vendor/clang/clang-trunk-r351319

1 files changed, 455 insertions, 193 deletions

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 8c5e0df0969b8..244738042cef0 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -36,14 +36,15 @@
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/CharInfo.h"
+#include "clang/Basic/CodeGenOptions.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/Module.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/Version.h"
 #include "clang/CodeGen/ConstantInitBuilder.h"
-#include "clang/Frontend/CodeGenOptions.h"
-#include "clang/Sema/SemaDiagnostic.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/IR/CallSite.h"
@@ -53,6 +54,7 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/ProfileData/InstrProfReader.h"
+#include "llvm/Support/CodeGen.h"
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MD5.h"
@@ -124,7 +126,7 @@ CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
 
   RuntimeCC = getTargetCodeGenInfo().getABIInfo().getRuntimeCC();
 
-  if (LangOpts.ObjC1)
+  if (LangOpts.ObjC)
     createObjCRuntime();
   if (LangOpts.OpenCL)
     createOpenCLRuntime();
@@ -147,12 +149,12 @@ CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
 
   Block.GlobalUniqueCount = 0;
 
-  if (C.getLangOpts().ObjC1)
+  if (C.getLangOpts().ObjC)
     ObjCData.reset(new ObjCEntrypoints());
 
   if (CodeGenOpts.hasProfileClangUse()) {
     auto ReaderOrErr = llvm::IndexedInstrProfReader::create(
-        CodeGenOpts.ProfileInstrumentUsePath);
+        CodeGenOpts.ProfileInstrumentUsePath, CodeGenOpts.ProfileRemappingFile);
     if (auto E = ReaderOrErr.takeError()) {
       unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
                                               "Could not read profile %0: %1");
@@ -320,8 +322,6 @@ void CodeGenModule::checkAliases() {
       assert(FTy);
       if (!FTy->getReturnType()->isPointerTy())
         Diags.Report(Location, diag::err_ifunc_resolver_return);
-      if (FTy->getNumParams())
-        Diags.Report(Location, diag::err_ifunc_resolver_params);
     }
 
     llvm::Constant *Aliasee = Alias->getIndirectSymbol();
@@ -458,9 +458,12 @@ void CodeGenModule::Release() {
     // Indicate that we want CodeView in the metadata.
     getModule().addModuleFlag(llvm::Module::Warning, "CodeView", 1);
   }
+  if (CodeGenOpts.CodeViewGHash) {
+    getModule().addModuleFlag(llvm::Module::Warning, "CodeViewGHash", 1);
+  }
   if (CodeGenOpts.ControlFlowGuard) {
     // We want function ID tables for Control Flow Guard.
-    getModule().addModuleFlag(llvm::Module::Warning, "cfguard", 1);
+    getModule().addModuleFlag(llvm::Module::Warning, "cfguardtable", 1);
   }
   if (CodeGenOpts.OptimizationLevel > 0 && CodeGenOpts.StrictVTablePointers) {
     // We don't support LTO with 2 with different StrictVTablePointers
@@ -556,6 +559,20 @@ void CodeGenModule::Release() {
       getModule().setPIELevel(static_cast<llvm::PIELevel::Level>(PLevel));
   }
 
+  if (getCodeGenOpts().CodeModel.size() > 0) {
+    unsigned CM = llvm::StringSwitch<unsigned>(getCodeGenOpts().CodeModel)
+                  .Case("tiny", llvm::CodeModel::Tiny)
+                  .Case("small", llvm::CodeModel::Small)
+                  .Case("kernel", llvm::CodeModel::Kernel)
+                  .Case("medium", llvm::CodeModel::Medium)
+                  .Case("large", llvm::CodeModel::Large)
+                  .Default(~0u);
+    if (CM != ~0u) {
+      llvm::CodeModel::Model codeModel = static_cast<llvm::CodeModel::Model>(CM);
+      getModule().setCodeModel(codeModel);
+    }
+  }
+
   if (CodeGenOpts.NoPLT)
     getModule().setRtLibUseGOT();
 
