gcc/gimple-range-path.h

   1 /* Header file for jump threading path solver.
   2    Copyright (C) 2021 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 // Only SSA names passed in IMPORTS are precomputed, and can be
  30 // queried.
  31 //
  32 // Note that the blocks are in reverse order, thus the exit block is
  33 // path[0].
  34
  35 class path_range_query : public range_query
  36 {
  37 public:
  38   path_range_query (class gimple_ranger &ranger);
  39   virtual ~path_range_query ();
  40   void precompute_ranges (const vec<basic_block> &path,
  41                           const bitmap_head *imports);
  42   bool range_of_expr (irange &r, tree name, gimple * = NULL) override;
  43   bool range_of_stmt (irange &r, gimple *, tree name = NULL) override;
  44   void dump (FILE *) override;
  45   void debug ();
  46
  47 private:
  48   // Cache manipulation.
  49   void set_cache (const irange &r, tree name);
  50   bool get_cache (irange &r, tree name);
  51   void clear_cache (tree name);
  52
  53   // Methods to precompute ranges for the given path.
  54   bool range_defined_in_block (irange &, tree name, basic_block bb);
  55   void precompute_ranges_in_block (basic_block bb);
  56   void ssa_range_in_phi (irange &r, gphi *phi);
  57
  58   // Path navigation.
  59   void set_path (const vec<basic_block> &);
  60   basic_block entry_bb () { return (*m_path)[m_path->length () - 1]; }
  61   basic_block exit_bb ()  { return (*m_path)[0]; }
  62   basic_block curr_bb ()  { return (*m_path)[m_pos]; }
  63   basic_block prev_bb ()  { return (*m_path)[m_pos + 1]; }
  64   basic_block next_bb ()  { return (*m_path)[m_pos - 1]; }
  65   bool at_entry ()        { return m_pos == m_path->length () - 1; }
  66   bool at_exit ()         { return m_pos == 0; }
  67   void move_next ()       { --m_pos; }
  68
  69   // Range cache for SSA names.
  70   ssa_global_cache *m_cache;
  71
  72   // Set for each SSA that has an active entry in the cache.
  73   bitmap m_has_cache_entry;
  74
  75   // Path being analyzed.
  76   const vec<basic_block> *m_path;
  77
  78   // Current path position.
  79   unsigned m_pos;
  80
  81   const bitmap_head *m_imports;
  82   gimple_ranger &m_ranger;
  83 };
  84
  85 #endif // GCC_TREE_SSA_THREADSOLVER_H