gcc/cfghooks.h

   1 /* Hooks for cfg representation specific functions.
   2    Copyright (C) 2003-2019 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.c.  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.c
  36    and one CFG hook per CFG mode.  */
  37 struct profile_record
  38 {
  39   /* The number of basic blocks where sum(freq) of the block's predecessors
  40      doesn't match reasonably well with the incoming frequency.  */
  41   int num_mismatched_freq_in;
  42   /* Likewise for a basic block's successors.  */
  43   int num_mismatched_freq_out;
  44   /* The number of basic blocks where sum(count) of the block's predecessors
  45      doesn't match reasonably well with the incoming frequency.  */
  46   int num_mismatched_count_in;
  47   /* Likewise for a basic block's successors.  */
  48   int num_mismatched_count_out;
  49   /* A weighted cost of the run-time of the function body.  */
  50   gcov_type_unsigned time;
  51   /* A weighted cost of the size of the function body.  */
  52   int size;
  53   /* True iff this pass actually was run.  */
  54   bool run;
  55 };
  56
  57 typedef int_hash <unsigned short, 0> dependence_hash;
  58
  59 /* Optional data for duplicate_block.   */
  60
  61 struct copy_bb_data
  62 {
  63   copy_bb_data() : dependence_map (NULL) {}
  64   ~copy_bb_data () { delete dependence_map; }
  65
  66   /* A map from the copied BBs dependence info cliques to
  67      equivalents in the BBs duplicated to.  */
  68   hash_map<dependence_hash, unsigned short> *dependence_map;
  69 };
  70
  71 struct cfg_hooks
  72 {
  73   /* Name of the corresponding ir.  */
  74   const char *name;
  75
  76   /* Debugging.  */
  77   int (*verify_flow_info) (void);
  78   void (*dump_bb) (FILE *, basic_block, int, dump_flags_t);
  79   void (*dump_bb_for_graph) (pretty_printer *, basic_block);
  80
  81   /* Basic CFG manipulation.  */
  82
  83   /* Return new basic block.  */
  84   basic_block (*create_basic_block) (void *head, void *end, basic_block after);
  85
  86   /* Redirect edge E to the given basic block B and update underlying program
  87      representation.  Returns edge representing redirected branch (that may not
  88      be equivalent to E in the case of duplicate edges being removed) or NULL
  89      if edge is not easily redirectable for whatever reason.  */
  90   edge (*redirect_edge_and_branch) (edge e, basic_block b);
  91
  92   /* Same as the above but allows redirecting of fallthru edges.  In that case
  93      newly created forwarder basic block is returned.  The edge must
  94      not be abnormal.  */
  95   basic_block (*redirect_edge_and_branch_force) (edge, basic_block);
  96
  97   /* Returns true if it is possible to remove the edge by redirecting it
  98      to the destination of the other edge going from its source.  */
  99   bool (*can_remove_branch_p) (const_edge);
 100
 101   /* Remove statements corresponding to a given basic block.  */
 102   void (*delete_basic_block) (basic_block);
 103
 104   /* Creates a new basic block just after basic block B by splitting
 105      everything after specified instruction I.  */
 106   basic_block (*split_block) (basic_block b, void * i);
 107
 108   /* Move block B immediately after block A.  */
 109   bool (*move_block_after) (basic_block b, basic_block a);
 110
 111   /* Return true when blocks A and B can be merged into single basic block.  */
 112   bool (*can_merge_blocks_p) (basic_block a, basic_block b);
 113
 114   /* Merge blocks A and B.  */
 115   void (*merge_blocks) (basic_block a, basic_block b);
 116
 117   /* Predict edge E using PREDICTOR to given PROBABILITY.  */
 118   void (*predict_edge) (edge e, enum br_predictor predictor, int probability);
 119
 120   /* Return true if the one of outgoing edges is already predicted by
 121      PREDICTOR.  */
 122   bool (*predicted_by_p) (const_basic_block bb, enum br_predictor predictor);
