Update aosp/master LLVM for rebase to r222494.

Change-Id: Ic787f5e0124df789bd26f3f24680f45e678eef2d

3 files changed, 189 insertions, 159 deletions

diff --git a/lib/LTO/LLVMBuild.txt b/lib/LTO/LLVMBuild.txt
index 29ed92c..b9178e9 100644
--- a/lib/LTO/LLVMBuild.txt
+++ b/lib/LTO/LLVMBuild.txt
@@ -19,4 +19,4 @@
 type = Library
 name = LTO
 parent = Libraries
-required_libraries = BitReader BitWriter Core IPA IPO InstCombine Linker MC MCParser ObjCARC Object Scalar Support Target TransformUtils
+required_libraries = BitReader BitWriter Core IPA IPO InstCombine Linker MC ObjCARC Object Scalar Support Target TransformUtils CodeGen
diff --git a/lib/LTO/LTOCodeGenerator.cpp b/lib/LTO/LTOCodeGenerator.cpp
index 335197a..c663d43 100644
--- a/lib/LTO/LTOCodeGenerator.cpp
+++ b/lib/LTO/LTOCodeGenerator.cpp
@@ -48,6 +48,7 @@
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetOptions.h"
 #include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm/Transforms/ObjCARC.h"
@@ -63,18 +64,30 @@ const char* LTOCodeGenerator::getVersionString() {
 }
 
 LTOCodeGenerator::LTOCodeGenerator()
-    : Context(getGlobalContext()), IRLinker(new Module("ld-temp.o", Context)),
-      TargetMach(nullptr), EmitDwarfDebugInfo(false),
-      ScopeRestrictionsDone(false), CodeModel(LTO_CODEGEN_PIC_MODEL_DEFAULT),
-      NativeObjectFile(nullptr), DiagHandler(nullptr), DiagContext(nullptr) {
+    : Context(getGlobalContext()), IRLinker(new Module("ld-temp.o", Context)) {
+  initialize();
+}
+
+LTOCodeGenerator::LTOCodeGenerator(std::unique_ptr<LLVMContext> Context)
+    : OwnedContext(std::move(Context)), Context(*OwnedContext),
+      IRLinker(new Module("ld-temp.o", *OwnedContext)) {
+  initialize();
+}
+
+void LTOCodeGenerator::initialize() {
+  TargetMach = nullptr;
+  EmitDwarfDebugInfo = false;
+  ScopeRestrictionsDone = false;
+  CodeModel = LTO_CODEGEN_PIC_MODEL_DEFAULT;
+  DiagHandler = nullptr;
+  DiagContext = nullptr;
+
   initializeLTOPasses();
 }
 
 LTOCodeGenerator::~LTOCodeGenerator() {
   delete TargetMach;
-  delete NativeObjectFile;
   TargetMach = nullptr;
-  NativeObjectFile = nullptr;
 
   IRLinker.deleteModule();
 
@@ -107,14 +120,18 @@ void LTOCodeGenerator::initializeLTOPasses() {
   initializeFunctionAttrsPass(R);
   initializeGlobalsModRefPass(R);
   initializeLICMPass(R);
+  initializeMergedLoadStoreMotionPass(R);
   initializeGVNPass(R);
   initializeMemCpyOptPass(R);
   initializeDCEPass(R);
   initializeCFGSimplifyPassPass(R);
 }
 
-bool LTOCodeGenerator::addModule(LTOModule* mod, std::string& errMsg) {
-  bool ret = IRLinker.linkInModule(&mod->getModule(), &errMsg);
+bool LTOCodeGenerator::addModule(LTOModule *mod) {
+  assert(&mod->getModule().getContext() == &Context &&
+         "Expected module in same context");
+
+  bool ret = IRLinker.linkInModule(&mod->getModule());
 
   const std::vector<const char*> &undefs = mod->getAsmUndefinedRefs();
   for (int i = 0, e = undefs.size(); i != e; ++i)
@@ -161,9 +178,9 @@ bool LTOCodeGenerator::writeMergedModules(const char *path,
   applyScopeRestrictions();
 
