gcc/cfghooks.h

   1 /* Hooks for cfg representation specific functions.
   2    Copyright (C) 2003-2023 Free Software Foundation, Inc.
   3    Contributed by Sebastian Pop <s.pop@laposte.net>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_CFGHOOKS_H
  22 #define GCC_CFGHOOKS_H
  23
  24 #include "predict.h"
  25
  26 /* Structure to gather statistic about profile consistency, per pass.
  27    An array of this structure, indexed by pass static number, is allocated
  28    in passes.cc.  The structure is defined here so that different CFG modes
  29    can do their book-keeping via CFG hooks.
  30
  31    For every field[2], field[0] is the count before the pass runs, and
  32    field[1] is the post-pass count.  This allows us to monitor the effect
  33    of each individual pass on the profile consistency.
  34
  35    This structure is not supposed to be used by anything other than passes.cc
  36    and one CFG hook per CFG mode.  */
  37 struct profile_record
  38 {
  39   /* A weighted cost of the run-time of the function body.  */
  40   double time;
  41   /* Frequency of execution of basic blocks where sum(prob) of the block's
  42      predecessors doesn't match reasonably probability 1.  */
  43   double dyn_mismatched_prob_out;
  44   /* Frequency of execution basic blocks where sum(count) of the block's
  45      predecessors doesn't match reasonably well with the incoming frequency.  */
  46   double dyn_mismatched_count_in;
  47   /* The number of basic blocks where sum(prob) of the block's predecessors
  48      doesn't match reasonably probability 1.  */
  49   int num_mismatched_prob_out;
  50   /* The number of basic blocks where sum(count) of the block's predecessors
  51      doesn't match reasonably well with the incoming frequency.  */
  52   int num_mismatched_count_in;
  53   /* A weighted cost of the size of the function body.  */
  54   int size;
  55   /* True iff this pass actually was run.  */
  56   bool run;
  57   bool fdo;
  58 };
  59
  60 typedef int_hash <unsigned short, 0> dependence_hash;
  61
  62 /* Optional data for duplicate_block.   */
  63
  64 class copy_bb_data
  65 {
  66 public:
  67   copy_bb_data() : dependence_map (NULL) {}
  68   ~copy_bb_data () { delete dependence_map; }
  69
  70   /* A map from the copied BBs dependence info cliques to
  71      equivalents in the BBs duplicated to.  */
  72   hash_map<dependence_hash, unsigned short> *dependence_map;
  73 };
  74
  75 struct cfg_hooks
  76 {
  77   /* Name of the corresponding ir.  */
  78   const char *name;
  79
  80   /* Debugging.  */
  81   bool (*verify_flow_info) (void);
  82   void (*dump_bb) (FILE *, basic_block, int, dump_flags_t);
  83   void (*dump_bb_for_graph) (pretty_printer *, basic_block);
  84
  85   /* Basic CFG manipulation.  */
  86
  87   /* Return new basic block.  */
  88   basic_block (*create_basic_block) (void *head, void *end, basic_block after);
  89
  90   /* Redirect edge E to the given basic block B and update underlying program
  91      representation.  Returns edge representing redirected branch (that may not
  92      be equivalent to E in the case of duplicate edges being removed) or NULL
  93      if edge is not easily redirectable for whatever reason.  */
  94   edge (*redirect_edge_and_branch) (edge e, basic_block b);
  95
  96   /* Same as the above but allows redirecting of fallthru edges.  In that case
  97      newly created forwarder basic block is returned.  The edge must
  98      not be abnormal.  */
  99   basic_block (*redirect_edge_and_branch_force) (edge, basic_block);
 100
 101   /* Returns true if it is possible to remove the edge by redirecting it
 102      to the destination of the other edge going from its source.  */
 103   bool (*can_remove_branch_p) (const_edge);
 104
 105   /* Remove statements corresponding to a given basic block.  */
 106   void (*delete_basic_block) (basic_block);
 107
 108   /* Creates a new basic block just after basic block B by splitting
 109      everything after specified instruction I.  */
 110   basic_block (*split_block) (basic_block b, void * i);
 111
 112   /* Move block B immediately after block A.  */
