gcc/cfghooks.h

   1 /* Hooks for cfg representation specific functions.
   2    Copyright (C) 2003-2018 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[2];
  42   /* Likewise for a basic block's successors.  */
  43   int num_mismatched_freq_out[2];
  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[2];
  47   /* Likewise for a basic block's successors.  */
  48   int num_mismatched_count_out[2];
  49   /* A weighted cost of the run-time of the function body.  */
  50   gcov_type time[2];
  51   /* A weighted cost of the size of the function body.  */
  52   int size[2];
  53   /* True iff this pass actually was run.  */
  54   bool run;
  55 };
  56
  57
  58 struct cfg_hooks
  59 {
  60   /* Name of the corresponding ir.  */
  61   const char *name;
  62
  63   /* Debugging.  */
  64   int (*verify_flow_info) (void);
  65   void (*dump_bb) (FILE *, basic_block, int, dump_flags_t);
  66   void (*dump_bb_for_graph) (pretty_printer *, basic_block);
  67
  68   /* Basic CFG manipulation.  */
  69
  70   /* Return new basic block.  */
  71   basic_block (*create_basic_block) (void *head, void *end, basic_block after);
  72
  73   /* Redirect edge E to the given basic block B and update underlying program
  74      representation.  Returns edge representing redirected branch (that may not
  75      be equivalent to E in the case of duplicate edges being removed) or NULL
  76      if edge is not easily redirectable for whatever reason.  */
  77   edge (*redirect_edge_and_branch) (edge e, basic_block b);
  78
  79   /* Same as the above but allows redirecting of fallthru edges.  In that case
  80      newly created forwarder basic block is returned.  The edge must
  81      not be abnormal.  */
  82   basic_block (*redirect_edge_and_branch_force) (edge, basic_block);
  83
  84   /* Returns true if it is possible to remove the edge by redirecting it
  85      to the destination of the other edge going from its source.  */
  86   bool (*can_remove_branch_p) (const_edge);
  87
  88   /* Remove statements corresponding to a given basic block.  */
  89   void (*delete_basic_block) (basic_block);
  90
  91   /* Creates a new basic block just after basic block B by splitting
  92      everything after specified instruction I.  */
  93   basic_block (*split_block) (basic_block b, void * i);
  94
  95   /* Move block B immediately after block A.  */
  96   bool (*move_block_after) (basic_block b, basic_block a);
  97
  98   /* Return true when blocks A and B can be merged into single basic block.  */
  99   bool (*can_merge_blocks_p) (basic_block a, basic_block b);
 100
 101   /* Merge blocks A and B.  */
 102   void (*merge_blocks) (basic_block a, basic_block b);
 103
 104   /* Predict edge E using PREDICTOR to given PROBABILITY.  */
 105   void (*predict_edge) (edge e, enum br_predictor predictor, int probability);
 106
 107   /* Return true if the one of outgoing edges is already predicted by
 108      PREDICTOR.  */
 109   bool (*predicted_by_p) (const_basic_block bb, enum br_predictor predictor);
 110
 111   /* Return true when block A can be duplicated.  */
 112   bool (*can_duplicate_block_p) (const_basic_block a);
 113
 114   /* Duplicate block A.  */
 115   basic_block (*duplicate_block) (basic_block a);
 116
 117   /* Higher level functions representable by primitive operations above if
 118      we didn't have some oddities in RTL and Tree representations.  */
 119   basic_block (*split_edge) (edge);
 120   void (*make_forwarder_block) (edge);
 121
 122   /* Try to make the edge fallthru.  */
 123   void (*tidy_fallthru_edge) (edge);
 124
 125   /* Make the edge non-fallthru.  */
 126   basic_block (*force_nonfallthru) (edge);
 127
 128   /* Say whether a block ends with a call, possibly followed by some
 129      other code that must stay with the call.  */
 130   bool (*block_ends_with_call_p) (basic_block);
 131
 132   /* Say whether a block ends with a conditional branch.  Switches
 133      and unconditional branches do not qualify.  */
 134   bool (*block_ends_with_condjump_p) (const_basic_block);
 135
 136   /* Add fake edges to the function exit for any non constant and non noreturn
 137      calls, volatile inline assembly in the bitmap of blocks specified by
 138      BLOCKS or to the whole CFG if BLOCKS is zero.  Return the number of blocks
 139      that were split.
