| // icf.h -- Identical Code Folding |
| |
| // Copyright 2009, 2010 Free Software Foundation, Inc. |
| // Written by Sriraman Tallam <tmsriram@google.com>. |
| |
| // This file is part of gold. |
| |
| // This program is free software; you can redistribute it and/or modify |
| // it under the terms of the GNU General Public License as published by |
| // the Free Software Foundation; either version 3 of the License, or |
| // (at your option) any later version. |
| |
| // This program is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with this program; if not, write to the Free Software |
| // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| // MA 02110-1301, USA. |
| |
| #ifndef GOLD_ICF_H |
| #define GOLD_ICF_H |
| |
| #include <vector> |
| |
| #include "elfcpp.h" |
| #include "symtab.h" |
| #include "object.h" |
| |
| namespace gold |
| { |
| |
| class Object; |
| class Input_objects; |
| class Symbol_table; |
| |
| class Icf |
| { |
| public: |
| typedef std::vector<Section_id> Sections_reachable_list; |
| typedef std::vector<Symbol*> Symbol_info; |
| typedef std::vector<std::pair<long long, long long> > Addend_info; |
| typedef Unordered_map<Section_id, |
| Sections_reachable_list, |
| Section_id_hash> Section_list; |
| typedef Unordered_map<Section_id, Symbol_info, Section_id_hash> Symbol_list; |
| typedef Unordered_map<Section_id, Addend_info, Section_id_hash> Addend_list; |
| typedef Unordered_map<Section_id, |
| unsigned int, |
| Section_id_hash> Uniq_secn_id_map; |
| |
| Icf() |
| : id_section_(), section_id_(), kept_section_id_(), |
| num_tracked_relocs(NULL), icf_ready_(false), |
| section_reloc_list_(), symbol_reloc_list_(), |
| addend_reloc_list_() |
| { } |
| |
| // Returns the kept folded identical section corresponding to |
| // dup_obj and dup_shndx. |
| Section_id |
| get_folded_section(Object* dup_obj, unsigned int dup_shndx); |
| |
| // Forms groups of identical sections where the first member |
| // of each group is the kept section during folding. |
| void |
| find_identical_sections(const Input_objects* input_objects, |
| Symbol_table* symtab); |
| |
| // This is set when ICF has been run and the groups of |
| // identical sections have been formed. |
| void |
| icf_ready() |
| { this->icf_ready_ = true; } |
| |
| // Returns true if ICF has been run. |
| bool |
| is_icf_ready() |
| { return this->icf_ready_; } |
| |
| // Unfolds the section denoted by OBJ and SHNDX if folded. |
| void |
| unfold_section(Object* obj, unsigned int shndx); |
| |
| // Returns the kept section corresponding to the |
| // given section. |
| bool |
| is_section_folded(Object* obj, unsigned int shndx); |
| |
| // Returns a map of a section to a list of all sections referenced |
| // by its relocations. |
| Section_list& |
| section_reloc_list() |
| { return this->section_reloc_list_; } |
| |
| // Returns a map of a section to a list of all symbols referenced |
| // by its relocations. |
| Symbol_list& |
| symbol_reloc_list() |
| { return this->symbol_reloc_list_; } |
| |
| // Returns a maps of a section to a list of symbol values and addends |
| // of its relocations. |
| Addend_list& |
| addend_reloc_list() |
| { return this->addend_reloc_list_; } |
| |
| // Returns a mapping of each section to a unique integer. |
| Uniq_secn_id_map& |
| section_to_int_map() |
| { return this->section_id_; } |
| |
| private: |
| |
| // Maps integers to sections. |
| std::vector<Section_id> id_section_; |
| // Does the reverse. |
| Uniq_secn_id_map section_id_; |
| // Given a section id, this maps it to the id of the kept |
| // section. If the id's are the same then this section is |
| // not folded. |
| std::vector<unsigned int> kept_section_id_; |
| unsigned int* num_tracked_relocs; |
| // Flag to indicate if ICF has been run. |
| bool icf_ready_; |
| |
| // These lists are populated by gc_process_relocs in gc.h. |
| Section_list section_reloc_list_; |
| Symbol_list symbol_reloc_list_; |
| Addend_list addend_reloc_list_; |
| }; |
| |
| // This function returns true if this section corresponds to a function that |
| // should be considered by icf as a possible candidate for folding. Some |
| // earlier gcc versions, like 4.0.3, put constructors and destructors in |
| // .gnu.linkonce.t sections and hence should be included too. |
| inline bool |
| is_section_foldable_candidate(const char* section_name) |
| { |
| return (is_prefix_of(".text", section_name) |
| || is_prefix_of(".gnu.linkonce.t", section_name)); |
| } |
| |
| } // End of namespace gold. |
| |
| #endif |