 113   bool (*move_block_after) (basic_block b, basic_block a);
 114
 115   /* Return true when blocks A and B can be merged into single basic block.  */
 116   bool (*can_merge_blocks_p) (basic_block a, basic_block b);
 117
 118   /* Merge blocks A and B.  */
 119   void (*merge_blocks) (basic_block a, basic_block b);
 120
 121   /* Predict edge E using PREDICTOR to given PROBABILITY.  */
 122   void (*predict_edge) (edge e, enum br_predictor predictor, int probability);
 123
 124   /* Return true if the one of outgoing edges is already predicted by
 125      PREDICTOR.  */
 126   bool (*predicted_by_p) (const_basic_block bb, enum br_predictor predictor);
 127
 128   /* Return true when block A can be duplicated.  */
 129   bool (*can_duplicate_block_p) (const_basic_block a);
 130
 131   /* Duplicate block A.  */
 132   basic_block (*duplicate_block) (basic_block a, copy_bb_data *);
 133
 134   /* Higher level functions representable by primitive operations above if
 135      we didn't have some oddities in RTL and Tree representations.  */
 136   basic_block (*split_edge) (edge);
 137   void (*make_forwarder_block) (edge);
 138
 139   /* Try to make the edge fallthru.  */
 140   void (*tidy_fallthru_edge) (edge);
 141
 142   /* Make the edge non-fallthru.  */
 143   basic_block (*force_nonfallthru) (edge);
 144
 145   /* Say whether a block ends with a call, possibly followed by some
 146      other code that must stay with the call.  */
 147   bool (*block_ends_with_call_p) (basic_block);
 148
 149   /* Say whether a block ends with a conditional branch.  Switches
 150      and unconditional branches do not qualify.  */
 151   bool (*block_ends_with_condjump_p) (const_basic_block);
 152
 153   /* Add fake edges to the function exit for any non constant and non noreturn
 154      calls, volatile inline assembly in the bitmap of blocks specified by
 155      BLOCKS or to the whole CFG if BLOCKS is zero.  Return the number of blocks
 156      that were split.
 157
 158      The goal is to expose cases in which entering a basic block does not imply
 159      that all subsequent instructions must be executed.  */
 160   int (*flow_call_edges_add) (sbitmap);
 161
 162   /* This function is called immediately after edge E is added to the
 163      edge vector E->dest->preds.  */
 164   void (*execute_on_growing_pred) (edge);
 165
 166   /* This function is called immediately before edge E is removed from
 167      the edge vector E->dest->preds.  */
 168   void (*execute_on_shrinking_pred) (edge);
 169
 170   /* A hook for duplicating loop in CFG, currently this is used
 171      in loop versioning.  */
 172   bool (*cfg_hook_duplicate_loop_body_to_header_edge) (class loop *, edge,
 173                                                        unsigned, sbitmap, edge,
 174                                                        vec<edge> *, int);
 175
 176   /* Add condition to new basic block and update CFG used in loop
 177      versioning.  */
 178   void (*lv_add_condition_to_bb) (basic_block, basic_block, basic_block,
 179                                   void *);
 180   /* Update the PHI nodes in case of loop versioning.  */
 181   void (*lv_adjust_loop_header_phi) (basic_block, basic_block,
 182                                      basic_block, edge);
 183
 184   /* Given a condition BB extract the true/false taken/not taken edges
 185      (depending if we are on tree's or RTL). */
 186   void (*extract_cond_bb_edges) (basic_block, edge *, edge *);
 187
 188
 189   /* Add PHI arguments queued in PENDINT_STMT list on edge E to edge
 190      E->dest (only in tree-ssa loop versioning.  */
 191   void (*flush_pending_stmts) (edge);
 192
 193   /* True if a block contains no executable instructions.  */
 194   bool (*empty_block_p) (basic_block);
 195
 196   /* Split a basic block if it ends with a conditional branch and if
 197      the other part of the block is not empty.  */
 198   basic_block (*split_block_before_cond_jump) (basic_block);
 199
 200   /* Do book-keeping of a basic block for the profile consistency checker.  */
 201   void (*account_profile_record) (basic_block, struct profile_record *);
