1/* Definitions for branch prediction routines in the GNU compiler.
2 Copyright (C) 2001-2023 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#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,
37enum br_predictor
38{
39#include "predict.def"
40
41 /* Upper bound on non-language-specific builtins. */
42 END_PREDICTORS
43};
44#undef DEF_PREDICTOR
45enum prediction
46{
47 NOT_TAKEN,
48 TAKEN
49};
50
51/* In emit-rtl.cc. */
52extern profile_probability split_branch_probability;
53
54extern gcov_type get_hot_bb_threshold (void);
55extern void set_hot_bb_threshold (gcov_type);
56extern bool maybe_hot_count_p (struct function *, profile_count);
57extern bool maybe_hot_bb_p (struct function *, const_basic_block);
58extern bool maybe_hot_edge_p (edge);
59extern bool probably_never_executed_bb_p (struct function *, const_basic_block);
60extern bool probably_never_executed_edge_p (struct function *, edge);
61extern enum optimize_size_level optimize_function_for_size_p (struct function *);
62extern bool optimize_function_for_speed_p (struct function *);
63extern optimization_type function_optimization_type (struct function *);
64extern enum optimize_size_level optimize_bb_for_size_p (const_basic_block);
65extern bool optimize_bb_for_speed_p (const_basic_block);
66extern optimization_type bb_optimization_type (const_basic_block);
67extern enum optimize_size_level optimize_edge_for_size_p (edge);
68extern bool optimize_edge_for_speed_p (edge);
69extern enum optimize_size_level optimize_insn_for_size_p (void);
70extern bool optimize_insn_for_speed_p (void);
71extern optimization_type insn_optimization_type ();
72extern enum optimize_size_level optimize_loop_for_size_p (class loop *);
73extern bool optimize_loop_for_speed_p (class loop *);
74extern bool optimize_loop_nest_for_speed_p (class loop *);
75extern enum optimize_size_level optimize_loop_nest_for_size_p (class loop *);
76extern bool predictable_edge_p (edge);
77extern void rtl_profile_for_bb (basic_block);
78extern void rtl_profile_for_edge (edge);
79extern void default_rtl_profile (void);
80extern bool rtl_predicted_by_p (const_basic_block, enum br_predictor);
81extern bool gimple_predicted_by_p (const_basic_block, enum br_predictor);
82extern bool edge_probability_reliable_p (const_edge);
83extern bool br_prob_note_reliable_p (const_rtx);
84extern void predict_insn_def (rtx_insn *, enum br_predictor, enum prediction);
85extern void rtl_predict_edge (edge, enum br_predictor, int);
86extern void gimple_predict_edge (edge, enum br_predictor, int);
87extern void remove_predictions_associated_with_edge (edge);
88extern void predict_edge_def (edge, enum br_predictor, enum prediction);
89extern void invert_br_probabilities (rtx);
90extern void guess_outgoing_edge_probabilities (basic_block);
91extern void tree_guess_outgoing_edge_probabilities (basic_block);
92extern void tree_estimate_probability (bool);
93extern void handle_missing_profiles (void);
94extern bool update_max_bb_count (void);
95extern bool expensive_function_p (int);
96extern void compute_function_frequency (void);
97extern tree build_predict_expr (enum br_predictor, enum prediction);
98extern const char *predictor_name (enum br_predictor);
99extern void rebuild_frequencies (void);
100extern void report_predictor_hitrates (void);
101extern void force_edge_cold (edge, bool);
102extern void propagate_unlikely_bbs_forward (void);
103
104extern void add_reg_br_prob_note (rtx_insn *, profile_probability);
105
106/* In ipa-pure-const.cc */
107extern void warn_function_cold (tree);
108
109#endif /* GCC_PREDICT_H */
110

source code of gcc/predict.h