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[ELF][Reader] Improve performance by removing calls to malloc. 

llvm-svn: 174275
This commit is contained in:
Michael J. Spencer 2013-02-03 10:49:47 +00:00
parent 9a1da075b2
commit 7e813242af
1 changed files with 49 additions and 17 deletions
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66
lld/lib/ReaderWriter/ELF/File.h
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@ -36,6 +36,17 @@
#include "llvm/Support/system_error.h"
#include <map>
#include <unordered_map>
namespace std {
template <> struct hash<llvm::StringRef> {
public:
size_t operator()(const llvm::StringRef &s) const {
using llvm::hash_value;
return hash_value(s);
}
};
}
namespace lld {
namespace elf {
@ -86,6 +97,15 @@ public:
return;
const Elf_Shdr *section = _objFile->getElfSection(sit);
switch (section->sh_type) {
case llvm::ELF::SHT_NOTE:
case llvm::ELF::SHT_STRTAB:
case llvm::ELF::SHT_SYMTAB:
case llvm::ELF::SHT_SYMTAB_SHNDX:
continue;
}
if (section->sh_size == 0)
continue;
// Create a sectionSymbols entry for every progbits section.
if (section->sh_type == llvm::ELF::SHT_PROGBITS)
@ -312,24 +332,34 @@ private:
// Only relocations that are inside the domain of the atom are added.
// Add Rela (those with r_addend) references:
for (auto &rai : _relocationAddendRefences[sectionName]) {
if (!((rai->r_offset >= symbol->st_value) &&
(rai->r_offset < symbol->st_value + content.size())))
continue;
auto *ERef = new (_readerStorage)
ELFReference<ELFT>(rai, rai->r_offset - symbol->st_value, nullptr);
_references.push_back(ERef);
}
// Add Rel references.
for (auto &ri : _relocationReferences[sectionName]) {
if ((ri->r_offset >= symbol->st_value) &&
(ri->r_offset < symbol->st_value + content.size())) {
auto rari = _relocationAddendRefences.find(sectionName);
auto rri = _relocationReferences.find(sectionName);
unsigned refs = 0;
if (rari != _relocationAddendRefences.end())
refs += rari->second.size();
if (rri != _relocationReferences.end())
refs += rri->second.size();
_references.reserve(_references.size() + refs);
if (rari != _relocationAddendRefences.end())
for (auto &rai : rari->second) {
if (!((rai->r_offset >= symbol->st_value) &&
(rai->r_offset < symbol->st_value + content.size())))
continue;
auto *ERef = new (_readerStorage)
ELFReference<ELFT>(ri, ri->r_offset - symbol->st_value, nullptr);
ELFReference<ELFT>(rai, rai->r_offset - symbol->st_value, nullptr);
_references.push_back(ERef);
}
}
// Add Rel references.
if (rri != _relocationReferences.end())
for (auto &ri : rri->second) {
if ((ri->r_offset >= symbol->st_value) &&
(ri->r_offset < symbol->st_value + content.size())) {
auto *ERef = new (_readerStorage)
ELFReference<ELFT>(ri, ri->r_offset - symbol->st_value, nullptr);
_references.push_back(ERef);
}
}
// Create the DefinedAtom and add it to the list of DefinedAtoms.
return new (_readerStorage) ELFDefinedAtom<
@ -348,8 +378,10 @@ private:
/// relocations will also have a section named ".rel.text" or ".rela.text"
/// which will hold the entries. -- .rel or .rela is prepended to create
/// the SHT_REL(A) section name.
std::map<StringRef, std::vector<const Elf_Rela *> > _relocationAddendRefences;
std::map<StringRef, std::vector<const Elf_Rel *> > _relocationReferences;
std::unordered_map<StringRef,
std::vector<const Elf_Rela *> > _relocationAddendRefences;
std::unordered_map<StringRef,
std::vector<const Elf_Rel *> > _relocationReferences;
std::vector<ELFReference<ELFT> *> _references;
llvm::DenseMap<const Elf_Sym *, Atom *> _symbolToAtomMapping;
llvm::BumpPtrAllocator _readerStorage;