Query the StringMap only once when creating MDString (NFC)
Summary: Loading IR with debug info improves MDString::get() from 19ms to 10ms.
Reviewers: dexonsmith
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D16597
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 261030
diff --git a/llvm/include/llvm/IR/Metadata.h b/llvm/include/llvm/IR/Metadata.h
index df8ce35..bb21d7a 100644
--- a/llvm/include/llvm/IR/Metadata.h
+++ b/llvm/include/llvm/IR/Metadata.h
@@ -592,9 +592,9 @@
StringMapEntry<MDString> *Entry;
MDString() : Metadata(MDStringKind, Uniqued), Entry(nullptr) {}
- MDString(MDString &&) : Metadata(MDStringKind, Uniqued) {}
public:
+ MDString(MDString &&R) = default;
static MDString *get(LLVMContext &Context, StringRef Str);
static MDString *get(LLVMContext &Context, const char *Str) {
return get(Context, Str ? StringRef(Str) : StringRef());
diff --git a/llvm/lib/IR/Metadata.cpp b/llvm/lib/IR/Metadata.cpp
index cc0c568..ddb9cc4 100644
--- a/llvm/lib/IR/Metadata.cpp
+++ b/llvm/lib/IR/Metadata.cpp
@@ -397,17 +397,12 @@
MDString *MDString::get(LLVMContext &Context, StringRef Str) {
auto &Store = Context.pImpl->MDStringCache;
- auto I = Store.find(Str);
- if (I != Store.end())
- return &I->second;
-
- auto *Entry =
- StringMapEntry<MDString>::Create(Str, Store.getAllocator(), MDString());
- bool WasInserted = Store.insert(Entry);
- (void)WasInserted;
- assert(WasInserted && "Expected entry to be inserted");
- Entry->second.Entry = Entry;
- return &Entry->second;
+ auto I = Store.insert(std::make_pair(Str, MDString()));
+ auto &MapEntry = I.first->getValue();
+ if (!I.second)
+ return &MapEntry;
+ MapEntry.Entry = &*I.first;
+ return &MapEntry;
}
StringRef MDString::getString() const {