 123
 124   /* Return true when block A can be duplicated.  */
 125   bool (*can_duplicate_block_p) (const_basic_block a);
 126
 127   /* Duplicate block A.  */
 128   basic_block (*duplicate_block) (basic_block a, copy_bb_data *);
 129
 130   /* Higher level functions representable by primitive operations above if
 131      we didn't have some oddities in RTL and Tree representations.  */
 132   basic_block (*split_edge) (edge);
 133   void (*make_forwarder_block) (edge);
 134
 135   /* Try to make the edge fallthru.  */
 136   void (*tidy_fallthru_edge) (edge);
 137
 138   /* Make the edge non-fallthru.  */
 139   basic_block (*force_nonfallthru) (edge);
 140
 141   /* Say whether a block ends with a call, possibly followed by some
 142      other code that must stay with the call.  */
 143   bool (*block_ends_with_call_p) (basic_block);
 144
 145   /* Say whether a block ends with a conditional branch.  Switches
 146      and unconditional branches do not qualify.  */
 147   bool (*block_ends_with_condjump_p) (const_basic_block);
 148
 149   /* Add fake edges to the function exit for any non constant and non noreturn
 150      calls, volatile inline assembly in the bitmap of blocks specified by
 151      BLOCKS or to the whole CFG if BLOCKS is zero.  Return the number of blocks
 152      that were split.
 153
 154      The goal is to expose cases in which entering a basic block does not imply
 155      that all subsequent instructions must be executed.  */
 156   int (*flow_call_edges_add) (sbitmap);
 157
 158   /* This function is called immediately after edge E is added to the
 159      edge vector E->dest->preds.  */
 160   void (*execute_on_growing_pred) (edge);
 161
 162   /* This function is called immediately before edge E is removed from
 163      the edge vector E->dest->preds.  */
 164   void (*execute_on_shrinking_pred) (edge);
 165
 166   /* A hook for duplicating loop in CFG, currently this is used
 167      in loop versioning.  */
 168   bool (*cfg_hook_duplicate_loop_to_header_edge) (struct loop *, edge,
 169                                                   unsigned, sbitmap,
 170                                                   edge, vec<edge> *,
 171                                                   int);
 172
 173   /* Add condition to new basic block and update CFG used in loop
 174      versioning.  */
 175   void (*lv_add_condition_to_bb) (basic_block, basic_block, basic_block,
 176                                   void *);
 177   /* Update the PHI nodes in case of loop versioning.  */
 178   void (*lv_adjust_loop_header_phi) (basic_block, basic_block,
 179                                      basic_block, edge);
 180
 181   /* Given a condition BB extract the true/false taken/not taken edges
 182      (depending if we are on tree's or RTL). */
 183   void (*extract_cond_bb_edges) (basic_block, edge *, edge *);
 184
 185
 186   /* Add PHI arguments queued in PENDINT_STMT list on edge E to edge
 187      E->dest (only in tree-ssa loop versioning.  */
 188   void (*flush_pending_stmts) (edge);
 189
 190   /* True if a block contains no executable instructions.  */
 191   bool (*empty_block_p) (basic_block);
 192
 193   /* Split a basic block if it ends with a conditional branch and if
 194      the other part of the block is not empty.  */
 195   basic_block (*split_block_before_cond_jump) (basic_block);
 196
 197   /* Do book-keeping of a basic block for the profile consistency checker.  */
 198   void (*account_profile_record) (basic_block, struct profile_record *);
 199 };
 200
 201 extern void verify_flow_info (void);
 202
 203 /* Check control flow invariants, if internal consistency checks are
 204    enabled.  */
 205
 206 static inline void
 207 checking_verify_flow_info (void)
 208 {
 209   /* TODO: Add a separate option for -fchecking=cfg.  */
 210   if (flag_checking)
 211     verify_flow_info ();
 212 }
 213