   // create output file
-  std::string ErrInfo;
-  tool_output_file Out(path, ErrInfo, sys::fs::F_None);
-  if (!ErrInfo.empty()) {
+  std::error_code EC;
+  tool_output_file Out(path, EC, sys::fs::F_None);
+  if (EC) {
     errMsg = "could not open bitcode file for writing: ";
     errMsg += path;
     return false;
@@ -188,6 +205,7 @@ bool LTOCodeGenerator::compile_to_file(const char** name,
                                        bool disableOpt,
                                        bool disableInline,
                                        bool disableGVNLoadPRE,
+                                       bool disableVectorization,
                                        std::string& errMsg) {
   // make unique temp .o file to put generated object file
   SmallString<128> Filename;
@@ -202,8 +220,9 @@ bool LTOCodeGenerator::compile_to_file(const char** name,
   // generate object file
   tool_output_file objFile(Filename.c_str(), FD);
 
-  bool genResult = generateObjectFile(objFile.os(), disableOpt, disableInline,
-                                      disableGVNLoadPRE, errMsg);
+  bool genResult =
+      generateObjectFile(objFile.os(), disableOpt, disableInline,
+                         disableGVNLoadPRE, disableVectorization, errMsg);
   objFile.os().close();
   if (objFile.os().has_error()) {
     objFile.os().clear_error();
@@ -226,15 +245,13 @@ const void* LTOCodeGenerator::compile(size_t* length,
                                       bool disableOpt,
                                       bool disableInline,
                                       bool disableGVNLoadPRE,
+                                      bool disableVectorization,
                                       std::string& errMsg) {
   const char *name;
   if (!compile_to_file(&name, disableOpt, disableInline, disableGVNLoadPRE,
-                       errMsg))
+                       disableVectorization, errMsg))
     return nullptr;
 
-  // remove old buffer if compile() called twice
-  delete NativeObjectFile;
-
   // read .o file into memory buffer
   ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
       MemoryBuffer::getFile(name, -1, false);
@@ -243,7 +260,7 @@ const void* LTOCodeGenerator::compile(size_t* length,
     sys::fs::remove(NativeObjectPath);
     return nullptr;
   }
-  NativeObjectFile = BufferOrErr.get().release();
+  NativeObjectFile = std::move(*BufferOrErr);
 
   // remove temp files
   sys::fs::remove(NativeObjectPath);
@@ -298,8 +315,7 @@ bool LTOCodeGenerator::determineTarget(std::string &errMsg) {
       MCpu = "core2";
     else if (Triple.getArch() == llvm::Triple::x86)
       MCpu = "yonah";
-    else if (Triple.getArch() == llvm::Triple::arm64 ||
-             Triple.getArch() == llvm::Triple::aarch64)
+    else if (Triple.getArch() == llvm::Triple::aarch64)
       MCpu = "cyclone";
   }
 
@@ -311,9 +327,9 @@ bool LTOCodeGenerator::determineTarget(std::string &errMsg) {
 
 void LTOCodeGenerator::
 applyRestriction(GlobalValue &GV,
-                 const ArrayRef<StringRef> &Libcalls,
+                 ArrayRef<StringRef> Libcalls,
                  std::vector<const char*> &MustPreserveList,
-                 SmallPtrSet<GlobalValue*, 8> &AsmUsed,
+                 SmallPtrSetImpl<GlobalValue*> &AsmUsed,
                  Mangler &Mangler) {
   // There are no restrictions to apply to declarations.
   if (GV.isDeclaration())
@@ -342,7 +358,7 @@ applyRestriction(GlobalValue &GV,
 }
 
 static void findUsedValues(GlobalVariable *LLVMUsed,
-                           SmallPtrSet<GlobalValue*, 8> &UsedValues) {
+                           SmallPtrSetImpl<GlobalValue*> &UsedValues) {
   if (!LLVMUsed) return;
 
   ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
@@ -390,12 +406,13 @@ void LTOCodeGenerator::applyScopeRestrictions() {
   passes.add(createDebugInfoVerifierPass());
 