 140
 141      The goal is to expose cases in which entering a basic block does not imply
 142      that all subsequent instructions must be executed.  */
 143   int (*flow_call_edges_add) (sbitmap);
 144
 145   /* This function is called immediately after edge E is added to the
 146      edge vector E->dest->preds.  */
 147   void (*execute_on_growing_pred) (edge);
 148
 149   /* This function is called immediately before edge E is removed from
 150      the edge vector E->dest->preds.  */
 151   void (*execute_on_shrinking_pred) (edge);
 152
 153   /* A hook for duplicating loop in CFG, currently this is used
 154      in loop versioning.  */
 155   bool (*cfg_hook_duplicate_loop_to_header_edge) (struct loop *, edge,
 156                                                   unsigned, sbitmap,
 157                                                   edge, vec<edge> *,
 158                                                   int);
 159
 160   /* Add condition to new basic block and update CFG used in loop
 161      versioning.  */
 162   void (*lv_add_condition_to_bb) (basic_block, basic_block, basic_block,
 163                                   void *);
 164   /* Update the PHI nodes in case of loop versioning.  */
 165   void (*lv_adjust_loop_header_phi) (basic_block, basic_block,
 166                                      basic_block, edge);
 167
 168   /* Given a condition BB extract the true/false taken/not taken edges
 169      (depending if we are on tree's or RTL). */
 170   void (*extract_cond_bb_edges) (basic_block, edge *, edge *);
 171
 172
 173   /* Add PHI arguments queued in PENDINT_STMT list on edge E to edge
 174      E->dest (only in tree-ssa loop versioning.  */
 175   void (*flush_pending_stmts) (edge);
 176
 177   /* True if a block contains no executable instructions.  */
 178   bool (*empty_block_p) (basic_block);
 179
 180   /* Split a basic block if it ends with a conditional branch and if
 181      the other part of the block is not empty.  */
 182   basic_block (*split_block_before_cond_jump) (basic_block);
 183
 184   /* Do book-keeping of a basic block for the profile consistency checker.  */
 185   void (*account_profile_record) (basic_block, int, struct profile_record *);
 186 };
 187
 188 extern void verify_flow_info (void);
 189
 190 /* Check control flow invariants, if internal consistency checks are
 191    enabled.  */
 192
 193 static inline void
 194 checking_verify_flow_info (void)
 195 {
 196   /* TODO: Add a separate option for -fchecking=cfg.  */
 197   if (flag_checking)
 198     verify_flow_info ();
 199 }
 200
 201 extern void dump_bb (FILE *, basic_block, int, dump_flags_t);
 202 extern void dump_bb_for_graph (pretty_printer *, basic_block);
 203 extern void dump_flow_info (FILE *, dump_flags_t);
 204
 205 extern edge redirect_edge_and_branch (edge, basic_block);
 206 extern basic_block redirect_edge_and_branch_force (edge, basic_block);
 207 extern edge redirect_edge_succ_nodup (edge, basic_block);
 208 extern bool can_remove_branch_p (const_edge);
 209 extern void remove_branch (edge);
 210 extern void remove_edge (edge);
 211 extern edge split_block (basic_block, rtx);
 212 extern edge split_block (basic_block, gimple *);
 213 extern edge split_block_after_labels (basic_block);
 214 extern bool move_block_after (basic_block, basic_block);
 215 extern void delete_basic_block (basic_block);
 216 extern basic_block split_edge (edge);
 217 extern basic_block create_basic_block (rtx, rtx, basic_block);
 218 extern basic_block create_basic_block (gimple_seq, basic_block);
 219 extern basic_block create_empty_bb (basic_block);
 220 extern bool can_merge_blocks_p (basic_block, basic_block);
 221 extern void merge_blocks (basic_block, basic_block);
 222 extern edge make_forwarder_block (basic_block, bool (*)(edge),
 223                                   void (*) (basic_block));
 224 extern basic_block force_nonfallthru (edge);
 225 extern void tidy_fallthru_edge (edge);
 226 extern void tidy_fallthru_edges (void);
 227 extern void predict_edge (edge e, enum br_predictor predictor, int probability);
 228 extern bool predicted_by_p (const_basic_block bb, enum br_predictor predictor);
 229 extern bool can_duplicate_block_p (const_basic_block);
 230 extern basic_block duplicate_block (basic_block, edge, basic_block);
 231 extern bool block_ends_with_call_p (basic_block bb);
 232 extern bool empty_block_p (basic_block);
 233 extern basic_block split_block_before_cond_jump (basic_block);
 234 extern bool block_ends_with_condjump_p (const_basic_block bb);
 235 extern int flow_call_edges_add (sbitmap);
 236 extern void execute_on_growing_pred (edge);
 237 extern void execute_on_shrinking_pred (edge);
 238 extern bool cfg_hook_duplicate_loop_to_header_edge (struct loop *loop, edge,
 239                                                     unsigned int ndupl,
 240                                                     sbitmap wont_exit,
 241                                                     edge orig,
 242                                                     vec<edge> *to_remove,
 243                                                     int flags);
 244
 245 extern void lv_flush_pending_stmts (edge);
 246 extern void extract_cond_bb_edges (basic_block, edge *, edge*);
 247 extern void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block,
 248                                        edge);
 249 extern void lv_add_condition_to_bb (basic_block, basic_block, basic_block,
 250                                     void *);
 251
 252 extern bool can_copy_bbs_p (basic_block *, unsigned);
 253 extern void copy_bbs (basic_block *, unsigned, basic_block *,
 254                       edge *, unsigned, edge *, struct loop *,
 255                       basic_block, bool);
 256
 257 void account_profile_record (struct profile_record *, int);
 258
 259 /* Hooks containers.  */
 260 extern struct cfg_hooks gimple_cfg_hooks;
 261 extern struct cfg_hooks rtl_cfg_hooks;
 262 extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
 263
 264 /* Declarations.  */
 265 extern enum ir_type current_ir_type (void);
 266 extern void rtl_register_cfg_hooks (void);
 267 extern void cfg_layout_rtl_register_cfg_hooks (void);
 268 extern void gimple_register_cfg_hooks (void);
 269 extern struct cfg_hooks get_cfg_hooks (void);
 270 extern void set_cfg_hooks (struct cfg_hooks);
 271
 272 #endif /* GCC_CFGHOOKS_H */