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ef15dade ST |
1 | // icf.h -- Identical Code Folding |
2 | ||
55a2bb35 | 3 | // Copyright 2009, 2010 Free Software Foundation, Inc. |
ef15dade ST |
4 | // Written by Sriraman Tallam <tmsriram@google.com>. |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program 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 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program 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 this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
23 | #ifndef GOLD_ICF_H | |
24 | #define GOLD_ICF_H | |
25 | ||
26 | #include <vector> | |
27 | ||
28 | #include "elfcpp.h" | |
29 | #include "symtab.h" | |
5ac169d4 | 30 | #include "object.h" |
ef15dade ST |
31 | |
32 | namespace gold | |
33 | { | |
34 | ||
35 | class Object; | |
36 | class Input_objects; | |
37 | class Symbol_table; | |
38 | ||
ef15dade ST |
39 | class Icf |
40 | { | |
41 | public: | |
ef15dade ST |
42 | typedef std::vector<Section_id> Sections_reachable_list; |
43 | typedef std::vector<Symbol*> Symbol_info; | |
44 | typedef std::vector<std::pair<long long, long long> > Addend_info; | |
45 | typedef Unordered_map<Section_id, | |
46 | Sections_reachable_list, | |
47 | Section_id_hash> Section_list; | |
48 | typedef Unordered_map<Section_id, Symbol_info, Section_id_hash> Symbol_list; | |
49 | typedef Unordered_map<Section_id, Addend_info, Section_id_hash> Addend_list; | |
50 | typedef Unordered_map<Section_id, | |
51 | unsigned int, | |
52 | Section_id_hash> Uniq_secn_id_map; | |
53 | ||
54 | Icf() | |
55 | : id_section_(), section_id_(), kept_section_id_(), | |
56 | num_tracked_relocs(NULL), icf_ready_(false), | |
57 | section_reloc_list_(), symbol_reloc_list_(), | |
58 | addend_reloc_list_() | |
59 | { } | |
60 | ||
61 | // Returns the kept folded identical section corresponding to | |
62 | // dup_obj and dup_shndx. | |
63 | Section_id | |
64 | get_folded_section(Object* dup_obj, unsigned int dup_shndx); | |
65 | ||
66 | // Forms groups of identical sections where the first member | |
67 | // of each group is the kept section during folding. | |
68 | void | |
69 | find_identical_sections(const Input_objects* input_objects, | |
70 | Symbol_table* symtab); | |
71 | ||
72 | // This is set when ICF has been run and the groups of | |
73 | // identical sections have been formed. | |
74 | void | |
75 | icf_ready() | |
76 | { this->icf_ready_ = true; } | |
77 | ||
78 | // Returns true if ICF has been run. | |
79 | bool | |
80 | is_icf_ready() | |
81 | { return this->icf_ready_; } | |
82 | ||
48c187ce ST |
83 | // Unfolds the section denoted by OBJ and SHNDX if folded. |
84 | void | |
85 | unfold_section(Object* obj, unsigned int shndx); | |
86 | ||
ef15dade ST |
87 | // Returns the kept section corresponding to the |
88 | // given section. | |
89 | bool | |
90 | is_section_folded(Object* obj, unsigned int shndx); | |
91 | ||
92 | // Returns a map of a section to a list of all sections referenced | |
93 | // by its relocations. | |
94 | Section_list& | |
95 | section_reloc_list() | |
96 | { return this->section_reloc_list_; } | |
97 | ||
98 | // Returns a map of a section to a list of all symbols referenced | |
99 | // by its relocations. | |
100 | Symbol_list& | |
101 | symbol_reloc_list() | |
102 | { return this->symbol_reloc_list_; } | |
103 | ||
104 | // Returns a maps of a section to a list of symbol values and addends | |
105 | // of its relocations. | |
106 | Addend_list& | |
107 | addend_reloc_list() | |
108 | { return this->addend_reloc_list_; } | |
109 | ||
110 | // Returns a mapping of each section to a unique integer. | |
111 | Uniq_secn_id_map& | |
112 | section_to_int_map() | |
113 | { return this->section_id_; } | |
114 | ||
115 | private: | |
116 | ||
117 | // Maps integers to sections. | |
118 | std::vector<Section_id> id_section_; | |
119 | // Does the reverse. | |
120 | Uniq_secn_id_map section_id_; | |
121 | // Given a section id, this maps it to the id of the kept | |
122 | // section. If the id's are the same then this section is | |
123 | // not folded. | |
124 | std::vector<unsigned int> kept_section_id_; | |
125 | unsigned int* num_tracked_relocs; | |
126 | // Flag to indicate if ICF has been run. | |
127 | bool icf_ready_; | |
128 | ||
129 | // These lists are populated by gc_process_relocs in gc.h. | |
130 | Section_list section_reloc_list_; | |
131 | Symbol_list symbol_reloc_list_; | |
132 | Addend_list addend_reloc_list_; | |
133 | }; | |
134 | ||
55a2bb35 ST |
135 | // This function returns true if this section corresponds to a function that |
136 | // should be considered by icf as a possible candidate for folding. Some | |
137 | // earlier gcc versions, like 4.0.3, put constructors and destructors in | |
138 | // .gnu.linkonce.t sections and hence should be included too. | |
139 | inline bool | |
140 | is_section_foldable_candidate(const char* section_name) | |
141 | { | |
142 | return (is_prefix_of(".text", section_name) | |
143 | || is_prefix_of(".gnu.linkonce.t", section_name)); | |
144 | } | |
145 | ||
ef15dade ST |
146 | } // End of namespace gold. |
147 | ||
148 | #endif |