   // mark which symbols can not be internalized
-  Mangler Mangler(TargetMach->getDataLayout());
+  Mangler Mangler(TargetMach->getSubtargetImpl()->getDataLayout());
   std::vector<const char*> MustPreserveList;
   SmallPtrSet<GlobalValue*, 8> AsmUsed;
   std::vector<StringRef> Libcalls;
   TargetLibraryInfo TLI(Triple(TargetMach->getTargetTriple()));
-  accumulateAndSortLibcalls(Libcalls, TLI, TargetMach->getTargetLowering());
+  accumulateAndSortLibcalls(
+      Libcalls, TLI, TargetMach->getSubtargetImpl()->getTargetLowering());
 
   for (Module::iterator f = mergedModule->begin(),
          e = mergedModule->end(); f != e; ++f)
@@ -444,6 +461,7 @@ bool LTOCodeGenerator::generateObjectFile(raw_ostream &out,
                                           bool DisableOpt,
                                           bool DisableInline,
                                           bool DisableGVNLoadPRE,
+                                          bool DisableVectorization,
                                           std::string &errMsg) {
   if (!this->determineTarget(errMsg))
     return false;
@@ -456,35 +474,27 @@ bool LTOCodeGenerator::generateObjectFile(raw_ostream &out,
   // Instantiate the pass manager to organize the passes.
   PassManager passes;
 
-  // Start off with a verification pass.
-  passes.add(createVerifierPass());
-  passes.add(createDebugInfoVerifierPass());
-
   // Add an appropriate DataLayout instance for this module...
-  mergedModule->setDataLayout(TargetMach->getDataLayout());
-  passes.add(new DataLayoutPass(mergedModule));
-
-  // Add appropriate TargetLibraryInfo for this module.
-  passes.add(new TargetLibraryInfo(Triple(TargetMach->getTargetTriple())));
-
-  TargetMach->addAnalysisPasses(passes);
-
-  // Enabling internalize here would use its AllButMain variant. It
-  // keeps only main if it exists and does nothing for libraries. Instead
-  // we create the pass ourselves with the symbol list provided by the linker.
-  if (!DisableOpt)
-    PassManagerBuilder().populateLTOPassManager(passes,
-                                              /*Internalize=*/false,
-                                              !DisableInline,
-                                              DisableGVNLoadPRE);
-
-  // Make sure everything is still good.
-  passes.add(createVerifierPass());
-  passes.add(createDebugInfoVerifierPass());
+  mergedModule->setDataLayout(TargetMach->getSubtargetImpl()->getDataLayout());
+
+  Triple TargetTriple(TargetMach->getTargetTriple());
+  PassManagerBuilder PMB;
+  PMB.DisableGVNLoadPRE = DisableGVNLoadPRE;
+  PMB.LoopVectorize = !DisableVectorization;
+  PMB.SLPVectorize = !DisableVectorization;
+  if (!DisableInline)
+    PMB.Inliner = createFunctionInliningPass();
+  PMB.LibraryInfo = new TargetLibraryInfo(TargetTriple);
+  if (DisableOpt)
+    PMB.OptLevel = 0;
+  PMB.VerifyInput = true;
+  PMB.VerifyOutput = true;
+
+  PMB.populateLTOPassManager(passes, TargetMach);
 
   PassManager codeGenPasses;
 
-  codeGenPasses.add(new DataLayoutPass(mergedModule));
+  codeGenPasses.add(new DataLayoutPass());
 
   formatted_raw_ostream Out(out);
 
@@ -571,5 +581,6 @@ LTOCodeGenerator::setDiagnosticHandler(lto_diagnostic_handler_t DiagHandler,
     return Context.setDiagnosticHandler(nullptr, nullptr);
   // Register the LTOCodeGenerator stub in the LLVMContext to forward the
   // diagnostic to the external DiagHandler.
-  Context.setDiagnosticHandler(LTOCodeGenerator::DiagnosticHandler, this);
+  Context.setDiagnosticHandler(LTOCodeGenerator::DiagnosticHandler, this,
+                               /* RespectFilters */ true);
 }
diff --git a/lib/LTO/LTOModule.cpp b/lib/LTO/LTOModule.cpp
index 844c0f2..4108ef2 100644
--- a/lib/LTO/LTOModule.cpp
+++ b/lib/LTO/LTOModule.cpp
@@ -15,6 +15,7 @@
 #include "llvm/LTO/LTOModule.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/CodeGen/Analysis.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Metadata.h"
@@ -28,6 +29,8 @@
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCTargetAsmParser.h"
 #include "llvm/MC/SubtargetFeature.h"
+#include "llvm/Object/IRObjectFile.h"
+#include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Host.h"
@@ -39,32 +42,51 @@
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 #include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
 #include "llvm/Transforms/Utils/GlobalStatus.h"
 #include <system_error>
 using namespace llvm;
+using namespace llvm::object;
 