@@ -573,6 +590,9 @@ void CodeGenModule::Release() {
   if (getCodeGenOpts().EmitVersionIdentMetadata)
     EmitVersionIdentMetadata();
 
+  if (!getCodeGenOpts().RecordCommandLine.empty())
+    EmitCommandLineMetadata();
+
   EmitTargetMetadata();
 }
 
@@ -683,8 +703,8 @@ void CodeGenModule::ErrorUnsupported(const Stmt *S, const char *Type) {
   unsigned DiagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error,
                                                "cannot compile this %0 yet");
   std::string Msg = Type;
-  getDiags().Report(Context.getFullLoc(S->getLocStart()), DiagID)
-    << Msg << S->getSourceRange();
+  getDiags().Report(Context.getFullLoc(S->getBeginLoc()), DiagID)
+      << Msg << S->getSourceRange();
 }
 
 /// ErrorUnsupported - Print out an error that codegen doesn't support the
@@ -730,6 +750,14 @@ static bool shouldAssumeDSOLocal(const CodeGenModule &CGM,
     return false;
 
   const llvm::Triple &TT = CGM.getTriple();
+  if (TT.isWindowsGNUEnvironment()) {
+    // In MinGW, variables without DLLImport can still be automatically
+    // imported from a DLL by the linker; don't mark variables that
+    // potentially could come from another DLL as DSO local.
+    if (GV->isDeclarationForLinker() && isa<llvm::GlobalVariable>(GV) &&
+        !GV->isThreadLocal())
+      return false;
+  }
   // Every other GV is local on COFF.
   // Make an exception for windows OS in the triple: Some firmware builds use
   // *-win32-macho triples. This (accidentally?) produced windows relocations
@@ -869,11 +897,13 @@ static std::string getCPUSpecificMangling(const CodeGenModule &CGM,
 
 static void AppendCPUSpecificCPUDispatchMangling(const CodeGenModule &CGM,
                                                  const CPUSpecificAttr *Attr,
+                                                 unsigned CPUIndex,
                                                  raw_ostream &Out) {
-  // cpu_specific gets the current name, dispatch gets the resolver.
+  // cpu_specific gets the current name, dispatch gets the resolver if IFunc is
+  // supported.
   if (Attr)
-    Out << getCPUSpecificMangling(CGM, Attr->getCurCPUName()->getName());
-  else
+    Out << getCPUSpecificMangling(CGM, Attr->getCPUName(CPUIndex)->getName());
+  else if (CGM.getTarget().supportsIFunc())
     Out << ".resolver";
 }
 
@@ -939,11 +969,19 @@ static std::string getMangledNameImpl(const CodeGenModule &CGM, GlobalDecl GD,
 
   if (const auto *FD = dyn_cast<FunctionDecl>(ND))
     if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
-      if (FD->isCPUDispatchMultiVersion() || FD->isCPUSpecificMultiVersion())
-        AppendCPUSpecificCPUDispatchMangling(
-            CGM, FD->getAttr<CPUSpecificAttr>(), Out);
-      else
+      switch (FD->getMultiVersionKind()) {
+      case MultiVersionKind::CPUDispatch:
+      case MultiVersionKind::CPUSpecific:
+        AppendCPUSpecificCPUDispatchMangling(CGM,
+                                             FD->getAttr<CPUSpecificAttr>(),
+                                             GD.getMultiVersionIndex(), Out);
+        break;
+      case MultiVersionKind::Target:
         AppendTargetMangling(CGM, FD->getAttr<TargetAttr>(), Out);
+        break;
+      case MultiVersionKind::None:
+        llvm_unreachable("None multiversion type isn't valid here");
+      }
     }
 
   return Out.str();
@@ -968,8 +1006,10 @@ void CodeGenModule::UpdateMultiVersionNames(GlobalDecl GD,
            "Other GD should now be a multiversioned function");
     // OtherFD is the version of this function that was mangled BEFORE
     // becoming a MultiVersion function.  It potentially needs to be updated.
-    const FunctionDecl *OtherFD =
-        OtherGD.getCanonicalDecl().getDecl()->getAsFunction();
+    const FunctionDecl *OtherFD = OtherGD.getCanonicalDecl()
+                                      .getDecl()
+                                      ->getAsFunction()
+                                      ->getMostRecentDecl();
     std::string OtherName = getMangledNameImpl(*this, OtherGD, OtherFD);
     // This is so that if the initial version was already the 'default'
     // version, we don't try to update it.
@@ -1001,26 +1041,6 @@ StringRef CodeGenModule::getMangledName(GlobalDecl GD) {
     }
   }
 
