pattern_stmt;) { bool is_store; if (transform_pattern_stmt) stmt = pattern_stmt; else { stmt = gsi_stmt (si); /* During vectorization remove existing clobber stmts. */ if (gimple_clobber_p (stmt)) { unlink_stmt_vdef (stmt); gsi_remove (&si, true); release_defs (stmt); continue; } } if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "------>vectorizing statement: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, stmt, 0); dump_printf (MSG_NOTE, "\n"); } stmt_info = vinfo_for_stmt (stmt); /* vector stmts created in the outer-loop during vectorization of stmts in an inner-loop may not have a stmt_info, and do not need to be vectorized. */ if (!stmt_info) { gsi_next (&si); continue; } if (MAY_HAVE_DEBUG_STMTS && !STMT_VINFO_LIVE_P (stmt_info)) vect_loop_kill_debug_uses (loop, stmt); if (!STMT_VINFO_RELEVANT_P (stmt_info) && !STMT_VINFO_LIVE_P (stmt_info)) { if (STMT_VINFO_IN_PATTERN_P (stmt_info) && (pattern_stmt = STMT_VINFO_RELATED_STMT (stmt_info)) && (STMT_VINFO_RELEVANT_P (vinfo_for_stmt (pattern_stmt)) || STMT_VINFO_LIVE_P (vinfo_for_stmt (pattern_stmt)))) { stmt = pattern_stmt; stmt_info = vinfo_for_stmt (stmt); } else { gsi_next (&si); continue; } } else if (STMT_VINFO_IN_PATTERN_P (stmt_info) && (pattern_stmt = STMT_VINFO_RELATED_STMT (stmt_info)) && (STMT_VINFO_RELEVANT_P (vinfo_for_stmt (pattern_stmt)) || STMT_VINFO_LIVE_P (vinfo_for_stmt (pattern_stmt)))) transform_pattern_stmt = true; /* If pattern statement has def stmts, vectorize them too. */ if (is_pattern_stmt_p (stmt_info)) { if (pattern_def_seq == NULL) { pattern_def_seq = STMT_VINFO_PATTERN_DEF_SEQ (stmt_info); pattern_def_si = gsi_start (pattern_def_seq); } else if (!gsi_end_p (pattern_def_si)) gsi_next (&pattern_def_si); if (pattern_def_seq != NULL) { gimple *pattern_def_stmt = NULL; stmt_vec_info pattern_def_stmt_info = NULL; while (!gsi_end_p (pattern_def_si)) { pattern_def_stmt = gsi_stmt (pattern_def_si); pattern_def_stmt_info = vinfo_for_stmt (pattern_def_stmt); if (STMT_VINFO_RELEVANT_P (pattern_def_stmt_info) || STMT_VINFO_LIVE_P (pattern_def_stmt_info)) break; gsi_next (&pattern_def_si); } if (!gsi_end_p (pattern_def_si)) { if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "==> vectorizing pattern def " "stmt: "); dump_gimple_stmt (MSG_NOTE, TDF_SLIM, pattern_def_stmt, 0); dump_printf (MSG_NOTE, "\n"); } stmt = pattern_def_stmt; stmt_info = pattern_def_stmt_info; } else { pattern_def_si = gsi_none (); transform_pattern_stmt = false; } } else transform_pattern_stmt = false; } if (STMT_VINFO_VECTYPE (stmt_info)) { unsigned int nunits = (unsigned int) TYPE_VECTOR_SUBPARTS (STMT_VINFO_VECTYPE (stmt_info)); if (!STMT_SLP_TYPE (stmt_info) && nunits != (unsigned int) vectorization_factor && dump_enabled_p ()) /* For SLP VF is set according to unrolling factor, and not to vector size, hence for SLP this print is not valid. */ dump_printf_loc (MSG_NOTE, vect_location, "multiple-types.\n"); } /* SLP. Schedule all the SLP instances when the first SLP stmt is reached. */ if (STMT_SLP_TYPE (stmt_info)) { if (!slp_scheduled) { slp_scheduled = true; if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "=== scheduling SLP instances ===\n"); vect_schedule_slp (loop_vinfo); } /* Hybrid SLP stmts must be vectorized in addition to SLP. */ if (!vinfo_for_stmt (stmt) || PURE_SLP_STMT (stmt_info)) { if (!transform_pattern_stmt && gsi_end_p (pattern_def_si)) { pattern_def_seq = NULL; gsi_next (&si); } continue; } } /* -------- vectorize statement ------------ */ if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, "transform statement.\n"); grouped_store = false; is_store = vect_transform_stmt (stmt, &si, &grouped_store, NULL, NULL); if (is_store) { if (STMT_VINFO_GROUPED_ACCESS (stmt_info)) { /* Interleaving. If IS_STORE is TRUE, the vectorization of the interleaving chain was completed - free all the stores in the chain. */ gsi_next (&si); vect_remove_stores (GROUP_FIRST_ELEMENT (stmt_info)); } else { /* Free the attached stmt_vec_info and remove the stmt. */ gimple *store = gsi_stmt (si); free_stmt_vec_info (store); unlink_stmt_vdef (store); gsi_remove (&si, true); release_defs (store); } /* Stores can only appear at the end of pattern statements. */ gcc_assert (!transform_pattern_stmt); pattern_def_seq = NULL; } else if (!transform_pattern_stmt && gsi_end_p (pattern_def_si)) { pattern_def_seq = NULL; gsi_next (&si); } } /* stmts in BB */ } /* BBs in loop */ slpeel_make_loop_iterate_ntimes (loop, ratio); /* Reduce loop iterations by the vectorization factor. */ scale_loop_profile (loop, GCOV_COMPUTE_SCALE (1, vectorization_factor), expected_iterations / vectorization_factor); loop->nb_iterations_upper_bound = wi::udiv_floor (loop->nb_iterations_upper_bound, vectorization_factor); if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) && loop->nb_iterations_upper_bound != 0) loop->nb_iterations_upper_bound = loop->nb_iterations_upper_bound - 1; if (loop->any_estimate) { loop->nb_iterations_estimate = wi::udiv_floor (loop->nb_iterations_estimate, vectorization_factor); if (LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) && loop->nb_iterations_estimate != 0) loop->nb_iterations_estimate = loop->nb_iterations_estimate - 1; } if (dump_enabled_p ()) { dump_printf_loc (MSG_NOTE, vect_location, "LOOP VECTORIZED\n"); if (loop->inner) dump_printf_loc (MSG_NOTE, vect_location, "OUTER LOOP VECTORIZED\n"); dump_printf (MSG_NOTE, "\n"); } }