1 | /* Data structures and function declarations for the SSA value propagation |
2 | engine. |
3 | Copyright (C) 2004-2023 Free Software Foundation, Inc. |
4 | Contributed by Diego Novillo <dnovillo@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 _TREE_SSA_PROPAGATE_H |
23 | #define _TREE_SSA_PROPAGATE_H 1 |
24 | |
25 | #include "value-query.h" |
26 | |
27 | /* If SIM_P is true, statement S will be simulated again. */ |
28 | |
29 | inline void |
30 | prop_set_simulate_again (gimple *s, bool visit_p) |
31 | { |
32 | gimple_set_visited (stmt: s, visited_p: visit_p); |
33 | } |
34 | |
35 | /* Return true if statement T should be simulated again. */ |
36 | |
37 | inline bool |
38 | prop_simulate_again_p (gimple *s) |
39 | { |
40 | return gimple_visited_p (stmt: s); |
41 | } |
42 | |
43 | /* Lattice values used for propagation purposes. Specific instances |
44 | of a propagation engine must return these values from the statement |
45 | and PHI visit functions to direct the engine. */ |
46 | enum ssa_prop_result { |
47 | /* The statement produces nothing of interest. No edges will be |
48 | added to the work lists. */ |
49 | SSA_PROP_NOT_INTERESTING, |
50 | |
51 | /* The statement produces an interesting value. The set SSA_NAMEs |
52 | returned by SSA_PROP_VISIT_STMT should be added to |
53 | INTERESTING_SSA_EDGES. If the statement being visited is a |
54 | conditional jump, SSA_PROP_VISIT_STMT should indicate which edge |
55 | out of the basic block should be marked executable. */ |
56 | SSA_PROP_INTERESTING, |
57 | |
58 | /* The statement produces a varying (i.e., useless) value and |
59 | should not be simulated again. If the statement being visited |
60 | is a conditional jump, all the edges coming out of the block |
61 | will be considered executable. */ |
62 | SSA_PROP_VARYING |
63 | }; |
64 | |
65 | |
66 | extern void move_ssa_defining_stmt_for_defs (gimple *, gimple *); |
67 | extern bool stmt_makes_single_store (gimple *); |
68 | extern bool may_propagate_copy (tree, tree, bool = false); |
69 | extern bool may_propagate_copy_into_stmt (gimple *, tree); |
70 | extern bool may_propagate_copy_into_asm (tree); |
71 | extern void propagate_value (use_operand_p, tree); |
72 | extern void replace_exp (use_operand_p, tree); |
73 | extern void propagate_tree_value (tree *, tree); |
74 | extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree); |
75 | |
76 | /* Public interface into the SSA propagation engine. Clients should inherit |
77 | from this class and provide their own visitors. */ |
78 | |
79 | class ssa_propagation_engine |
80 | { |
81 | public: |
82 | |
83 | virtual ~ssa_propagation_engine (void) { } |
84 | |
85 | /* Virtual functions the clients must provide to visit statements |
86 | and phi nodes respectively. */ |
87 | virtual enum ssa_prop_result visit_stmt (gimple *, edge *, tree *) = 0; |
88 | virtual enum ssa_prop_result visit_phi (gphi *) = 0; |
89 | |
90 | /* Main interface into the propagation engine. */ |
91 | void ssa_propagate (void); |
92 | |
93 | private: |
94 | /* Internal implementation details. */ |
95 | void simulate_stmt (gimple *stmt); |
96 | void simulate_block (basic_block); |
97 | }; |
98 | |
99 | class substitute_and_fold_engine : public range_query |
100 | { |
101 | public: |
102 | substitute_and_fold_engine (bool fold_all_stmts = false) |
103 | : fold_all_stmts (fold_all_stmts) { } |
104 | |
105 | virtual tree value_of_expr (tree expr, gimple * = NULL) = 0; |
106 | virtual tree value_on_edge (edge, tree expr) override; |
107 | virtual tree value_of_stmt (gimple *, tree name = NULL) override; |
108 | virtual bool range_of_expr (vrange &r, tree expr, gimple * = NULL); |
109 | |
110 | virtual ~substitute_and_fold_engine (void) { } |
111 | virtual bool fold_stmt (gimple_stmt_iterator *) { return false; } |
112 | |
113 | bool substitute_and_fold (basic_block = NULL); |
114 | bool replace_uses_in (gimple *); |
115 | bool replace_phi_args_in (gphi *); |
116 | |
117 | virtual void pre_fold_bb (basic_block) { } |
118 | virtual void post_fold_bb (basic_block) { } |
119 | virtual void pre_fold_stmt (gimple *) { } |
120 | virtual void post_new_stmt (gimple *) { } |
121 | |
122 | bool propagate_into_phi_args (basic_block); |
123 | |
124 | /* Users like VRP can set this when they want to perform |
125 | folding for every propagation. */ |
126 | bool fold_all_stmts; |
127 | }; |
128 | |
129 | #endif /* _TREE_SSA_PROPAGATE_H */ |
130 | |