RPCS3/llvm
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm.git synced 2024-12-16 00:17:32 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Use StringRef's in resolved path cache to avoid extra internString lookups. NFC.

Browse Source 
ResolvedPaths was storing std::string's as a cache. We would then take those strings and look them up in the internString pool to get a unique StringRef for each path.

This patch changes ResolvedPaths to store the StringRef pointing in to the internString pool itself. This way, when getResolvedPath returns a string, we know we have the StringRef we would find in the pool anyway. We can avoid the duplicate memory of the std::string's, and also the time from the lookup.

Unfortunately my profiles show no runtime change here, but it should still save memory allocations which is nice.

Reviewed by Frederic Riss.

Differential Revision: http://reviews.llvm.org/D18259

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263774 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Pete Cooper 2016-03-18 03:48:09 +00:00
parent 2b341f70ca
commit 3175d6f980
1 changed files with 16 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
tools/dsymutil/DwarfLinker.cpp
View File

@ -315,16 +315,15 @@ public:
const std::vector<AccelInfo> &getPubtypes() const { return Pubtypes; }
/// Get the full path for file \a FileNum in the line table
const char *getResolvedPath(unsigned FileNum) {
StringRef getResolvedPath(unsigned FileNum) {
if (FileNum >= ResolvedPaths.size())
return nullptr;
return ResolvedPaths[FileNum].size() ? ResolvedPaths[FileNum].c_str()
: nullptr;
return StringRef();
return ResolvedPaths[FileNum];
}
/// Set the fully resolved path for the line-table's file \a FileNum
/// to \a Path.
void setResolvedPath(unsigned FileNum, const std::string &Path) {
void setResolvedPath(unsigned FileNum, StringRef Path) {
if (ResolvedPaths.size() <= FileNum)
ResolvedPaths.resize(FileNum + 1);
ResolvedPaths[FileNum] = Path;
@ -378,7 +377,10 @@ private:
/// @}
/// Cached resolved paths from the line table.
std::vector<std::string> ResolvedPaths;
/// Note, the StringRefs here point in to the intern (uniquing) string pool.
/// This means that a StringRef returned here doesn't need to then be uniqued
/// for the purposes of getting a unique address for each string.
std::vector<StringRef> ResolvedPaths;
/// Is this unit subject to the ODR rule?
bool HasODR;
@ -1604,7 +1606,6 @@ PointerIntPair<DeclContext *, 1> DeclContextTree::getChildDeclContext(
Tag != dwarf::DW_TAG_enumeration_type && NameRef.empty())
return PointerIntPair<DeclContext *, 1>(nullptr);
std::string File;
unsigned Line = 0;
unsigned ByteSize = UINT32_MAX;
@ -1632,6 +1633,7 @@ PointerIntPair<DeclContext *, 1> DeclContextTree::getChildDeclContext(
// FIXME: Passing U.getOrigUnit().getCompilationDir()
// instead of "" would allow more uniquing, but for now, do
// it this way to match dsymutil-classic.
std::string File;
if (LT->getFileNameByIndex(
FileNum, "",
DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
@ -1640,17 +1642,20 @@ PointerIntPair<DeclContext *, 1> DeclContextTree::getChildDeclContext(
&U.getOrigUnit(), dwarf::DW_AT_decl_line, 0);
#ifdef HAVE_REALPATH
// Cache the resolved paths, because calling realpath is expansive.
if (const char *ResolvedPath = U.getResolvedPath(FileNum)) {
File = ResolvedPath;
StringRef ResolvedPath = U.getResolvedPath(FileNum);
if (!ResolvedPath.empty()) {
FileRef = ResolvedPath;
} else {
char RealPath[PATH_MAX + 1];
RealPath[PATH_MAX] = 0;
if (::realpath(File.c_str(), RealPath))
File = RealPath;
U.setResolvedPath(FileNum, File);
FileRef = StringPool.internString(File);
U.setResolvedPath(FileNum, FileRef);
}
#endif
#else
FileRef = StringPool.internString(File);
#endif
}
}
}