-  const auto *FD = dyn_cast<FunctionDecl>(GD.getDecl());
-  // Since CPUSpecific can require multiple emits per decl, store the manglings
-  // separately.
-  if (FD &&
-      (FD->isCPUDispatchMultiVersion() || FD->isCPUSpecificMultiVersion())) {
-    const auto *SD = FD->getAttr<CPUSpecificAttr>();
-
-    std::pair<GlobalDecl, unsigned> SpecCanonicalGD{
-        CanonicalGD,
-        SD ? SD->ActiveArgIndex : std::numeric_limits<unsigned>::max()};
-
-    auto FoundName = CPUSpecificMangledDeclNames.find(SpecCanonicalGD);
-    if (FoundName != CPUSpecificMangledDeclNames.end())
-      return FoundName->second;
-
-    auto Result = CPUSpecificManglings.insert(
-        std::make_pair(getMangledNameImpl(*this, GD, FD), SpecCanonicalGD));
-    return CPUSpecificMangledDeclNames[SpecCanonicalGD] = Result.first->first();
-  }
-
   auto FoundName = MangledDeclNames.find(CanonicalGD);
   if (FoundName != MangledDeclNames.end())
     return FoundName->second;
@@ -1082,11 +1102,12 @@ void CodeGenModule::EmitCtorList(CtorList &Fns, const char *GlobalName) {
 
   // Ctor function type is void()*.
   llvm::FunctionType* CtorFTy = llvm::FunctionType::get(VoidTy, false);
-  llvm::Type *CtorPFTy = llvm::PointerType::getUnqual(CtorFTy);
+  llvm::Type *CtorPFTy = llvm::PointerType::get(CtorFTy,
+      TheModule.getDataLayout().getProgramAddressSpace());
 
   // Get the type of a ctor entry, { i32, void ()*, i8* }.
   llvm::StructType *CtorStructTy = llvm::StructType::get(
-      Int32Ty, llvm::PointerType::getUnqual(CtorFTy), VoidPtrTy);
+      Int32Ty, CtorPFTy, VoidPtrTy);
 
   // Construct the constructor and destructor arrays.
   ConstantInitBuilder builder(*this);
@@ -1142,12 +1163,12 @@ llvm::ConstantInt *CodeGenModule::CreateCrossDsoCfiTypeId(llvm::Metadata *MD) {
   return llvm::ConstantInt::get(Int64Ty, llvm::MD5Hash(MDS->getString()));
 }
 
-void CodeGenModule::SetLLVMFunctionAttributes(const Decl *D,
+void CodeGenModule::SetLLVMFunctionAttributes(GlobalDecl GD,
                                               const CGFunctionInfo &Info,
                                               llvm::Function *F) {
   unsigned CallingConv;
   llvm::AttributeList PAL;
-  ConstructAttributeList(F->getName(), Info, D, PAL, CallingConv, false);
+  ConstructAttributeList(F->getName(), Info, GD, PAL, CallingConv, false);
   F->setAttributes(PAL);
   F->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
 }
@@ -1277,9 +1298,19 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
     // Otherwise, propagate the inline hint attribute and potentially use its
     // absence to mark things as noinline.
     if (auto *FD = dyn_cast<FunctionDecl>(D)) {
-      if (any_of(FD->redecls(), [&](const FunctionDecl *Redecl) {
-            return Redecl->isInlineSpecified();
-          })) {
+      // Search function and template pattern redeclarations for inline.
+      auto CheckForInline = [](const FunctionDecl *FD) {
+        auto CheckRedeclForInline = [](const FunctionDecl *Redecl) {
+          return Redecl->isInlineSpecified();
+        };
+        if (any_of(FD->redecls(), CheckRedeclForInline))
+          return true;
+        const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern();
+        if (!Pattern)
+          return false;
+        return any_of(Pattern->redecls(), CheckRedeclForInline);
+      };
+      if (CheckForInline(FD)) {
         B.addAttribute(llvm::Attribute::InlineHint);
       } else if (CodeGenOpts.getInlining() ==
                      CodeGenOptions::OnlyHintInlining &&
@@ -1350,23 +1381,30 @@ void CodeGenModule::SetCommonAttributes(GlobalDecl GD, llvm::GlobalValue *GV) {
 
