1 | /* Header file for SSA jump threading. |
2 | Copyright (C) 2013-2023 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #ifndef GCC_TREE_SSA_THREADEDGE_H |
21 | #define GCC_TREE_SSA_THREADEDGE_H |
22 | |
23 | // Class used to maintain path state in the jump threader and pass it |
24 | // to the jump threader simplifier. |
25 | |
26 | class jt_state |
27 | { |
28 | public: |
29 | virtual ~jt_state () { } |
30 | virtual void push (edge); |
31 | virtual void pop (); |
32 | virtual void register_equiv (tree dest, tree src, bool update_range); |
33 | virtual void register_equivs_edge (edge e); |
34 | virtual void register_equivs_stmt (gimple *, basic_block, |
35 | class jt_simplifier *); |
36 | virtual void record_ranges_from_stmt (gimple *stmt, bool temporary); |
37 | void get_path (vec<basic_block> &); |
38 | void append_path (basic_block); |
39 | void dump (FILE *); |
40 | void debug (); |
41 | |
42 | private: |
43 | auto_vec<basic_block> m_blocks; |
44 | static const basic_block BB_MARKER; |
45 | }; |
46 | |
47 | // Statement simplifier callback for the jump threader. |
48 | |
49 | class jt_simplifier |
50 | { |
51 | public: |
52 | virtual ~jt_simplifier () { } |
53 | virtual tree simplify (gimple *, gimple *, basic_block, jt_state *) = 0; |
54 | }; |
55 | |
56 | class hybrid_jt_state : public jt_state |
57 | { |
58 | private: |
59 | void register_equivs_stmt (gimple *, basic_block, jt_simplifier *) override |
60 | { |
61 | // Ranger has no need to simplify anything. |
62 | } |
63 | }; |
64 | |
65 | class hybrid_jt_simplifier : public jt_simplifier |
66 | { |
67 | public: |
68 | hybrid_jt_simplifier (class gimple_ranger *r, class path_range_query *q); |
69 | tree simplify (gimple *stmt, gimple *, basic_block, jt_state *) override; |
70 | |
71 | private: |
72 | void compute_exit_dependencies (bitmap dependencies, |
73 | const vec<basic_block> &path, |
74 | gimple *stmt); |
75 | |
76 | gimple_ranger *m_ranger; |
77 | path_range_query *m_query; |
78 | }; |
79 | |
80 | // This is the high level threader. The entry point is |
81 | // thread_outgoing_edges(), which calculates and registers paths to be |
82 | // threaded. When all candidates have been registered, |
83 | // thread_through_all_blocks() is called to actually change the CFG. |
84 | |
85 | class jump_threader |
86 | { |
87 | public: |
88 | jump_threader (jt_simplifier *, class jt_state *); |
89 | ~jump_threader (); |
90 | void thread_outgoing_edges (basic_block); |
91 | void remove_jump_threads_including (edge_def *); |
92 | bool thread_through_all_blocks (bool ); |
93 | |
94 | private: |
95 | tree simplify_control_stmt_condition (edge, gimple *); |
96 | tree simplify_control_stmt_condition_1 (edge, |
97 | gimple *, |
98 | tree op0, |
99 | tree_code cond_code, |
100 | tree op1, |
101 | unsigned limit); |
102 | |
103 | bool thread_around_empty_blocks (vec<class jump_thread_edge *> *path, |
104 | edge, bitmap visited); |
105 | int thread_through_normal_block (vec<jump_thread_edge *> *path, |
106 | edge, bitmap visited); |
107 | void thread_across_edge (edge); |
108 | bool record_temporary_equivalences_from_phis (edge); |
109 | gimple *record_temporary_equivalences_from_stmts_at_dest (edge); |
110 | |
111 | // Dummy condition to avoid creating lots of throw away statements. |
112 | gcond *dummy_cond; |
113 | |
114 | class fwd_jt_path_registry *m_registry; |
115 | jt_simplifier *m_simplifier; |
116 | jt_state *m_state; |
117 | }; |
118 | |
119 | extern void propagate_threaded_block_debug_into (basic_block, basic_block); |
120 | extern bool single_succ_to_potentially_threadable_block (basic_block); |
121 | |
122 | // ?? All this ssa_name_values stuff is the store of values for |
123 | // avail_exprs_stack and const_and_copies, so it really belongs in the |
124 | // jump_threader class. However, it's probably not worth touching |
125 | // this, since all this windable state is slated to go with the |
126 | // ranger. |
127 | extern vec<tree> ssa_name_values; |
128 | #define SSA_NAME_VALUE(x) \ |
129 | (SSA_NAME_VERSION (x) < ssa_name_values.length () \ |
130 | ? ssa_name_values[SSA_NAME_VERSION (x)] \ |
131 | : NULL_TREE) |
132 | extern void set_ssa_name_value (tree, tree); |
133 | |
134 | #endif /* GCC_TREE_SSA_THREADEDGE_H */ |
135 | |