gcc/domwalk.h

   1 /* Generic dominator tree walker
   2    Copyright (C) 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
   3    Contributed by Diego Novillo <dnovillo@redhat.com>
   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 typedef void *void_p;
  22 DEF_VEC_P(void_p);
  23 DEF_VEC_ALLOC_P(void_p,heap);
  24
  25 /* This is the main data structure for the dominator walker.  It provides
  26    the callback hooks as well as a convenient place to hang block local
  27    data and pass-global data.  */
  28
  29 struct dom_walk_data
  30 {
  31   /* This is the direction of the dominator tree we want to walk.  i.e.,
  32      if it is set to CDI_DOMINATORS, then we walk the dominator tree,
  33      if it is set to CDI_POST_DOMINATORS, then we walk the post
  34      dominator tree.  */
  35   ENUM_BITFIELD (cdi_direction) dom_direction : 2;
  36
  37   /* Nonzero if the statement walker should walk the statements from
  38      last to first within a basic block instead of first to last.
  39
  40      Note this affects both statement walkers.  We haven't yet needed
  41      to use the second statement walker for anything, so it's hard to
  42      predict if we really need the ability to select their direction
  43      independently.  */
  44   BOOL_BITFIELD walk_stmts_backward : 1;
  45
  46   /* Function to initialize block local data.
  47
  48      Note that the dominator walker infrastructure may provide a new
  49      fresh, and zero'd block local data structure, or it may re-use an
  50      existing block local data structure.
  51
  52      If the block local structure has items such as virtual arrays, then
  53      that allows your optimizer to re-use those arrays rather than
  54      creating new ones.  */
  55   void (*initialize_block_local_data) (struct dom_walk_data *,
  56                                        basic_block, bool);
  57
  58   /* Function to call before the statement walk occurring before the
  59      recursive walk of the dominator children.
  60
  61      This typically initializes a block local data and pushes that
  62      data onto BLOCK_DATA_STACK.  */
  63   void (*before_dom_children_before_stmts) (struct dom_walk_data *,
  64                                             basic_block);
  65
  66   /* Function to call to walk statements before the recursive walk
  67      of the dominator children.  */
  68   void (*before_dom_children_walk_stmts) (struct dom_walk_data *,
  69                                           basic_block, gimple_stmt_iterator);
  70
  71   /* Function to call after the statement walk occurring before the
  72      recursive walk of the dominator children.  */
  73   void (*before_dom_children_after_stmts) (struct dom_walk_data *,
  74                                            basic_block);
  75
  76   /* Function to call before the statement walk occurring after the
  77      recursive walk of the dominator children.  */
  78   void (*after_dom_children_before_stmts) (struct dom_walk_data *,
  79                                            basic_block);
  80
  81   /* Function to call to walk statements after the recursive walk
  82      of the dominator children.  */
  83   void (*after_dom_children_walk_stmts) (struct dom_walk_data *,
  84                                          basic_block, gimple_stmt_iterator);
  85
  86   /* Function to call after the statement walk occurring after the
  87      recursive walk of the dominator children.
  88
  89      This typically finalizes any block local data and pops
  90      that data from BLOCK_DATA_STACK.  */
  91   void (*after_dom_children_after_stmts) (struct dom_walk_data *,
  92                                           basic_block);
  93
  94   /* Global data for a walk through the dominator tree.  */
  95   void *global_data;
  96
  97   /* Stack of any data we need to keep on a per-block basis.
  98
  99      If you have no local data, then BLOCK_DATA_STACK will be NULL.  */
 100   VEC(void_p,heap) *block_data_stack;
 101
 102   /* Size of the block local data.   If this is zero, then it is assumed
 103      you have no local data and thus no BLOCK_DATA_STACK as well.  */
 104   size_t block_local_data_size;
 105
 106   /* From here below are private data.  Please do not use this
 107      information/data outside domwalk.c.  */
 108
 109   /* Stack of available block local structures.  */
 110   VEC(void_p,heap) *free_block_data;
 111
 112   /* Interesting blocks to process.  If this field is not NULL, this
 113      set is used to determine which blocks to walk.  If we encounter
 114      block I in the dominator traversal, but block I is not present in
 115      INTERESTING_BLOCKS, then none of the callback functions are
 116      invoked on it.  This is useful when a particular traversal wants
 117      to filter out non-interesting blocks from the dominator tree.  */
 118   sbitmap interesting_blocks;
 119 };
 120
 121 void walk_dominator_tree (struct dom_walk_data *, basic_block);
 122 void init_walk_dominator_tree (struct dom_walk_data *);
 123 void fini_walk_dominator_tree (struct dom_walk_data *);