   if (D && D->hasAttr<UsedAttr>())
     addUsedGlobal(GV);
+
+  if (CodeGenOpts.KeepStaticConsts && D && isa<VarDecl>(D)) {
+    const auto *VD = cast<VarDecl>(D);
+    if (VD->getType().isConstQualified() &&
+        VD->getStorageDuration() == SD_Static)
+      addUsedGlobal(GV);
+  }
 }
 
-bool CodeGenModule::GetCPUAndFeaturesAttributes(const Decl *D,
+bool CodeGenModule::GetCPUAndFeaturesAttributes(GlobalDecl GD,
                                                 llvm::AttrBuilder &Attrs) {
   // Add target-cpu and target-features attributes to functions. If
   // we have a decl for the function and it has a target attribute then
   // parse that and add it to the feature set.
   StringRef TargetCPU = getTarget().getTargetOpts().CPU;
   std::vector<std::string> Features;
-  const auto *FD = dyn_cast_or_null<FunctionDecl>(D);
+  const auto *FD = dyn_cast_or_null<FunctionDecl>(GD.getDecl());
   FD = FD ? FD->getMostRecentDecl() : FD;
   const auto *TD = FD ? FD->getAttr<TargetAttr>() : nullptr;
   const auto *SD = FD ? FD->getAttr<CPUSpecificAttr>() : nullptr;
   bool AddedAttr = false;
   if (TD || SD) {
     llvm::StringMap<bool> FeatureMap;
-    getFunctionFeatureMap(FeatureMap, FD);
+    getFunctionFeatureMap(FeatureMap, GD);
 
     // Produce the canonical string for this set of features.
     for (const llvm::StringMap<bool>::value_type &Entry : FeatureMap)
@@ -1393,7 +1431,7 @@ bool CodeGenModule::GetCPUAndFeaturesAttributes(const Decl *D,
     AddedAttr = true;
   }
   if (!Features.empty()) {
-    llvm::sort(Features.begin(), Features.end());
+    llvm::sort(Features);
     Attrs.addAttribute("target-features", llvm::join(Features, ","));
     AddedAttr = true;
   }
@@ -1422,7 +1460,7 @@ void CodeGenModule::setNonAliasAttributes(GlobalDecl GD,
           F->addFnAttr("implicit-section-name", SA->getName());
 
       llvm::AttrBuilder Attrs;
-      if (GetCPUAndFeaturesAttributes(D, Attrs)) {
+      if (GetCPUAndFeaturesAttributes(GD, Attrs)) {
         // We know that GetCPUAndFeaturesAttributes will always have the
         // newest set, since it has the newest possible FunctionDecl, so the
         // new ones should replace the old.
@@ -1445,7 +1483,7 @@ void CodeGenModule::SetInternalFunctionAttributes(GlobalDecl GD,
                                                   llvm::Function *F,
                                                   const CGFunctionInfo &FI) {
   const Decl *D = GD.getDecl();
-  SetLLVMFunctionAttributes(D, FI, F);
+  SetLLVMFunctionAttributes(GD, FI, F);
   SetLLVMFunctionAttributesForDefinition(D, F);
 
