Reduce heap trashing due to std::string construction / concatenation via caching of section flags string representations
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54842 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/TargetAsmInfo.cpp b/lib/Target/TargetAsmInfo.cpp
index 9bc0b40..1ef2182 100644
--- a/lib/Target/TargetAsmInfo.cpp
+++ b/lib/Target/TargetAsmInfo.cpp
@@ -291,7 +291,7 @@
// If section is named we need to switch into it via special '.section'
// directive and also append funky flags. Otherwise - section name is just
// some magic assembler directive.
- return getSwitchToSectionDirective() + S->Name + PrintSectionFlags(S->Flags);
+ return getSwitchToSectionDirective() + S->Name + getSectionFlags(S->Flags);
}
// Lame default implementation. Calculate the section name for global.
@@ -376,3 +376,16 @@
return &S;
}
+
+const std::string&
+TargetAsmInfo::getSectionFlags(unsigned Flags) const {
+ SectionFlags::FlagsStringsMapType::iterator I = FlagsStrings.find(Flags);
+
+ // We didn't print these flags yet, print and save them to map. This reduces
+ // amount of heap trashing due to std::string construction / concatenation.
+ if (I == FlagsStrings.end())
+ I = FlagsStrings.insert(std::make_pair(Flags,
+ printSectionFlags(Flags))).first;
+
+ return I->second;
+}