 214 extern void dump_bb (FILE *, basic_block, int, dump_flags_t);
 215 extern void dump_bb_for_graph (pretty_printer *, basic_block);
 216 extern void dump_flow_info (FILE *, dump_flags_t);
 217
 218 extern edge redirect_edge_and_branch (edge, basic_block);
 219 extern basic_block redirect_edge_and_branch_force (edge, basic_block);
 220 extern edge redirect_edge_succ_nodup (edge, basic_block);
 221 extern bool can_remove_branch_p (const_edge);
 222 extern void remove_branch (edge);
 223 extern void remove_edge (edge);
 224 extern edge split_block (basic_block, rtx);
 225 extern edge split_block (basic_block, gimple *);
 226 extern edge split_block_after_labels (basic_block);
 227 extern bool move_block_after (basic_block, basic_block);
 228 extern void delete_basic_block (basic_block);
 229 extern basic_block split_edge (edge);
 230 extern basic_block create_basic_block (rtx, rtx, basic_block);
 231 extern basic_block create_basic_block (gimple_seq, basic_block);
 232 extern basic_block create_empty_bb (basic_block);
 233 extern bool can_merge_blocks_p (basic_block, basic_block);
 234 extern void merge_blocks (basic_block, basic_block);
 235 extern edge make_forwarder_block (basic_block, bool (*)(edge),
 236                                   void (*) (basic_block));
 237 extern basic_block force_nonfallthru (edge);
 238 extern void tidy_fallthru_edge (edge);
 239 extern void tidy_fallthru_edges (void);
 240 extern void predict_edge (edge e, enum br_predictor predictor, int probability);
 241 extern bool predicted_by_p (const_basic_block bb, enum br_predictor predictor);
 242 extern bool can_duplicate_block_p (const_basic_block);
 243 extern basic_block duplicate_block (basic_block, edge, basic_block,
 244                                     copy_bb_data * = NULL);
 245 extern bool block_ends_with_call_p (basic_block bb);
 246 extern bool empty_block_p (basic_block);
 247 extern basic_block split_block_before_cond_jump (basic_block);
 248 extern bool block_ends_with_condjump_p (const_basic_block bb);
 249 extern int flow_call_edges_add (sbitmap);
 250 extern void execute_on_growing_pred (edge);
 251 extern void execute_on_shrinking_pred (edge);
 252 extern bool cfg_hook_duplicate_loop_to_header_edge (struct loop *loop, edge,
 253                                                     unsigned int ndupl,
 254                                                     sbitmap wont_exit,
 255                                                     edge orig,
 256                                                     vec<edge> *to_remove,
 257                                                     int flags);
 258
 259 extern void lv_flush_pending_stmts (edge);
 260 extern void extract_cond_bb_edges (basic_block, edge *, edge*);
 261 extern void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block,
 262                                        edge);
 263 extern void lv_add_condition_to_bb (basic_block, basic_block, basic_block,
 264                                     void *);
 265
 266 extern bool can_copy_bbs_p (basic_block *, unsigned);
 267 extern void copy_bbs (basic_block *, unsigned, basic_block *,
 268                       edge *, unsigned, edge *, struct loop *,
 269                       basic_block, bool);
 270
 271 void profile_record_check_consistency (profile_record *);
 272 void profile_record_account_profile (profile_record *);
 273
 274 /* Hooks containers.  */
 275 extern struct cfg_hooks gimple_cfg_hooks;
 276 extern struct cfg_hooks rtl_cfg_hooks;
 277 extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
 278
 279 /* Declarations.  */
 280 extern enum ir_type current_ir_type (void);
 281 extern void rtl_register_cfg_hooks (void);
 282 extern void cfg_layout_rtl_register_cfg_hooks (void);
 283 extern void gimple_register_cfg_hooks (void);
 284 extern struct cfg_hooks get_cfg_hooks (void);
 285 extern void set_cfg_hooks (struct cfg_hooks);
 286
 287 #endif /* GCC_CFGHOOKS_H */