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