1 /* Definitions for branch prediction routines in the GNU compiler. 2 Copyright (C) 2001-2021 Free Software Foundation, Inc. 3 4 This file is part of GCC. 5 6 GCC is free software; you can redistribute it and/or modify it under 7 the terms of the GNU General Public License as published by the Free 8 Software Foundation; either version 3, or (at your option) any later 9 version. 10 11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 12 WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GCC; see the file COPYING3. If not see 18 <http://www.gnu.org/licenses/>. */ 19 20 #ifndef GCC_PREDICT_H 21 #define GCC_PREDICT_H 22 23 #include "profile-count.h" 24 25 /* Random guesstimation given names. 26 PROB_VERY_UNLIKELY should be small enough so basic block predicted 27 by it gets below HOT_BB_FREQUENCY_FRACTION. */ 28 #define PROB_VERY_UNLIKELY (REG_BR_PROB_BASE / 2000 - 1) 29 #define PROB_EVEN (REG_BR_PROB_BASE / 2) 30 #define PROB_VERY_LIKELY (REG_BR_PROB_BASE - PROB_VERY_UNLIKELY) 31 #define PROB_ALWAYS (REG_BR_PROB_BASE) 32 #define PROB_UNLIKELY (REG_BR_PROB_BASE / 5 - 1) 33 #define PROB_LIKELY (REG_BR_PROB_BASE - PROB_UNLIKELY) 34 #define PROB_UNINITIALIZED (-1) 35 36 #define DEF_PREDICTOR(ENUM, NAME, HITRATE, FLAGS) ENUM, 37 enum br_predictor 38 { 39 #include "predict.def" 40 41 /* Upper bound on non-language-specific builtins. */ 42 END_PREDICTORS 43 }; 44 #undef DEF_PREDICTOR 45 enum prediction 46 { 47 NOT_TAKEN, 48 TAKEN 49 }; 50 51 /* In emit-rtl.c. */ 52 extern profile_probability split_branch_probability; 53 54 extern gcov_type get_hot_bb_threshold (void); 55 extern void set_hot_bb_threshold (gcov_type); 56 extern bool maybe_hot_count_p (struct function *, profile_count); 57 extern bool maybe_hot_bb_p (struct function *, const_basic_block); 58 extern bool maybe_hot_edge_p (edge); 59 extern bool probably_never_executed_bb_p (struct function *, const_basic_block); 60 extern bool probably_never_executed_edge_p (struct function *, edge); 61 extern enum optimize_size_level optimize_function_for_size_p (struct function *); 62 extern bool optimize_function_for_speed_p (struct function *); 63 extern optimization_type function_optimization_type (struct function *); 64 extern enum optimize_size_level optimize_bb_for_size_p (const_basic_block); 65 extern bool optimize_bb_for_speed_p (const_basic_block); 66 extern optimization_type bb_optimization_type (const_basic_block); 67 extern enum optimize_size_level optimize_edge_for_size_p (edge); 68 extern bool optimize_edge_for_speed_p (edge); 69 extern enum optimize_size_level optimize_insn_for_size_p (void); 70 extern bool optimize_insn_for_speed_p (void); 71 extern enum optimize_size_level optimize_loop_for_size_p (class loop *); 72 extern bool optimize_loop_for_speed_p (class loop *); 73 extern bool optimize_loop_nest_for_speed_p (class loop *); 74 extern enum optimize_size_level optimize_loop_nest_for_size_p (class loop *); 75 extern bool predictable_edge_p (edge); 76 extern void rtl_profile_for_bb (basic_block); 77 extern void rtl_profile_for_edge (edge); 78 extern void default_rtl_profile (void); 79 extern bool rtl_predicted_by_p (const_basic_block, enum br_predictor); 80 extern bool gimple_predicted_by_p (const_basic_block, enum br_predictor); 81 extern bool edge_probability_reliable_p (const_edge); 82 extern bool br_prob_note_reliable_p (const_rtx); 83 extern void predict_insn_def (rtx_insn *, enum br_predictor, enum prediction); 84 extern void rtl_predict_edge (edge, enum br_predictor, int); 85 extern void gimple_predict_edge (edge, enum br_predictor, int); 86 extern void remove_predictions_associated_with_edge (edge); 87 extern void predict_edge_def (edge, enum br_predictor, enum prediction); 88 extern void invert_br_probabilities (rtx); 89 extern void guess_outgoing_edge_probabilities (basic_block); 90 extern void tree_guess_outgoing_edge_probabilities (basic_block); 91 extern void tree_estimate_probability (bool); 92 extern void handle_missing_profiles (void); 93 extern bool update_max_bb_count (void); 94 extern bool expensive_function_p (int); 95 extern void estimate_bb_frequencies (bool); 96 extern void compute_function_frequency (void); 97 extern tree build_predict_expr (enum br_predictor, enum prediction); 98 extern const char *predictor_name (enum br_predictor); 99 extern void rebuild_frequencies (void); 100 extern void report_predictor_hitrates (void); 101 extern void force_edge_cold (edge, bool); 102 extern void propagate_unlikely_bbs_forward (void); 103 104 extern void add_reg_br_prob_note (rtx_insn *, profile_probability); 105 106 /* In ipa-pure-const.c */ 107 extern void warn_function_cold (tree); 108 109 #endif /* GCC_PREDICT_H */ 110