gcc/gimple-range-edge.h

   1 /* Gimple range edge header file.
   2    Copyright (C) 2020-2024 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 // THe switch_limit is the number of switch edges beyond which the switch
  39 // is ignored (ie, edge_range_p () will return NULL as if the sitch was not
  40 // there.  THis value can be adjusted any time via set_switch_limit ().
  41 // THe default is 0, no switches are precoessed until set_switch_limit () is
  42 // called, and then the default is INT_MAX.
  43 //
  44 // No memory is allocated until an edge for a switch is processed which also
  45 // falls under the edge limit criteria.
  46
  47 class gimple_outgoing_range
  48 {
  49 public:
  50   gimple_outgoing_range (int max_sw_edges = 0);
  51   virtual ~gimple_outgoing_range ();
  52   gimple *edge_range_p (irange &r, edge e);
  53   void set_switch_limit (int max_sw_edges = INT_MAX);
  54
  55   virtual bool edge_range_p (vrange &, edge, tree, range_query &)
  56     { return false; }
  57   virtual bool has_edge_range_p (tree, basic_block = NULL) { return false; }
  58   virtual bool has_edge_range_p (tree, edge ) { return false; }
  59   virtual void dump (FILE *) { }
  60   virtual bool compute_operand_range (vrange &, gimple *, const vrange &, tree,
  61                                       class fur_source &,
  62                                       class value_relation * = NULL)
  63     { return false; }
  64 private:
  65   void calc_switch_ranges (gswitch *sw);
  66   bool switch_edge_range (irange &r, gswitch *sw, edge e);
  67
  68   int m_max_edges;
  69   hash_map<edge, vrange_storage *> *m_edge_table;
  70   class vrange_allocator *m_range_allocator;
  71 };
  72
  73 // If there is a range control statement at the end of block BB, return it.
  74 gimple *gimple_outgoing_range_stmt_p (basic_block bb);
  75 // Return the range on edge E if it is from a GCOND.  Either TRUE or FALSE.
  76 void gcond_edge_range (irange &r, edge e);
  77
  78 #endif  // GIMPLE_RANGE_EDGE_H