 LTOModule::LTOModule(std::unique_ptr<object::IRObjectFile> Obj,
                      llvm::TargetMachine *TM)
     : IRFile(std::move(Obj)), _target(TM) {}
 
+LTOModule::LTOModule(std::unique_ptr<object::IRObjectFile> Obj,
+                     llvm::TargetMachine *TM,
+                     std::unique_ptr<LLVMContext> Context)
+    : OwnedContext(std::move(Context)), IRFile(std::move(Obj)), _target(TM) {}
+
+LTOModule::~LTOModule() {}
+
 /// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM
 /// bitcode.
-bool LTOModule::isBitcodeFile(const void *mem, size_t length) {
-  return sys::fs::identify_magic(StringRef((const char *)mem, length)) ==
-         sys::fs::file_magic::bitcode;
+bool LTOModule::isBitcodeFile(const void *Mem, size_t Length) {
+  ErrorOr<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer(
+      MemoryBufferRef(StringRef((const char *)Mem, Length), "<mem>"));
+  return bool(BCData);
 }
 
-bool LTOModule::isBitcodeFile(const char *path) {
-  sys::fs::file_magic type;
-  if (sys::fs::identify_magic(path, type))
+bool LTOModule::isBitcodeFile(const char *Path) {
+  ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+      MemoryBuffer::getFile(Path);
+  if (!BufferOrErr)
     return false;
-  return type == sys::fs::file_magic::bitcode;
+
+  ErrorOr<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer(
+      BufferOrErr.get()->getMemBufferRef());
+  return bool(BCData);
 }
 
-bool LTOModule::isBitcodeForTarget(MemoryBuffer *buffer,
-                                   StringRef triplePrefix) {
-  std::string Triple = getBitcodeTargetTriple(buffer, getGlobalContext());
-  return StringRef(Triple).startswith(triplePrefix);
+bool LTOModule::isBitcodeForTarget(MemoryBuffer *Buffer,
+                                   StringRef TriplePrefix) {
+  ErrorOr<MemoryBufferRef> BCOrErr =
+      IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef());
+  if (!BCOrErr)
+    return false;
+  LLVMContext Context;
+  std::string Triple = getBitcodeTargetTriple(*BCOrErr, Context);
+  return StringRef(Triple).startswith(TriplePrefix);
 }
 
 LTOModule *LTOModule::createFromFile(const char *path, TargetOptions options,
@@ -75,7 +97,9 @@ LTOModule *LTOModule::createFromFile(const char *path, TargetOptions options,
     errMsg = EC.message();
     return nullptr;
   }
-  return makeLTOModule(std::move(BufferOrErr.get()), options, errMsg);
+  std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get());
+  return makeLTOModule(Buffer->getMemBufferRef(), options, errMsg,
+                       &getGlobalContext());
 }
 
 LTOModule *LTOModule::createFromOpenFile(int fd, const char *path, size_t size,
@@ -94,23 +118,50 @@ LTOModule *LTOModule::createFromOpenFileSlice(int fd, const char *path,
     errMsg = EC.message();
     return nullptr;
   }
-  return makeLTOModule(std::move(BufferOrErr.get()), options, errMsg);
+  std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get());
+  return makeLTOModule(Buffer->getMemBufferRef(), options, errMsg,
+                       &getGlobalContext());
 }
 
 LTOModule *LTOModule::createFromBuffer(const void *mem, size_t length,
                                        TargetOptions options,
                                        std::string &errMsg, StringRef path) {
-  std::unique_ptr<MemoryBuffer> buffer(makeBuffer(mem, length, path));
-  if (!buffer)
-    return nullptr;
-  return makeLTOModule(std::move(buffer), options, errMsg);
+  return createInContext(mem, length, options, errMsg, path,
+                         &getGlobalContext());
+}
+
+LTOModule *LTOModule::createInLocalContext(const void *mem, size_t length,
+                                           TargetOptions options,
+                                           std::string &errMsg,
+                                           StringRef path) {
+  return createInContext(mem, length, options, errMsg, path, nullptr);
 }
 
