gcc/cfghooks.h

   1 /* Hooks for cfg representation specific functions.
   2    Copyright (C) 2003, 2004, 2005, 2006, 2007 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 struct cfg_hooks
  25 {
  26   /* Name of the corresponding ir.  */
  27   const char *name;
  28
  29   /* Debugging.  */
  30   int (*verify_flow_info) (void);
  31   void (*dump_bb) (basic_block, FILE *, int);
  32
  33   /* Basic CFG manipulation.  */
  34
  35   /* Return new basic block.  */
  36   basic_block (*create_basic_block) (void *head, void *end, basic_block after);
  37
  38   /* Redirect edge E to the given basic block B and update underlying program
  39      representation.  Returns edge representing redirected branch (that may not
  40      be equivalent to E in the case of duplicate edges being removed) or NULL
  41      if edge is not easily redirectable for whatever reason.  */
  42   edge (*redirect_edge_and_branch) (edge e, basic_block b);
  43
  44   /* Same as the above but allows redirecting of fallthru edges.  In that case
  45      newly created forwarder basic block is returned.  The edge must
  46      not be abnormal.  */
  47   basic_block (*redirect_edge_and_branch_force) (edge, basic_block);
  48
  49   /* Returns true if it is possible to remove the edge by redirecting it
  50      to the destination of the other edge going from its source.  */
  51   bool (*can_remove_branch_p) (const_edge);
  52
  53   /* Remove statements corresponding to a given basic block.  */
  54   void (*delete_basic_block) (basic_block);
  55
  56   /* Creates a new basic block just after basic block B by splitting
  57      everything after specified instruction I.  */
  58   basic_block (*split_block) (basic_block b, void * i);
  59
  60   /* Move block B immediately after block A.  */
  61   bool (*move_block_after) (basic_block b, basic_block a);
  62
  63   /* Return true when blocks A and B can be merged into single basic block.  */
  64   bool (*can_merge_blocks_p) (basic_block a, basic_block b);
  65
  66   /* Merge blocks A and B.  */
  67   void (*merge_blocks) (basic_block a, basic_block b);
  68
  69   /* Predict edge E using PREDICTOR to given PROBABILITY.  */
  70   void (*predict_edge) (edge e, enum br_predictor predictor, int probability);
  71
  72   /* Return true if the one of outgoing edges is already predicted by
  73      PREDICTOR.  */
  74   bool (*predicted_by_p) (const_basic_block bb, enum br_predictor predictor);
  75
  76   /* Return true when block A can be duplicated.  */
  77   bool (*can_duplicate_block_p) (const_basic_block a);
  78
  79   /* Duplicate block A.  */
  80   basic_block (*duplicate_block) (basic_block a);
  81
  82   /* Higher level functions representable by primitive operations above if
  83      we didn't have some oddities in RTL and Tree representations.  */
  84   basic_block (*split_edge) (edge);
  85   void (*make_forwarder_block) (edge);
  86
  87   /* Tries to make the edge fallthru.  */
  88   void (*tidy_fallthru_edge) (edge);
  89
  90   /* Say whether a block ends with a call, possibly followed by some
  91      other code that must stay with the call.  */
  92   bool (*block_ends_with_call_p) (basic_block);
  93
  94   /* Say whether a block ends with a conditional branch.  Switches
  95      and unconditional branches do not qualify.  */
  96   bool (*block_ends_with_condjump_p) (const_basic_block);
  97
  98   /* Add fake edges to the function exit for any non constant and non noreturn
  99      calls, volatile inline assembly in the bitmap of blocks specified by
 100      BLOCKS or to the whole CFG if BLOCKS is zero.  Return the number of blocks
 101      that were split.
