1 /* Control flow graph manipulation code header file. 2 Copyright (C) 2014-2020 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 83 84 extern void init_flow (function *); 85 extern void clear_edges (function *); 86 extern basic_block alloc_block (void); 87 extern void link_block (basic_block, basic_block); 88 extern void unlink_block (basic_block); 89 extern void compact_blocks (void); 90 extern void expunge_block (basic_block); 91 extern edge unchecked_make_edge (basic_block, basic_block, int); 92 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int); 93 extern edge make_edge (basic_block, basic_block, int); 94 extern edge make_single_succ_edge (basic_block, basic_block, int); 95 extern void remove_edge_raw (edge); 96 extern void redirect_edge_succ (edge, basic_block); 97 extern void redirect_edge_pred (edge, basic_block); 98 extern void clear_bb_flags (void); 99 extern void dump_edge_info (FILE *, edge, dump_flags_t, int); 100 extern void debug (edge_def &ref); 101 extern void debug (edge_def *ptr); 102 extern void alloc_aux_for_blocks (int); 103 extern void clear_aux_for_blocks (void); 104 extern void free_aux_for_blocks (void); 105 extern void alloc_aux_for_edge (edge, int); 106 extern void alloc_aux_for_edges (int); 107 extern void clear_aux_for_edges (void); 108 extern void free_aux_for_edges (void); 109 extern void debug_bb (basic_block); 110 extern basic_block debug_bb_n (int); 111 extern void dump_bb_info (FILE *, basic_block, int, dump_flags_t, bool, bool); 112 extern void brief_dump_cfg (FILE *, dump_flags_t); 113 extern void update_bb_profile_for_threading (basic_block, profile_count, edge); 114 extern void scale_bbs_frequencies_profile_count (basic_block *, int, 115 profile_count, profile_count); 116 extern void scale_bbs_frequencies (basic_block *, int, profile_probability); 117 extern void initialize_original_copy_tables (void); 118 extern void reset_original_copy_tables (void); 119 extern void free_original_copy_tables (void); 120 extern bool original_copy_tables_initialized_p (void); 121 extern void set_bb_original (basic_block, basic_block); 122 extern basic_block get_bb_original (basic_block); 123 extern void set_bb_copy (basic_block, basic_block); 124 extern basic_block get_bb_copy (basic_block); 125 void set_loop_copy (class loop *, class loop *); 126 class loop *get_loop_copy (class loop *); 127 128 /* Generic RAII class to allocate a bit from storage of integer type T. 129 The allocated bit is accessible as mask with the single bit set 130 via the conversion operator to T. */ 131 132 template <class T> 133 class auto_flag 134 { 135 public: 136 /* static assert T is integer type of max HOST_WIDE_INT precision. */ auto_flag(T * sptr)137 auto_flag (T *sptr) 138 { 139 m_sptr = sptr; 140 int free_bit = ffs_hwi (~*sptr); 141 /* If there are no unset bits... */ 142 if (free_bit == 0) 143 gcc_unreachable (); 144 m_flag = HOST_WIDE_INT_1U << (free_bit - 1); 145 /* ...or if T is signed and thus the complement is sign-extended, 146 check if we ran out of bits. We could spare us this bit 147 if we could use C++11 std::make_unsigned<T>::type to pass 148 ~*sptr to ffs_hwi. */ 149 if (m_flag == 0) 150 gcc_unreachable (); 151 gcc_checking_assert ((*sptr & m_flag) == 0); 152 *sptr |= m_flag; 153 } ~auto_flag()154 ~auto_flag () 155 { 156 gcc_checking_assert ((*m_sptr & m_flag) == m_flag); 157 *m_sptr &= ~m_flag; 158 } T()159 operator T () const { return m_flag; } 160 private: 161 T *m_sptr; 162 T m_flag; 163 }; 164 165 /* RAII class to allocate an edge flag for temporary use. You have 166 to clear the flag from all edges when you are finished using it. */ 167 168 class auto_edge_flag : public auto_flag<int> 169 { 170 public: auto_edge_flag(function * fun)171 auto_edge_flag (function *fun) 172 : auto_flag<int> (&fun->cfg->edge_flags_allocated) {} 173 }; 174 175 /* RAII class to allocate a bb flag for temporary use. You have 176 to clear the flag from all edges when you are finished using it. */ 177 class auto_bb_flag : public auto_flag<int> 178 { 179 public: auto_bb_flag(function * fun)180 auto_bb_flag (function *fun) 181 : auto_flag<int> (&fun->cfg->bb_flags_allocated) {} 182 }; 183 184 #endif /* GCC_CFG_H */ 185