[ModuleSummary] use StringRefs to avoid a redundant copy; NFC

`Saver` is a StringSaver, which has a few overloads of `save` that all
ultimately just call `StringRef save(StringRef)`. Just take a StringRef
here instead of building up a std::string to convert it to a StringRef.

llvm-svn: 348650

2 files changed, 2 insertions, 2 deletions

diff --git a/llvm/include/llvm/IR/ModuleSummaryIndex.h b/llvm/include/llvm/IR/ModuleSummaryIndex.h
index 7e10fa1aa02..3b3de5cd16c 100644
--- a/llvm/include/llvm/IR/ModuleSummaryIndex.h
+++ b/llvm/include/llvm/IR/ModuleSummaryIndex.h
@@ -946,7 +946,7 @@ public:
   // Save a string in the Index. Use before passing Name to
   // getOrInsertValueInfo when the string isn't owned elsewhere (e.g. on the
   // module's Strtab).
-  StringRef saveString(std::string String) { return Saver.save(String); }
+  StringRef saveString(StringRef String) { return Saver.save(String); }
 
   /// Return a ValueInfo for \p GUID setting value \p Name.
   ValueInfo getOrInsertValueInfo(GlobalValue::GUID GUID, StringRef Name) {
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 3dea1b565bc..f9b3c930b05 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -4918,7 +4918,7 @@ void ModuleSummaryIndexBitcodeReader::setValueGUID(
   ValueIdToValueInfoMap[ValueID] = std::make_pair(
       TheIndex.getOrInsertValueInfo(
           ValueGUID,
-          UseStrtab ? ValueName : TheIndex.saveString(ValueName.str())),
+          UseStrtab ? ValueName : TheIndex.saveString(ValueName)),
       OriginalNameID);
 }