1/* Definitions for branch prediction routines in the GNU compiler. 2 Copyright (C) 2001-2015 Free Software Foundation, Inc. 3 4This file is part of GCC. 5 6GCC is free software; you can redistribute it and/or modify it under 7the terms of the GNU General Public License as published by the Free 8Software Foundation; either version 3, or (at your option) any later 9version. 10 11GCC is distributed in the hope that it will be useful, but WITHOUT ANY 12WARRANTY; without even the implied warranty of MERCHANTABILITY or 13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14for more details. 15 16You should have received a copy of the GNU General Public License 17along 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/* Random guesstimation given names. 24 PROB_VERY_UNLIKELY should be small enough so basic block predicted 25 by it gets below HOT_BB_FREQUENCY_FRACTION. */ 26#define PROB_VERY_UNLIKELY (REG_BR_PROB_BASE / 2000 - 1) 27#define PROB_EVEN (REG_BR_PROB_BASE / 2) 28#define PROB_VERY_LIKELY (REG_BR_PROB_BASE - PROB_VERY_UNLIKELY) 29#define PROB_ALWAYS (REG_BR_PROB_BASE) 30#define PROB_UNLIKELY (REG_BR_PROB_BASE / 5 - 1) 31#define PROB_LIKELY (REG_BR_PROB_BASE - PROB_UNLIKELY) 32 33#define DEF_PREDICTOR(ENUM, NAME, HITRATE, FLAGS) ENUM, 34enum br_predictor 35{ 36#include "predict.def" 37 38 /* Upper bound on non-language-specific builtins. */ 39 END_PREDICTORS 40}; 41#undef DEF_PREDICTOR 42enum prediction 43{ 44 NOT_TAKEN, 45 TAKEN 46}; 47 48extern gcov_type get_hot_bb_threshold (void); 49extern void set_hot_bb_threshold (gcov_type); 50extern bool maybe_hot_count_p (struct function *, gcov_type); 51extern bool maybe_hot_bb_p (struct function *, const_basic_block); 52extern bool maybe_hot_edge_p (edge); 53extern bool probably_never_executed_bb_p (struct function *, const_basic_block); 54extern bool probably_never_executed_edge_p (struct function *, edge); 55extern bool optimize_function_for_size_p (struct function *); 56extern bool optimize_function_for_speed_p (struct function *); 57extern bool optimize_bb_for_size_p (const_basic_block); 58extern bool optimize_bb_for_speed_p (const_basic_block); 59extern bool optimize_edge_for_size_p (edge); 60extern bool optimize_edge_for_speed_p (edge); 61extern bool optimize_insn_for_size_p (void); 62extern bool optimize_insn_for_speed_p (void); 63extern bool optimize_loop_for_size_p (struct loop *); 64extern bool optimize_loop_for_speed_p (struct loop *); 65extern bool optimize_loop_nest_for_speed_p (struct loop *); 66extern bool optimize_loop_nest_for_size_p (struct loop *); 67extern bool predictable_edge_p (edge); 68extern void rtl_profile_for_bb (basic_block); 69extern void rtl_profile_for_edge (edge); 70extern void default_rtl_profile (void); 71extern bool rtl_predicted_by_p (const_basic_block, enum br_predictor); 72extern bool gimple_predicted_by_p (const_basic_block, enum br_predictor); 73extern bool edge_probability_reliable_p (const_edge); 74extern bool br_prob_note_reliable_p (const_rtx); 75extern void predict_insn_def (rtx_insn *, enum br_predictor, enum prediction); 76extern void rtl_predict_edge (edge, enum br_predictor, int); 77extern void gimple_predict_edge (edge, enum br_predictor, int); 78extern void remove_predictions_associated_with_edge (edge); 79extern void predict_edge_def (edge, enum br_predictor, enum prediction); 80extern void invert_br_probabilities (rtx); 81extern void guess_outgoing_edge_probabilities (basic_block); 82extern void tree_estimate_probability (void); 83extern void handle_missing_profiles (void); 84extern int counts_to_freqs (void); 85extern bool expensive_function_p (int); 86extern void estimate_bb_frequencies (bool); 87extern void compute_function_frequency (void); 88extern tree build_predict_expr (enum br_predictor, enum prediction); 89extern const char *predictor_name (enum br_predictor); 90extern void rebuild_frequencies (void); 91 92#endif /* GCC_PREDICT_H */ 93