Author: rnk Date: Thu Jun 26 17:42:18 2014 New Revision: 211813 URL: http://llvm.org/viewvc/llvm-project?rev=211813&view=rev Log: Avoid extra back reference key lookup in msmangler
Avoid a second key lookup when the back reference key is going to be inserted in the StringMap. The string lookups in the msmangler are the main responsible for the huge overhead when compared to the itanium mangler. This patch makes a small but noticeable improvement. Reviewed by: rnk Differential Revision: http://reviews.llvm.org/D4130 Patch by Agustín Bergé! Modified: cfe/trunk/lib/AST/MicrosoftMangle.cpp Modified: cfe/trunk/lib/AST/MicrosoftMangle.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/MicrosoftMangle.cpp?rev=211813&r1=211812&r2=211813&view=diff ============================================================================== --- cfe/trunk/lib/AST/MicrosoftMangle.cpp (original) +++ cfe/trunk/lib/AST/MicrosoftMangle.cpp Thu Jun 26 17:42:18 2014 @@ -650,6 +650,7 @@ void MicrosoftCXXNameMangler::mangleUnqu // FIXME: Test alias template mangling with MSVC 2013. if (!isa<ClassTemplateDecl>(TD)) { mangleTemplateInstantiationName(TD, *TemplateArgs); + Out << '@'; return; } @@ -668,22 +669,13 @@ void MicrosoftCXXNameMangler::mangleUnqu // the mangled type name as a key to check the mangling of different types // for aliasing. - std::string TemplateMangling; - llvm::raw_string_ostream Stream(TemplateMangling); + llvm::SmallString<64> TemplateMangling; + llvm::raw_svector_ostream Stream(TemplateMangling); MicrosoftCXXNameMangler Extra(Context, Stream); Extra.mangleTemplateInstantiationName(TD, *TemplateArgs); Stream.flush(); - BackRefMap::iterator Found = NameBackReferences.find(TemplateMangling); - if (Found == NameBackReferences.end()) { - Out << TemplateMangling; - if (NameBackReferences.size() < 10) { - size_t Size = NameBackReferences.size(); - NameBackReferences[TemplateMangling] = Size; - } - } else { - Out << Found->second; - } + mangleSourceName(TemplateMangling); return; } @@ -1002,13 +994,20 @@ void MicrosoftCXXNameMangler::mangleOper void MicrosoftCXXNameMangler::mangleSourceName(StringRef Name) { // <source name> ::= <identifier> @ - BackRefMap::iterator Found = NameBackReferences.find(Name); + BackRefMap::iterator Found; + if (NameBackReferences.size() < 10) { + size_t Size = NameBackReferences.size(); + bool Inserted; + std::tie(Found, Inserted) = + NameBackReferences.insert(std::make_pair(Name, Size)); + if (Inserted) + Found = NameBackReferences.end(); + } else { + Found = NameBackReferences.find(Name); + } + if (Found == NameBackReferences.end()) { Out << Name << '@'; - if (NameBackReferences.size() < 10) { - size_t Size = NameBackReferences.size(); - NameBackReferences[Name] = Size; - } } else { Out << Found->second; } @@ -1104,10 +1103,9 @@ void MicrosoftCXXNameMangler::mangleExpr void MicrosoftCXXNameMangler::mangleTemplateArgs( const TemplateDecl *TD, const TemplateArgumentList &TemplateArgs) { - // <template-args> ::= <template-arg>+ @ + // <template-args> ::= <template-arg>+ for (const TemplateArgument &TA : TemplateArgs.asArray()) mangleTemplateArg(TD, TA); - Out << '@'; } void MicrosoftCXXNameMangler::mangleTemplateArg(const TemplateDecl *TD, _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