-LTOModule *LTOModule::makeLTOModule(std::unique_ptr<MemoryBuffer> Buffer,
-                                    TargetOptions options,
-                                    std::string &errMsg) {
-  ErrorOr<Module *> MOrErr =
-      getLazyBitcodeModule(Buffer.get(), getGlobalContext());
+LTOModule *LTOModule::createInContext(const void *mem, size_t length,
+                                      TargetOptions options,
+                                      std::string &errMsg, StringRef path,
+                                      LLVMContext *Context) {
+  StringRef Data((const char *)mem, length);
+  MemoryBufferRef Buffer(Data, path);
+  return makeLTOModule(Buffer, options, errMsg, Context);
+}
+
+LTOModule *LTOModule::makeLTOModule(MemoryBufferRef Buffer,
+                                    TargetOptions options, std::string &errMsg,
+                                    LLVMContext *Context) {
+  std::unique_ptr<LLVMContext> OwnedContext;
+  if (!Context) {
+    OwnedContext = llvm::make_unique<LLVMContext>();
+    Context = OwnedContext.get();
+  }
+
+  ErrorOr<MemoryBufferRef> MBOrErr =
+      IRObjectFile::findBitcodeInMemBuffer(Buffer);
+  if (std::error_code EC = MBOrErr.getError()) {
+    errMsg = EC.message();
+    return nullptr;
+  }
+  ErrorOr<Module *> MOrErr = parseBitcodeFile(*MBOrErr, *Context);
   if (std::error_code EC = MOrErr.getError()) {
     errMsg = EC.message();
     return nullptr;
@@ -138,20 +189,22 @@ LTOModule *LTOModule::makeLTOModule(std::unique_ptr<MemoryBuffer> Buffer,
       CPU = "core2";
     else if (Triple.getArch() == llvm::Triple::x86)
       CPU = "yonah";
-    else if (Triple.getArch() == llvm::Triple::arm64 ||
-             Triple.getArch() == llvm::Triple::aarch64)
+    else if (Triple.getArch() == llvm::Triple::aarch64)
       CPU = "cyclone";
   }
 
   TargetMachine *target = march->createTargetMachine(TripleStr, CPU, FeatureStr,
                                                      options);
-  M->materializeAllPermanently(true);
-  M->setDataLayout(target->getDataLayout());
+  M->setDataLayout(target->getSubtargetImpl()->getDataLayout());
 
   std::unique_ptr<object::IRObjectFile> IRObj(
-      new object::IRObjectFile(std::move(Buffer), std::move(M)));
+      new object::IRObjectFile(Buffer, std::move(M)));
 
-  LTOModule *Ret = new LTOModule(std::move(IRObj), target);
+  LTOModule *Ret;
+  if (OwnedContext)
+    Ret = new LTOModule(std::move(IRObj), target, std::move(OwnedContext));
+  else
+    Ret = new LTOModule(std::move(IRObj), target);
 
   if (Ret->parseSymbols(errMsg)) {
     delete Ret;
@@ -164,8 +217,8 @@ LTOModule *LTOModule::makeLTOModule(std::unique_ptr<MemoryBuffer> Buffer,
 }
 
 /// Create a MemoryBuffer from a memory range with an optional name.
-MemoryBuffer *LTOModule::makeBuffer(const void *mem, size_t length,
-                                    StringRef name) {
+std::unique_ptr<MemoryBuffer>
+LTOModule::makeBuffer(const void *mem, size_t length, StringRef name) {
   const char *startPtr = (const char*)mem;
   return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), name, false);
 }
@@ -196,27 +249,24 @@ void LTOModule::addObjCClass(const GlobalVariable *clgv) {
   // second slot in __OBJC,__class is pointer to superclass name
   std::string superclassName;
   if (objcClassNameFromExpression(c->getOperand(1), superclassName)) {
-    NameAndAttributes info;
-    StringMap<NameAndAttributes>::value_type &entry =
-      _undefines.GetOrCreateValue(superclassName);
-    if (!entry.getValue().name) {
-      const char *symbolName = entry.getKey().data();
-      info.name = symbolName;
+    auto IterBool =
+        _undefines.insert(std::make_pair(superclassName, NameAndAttributes()));
+    if (IterBool.second) {
+      NameAndAttributes &info = IterBool.first->second;
+      info.name = IterBool.first->first().data();
       info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
       info.isFunction = false;
       info.symbol = clgv;
-      entry.setValue(info);
     }
   }
 
