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 // 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 (class gimple_ranger &ranger, bool resolve);
  36   virtual ~path_range_query ();
  37   void compute_ranges (const vec<basic_block> &, const bitmap_head *imports = NULL);
  38   void compute_ranges (edge e);
  39   bool range_of_expr (irange &r, tree name, gimple * = NULL) override;
  40   bool range_of_stmt (irange &r, gimple *, tree name = NULL) override;
  41   bool unreachable_path_p ();
  42   void dump (FILE *) override;
  43   void debug ();
  44
  45 private:
  46   bool internal_range_of_expr (irange &r, tree name, gimple *);
  47   bool defined_outside_path (tree name);
  48   void range_on_path_entry (irange &r, tree name);
  49   path_oracle *get_path_oracle () { return (path_oracle *)m_oracle; }
  50
  51   // Cache manipulation.
  52   void set_cache (const irange &r, tree name);
  53   bool get_cache (irange &r, tree name);
  54   void clear_cache (tree name);
  55
  56   // Methods to compute ranges for the given path.
  57   bool range_defined_in_block (irange &, tree name, basic_block bb);
  58   void compute_ranges_in_block (basic_block bb);
  59   void adjust_for_non_null_uses (basic_block bb);
  60   void ssa_range_in_phi (irange &r, gphi *phi);
  61   void compute_outgoing_relations (basic_block bb, basic_block next);
  62   void compute_phi_relations (basic_block bb, basic_block prev);
  63   void maybe_register_phi_relation (gphi *, tree arg);
  64   void add_copies_to_imports ();
  65   bool add_to_imports (tree name, bitmap imports);
  66   inline bool import_p (tree name);
  67
  68   // Path navigation.
  69   void set_path (const vec<basic_block> &);
  70   basic_block entry_bb () { return m_path[m_path.length () - 1]; }
  71   basic_block exit_bb ()  { return m_path[0]; }
  72   basic_block curr_bb ()  { return m_path[m_pos]; }
  73   basic_block prev_bb ()  { return m_path[m_pos + 1]; }
  74   basic_block next_bb ()  { return m_path[m_pos - 1]; }
  75   bool at_entry ()        { return m_pos == m_path.length () - 1; }
  76   bool at_exit ()         { return m_pos == 0; }
  77   void move_next ()       { --m_pos; }
  78
  79   // Range cache for SSA names.
  80   ssa_global_cache *m_cache;
  81
  82   // Set for each SSA that has an active entry in the cache.
  83   bitmap m_has_cache_entry;
  84
  85   // Path being analyzed.
  86   auto_vec<basic_block> m_path;
  87
  88   auto_bitmap m_imports;
  89   gimple_ranger &m_ranger;
  90   non_null_ref m_non_null;
  91
  92   // Current path position.
  93   unsigned m_pos;
  94
  95   // Use ranger to resolve anything not known on entry.
  96   bool m_resolve;
  97
  98   // Set if there were any undefined expressions while pre-calculating path.
  99   bool m_undefined_path;
 100 };
 101
 102 // Return TRUE if NAME is in the import bitmap.
 103
 104 bool
 105 path_range_query::import_p (tree name)
 106 {
 107   return (TREE_CODE (name) == SSA_NAME
 108           && bitmap_bit_p (m_imports, SSA_NAME_VERSION (name)));
 109 }
 110
 111 #endif // GCC_TREE_SSA_THREADSOLVER_H