   F->setLinkage(llvm::Function::InternalLinkage);
@@ -1507,7 +1545,7 @@ void CodeGenModule::SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
   const auto *FD = cast<FunctionDecl>(GD.getDecl());
 
   if (!IsIncompleteFunction) {
-    SetLLVMFunctionAttributes(FD, getTypes().arrangeGlobalDeclaration(GD), F);
+    SetLLVMFunctionAttributes(GD, getTypes().arrangeGlobalDeclaration(GD), F);
     // Setup target-specific attributes.
     if (F->isDeclaration())
       getTargetCodeGenInfo().setTargetAttributes(FD, F, *this);
@@ -1654,6 +1692,8 @@ static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
   // Add linker options to link against the libraries/frameworks
   // described by this module.
   llvm::LLVMContext &Context = CGM.getLLVMContext();
+  bool IsELF = CGM.getTarget().getTriple().isOSBinFormatELF();
+  bool IsPS4 = CGM.getTarget().getTriple().isPS4();
 
   // For modules that use export_as for linking, use that module
   // name instead.
@@ -1673,11 +1713,19 @@ static void addLinkOptionsPostorder(CodeGenModule &CGM, Module *Mod,
     }
 
     // Link against a library.
-    llvm::SmallString<24> Opt;
-    CGM.getTargetCodeGenInfo().getDependentLibraryOption(
-      Mod->LinkLibraries[I-1].Library, Opt);
-    auto *OptString = llvm::MDString::get(Context, Opt);
-    Metadata.push_back(llvm::MDNode::get(Context, OptString));
+    if (IsELF && !IsPS4) {
+      llvm::Metadata *Args[2] = {
+          llvm::MDString::get(Context, "lib"),
+          llvm::MDString::get(Context, Mod->LinkLibraries[I - 1].Library),
+      };
+      Metadata.push_back(llvm::MDNode::get(Context, Args));
+    } else {
+      llvm::SmallString<24> Opt;
+      CGM.getTargetCodeGenInfo().getDependentLibraryOption(
+          Mod->LinkLibraries[I - 1].Library, Opt);
+      auto *OptString = llvm::MDString::get(Context, Opt);
+      Metadata.push_back(llvm::MDNode::get(Context, OptString));
+    }
   }
 }
 
@@ -1708,16 +1756,14 @@ void CodeGenModule::EmitModuleLinkOptions() {
     bool AnyChildren = false;
 
     // Visit the submodules of this module.
-    for (clang::Module::submodule_iterator Sub = Mod->submodule_begin(),
-                                        SubEnd = Mod->submodule_end();
-         Sub != SubEnd; ++Sub) {
+    for (const auto &SM : Mod->submodules()) {
       // Skip explicit children; they need to be explicitly imported to be
       // linked against.
-      if ((*Sub)->IsExplicit)
+      if (SM->IsExplicit)
         continue;
 
-      if (Visited.insert(*Sub).second) {
-        Stack.push_back(*Sub);
+      if (Visited.insert(SM).second) {
+        Stack.push_back(SM);
         AnyChildren = true;
       }
     }
@@ -1747,6 +1793,10 @@ void CodeGenModule::EmitModuleLinkOptions() {
 }
 
 void CodeGenModule::EmitDeferred() {
+  // Emit deferred declare target declarations.
+  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd)
+    getOpenMPRuntime().emitDeferredTargetDecls();
+
   // Emit code for any potentially referenced deferred decls.  Since a
   // previously unused static decl may become used during the generation of code
   // for a static function, iterate until no changes are made.
@@ -1949,9 +1999,6 @@ bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV,
 
 bool CodeGenModule::imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
                                    StringRef Category) const {
-  if (!LangOpts.XRayInstrument)
-    return false;
-
   const auto &XRayFilter = getContext().getXRayFilter();
   using ImbueAttr = XRayFunctionFilter::ImbueAttribute;
   auto Attr = ImbueAttr::NONE;
@@ -1981,6 +2028,13 @@ bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
   if (LangOpts.EmitAllDecls)
     return true;
 
+  if (CodeGenOpts.KeepStaticConsts) {
+    const auto *VD = dyn_cast<VarDecl>(Global);
+    if (VD && VD->getType().isConstQualified() &&
+        VD->getStorageDuration() == SD_Static)
+      return true;
+  }
+
   return getContext().DeclMustBeEmitted(Global);
 }
 
