diff options
Diffstat (limited to 'gold/common.cc')
| -rw-r--r-- | gold/common.cc | 101 |
1 files changed, 77 insertions, 24 deletions
diff --git a/gold/common.cc b/gold/common.cc index c5d830e..c4ff047 100644 --- a/gold/common.cc +++ b/gold/common.cc @@ -64,21 +64,26 @@ Allocate_commons_task::run(Workqueue*) this->symtab_->allocate_commons(this->layout_, this->mapfile_); } -// This class is used to sort the common symbol by size. We put the -// larger common symbols first. +// This class is used to sort the common symbol. We normally put the +// larger common symbols first. This can be changed by using +// --sort-commons, which tells the linker to sort by alignment. template<int size> class Sort_commons { public: - Sort_commons(const Symbol_table* symtab) - : symtab_(symtab) + Sort_commons(const Symbol_table* symtab, + Symbol_table::Sort_commons_order sort_order) + : symtab_(symtab), sort_order_(sort_order) { } bool operator()(const Symbol* a, const Symbol* b) const; private: + // The symbol table. const Symbol_table* symtab_; + // How to sort. + Symbol_table::Sort_commons_order sort_order_; }; template<int size> @@ -94,22 +99,48 @@ Sort_commons<size>::operator()(const Symbol* pa, const Symbol* pb) const const Sized_symbol<size>* psa = symtab->get_sized_symbol<size>(pa); const Sized_symbol<size>* psb = symtab->get_sized_symbol<size>(pb); - // Sort by largest size first. + // The size. typename Sized_symbol<size>::Size_type sa = psa->symsize(); typename Sized_symbol<size>::Size_type sb = psb->symsize(); + + // The alignment. + typename Sized_symbol<size>::Value_type aa = psa->value(); + typename Sized_symbol<size>::Value_type ab = psb->value(); + + if (this->sort_order_ == Symbol_table::SORT_COMMONS_BY_ALIGNMENT_DESCENDING) + { + if (aa < ab) + return false; + else if (ab < aa) + return true; + } + else if (this->sort_order_ + == Symbol_table::SORT_COMMONS_BY_ALIGNMENT_ASCENDING) + { + if (aa < ab) + return true; + else if (ab < aa) + return false; + } + else + gold_assert(this->sort_order_ + == Symbol_table::SORT_COMMONS_BY_SIZE_DESCENDING); + + // Sort by descending size. if (sa < sb) return false; else if (sb < sa) return true; - // When the symbols are the same size, we sort them by alignment, - // largest alignment first. - typename Sized_symbol<size>::Value_type va = psa->value(); - typename Sized_symbol<size>::Value_type vb = psb->value(); - if (va < vb) - return false; - else if (vb < va) - return true; + if (this->sort_order_ == Symbol_table::SORT_COMMONS_BY_SIZE_DESCENDING) + { + // When the symbols are the same size, we sort them by + // alignment, largest alignment first. + if (aa < ab) + return false; + else if (ab < aa) + return true; + } // Otherwise we stabilize the sort by sorting by name. return strcmp(psa->name(), psb->name()) < 0; @@ -120,10 +151,27 @@ Sort_commons<size>::operator()(const Symbol* pa, const Symbol* pb) const void Symbol_table::allocate_commons(Layout* layout, Mapfile* mapfile) { + Sort_commons_order sort_order; + if (!parameters->options().user_set_sort_common()) + sort_order = SORT_COMMONS_BY_SIZE_DESCENDING; + else + { + const char* order = parameters->options().sort_common(); + if (*order == '\0' || strcmp(order, "descending") == 0) + sort_order = SORT_COMMONS_BY_ALIGNMENT_DESCENDING; + else if (strcmp(order, "ascending") == 0) + sort_order = SORT_COMMONS_BY_ALIGNMENT_ASCENDING; + else + { + gold_error("invalid --sort-common argument: %s", order); + sort_order = SORT_COMMONS_BY_SIZE_DESCENDING; + } + } + if (parameters->target().get_size() == 32) { #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) - this->do_allocate_commons<32>(layout, mapfile); + this->do_allocate_commons<32>(layout, mapfile, sort_order); #else gold_unreachable(); #endif @@ -131,7 +179,7 @@ Symbol_table::allocate_commons(Layout* layout, Mapfile* mapfile) else if (parameters->target().get_size() == 64) { #if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) - this->do_allocate_commons<64>(layout, mapfile); + this->do_allocate_commons<64>(layout, mapfile, sort_order); #else gold_unreachable(); #endif @@ -144,20 +192,25 @@ Symbol_table::allocate_commons(Layout* layout, Mapfile* mapfile) template<int size> void -Symbol_table::do_allocate_commons(Layout* layout, Mapfile* mapfile) +Symbol_table::do_allocate_commons(Layout* layout, Mapfile* mapfile, + Sort_commons_order sort_order) { if (!this->commons_.empty()) this->do_allocate_commons_list<size>(layout, COMMONS_NORMAL, - &this->commons_, mapfile); + &this->commons_, mapfile, + sort_order); if (!this->tls_commons_.empty()) this->do_allocate_commons_list<size>(layout, COMMONS_TLS, - &this->tls_commons_, mapfile); + &this->tls_commons_, mapfile, + sort_order); if (!this->small_commons_.empty()) this->do_allocate_commons_list<size>(layout, COMMONS_SMALL, - &this->small_commons_, mapfile); + &this->small_commons_, mapfile, + sort_order); if (!this->large_commons_.empty()) this->do_allocate_commons_list<size>(layout, COMMONS_LARGE, - &this->large_commons_, mapfile); + &this->large_commons_, mapfile, + sort_order); } // Allocate the common symbols in a list. IS_TLS indicates whether @@ -169,7 +222,8 @@ Symbol_table::do_allocate_commons_list( Layout* layout, Commons_section_type commons_section_type, Commons_type* commons, - Mapfile* mapfile) + Mapfile* mapfile, + Sort_commons_order sort_order) { typedef typename Sized_symbol<size>::Value_type Value_type; typedef typename Sized_symbol<size>::Size_type Size_type; @@ -202,10 +256,9 @@ Symbol_table::do_allocate_commons_list( if (!any) return; - // Sort the common symbols by size, so that they pack better into - // memory. + // Sort the common symbols. std::sort(commons->begin(), commons->end(), - Sort_commons<size>(this)); + Sort_commons<size>(this, sort_order)); // Place them in a newly allocated BSS section. elfcpp::Elf_Xword flags = elfcpp::SHF_WRITE | elfcpp::SHF_ALLOC; |