 102
 103      The goal is to expose cases in which entering a basic block does not imply
 104      that all subsequent instructions must be executed.  */
 105   int (*flow_call_edges_add) (sbitmap);
 106
 107   /* This function is called immediately after edge E is added to the
 108      edge vector E->dest->preds.  */
 109   void (*execute_on_growing_pred) (edge);
 110
 111   /* This function is called immediately before edge E is removed from
 112      the edge vector E->dest->preds.  */
 113   void (*execute_on_shrinking_pred) (edge);
 114
 115   /* A hook for duplicating loop in CFG, currently this is used
 116      in loop versioning.  */
 117   bool (*cfg_hook_duplicate_loop_to_header_edge) (struct loop *, edge,
 118                                                   unsigned, sbitmap,
 119                                                   edge, VEC (edge, heap) **,
 120                                                   int);
 121
 122   /* Add condition to new basic block and update CFG used in loop
 123      versioning.  */
 124   void (*lv_add_condition_to_bb) (basic_block, basic_block, basic_block,
 125                                   void *);
 126   /* Update the PHI nodes in case of loop versioning.  */
 127   void (*lv_adjust_loop_header_phi) (basic_block, basic_block,
 128                                      basic_block, edge);
 129
 130   /* Given a condition BB extract the true/false taken/not taken edges
 131      (depending if we are on tree's or RTL). */
 132   void (*extract_cond_bb_edges) (basic_block, edge *, edge *);
 133
 134
 135   /* Add PHI arguments queued in PENDINT_STMT list on edge E to edge
 136      E->dest (only in tree-ssa loop versioning.  */
 137   void (*flush_pending_stmts) (edge);
 138 };
 139
 140 extern void verify_flow_info (void);
 141 extern void dump_bb (basic_block, FILE *, int);
 142 extern edge redirect_edge_and_branch (edge, basic_block);
 143 extern basic_block redirect_edge_and_branch_force (edge, basic_block);
 144 extern bool can_remove_branch_p (const_edge);
 145 extern void remove_branch (edge);
 146 extern void remove_edge (edge);
 147 extern edge split_block (basic_block, void *);
 148 extern edge split_block_after_labels (basic_block);
 149 extern bool move_block_after (basic_block, basic_block);
 150 extern void delete_basic_block (basic_block);
 151 extern basic_block split_edge (edge);
 152 extern basic_block create_basic_block (void *, void *, basic_block);
 153 extern basic_block create_empty_bb (basic_block);
 154 extern bool can_merge_blocks_p (basic_block, basic_block);
 155 extern void merge_blocks (basic_block, basic_block);
 156 extern edge make_forwarder_block (basic_block, bool (*)(edge),
 157                                   void (*) (basic_block));
 158 extern void tidy_fallthru_edge (edge);
 159 extern void tidy_fallthru_edges (void);
 160 extern void predict_edge (edge e, enum br_predictor predictor, int probability);
 161 extern bool predicted_by_p (const_basic_block bb, enum br_predictor predictor);
 162 extern bool can_duplicate_block_p (const_basic_block);
 163 extern basic_block duplicate_block (basic_block, edge, basic_block);
 164 extern bool block_ends_with_call_p (basic_block bb);
 165 extern bool block_ends_with_condjump_p (const_basic_block bb);
 166 extern int flow_call_edges_add (sbitmap);
 167 extern void execute_on_growing_pred (edge);
 168 extern void execute_on_shrinking_pred (edge);
 169 extern bool cfg_hook_duplicate_loop_to_header_edge (struct loop *loop, edge,
 170                                                     unsigned int ndupl,
 171                                                     sbitmap wont_exit,
 172                                                     edge orig,
 173                                                     VEC (edge, heap) **to_remove,
 174                                                     int flags);
 175
 176 extern void lv_flush_pending_stmts (edge);
 177 extern void extract_cond_bb_edges (basic_block, edge *, edge*);
 178 extern void lv_adjust_loop_header_phi (basic_block, basic_block, basic_block,
 179                                        edge);
 180 extern void lv_add_condition_to_bb (basic_block, basic_block, basic_block,
 181                                     void *);
 182
 183 /* Hooks containers.  */
 184 extern struct cfg_hooks tree_cfg_hooks;
 185 extern struct cfg_hooks rtl_cfg_hooks;
 186 extern struct cfg_hooks cfg_layout_rtl_cfg_hooks;
 187
 188 /* Declarations.  */
 189 extern enum ir_type current_ir_type (void);
 190 extern void rtl_register_cfg_hooks (void);
 191 extern void cfg_layout_rtl_register_cfg_hooks (void);
 192 extern void tree_register_cfg_hooks (void);
 193
 194 #endif  /* GCC_CFGHOOKS_H */