@@ -2000,7 +2054,8 @@ bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
   // codegen for global variables, because they may be marked as threadprivate.
   if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
       getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global) &&
-      !isTypeConstant(Global->getType(), false))
+      !isTypeConstant(Global->getType(), false) &&
+      !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Global))
     return false;
 
   return true;
@@ -2141,16 +2196,22 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
   } else {
     const auto *VD = cast<VarDecl>(Global);
     assert(VD->isFileVarDecl() && "Cannot emit local var decl as global.");
-    // We need to emit device-side global CUDA variables even if a
-    // variable does not have a definition -- we still need to define
-    // host-side shadow for it.
-    bool MustEmitForCuda = LangOpts.CUDA && !LangOpts.CUDAIsDevice &&
-                           !VD->hasDefinition() &&
-                           (VD->hasAttr<CUDAConstantAttr>() ||
-                            VD->hasAttr<CUDADeviceAttr>());
-    if (!MustEmitForCuda &&
-        VD->isThisDeclarationADefinition() != VarDecl::Definition &&
+    if (VD->isThisDeclarationADefinition() != VarDecl::Definition &&
         !Context.isMSStaticDataMemberInlineDefinition(VD)) {
+      if (LangOpts.OpenMP) {
+        // Emit declaration of the must-be-emitted declare target variable.
+        if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
+                OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD)) {
+          if (*Res == OMPDeclareTargetDeclAttr::MT_To) {
+            (void)GetAddrOfGlobalVar(VD);
+          } else {
+            assert(*Res == OMPDeclareTargetDeclAttr::MT_Link &&
+                   "link claue expected.");
+            (void)getOpenMPRuntime().getAddrOfDeclareTargetLink(VD);
+          }
+          return;
+        }
+      }
       // If this declaration may have caused an inline variable definition to
       // change linkage, make sure that it's emitted.
       if (Context.getInlineVariableDefinitionKind(VD) ==
@@ -2360,6 +2421,19 @@ bool CodeGenModule::shouldOpportunisticallyEmitVTables() {
   return CodeGenOpts.OptimizationLevel > 0;
 }
 
+void CodeGenModule::EmitMultiVersionFunctionDefinition(GlobalDecl GD,
+                                                       llvm::GlobalValue *GV) {
+  const auto *FD = cast<FunctionDecl>(GD.getDecl());
+
+  if (FD->isCPUSpecificMultiVersion()) {
+    auto *Spec = FD->getAttr<CPUSpecificAttr>();
+    for (unsigned I = 0; I < Spec->cpus_size(); ++I)
+      EmitGlobalFunctionDefinition(GD.getWithMultiVersionIndex(I), nullptr);
+    // Requires multiple emits.
+  } else
+    EmitGlobalFunctionDefinition(GD, GV);
+}
+
 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
   const auto *D = cast<ValueDecl>(GD.getDecl());
 
@@ -2367,7 +2441,7 @@ void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
                                  Context.getSourceManager(),
                                  "Generating code for declaration");
 
-  if (isa<FunctionDecl>(D)) {
+  if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
     // At -O0, don't generate IR for functions with available_externally
     // linkage.
     if (!shouldEmitFunction(GD))
@@ -2380,6 +2454,8 @@ void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
         ABI->emitCXXStructor(CD, getFromCtorType(GD.getCtorType()));
       else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Method))
         ABI->emitCXXStructor(DD, getFromDtorType(GD.getDtorType()));
+      else if (FD->isMultiVersion())
+        EmitMultiVersionFunctionDefinition(GD, GV);
       else
         EmitGlobalFunctionDefinition(GD, GV);
 
@@ -2389,6 +2465,8 @@ void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
       return;
     }
 
+    if (FD->isMultiVersion())
+      return EmitMultiVersionFunctionDefinition(GD, GV);
     return EmitGlobalFunctionDefinition(GD, GV);
   }
 
@@ -2401,9 +2479,22 @@ void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD, llvm::GlobalValue *GV) {
 static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
                                                       llvm::Function *NewFn);
 
