DwarfDebug: Store the filename/dirname pair as a zero-separated string in a stringmap, instead of using a highly inefficient std::map of a pair of std::strings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152541 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index fa62169..388cef4 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -523,20 +523,19 @@
DirName = "";
unsigned SrcId = SourceIdMap.size()+1;
- std::pair<std::string, std::string> SourceName =
- std::make_pair(FileName, DirName);
- std::pair<std::pair<std::string, std::string>, unsigned> Entry =
- make_pair(SourceName, SrcId);
- std::map<std::pair<std::string, std::string>, unsigned>::iterator I;
- bool NewlyInserted;
- llvm::tie(I, NewlyInserted) = SourceIdMap.insert(Entry);
- if (!NewlyInserted)
- return I->second;
+ // We look up the file/dir pair by concatenating them with a zero byte.
+ SmallString<128> NamePair;
+ NamePair += DirName;
+ NamePair += '\0'; // Zero bytes are not allowed in paths.
+ NamePair += FileName;
+
+ StringMapEntry<unsigned> &Ent = SourceIdMap.GetOrCreateValue(NamePair, SrcId);
+ if (Ent.getValue() != SrcId)
+ return Ent.getValue();
// Print out a .file directive to specify files for .loc directives.
- Asm->OutStreamer.EmitDwarfFileDirective(SrcId, Entry.first.second,
- Entry.first.first);
+ Asm->OutStreamer.EmitDwarfFileDirective(SrcId, DirName, FileName);
return SrcId;
}