   // third slot in __OBJC,__class is pointer to class name
   std::string className;
   if (objcClassNameFromExpression(c->getOperand(2), className)) {
-    StringSet::value_type &entry = _defines.GetOrCreateValue(className);
-    entry.setValue(1);
+    auto Iter = _defines.insert(className).first;
 
     NameAndAttributes info;
-    info.name = entry.getKey().data();
+    info.name = Iter->first().data();
     info.attributes = LTO_SYMBOL_PERMISSIONS_DATA |
       LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT;
     info.isFunction = false;
@@ -235,19 +285,17 @@ void LTOModule::addObjCCategory(const GlobalVariable *clgv) {
   if (!objcClassNameFromExpression(c->getOperand(1), targetclassName))
     return;
 
-  NameAndAttributes info;
-  StringMap<NameAndAttributes>::value_type &entry =
-    _undefines.GetOrCreateValue(targetclassName);
+  auto IterBool =
+      _undefines.insert(std::make_pair(targetclassName, NameAndAttributes()));
 
-  if (entry.getValue().name)
+  if (!IterBool.second)
     return;
 
-  const char *symbolName = entry.getKey().data();
-  info.name = symbolName;
+  NameAndAttributes &info = IterBool.first->second;
+  info.name = IterBool.first->first().data();
   info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
   info.isFunction = false;
   info.symbol = clgv;
-  entry.setValue(info);
 }
 
 /// addObjCClassRef - Parse i386/ppc ObjC class list data structure.
@@ -256,18 +304,17 @@ void LTOModule::addObjCClassRef(const GlobalVariable *clgv) {
   if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName))
     return;
 
-  NameAndAttributes info;
-  StringMap<NameAndAttributes>::value_type &entry =
-    _undefines.GetOrCreateValue(targetclassName);
-  if (entry.getValue().name)
+  auto IterBool =
+      _undefines.insert(std::make_pair(targetclassName, NameAndAttributes()));
+
+  if (!IterBool.second)
     return;
 
-  const char *symbolName = entry.getKey().data();
-  info.name = symbolName;
+  NameAndAttributes &info = IterBool.first->second;
+  info.name = IterBool.first->first().data();
   info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
   info.isFunction = false;
   info.symbol = clgv;
-  entry.setValue(info);
 }
 
 void LTOModule::addDefinedDataSymbol(const object::BasicSymbolRef &Sym) {
@@ -348,30 +395,6 @@ void LTOModule::addDefinedFunctionSymbol(const char *Name, const Function *F) {
   addDefinedSymbol(Name, F, true);
 }
 
-static bool canBeHidden(const GlobalValue *GV) {
-  // FIXME: this is duplicated with another static function in AsmPrinter.cpp
-  GlobalValue::LinkageTypes L = GV->getLinkage();
-
-  if (L != GlobalValue::LinkOnceODRLinkage)
-    return false;
-
-  if (GV->hasUnnamedAddr())
-    return true;
-
-  // If it is a non constant variable, it needs to be uniqued across shared
-  // objects.
-  if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) {
-    if (!Var->isConstant())
-      return false;
-  }
-
-  GlobalStatus GS;
-  if (GlobalStatus::analyzeGlobal(GV, GS))
-    return false;
-
-  return !GS.IsCompared;
-}
-
 void LTOModule::addDefinedSymbol(const char *Name, const GlobalValue *def,
                                  bool isFunction) {
   // set alignment part log2() can have rounding errors
@@ -405,17 +428,16 @@ void LTOModule::addDefinedSymbol(const char *Name, const GlobalValue *def,
     attr |= LTO_SYMBOL_SCOPE_HIDDEN;
   else if (def->hasProtectedVisibility())
     attr |= LTO_SYMBOL_SCOPE_PROTECTED;
-  else if (canBeHidden(def))
+  else if (canBeOmittedFromSymbolTable(def))
     attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN;
   else
     attr |= LTO_SYMBOL_SCOPE_DEFAULT;
 
-  StringSet::value_type &entry = _defines.GetOrCreateValue(Name);
-  entry.setValue(1);
+  auto Iter = _defines.insert(Name).first;
 