+static unsigned
+TargetMVPriority(const TargetInfo &TI,
+                 const CodeGenFunction::MultiVersionResolverOption &RO) {
+  unsigned Priority = 0;
+  for (StringRef Feat : RO.Conditions.Features)
+    Priority = std::max(Priority, TI.multiVersionSortPriority(Feat));
+
+  if (!RO.Conditions.Architecture.empty())
+    Priority = std::max(
+        Priority, TI.multiVersionSortPriority(RO.Conditions.Architecture));
+  return Priority;
+}
+
 void CodeGenModule::emitMultiVersionFunctions() {
   for (GlobalDecl GD : MultiVersionFuncs) {
-    SmallVector<CodeGenFunction::TargetMultiVersionResolverOption, 10> Options;
+    SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
     const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
     getContext().forEachMultiversionedFunctionVersion(
         FD, [this, &GD, &Options](const FunctionDecl *CurFD) {
@@ -2424,20 +2515,36 @@ void CodeGenModule::emitMultiVersionFunctions() {
             }
             assert(Func && "This should have just been created");
           }
-          Options.emplace_back(getTarget(), cast<llvm::Function>(Func),
-                               CurFD->getAttr<TargetAttr>()->parse());
+
+          const auto *TA = CurFD->getAttr<TargetAttr>();
+          llvm::SmallVector<StringRef, 8> Feats;
+          TA->getAddedFeatures(Feats);
+
+          Options.emplace_back(cast<llvm::Function>(Func),
+                               TA->getArchitecture(), Feats);
         });
 
-    llvm::Function *ResolverFunc = cast<llvm::Function>(
-        GetGlobalValue((getMangledName(GD) + ".resolver").str()));
+    llvm::Function *ResolverFunc;
+    const TargetInfo &TI = getTarget();
+
+    if (TI.supportsIFunc() || FD->isTargetMultiVersion())
+      ResolverFunc = cast<llvm::Function>(
+          GetGlobalValue((getMangledName(GD) + ".resolver").str()));
+    else
+      ResolverFunc = cast<llvm::Function>(GetGlobalValue(getMangledName(GD)));
+
     if (supportsCOMDAT())
       ResolverFunc->setComdat(
           getModule().getOrInsertComdat(ResolverFunc->getName()));
+
     std::stable_sort(
         Options.begin(), Options.end(),
-        std::greater<CodeGenFunction::TargetMultiVersionResolverOption>());
+        [&TI](const CodeGenFunction::MultiVersionResolverOption &LHS,
+              const CodeGenFunction::MultiVersionResolverOption &RHS) {
+          return TargetMVPriority(TI, LHS) > TargetMVPriority(TI, RHS);
+        });
     CodeGenFunction CGF(*this);
-    CGF.EmitTargetMultiVersionResolver(ResolverFunc, Options);
+    CGF.EmitMultiVersionResolver(ResolverFunc, Options);
   }
 }
 
@@ -2446,27 +2553,58 @@ void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
   assert(FD && "Not a FunctionDecl?");
   const auto *DD = FD->getAttr<CPUDispatchAttr>();
   assert(DD && "Not a cpu_dispatch Function?");
-  llvm::Type *DeclTy = getTypes().ConvertTypeForMem(FD->getType());
+  QualType CanonTy = Context.getCanonicalType(FD->getType());
+  llvm::Type *DeclTy = getTypes().ConvertFunctionType(CanonTy, FD);
+
+  if (const auto *CXXFD = dyn_cast<CXXMethodDecl>(FD)) {
+    const CGFunctionInfo &FInfo = getTypes().arrangeCXXMethodDeclaration(CXXFD);
+    DeclTy = getTypes().GetFunctionType(FInfo);
+  }
 
