gimple-range-infer.h

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/* Header file for gimple range inference.
   Copyright (C) 2022-2024 Free Software Foundation, Inc.
   Contributed by Andrew MacLeod <amacleod@redhat.com>.
 
This file is part of GCC.
 
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
 
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 for more details.
 
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */
 
#ifndef GCC_GIMPLE_RANGE_SIDE_H
#define GCC_GIMPLE_RANGE_SIDE_H
 
// Inferred ranges are ranges which are applied to use operands as a by product
// of executing an operation.
 
// This class manages an on-demand summary of inferred ranges for a statement.
// It can be instantiated as required and provides a list of inferred ranges.
// New inferred ranges should be added in the constructor of this class.
 
class gimple_infer_range
{
public:
  gimple_infer_range (gimple *s, bool use_rangeops = false);
  gimple_infer_range (tree name, vrange &r);
  inline unsigned num () const { return num_args; }
  inline tree name (unsigned index) const
    { gcc_checking_assert (index < num_args); return m_names[index]; }
  inline const vrange& range (unsigned index) const
    { gcc_checking_assert (index < num_args); return m_ranges[index]; }
private:
  void add_range (tree name, vrange &range);
  void add_nonzero (tree name);
  void check_assume_func (gcall *call);
  unsigned num_args;
  static const int size_limit = 10;
  tree m_names[size_limit];
  value_range m_ranges[size_limit];
  inline void bump_index () { if (num_args < size_limit - 1) num_args++; }
  friend class non_null_wrapper;
};
 
// This is the basic infer oracle API.  Default functionaility does nothing.
 
class infer_range_oracle
{
public:
  infer_range_oracle () { }
  virtual ~infer_range_oracle () { }
  virtual void add_ranges (gimple *, gimple_infer_range &) { }
  virtual bool has_range_p (basic_block, tree = NULL_TREE) { return false; }
  virtual bool maybe_adjust_range (vrange &, tree, basic_block)
      { return false; }
};
 
// This class manages a list of inferred ranges for each basic block.
// As inferences are made, they can be registered to a block and later
// queried.  When constructed with a TRUE flag, immediate uses chains are
// followed the first time a name is referenced and block populated if
// there are any inferred ranges.
 
class infer_range_manager : public infer_range_oracle
{
public:
  infer_range_manager (bool do_search);
  virtual ~infer_range_manager ();
  virtual void add_ranges (gimple *s, gimple_infer_range &ir);
  virtual bool has_range_p (basic_block bb, tree name = NULL_TREE);
  virtual bool maybe_adjust_range (vrange &r, tree name, basic_block bb);
private:
  void add_range (tree name, gimple *s, const vrange &r);
  void add_nonzero (tree name, gimple *s);
  class exit_range_head
  {
  public:
    bitmap m_names;             // list of names with an outgoing range.
    class exit_range *head;
    int m_num_ranges;
    exit_range *find_ptr (tree name);
  };
  void register_all_uses (tree name);
  vec <exit_range_head> m_on_exit;
  const vrange &get_nonzero (tree name);
  vec <vrange *> m_nonzero;
  bitmap m_seen;
  bitmap_obstack m_bitmaps;
  struct obstack m_list_obstack;
  class vrange_allocator *m_range_allocator;
};
 
#endif // GCC_GIMPLE_RANGE_SIDE_H