[TableGen] Use StringMap instead of DenseMap<StringRef> to unique CodeInit and StringInit objects. Override the allocator to keep using the BumpPtrAllocator. NFCI

StringMap is better suited to mapping strings than a DenseMap.

llvm-svn: 304178

1 files changed, 10 insertions, 16 deletions

diff --git a/llvm/lib/TableGen/Record.cpp b/llvm/lib/TableGen/Record.cpp
index 474633a5b31..f07208b1fb9 100644
--- a/llvm/lib/TableGen/Record.cpp
+++ b/llvm/lib/TableGen/Record.cpp
@@ -405,27 +405,21 @@ IntInit::convertInitializerBitRange(ArrayRef<unsigned> Bits) const {
 }
 
 CodeInit *CodeInit::get(StringRef V) {
-  static DenseMap<StringRef, CodeInit*> ThePool;
+  static StringMap<CodeInit*, BumpPtrAllocator &> ThePool(Allocator);
 
-  auto I = ThePool.insert(std::make_pair(V, nullptr));
-  if (I.second) {
-    StringRef VCopy = V.copy(Allocator);
-    I.first->first = VCopy;
-    I.first->second = new(Allocator) CodeInit(VCopy);
-  }
-  return I.first->second;
+  auto &Entry = *ThePool.insert(std::make_pair(V, nullptr)).first;
+  if (!Entry.second)
+    Entry.second = new(Allocator) CodeInit(Entry.getKey());
+  return Entry.second;
 }
 
 StringInit *StringInit::get(StringRef V) {
-  static DenseMap<StringRef, StringInit*> ThePool;
+  static StringMap<StringInit*, BumpPtrAllocator &> ThePool(Allocator);
 
-  auto I = ThePool.insert(std::make_pair(V, nullptr));
-  if (I.second) {
-    StringRef VCopy = V.copy(Allocator);
-    I.first->first = VCopy;
-    I.first->second = new(Allocator) StringInit(VCopy);
-  }
-  return I.first->second;
+  auto &Entry = *ThePool.insert(std::make_pair(V, nullptr)).first;
+  if (!Entry.second)
+    Entry.second = new(Allocator) StringInit(Entry.getKey());
+  return Entry.second;
 }
 
 Init *StringInit::convertInitializerTo(RecTy *Ty) const {