xref: /netbsd-src/external/gpl3/gcc/dist/gcc/gimple-range-edge.h (revision b1e838363e3c6fc78a55519254d99869742dd33c)
1 /* Gimple range edge header file.
2    Copyright (C) 2020-2022 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 evalauted 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 get_edge_range (irange &r, gimple *s, edge e);
47 
48   int m_max_edges;
49   hash_map<edge, irange *> *m_edge_table;
50   irange_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
59