gcc/cfg.h

   1 /* Control flow graph manipulation code header file.
   2    Copyright (C) 2014-2023 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_CFG_H
  21 #define GCC_CFG_H
  22
  23 #include "dominance.h"
  24
  25 /* What sort of profiling information we have.  */
  26 enum profile_status_d
  27 {
  28   PROFILE_ABSENT,
  29   PROFILE_GUESSED,
  30   PROFILE_READ,
  31   PROFILE_LAST  /* Last value, used by profile streaming.  */
  32 };
  33
  34 /* A structure to group all the per-function control flow graph data.
  35    The x_* prefixing is necessary because otherwise references to the
  36    fields of this struct are interpreted as the defines for backward
  37    source compatibility following the definition of this struct.  */
  38 struct GTY(()) control_flow_graph {
  39   /* Block pointers for the exit and entry of a function.
  40      These are always the head and tail of the basic block list.  */
  41   basic_block x_entry_block_ptr;
  42   basic_block x_exit_block_ptr;
  43
  44   /* Index by basic block number, get basic block struct info.  */
  45   vec<basic_block, va_gc> *x_basic_block_info;
  46
  47   /* Number of basic blocks in this flow graph.  */
  48   int x_n_basic_blocks;
  49
  50   /* Number of edges in this flow graph.  */
  51   int x_n_edges;
  52
  53   /* The first free basic block number.  */
  54   int x_last_basic_block;
  55
  56   /* UIDs for LABEL_DECLs.  */
  57   int last_label_uid;
  58
  59   /* Mapping of labels to their associated blocks.  At present
  60      only used for the gimple CFG.  */
  61   vec<basic_block, va_gc> *x_label_to_block_map;
  62
  63   enum profile_status_d x_profile_status;
  64
  65   /* Whether the dominators and the postdominators are available.  */
  66   enum dom_state x_dom_computed[2];
  67
  68   /* Number of basic blocks in the dominance tree.  */
  69   unsigned x_n_bbs_in_dom_tree[2];
  70
  71   /* Maximal number of entities in the single jumptable.  Used to estimate
  72      final flowgraph size.  */
  73   int max_jumptable_ents;
  74
  75   /* Maximal count of BB in function.  */
  76   profile_count count_max;
  77
  78   /* Dynamically allocated edge/bb flags.  */
  79   int edge_flags_allocated;
  80   int bb_flags_allocated;
  81
  82   /* Set if the profile is computed on every edge and basic block.  */
  83   bool full_profile;
  84 };
  85
  86
  87 extern void init_flow (function *);
  88 extern void free_cfg (function *);
  89 extern basic_block alloc_block (void);
  90 extern void link_block (basic_block, basic_block);
  91 extern void unlink_block (basic_block);
  92 extern void compact_blocks (void);
  93 extern void expunge_block (basic_block);
  94 extern edge unchecked_make_edge (basic_block, basic_block, int);
  95 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int);
  96 extern edge make_edge (basic_block, basic_block, int);
  97 extern edge make_single_succ_edge (basic_block, basic_block, int);
  98 extern void remove_edge_raw (edge);
  99 extern void redirect_edge_succ (edge, basic_block);
 100 extern void redirect_edge_pred (edge, basic_block);
 101 extern void clear_bb_flags (void);
 102 extern void dump_edge_info (FILE *, edge, dump_flags_t, int);
 103 extern void debug (edge_def &ref);
 104 extern void debug (edge_def *ptr);
 105 extern void alloc_aux_for_blocks (int);
 106 extern void clear_aux_for_blocks (void);
 107 extern void free_aux_for_blocks (void);
 108 extern void alloc_aux_for_edge (edge, int);
 109 extern void alloc_aux_for_edges (int);
 110 extern void clear_aux_for_edges (void);
 111 extern void free_aux_for_edges (void);
 112 extern void debug_bb (basic_block);
 113 extern basic_block debug_bb_n (int);
 114 extern void debug_bb (basic_block, dump_flags_t);
 115 extern basic_block debug_bb_n (int, dump_flags_t);
 116 extern void dump_bb_info (FILE *, basic_block, int, dump_flags_t, bool, bool);
 117 extern void brief_dump_cfg (FILE *, dump_flags_t);
 118 extern void set_edge_probability_and_rescale_others (edge, profile_probability);
 119 extern void update_bb_profile_for_threading (basic_block, profile_count, edge);
 120 extern void scale_bbs_frequencies_profile_count (basic_block *, int,
 121                                              profile_count, profile_count);
 122 extern void scale_bbs_frequencies (basic_block *, int, profile_probability);
 123 extern void initialize_original_copy_tables (void);
 124 extern void reset_original_copy_tables (void);
 125 extern void free_original_copy_tables (void);
 126 extern bool original_copy_tables_initialized_p (void);
 127 extern void set_bb_original (basic_block, basic_block);
 128 extern basic_block get_bb_original (basic_block);
 129 extern void set_bb_copy (basic_block, basic_block);
 130 extern basic_block get_bb_copy (basic_block);
 131 void set_loop_copy (class loop *, class loop *);
 132 class loop *get_loop_copy (class loop *);
 133 void scale_strictly_dominated_blocks (basic_block,
 134                                       profile_count, profile_count);
 135
 136 /* Generic RAII class to allocate a bit from storage of integer type T.
 137    The allocated bit is accessible as mask with the single bit set
 138    via the conversion operator to T.  */
 139
 140 template <class T>
 141 class auto_flag
 142 {
 143 public:
 144   /* static assert T is integer type of max HOST_WIDE_INT precision.  */
 145   auto_flag (T *sptr)
 146     {
 147       m_sptr = sptr;
 148       int free_bit = ffs_hwi (~*sptr);
 149       /* If there are no unset bits... */
 150       if (free_bit == 0)
 151         gcc_unreachable ();
 152       m_flag = HOST_WIDE_INT_1U << (free_bit - 1);
 153       /* ...or if T is signed and thus the complement is sign-extended,
 154          check if we ran out of bits.  We could spare us this bit
 155          if we could use C++11 std::make_unsigned<T>::type to pass
 156          ~*sptr to ffs_hwi.  */
 157       if (m_flag == 0)
 158         gcc_unreachable ();
 159       gcc_checking_assert ((*sptr & m_flag) == 0);
 160       *sptr |= m_flag;
 161     }
 162   ~auto_flag ()
 163     {
 164       gcc_checking_assert ((*m_sptr & m_flag) == m_flag);
 165       *m_sptr &= ~m_flag;
 166     }
 167   operator T () const { return m_flag; }
 168 private:
 169   T *m_sptr;
 170   T m_flag;
 171 };
 172
 173 /* RAII class to allocate an edge flag for temporary use.  You have
 174    to clear the flag from all edges when you are finished using it.  */
 175
 176 class auto_edge_flag : public auto_flag<int>
 177 {
 178 public:
 179   auto_edge_flag (function *fun)
 180     : auto_flag<int> (&fun->cfg->edge_flags_allocated) {}
 181 };
 182
 183 /* RAII class to allocate a bb flag for temporary use.  You have
 184    to clear the flag from all edges when you are finished using it.  */
 185 class auto_bb_flag : public auto_flag<int>
 186 {
 187 public:
 188   auto_bb_flag (function *fun)
 189     : auto_flag<int> (&fun->cfg->bb_flags_allocated) {}
 190 };
 191
 192 #endif /* GCC_CFG_H */