gcc/predict.h

   1 /* Definitions for branch prediction routines in the GNU compiler.
   2    Copyright (C) 2001-2014 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 void predict_insn_def (rtx, enum br_predictor, enum prediction);
  49 extern int counts_to_freqs (void);
  50 extern void handle_missing_profiles (void);
  51 extern void estimate_bb_frequencies (bool);
  52 extern const char *predictor_name (enum br_predictor);
  53 extern tree build_predict_expr (enum br_predictor, enum prediction);
  54 extern void tree_estimate_probability (void);
  55 extern void compute_function_frequency (void);
  56 extern void rebuild_frequencies (void);
  57
  58 #endif  /* GCC_PREDICT_H */