gcc/gimple-range-path.h

   1 /* Header file for jump threading path solver.
   2    Copyright (C) 2021-2022 Free Software Foundation, Inc.
   3    Contributed by Aldy Hernandez <aldyh@redhat.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  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_TREE_SSA_THREADSOLVER_H
  22 #define GCC_TREE_SSA_THREADSOLVER_H
  23
  24 // This class is a basic block path solver.  Given a set of BBs
  25 // indicating a path through the CFG, range_of_expr and range_of_stmt
  26 // will calculate the range of an SSA or STMT as if the BBs in the
  27 // path would have been executed in order.
  28 //
  29 // Note that the blocks are in reverse order, thus the exit block is
  30 // path[0].
  31
  32 class path_range_query : public range_query
  33 {
  34 public:
  35   path_range_query (bool resolve = true, class gimple_ranger *ranger = NULL);
  36   virtual ~path_range_query ();
  37   void compute_ranges (const vec<basic_block> &,
  38                        const bitmap_head *imports = NULL);
  39   void compute_ranges (edge e);
  40   void compute_imports (bitmap imports, basic_block exit);
  41   bool range_of_expr (irange &r, tree name, gimple * = NULL) override;
  42   bool range_of_stmt (irange &r, gimple *, tree name = NULL) override;
  43   bool unreachable_path_p ();
  44   void dump (FILE *) override;
  45   void debug ();
  46
  47 private:
  48   bool internal_range_of_expr (irange &r, tree name, gimple *);
  49   bool defined_outside_path (tree name);
  50   void range_on_path_entry (irange &r, tree name);
  51   path_oracle *get_path_oracle () { return (path_oracle *)m_oracle; }
  52
  53   // Cache manipulation.
  54   void set_cache (const irange &r, tree name);
  55   bool get_cache (irange &r, tree name);
  56   void clear_cache (tree name);
  57
  58   // Methods to compute ranges for the given path.
  59   bool range_defined_in_block (irange &, tree name, basic_block bb);
  60   void compute_ranges_in_block (basic_block bb);
  61   void compute_ranges_in_phis (basic_block bb);
  62   void adjust_for_non_null_uses (basic_block bb);
  63   void ssa_range_in_phi (irange &r, gphi *phi);
  64   void compute_outgoing_relations (basic_block bb, basic_block next);
  65   void compute_phi_relations (basic_block bb, basic_block prev);
  66   void maybe_register_phi_relation (gphi *, tree arg);
  67   bool add_to_imports (tree name, bitmap imports);
  68   bool import_p (tree name);
  69   bool ssa_defined_in_bb (tree name, basic_block bb);
  70
  71   // Path navigation.
  72   void set_path (const vec<basic_block> &);
  73   basic_block entry_bb () { return m_path[m_path.length () - 1]; }
  74   basic_block exit_bb ()  { return m_path[0]; }
  75   basic_block curr_bb ()  { return m_path[m_pos]; }
  76   basic_block prev_bb ()  { return m_path[m_pos + 1]; }
  77   basic_block next_bb ()  { return m_path[m_pos - 1]; }
  78   bool at_entry ()        { return m_pos == m_path.length () - 1; }
  79   bool at_exit ()         { return m_pos == 0; }
  80   void move_next ()       { --m_pos; }
  81
  82   // Range cache for SSA names.
  83   ssa_global_cache *m_cache;
  84
  85   // Set for each SSA that has an active entry in the cache.
  86   bitmap m_has_cache_entry;
  87
  88   // Path being analyzed.
  89   auto_vec<basic_block> m_path;
  90
  91   auto_bitmap m_imports;
  92   gimple_ranger *m_ranger;
  93   non_null_ref m_non_null;
  94
  95   // Current path position.
  96   unsigned m_pos;
  97
  98   // Use ranger to resolve anything not known on entry.
  99   bool m_resolve;
 100
 101   // Set if there were any undefined expressions while pre-calculating path.
 102   bool m_undefined_path;
 103
 104   // True if m_ranger was allocated in this class and must be freed at
 105   // destruction.
 106   bool m_alloced_ranger;
 107 };
 108
 109 #endif // GCC_TREE_SSA_THREADSOLVER_H