 202 };
 203
 204 extern void verify_flow_info (void);
 205
 206 /* Check control flow invariants, if internal consistency checks are
 207    enabled.  */
 208
 209 inline void
 210 checking_verify_flow_info (void)
 211 {
 212   /* TODO: Add a separate option for -fchecking=cfg.  */
 213   if (flag_checking)
 214     verify_flow_info ();
 215 }
 216
 217 extern void dump_bb (FILE *, basic_block, int, dump_flags_t);
 218 extern void dump_bb_for_graph (pretty_printer *, basic_block);
 219 extern void dump_flow_info (FILE *, dump_flags_t);
 220
 221 extern edge redirect_edge_and_branch (edge, basic_block);
 222 extern basic_block redirect_edge_and_branch_force (edge, basic_block);
 223 extern edge redirect_edge_succ_nodup (edge, basic_block);
 224 extern bool can_remove_branch_p (const_edge);
 225 extern void remove_branch (edge);
 226 extern void remove_edge (edge);
 227 extern edge split_block (basic_block, rtx);
 228 extern edge split_block (basic_block, gimple *);
 229 extern edge split_block_after_labels (basic_block);
 230 extern bool move_block_after (basic_block, basic_block);
 231 extern void delete_basic_block (basic_block);
 232 extern basic_block split_edge (edge);
 233 extern basic_block create_basic_block (rtx, rtx, basic_block);
 234 extern basic_block create_basic_block (gimple_seq, basic_block);
 235 extern basic_block create_empty_bb (basic_block);
 236 extern bool can_merge_blocks_p (basic_block, basic_block);
 237 extern void merge_blocks (basic_block, basic_block);
 238 extern edge make_forwarder_block (basic_block, bool (*)(edge),
 239                                   void (*) (basic_block));
 240 extern basic_block force_nonfallthru (edge);
 241 extern void tidy_fallthru_edge (edge);
 242 extern void tidy_fallthru_edges (void);
 243 extern void predict_edge (edge e, enum br_predictor predictor, int probability);
 244 extern bool predicted_by_p (const_basic_block bb, enum br_predictor predictor);
 245 extern bool can_duplicate_block_p (const_basic_block);
 246 extern basic_block duplicate_block (basic_block, edge, basic_block,
 247                                     copy_bb_data * = NULL);
 248 extern bool block_ends_with_call_p (basic_block bb);
 249 extern bool empty_block_p (basic_block);
 250 extern basic_block split_block_before_cond_jump (basic_block);
 251 extern bool block_ends_with_condjump_p (const_basic_block bb);
 252 extern int flow_call_edges_add (sbitmap);
 253 extern void execute_on_growing_pred (edge);
 254 extern void execute_on_shrinking_pred (edge);
 255 extern bool
 256 cfg_hook_duplicate_loop_body_to_header_edge (class loop *loop, edge,
 257                                              unsigned int ndupl,
 258                                              sbitmap wont_exit, edge orig,
 259                                              vec<edge> *to_remove, int flags);
 260
 261 extern void lv_flush_pending_stmts (edge);
 262 extern void extract_cond_bb_edges (basic_block, edge *, edge*);
 263 extern void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block,
 264                                        edge);
 265 extern void lv_add_condition_to_bb (basic_block, basic_block, basic_block,
 266                                     void *);
 267
 268 extern bool can_copy_bbs_p (basic_block *, unsigned);
 269 extern void copy_bbs (basic_block *, unsigned, basic_block *,
 270                       edge *, unsigned, edge *, class loop *,
 271                       basic_block, bool);
 272
 273 void profile_record_check_consistency (profile_record *);
 274 void profile_record_account_profile (profile_record *);
 275
 276 /* Hooks containers.  */
 277 extern struct cfg_hooks gimple_cfg_hooks;
 278 extern struct cfg_hooks rtl_cfg_hooks;
 279 extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
 280
 281 /* Declarations.  */
 282 extern enum ir_type current_ir_type (void);
 283 extern void rtl_register_cfg_hooks (void);
 284 extern void cfg_layout_rtl_register_cfg_hooks (void);
 285 extern void gimple_register_cfg_hooks (void);
 286 extern struct cfg_hooks get_cfg_hooks (void);
 287 extern void set_cfg_hooks (struct cfg_hooks);
 288
 289 #endif /* GCC_CFGHOOKS_H */