1 | /* Header file for jump threading path solver. |
2 | Copyright (C) 2021-2023 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, |
36 | const vec<basic_block> &path, |
37 | const bitmap_head *dependencies = NULL, |
38 | bool resolve = true); |
39 | path_range_query (gimple_ranger &ranger, bool resolve = true); |
40 | virtual ~path_range_query (); |
41 | void reset_path (const vec<basic_block> &, const bitmap_head *dependencies); |
42 | bool range_of_expr (vrange &r, tree name, gimple * = NULL) override; |
43 | bool range_of_stmt (vrange &r, gimple *, tree name = NULL) override; |
44 | bool unreachable_path_p (); |
45 | void dump (FILE *) override; |
46 | void debug (); |
47 | |
48 | private: |
49 | bool internal_range_of_expr (vrange &r, tree name, gimple *); |
50 | void compute_ranges (const bitmap_head *dependencies); |
51 | void compute_exit_dependencies (bitmap_head *dependencies); |
52 | bool defined_outside_path (tree name); |
53 | void range_on_path_entry (vrange &r, tree name); |
54 | path_oracle *get_path_oracle () { return (path_oracle *)m_oracle; } |
55 | |
56 | // Cache manipulation. |
57 | bool get_cache (vrange &r, tree name); |
58 | |
59 | // Methods to compute ranges for the given path. |
60 | bool range_defined_in_block (vrange &, tree name, basic_block bb); |
61 | void compute_ranges_in_block (basic_block bb); |
62 | void compute_ranges_in_phis (basic_block bb); |
63 | void adjust_for_non_null_uses (basic_block bb); |
64 | void ssa_range_in_phi (vrange &r, gphi *phi); |
65 | void compute_outgoing_relations (basic_block bb, basic_block next); |
66 | void compute_phi_relations (basic_block bb, basic_block prev); |
67 | void maybe_register_phi_relation (gphi *, edge e); |
68 | bool add_to_exit_dependencies (tree name, bitmap dependencies); |
69 | bool exit_dependency_p (tree name); |
70 | bool ssa_defined_in_bb (tree name, basic_block bb); |
71 | bool relations_may_be_invalidated (edge); |
72 | |
73 | // Path navigation. |
74 | basic_block entry_bb () { return m_path[m_path.length () - 1]; } |
75 | basic_block exit_bb () { return m_path[0]; } |
76 | basic_block curr_bb () { return m_path[m_pos]; } |
77 | basic_block prev_bb () { return m_path[m_pos + 1]; } |
78 | basic_block next_bb () { return m_path[m_pos - 1]; } |
79 | bool at_entry () { return m_pos == m_path.length () - 1; } |
80 | bool at_exit () { return m_pos == 0; } |
81 | void move_next () { --m_pos; } |
82 | |
83 | // Range cache for SSA names. |
84 | ssa_lazy_cache m_cache; |
85 | |
86 | // Path being analyzed. |
87 | auto_vec<basic_block> m_path; |
88 | |
89 | // This is a list of SSA names that may have relevant context |
90 | // information for solving the final conditional along the path. |
91 | // Ranges for these SSA names are pre-calculated and cached during a |
92 | // top-down traversal of the path, and are then used to answer |
93 | // questions at the path exit. |
94 | auto_bitmap m_exit_dependencies; |
95 | |
96 | // A ranger used to resolve ranges for SSA names whose values come |
97 | // from outside the path. |
98 | gimple_ranger &m_ranger; |
99 | |
100 | // Current path position. |
101 | unsigned m_pos; |
102 | |
103 | // Use ranger to resolve anything not known on entry. |
104 | bool m_resolve; |
105 | |
106 | // Set if there were any undefined expressions while pre-calculating path. |
107 | bool m_undefined_path; |
108 | }; |
109 | |
110 | #endif // GCC_TREE_SSA_THREADSOLVER_H |
111 | |