   // fill information structure
   NameAndAttributes info;
-  StringRef NameRef = entry.getKey();
+  StringRef NameRef = Iter->first();
   info.name = NameRef.data();
   assert(info.name[NameRef.size()] == '\0');
   info.attributes = attr;
@@ -430,15 +452,13 @@ void LTOModule::addDefinedSymbol(const char *Name, const GlobalValue *def,
 /// defined list.
 void LTOModule::addAsmGlobalSymbol(const char *name,
                                    lto_symbol_attributes scope) {
-  StringSet::value_type &entry = _defines.GetOrCreateValue(name);
+  auto IterBool = _defines.insert(name);
 
   // only add new define if not already defined
-  if (entry.getValue())
+  if (!IterBool.second)
     return;
 
-  entry.setValue(1);
-
-  NameAndAttributes &info = _undefines[entry.getKey().data()];
+  NameAndAttributes &info = _undefines[IterBool.first->first().data()];
 
   if (info.symbol == nullptr) {
     // FIXME: This is trying to take care of module ASM like this:
@@ -450,7 +470,7 @@ void LTOModule::addAsmGlobalSymbol(const char *name,
     // much.
 
     // fill information structure
-    info.name = entry.getKey().data();
+    info.name = IterBool.first->first().data();
     info.attributes =
       LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope;
     info.isFunction = false;
@@ -473,24 +493,21 @@ void LTOModule::addAsmGlobalSymbol(const char *name,
 /// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the
 /// undefined list.
 void LTOModule::addAsmGlobalSymbolUndef(const char *name) {
-  StringMap<NameAndAttributes>::value_type &entry =
-    _undefines.GetOrCreateValue(name);
+  auto IterBool = _undefines.insert(std::make_pair(name, NameAndAttributes()));
 
-  _asm_undefines.push_back(entry.getKey().data());
+  _asm_undefines.push_back(IterBool.first->first().data());
 
   // we already have the symbol
-  if (entry.getValue().name)
+  if (!IterBool.second)
     return;
 
   uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED;
   attr |= LTO_SYMBOL_SCOPE_DEFAULT;
-  NameAndAttributes info;
-  info.name = entry.getKey().data();
+  NameAndAttributes &info = IterBool.first->second;
+  info.name = IterBool.first->first().data();
   info.attributes = attr;
   info.isFunction = false;
   info.symbol = nullptr;
-
-  entry.setValue(info);
 }
 
 /// Add a symbol which isn't defined just yet to a list to be resolved later.
@@ -502,16 +519,15 @@ void LTOModule::addPotentialUndefinedSymbol(const object::BasicSymbolRef &Sym,
     Sym.printName(OS);
   }
 
-  StringMap<NameAndAttributes>::value_type &entry =
-    _undefines.GetOrCreateValue(name);
+  auto IterBool = _undefines.insert(std::make_pair(name, NameAndAttributes()));
 
   // we already have the symbol
-  if (entry.getValue().name)
+  if (!IterBool.second)
     return;
 
-  NameAndAttributes info;
+  NameAndAttributes &info = IterBool.first->second;
 
-  info.name = entry.getKey().data();
+  info.name = IterBool.first->first().data();
 
   const GlobalValue *decl = IRFile->getSymbolGV(Sym.getRawDataRefImpl());
 
@@ -522,8 +538,6 @@ void LTOModule::addPotentialUndefinedSymbol(const object::BasicSymbolRef &Sym,
 
   info.isFunction = isFunc;
   info.symbol = decl;
-
-  entry.setValue(info);
 }
 
 /// parseSymbols - Parse the symbols from the module and model-level ASM and add
@@ -596,10 +610,15 @@ void LTOModule::parseMetadata() {
       MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
       for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
         MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
-        StringRef Op = _linkeropt_strings.
-            GetOrCreateValue(MDOption->getString()).getKey();
-        StringRef DepLibName = _target->getTargetLowering()->
-            getObjFileLowering().getDepLibFromLinkerOpt(Op);
+        // FIXME: Make StringSet::insert match Self-Associative Container
+        // requirements, returning <iter,bool> rather than bool, and use that
+        // here.
+        StringRef Op =
+            _linkeropt_strings.insert(MDOption->getString()).first->first();
+        StringRef DepLibName = _target->getSubtargetImpl()
+                                   ->getTargetLowering()
+                                   ->getObjFileLowering()
+                                   .getDepLibFromLinkerOpt(Op);
         if (!DepLibName.empty())
           _deplibs.push_back(DepLibName.data());
         else if (!Op.empty())