1 /* Definitions for branch prediction routines in the GNU compiler. 2 Copyright (C) 2001-2016 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 /* 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, 34 enum br_predictor 35 { 36 #include "predict.def" 37 38 /* Upper bound on non-language-specific builtins. */ 39 END_PREDICTORS 40 }; 41 #undef DEF_PREDICTOR 42 enum prediction 43 { 44 NOT_TAKEN, 45 TAKEN 46 }; 47 48 extern gcov_type get_hot_bb_threshold (void); 49 extern void set_hot_bb_threshold (gcov_type); 50 extern bool maybe_hot_count_p (struct function *, gcov_type); 51 extern bool maybe_hot_bb_p (struct function *, const_basic_block); 52 extern bool maybe_hot_edge_p (edge); 53 extern bool probably_never_executed_bb_p (struct function *, const_basic_block); 54 extern bool probably_never_executed_edge_p (struct function *, edge); 55 extern bool optimize_function_for_size_p (struct function *); 56 extern bool optimize_function_for_speed_p (struct function *); 57 extern optimization_type function_optimization_type (struct function *); 58 extern bool optimize_bb_for_size_p (const_basic_block); 59 extern bool optimize_bb_for_speed_p (const_basic_block); 60 extern optimization_type bb_optimization_type (const_basic_block); 61 extern bool optimize_edge_for_size_p (edge); 62 extern bool optimize_edge_for_speed_p (edge); 63 extern bool optimize_insn_for_size_p (void); 64 extern bool optimize_insn_for_speed_p (void); 65 extern bool optimize_loop_for_size_p (struct loop *); 66 extern bool optimize_loop_for_speed_p (struct loop *); 67 extern bool optimize_loop_nest_for_speed_p (struct loop *); 68 extern bool optimize_loop_nest_for_size_p (struct loop *); 69 extern bool predictable_edge_p (edge); 70 extern void rtl_profile_for_bb (basic_block); 71 extern void rtl_profile_for_edge (edge); 72 extern void default_rtl_profile (void); 73 extern bool rtl_predicted_by_p (const_basic_block, enum br_predictor); 74 extern bool gimple_predicted_by_p (const_basic_block, enum br_predictor); 75 extern bool edge_probability_reliable_p (const_edge); 76 extern bool br_prob_note_reliable_p (const_rtx); 77 extern void predict_insn_def (rtx_insn *, enum br_predictor, enum prediction); 78 extern void rtl_predict_edge (edge, enum br_predictor, int); 79 extern void gimple_predict_edge (edge, enum br_predictor, int); 80 extern void remove_predictions_associated_with_edge (edge); 81 extern void predict_edge_def (edge, enum br_predictor, enum prediction); 82 extern void invert_br_probabilities (rtx); 83 extern void guess_outgoing_edge_probabilities (basic_block); 84 extern void tree_estimate_probability (void); 85 extern void handle_missing_profiles (void); 86 extern int counts_to_freqs (void); 87 extern bool expensive_function_p (int); 88 extern void estimate_bb_frequencies (bool); 89 extern void compute_function_frequency (void); 90 extern tree build_predict_expr (enum br_predictor, enum prediction); 91 extern const char *predictor_name (enum br_predictor); 92 extern void rebuild_frequencies (void); 93 94 #endif /* GCC_PREDICT_H */ 95