1  /* Gimple range edge header file.
       2     Copyright (C) 2020-2023 Free Software Foundation, Inc.
       3     Contributed by Andrew MacLeod <amacleod@redhat.com>
       4     and Aldy Hernandez <aldyh@redhat.com>.
       5  
       6  This file is part of GCC.
       7  
       8  GCC is free software; you can redistribute it and/or modify
       9  it under the terms of the GNU General Public License as published by
      10  the Free Software Foundation; either version 3, or (at your option)
      11  any later version.
      12  
      13  GCC is distributed in the hope that it will be useful,
      14  but WITHOUT ANY WARRANTY; without even the implied warranty of
      15  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      16  GNU General Public License for more details.
      17  
      18  You should have received a copy of the GNU General Public License
      19  along with GCC; see the file COPYING3.  If not see
      20  <http://www.gnu.org/licenses/>.  */
      21  
      22  #ifndef GIMPLE_RANGE_EDGE_H
      23  #define GIMPLE_RANGE_EDGE_H
      24  
      25  // This class is used to query ranges on constant edges in GIMPLE.
      26  //
      27  // For a COND_EXPR, the TRUE edge will return [1,1] and the false edge a [0,0].
      28  //
      29  // For SWITCH_EXPR, it is awkward to calculate ranges.  When a request
      30  // is made, the entire switch is evaluated and the results cached. 
      31  // Any future requests to that switch will use the cached value, providing
      32  // dramatic decrease in computation time.
      33  //
      34  // The API is simple, just ask for the range on the edge.
      35  // The return value is NULL for no range, or the branch statement which the
      36  // edge gets the range from, along with the range.
      37  
      38  class gimple_outgoing_range
      39  {
      40  public:
      41    gimple_outgoing_range (int max_sw_edges = INT_MAX);
      42    ~gimple_outgoing_range ();
      43    gimple *edge_range_p (irange &r, edge e);
      44  private:
      45    void calc_switch_ranges (gswitch *sw);
      46    bool switch_edge_range (irange &r, gswitch *sw, edge e);
      47  
      48    int m_max_edges;
      49    hash_map<edge, irange *> *m_edge_table;
      50    class obstack_vrange_allocator *m_range_allocator;
      51  };
      52  
      53  // If there is a range control statement at the end of block BB, return it.
      54  gimple *gimple_outgoing_range_stmt_p (basic_block bb);
      55  // Return the range on edge E if it is from a GCOND.  Either TRUE or FALSE.
      56  void gcond_edge_range (irange &r, edge e);
      57  
      58  #endif  // GIMPLE_RANGE_EDGE_H