Index: include/clang/Sema/AttributeList.h
===================================================================
--- include/clang/Sema/AttributeList.h
+++ include/clang/Sema/AttributeList.h
@@ -86,6 +86,8 @@
 typedef llvm::SmallVector<ArgsUnion, 12U> ArgsVector;
 
 struct ParsedAttrInfo {
+  /// Which spelling of the attribute this ParsedAttrInfo corresponds to
+  unsigned SpellingListIndex;
   /// Corresponds to the AttributeList::Kind enum
   unsigned AttrKind : 16;
   /// Corresponds to the AttributeList::Syntax enum
@@ -115,10 +117,10 @@
   unsigned IsLateParsed : 1;
 
   ParsedAttrInfo()
-  : AttrKind(0), Syntax(0), NumArgs(0), OptArgs(0), HasCustomParsing(0),
-    IsTargetSpecific(0), IsType(0), IsStmt(0), IsKnownToGCC(0),
-    IsUnevaluatedArgContext(0), IsIdentifierArg(0), IsTypeArg(0),
-    IsLateParsed(0) { }
+  : SpellingListIndex(0), AttrKind(0), Syntax(0), NumArgs(0), OptArgs(0),
+    HasCustomParsing(0), IsTargetSpecific(0), IsType(0), IsStmt(0),
+    IsKnownToGCC(0), IsUnevaluatedArgContext(0), IsIdentifierArg(0),
+    IsTypeArg(0), IsLateParsed(0) { }
 
   virtual ~ParsedAttrInfo() {}
 
Index: include/clang/Sema/CMakeLists.txt
===================================================================
--- include/clang/Sema/CMakeLists.txt
+++ include/clang/Sema/CMakeLists.txt
@@ -8,11 +8,6 @@
   SOURCE ../Basic/Attr.td
   TARGET ClangAttrParsedAttrList)
 
-clang_tablegen(AttrSpellingListIndex.inc -gen-clang-attr-spelling-index
-  -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
-  SOURCE ../Basic/Attr.td
-  TARGET ClangAttrSpellingListIndex)
-
 clang_tablegen(AttrParsedAttrImpl.inc -gen-clang-attr-parsed-attr-impl
   -I ${CMAKE_CURRENT_SOURCE_DIR}/../../
   SOURCE ../Basic/Attr.td
Index: lib/Sema/AttributeList.cpp
===================================================================
--- lib/Sema/AttributeList.cpp
+++ lib/Sema/AttributeList.cpp
@@ -163,15 +163,7 @@
 }
 
 unsigned AttributeList::getAttributeSpellingListIndex() const {
-  // Both variables will be used in tablegen generated
-  // attribute spell list index matching code.
-  StringRef Scope = ScopeName ? ScopeName->getName() : "";
-  StringRef Name = normalizeAttrName(AttrName->getName(), Scope,
-                                     (AttributeList::Syntax)SyntaxUsed);
-  Kind AttrKind = Kind(getInfo()->AttrKind);
-
-#include "clang/Sema/AttrSpellingListIndex.inc"
-
+  return getInfo()->SpellingListIndex;
 }
 
 unsigned AttributeList::getMinArgs() const {
Index: utils/TableGen/ClangAttrEmitter.cpp
===================================================================
--- utils/TableGen/ClangAttrEmitter.cpp
+++ utils/TableGen/ClangAttrEmitter.cpp
@@ -2274,40 +2274,6 @@
   OS << "}\n";
 }
 
-void EmitClangAttrSpellingListIndex(RecordKeeper &Records, raw_ostream &OS) {
-  emitSourceFileHeader("Code to translate different attribute spellings "
-                       "into internal identifiers", OS);
-
-  OS << "  switch (AttrKind) {\n";
-
-  ParsedAttrMap Attrs = getParsedAttrList(Records);
-  for (const auto &I : Attrs) {
-    const Record &R = *I.second;
-    std::vector<FlattenedSpelling> Spellings = GetFlattenedSpellings(R);
-    OS << "  case AT_" << I.first << ": {\n";
-    for (unsigned I = 0; I < Spellings.size(); ++ I) {
-      OS << "    if (Name == \"" << Spellings[I].name() << "\" && "
-         << "SyntaxUsed == "
-         << StringSwitch<unsigned>(Spellings[I].variety())
-                .Case("GNU", 0)
-                .Case("CXX11", 1)
-                .Case("Declspec", 2)
-                .Case("Microsoft", 3)
-                .Case("Keyword", 4)
-                .Case("Pragma", 5)
-                .Default(0)
-         << " && Scope == \"" << Spellings[I].nameSpace() << "\")\n"
-         << "        return " << I << ";\n";
-    }
-
-    OS << "    break;\n";
-    OS << "  }\n";
-  }
-
-  OS << "  }\n";
-  OS << "  return 0;\n";
-}
-
 // Emits code used by RecursiveASTVisitor to visit attributes
 void EmitClangAttrASTVisitor(RecordKeeper &Records, raw_ostream &OS) {
   emitSourceFileHeader("Used by RecursiveASTVisitor to visit attributes.", OS);
@@ -2810,6 +2776,7 @@
       std::string AttrInfoName = "AttrInfo" + std::to_string(SpellingIdx) + AttrName;
       OS << "struct " << AttrInfoName << " : public ParsedAttrInfo {\n";
       OS << "  " << AttrInfoName << "() {\n";
+      OS << "    SpellingListIndex = " << SpellingIdx << ";\n";
       if (Attr.getValueAsBit("Ignored")) {
         OS << "    AttrKind = AttributeList::IgnoredAttribute;\n";
       } else {
Index: utils/TableGen/TableGen.cpp
===================================================================
--- utils/TableGen/TableGen.cpp
+++ utils/TableGen/TableGen.cpp
@@ -29,7 +29,6 @@
   GenClangAttrPCHRead,
   GenClangAttrPCHWrite,
   GenClangAttrHasAttributeImpl,
-  GenClangAttrSpellingListIndex,
   GenClangAttrASTVisitor,
   GenClangAttrTemplateInstantiate,
   GenClangAttrParsedAttrList,
@@ -72,9 +71,6 @@
         clEnumValN(GenClangAttrHasAttributeImpl,
                    "gen-clang-attr-has-attribute-impl",
                    "Generate a clang attribute spelling list"),
-        clEnumValN(GenClangAttrSpellingListIndex,
-                   "gen-clang-attr-spelling-index",
-                   "Generate a clang attribute spelling index"),
         clEnumValN(GenClangAttrASTVisitor,
                    "gen-clang-attr-ast-visitor",
                    "Generate a recursive AST visitor for clang attributes"),
@@ -157,9 +153,6 @@
   case GenClangAttrHasAttributeImpl:
     EmitClangAttrHasAttrImpl(Records, OS);
     break;
-  case GenClangAttrSpellingListIndex:
-    EmitClangAttrSpellingListIndex(Records, OS);
-    break;
   case GenClangAttrASTVisitor:
     EmitClangAttrASTVisitor(Records, OS);
     break;
Index: utils/TableGen/TableGenBackends.h
===================================================================
--- utils/TableGen/TableGenBackends.h
+++ utils/TableGen/TableGenBackends.h
@@ -38,7 +38,6 @@
 void EmitClangAttrPCHRead(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrPCHWrite(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrHasAttrImpl(RecordKeeper &Records, raw_ostream &OS);
-void EmitClangAttrSpellingListIndex(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrASTVisitor(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrTemplateInstantiate(RecordKeeper &Records, raw_ostream &OS);
 void EmitClangAttrParsedAttrList(RecordKeeper &Records, raw_ostream &OS);