   StringRef ResolverName = getMangledName(GD);
-  llvm::Type *ResolverType = llvm::FunctionType::get(
-      llvm::PointerType::get(DeclTy,
-                             Context.getTargetAddressSpace(FD->getType())),
-      false);
-  auto *ResolverFunc = cast<llvm::Function>(
-      GetOrCreateLLVMFunction(ResolverName, ResolverType, GlobalDecl{},
-                              /*ForVTable=*/false));
-
-  SmallVector<CodeGenFunction::CPUDispatchMultiVersionResolverOption, 10>
-      Options;
+
+  llvm::Type *ResolverType;
+  GlobalDecl ResolverGD;
+  if (getTarget().supportsIFunc())
+    ResolverType = llvm::FunctionType::get(
+        llvm::PointerType::get(DeclTy,
+                               Context.getTargetAddressSpace(FD->getType())),
+        false);
+  else {
+    ResolverType = DeclTy;
+    ResolverGD = GD;
+  }
+
+  auto *ResolverFunc = cast<llvm::Function>(GetOrCreateLLVMFunction(
+      ResolverName, ResolverType, ResolverGD, /*ForVTable=*/false));
+
+  SmallVector<CodeGenFunction::MultiVersionResolverOption, 10> Options;
   const TargetInfo &Target = getTarget();
+  unsigned Index = 0;
   for (const IdentifierInfo *II : DD->cpus()) {
     // Get the name of the target function so we can look it up/create it.
     std::string MangledName = getMangledNameImpl(*this, GD, FD, true) +
                               getCPUSpecificMangling(*this, II->getName());
-    llvm::Constant *Func = GetOrCreateLLVMFunction(
-        MangledName, DeclTy, GD, /*ForVTable=*/false, /*DontDefer=*/false,
-        /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
+
+    llvm::Constant *Func = GetGlobalValue(MangledName);
+
+    if (!Func) {
+      GlobalDecl ExistingDecl = Manglings.lookup(MangledName);
+      if (ExistingDecl.getDecl() &&
+          ExistingDecl.getDecl()->getAsFunction()->isDefined()) {
+        EmitGlobalFunctionDefinition(ExistingDecl, nullptr);
+        Func = GetGlobalValue(MangledName);
+      } else {
+        if (!ExistingDecl.getDecl())
+          ExistingDecl = GD.getWithMultiVersionIndex(Index);
+
+      Func = GetOrCreateLLVMFunction(
+          MangledName, DeclTy, ExistingDecl,
+          /*ForVTable=*/false, /*DontDefer=*/true,
+          /*IsThunk=*/false, llvm::AttributeList(), ForDefinition);
+      }
+    }
+
     llvm::SmallVector<StringRef, 32> Features;
     Target.getCPUSpecificCPUDispatchFeatures(II->getName(), Features);
     llvm::transform(Features, Features.begin(),
@@ -2475,27 +2613,54 @@ void CodeGenModule::emitCPUDispatchDefinition(GlobalDecl GD) {
         Features.begin(), Features.end(), [&Target](StringRef Feat) {
           return !Target.validateCpuSupports(Feat);
         }), Features.end());
-    Options.emplace_back(cast<llvm::Function>(Func),
-                         CodeGenFunction::GetX86CpuSupportsMask(Features));
+    Options.emplace_back(cast<llvm::Function>(Func), StringRef{}, Features);
+    ++Index;
   }
 
   llvm::sort(
-      Options.begin(), Options.end(),
-      std::greater<CodeGenFunction::CPUDispatchMultiVersionResolverOption>());
+      Options, [](const CodeGenFunction::MultiVersionResolverOption &LHS,
+                  const CodeGenFunction::MultiVersionResolverOption &RHS) {
+        return CodeGenFunction::GetX86CpuSupportsMask(LHS.Conditions.Features) >
+               CodeGenFunction::GetX86CpuSupportsMask(RHS.Conditions.Features);
+      });
+
+  // If the list contains multiple 'default' versions, such as when it contains
+  // 'pentium' and 'generic', don't emit the call to the generic one (since we
+  // always run on at least a 'pentium'). We do this by deleting the 'least
+  // advanced' (read, lowest mangling letter).
+  while (Options.size() > 1 &&
+         CodeGenFunction::GetX86CpuSupportsMask(
+             (Options.end() - 2)->Conditions.Features) == 0) {
+    StringRef LHSName = (Options.end() - 2)->Function->getName();
+    StringRef RHSName = (Options.end() - 1)->Function->getName();
+    if (LHSName.compare(RHSName) < 0)
+      Options.erase(Options.end() - 2);
+    else
+      Options.erase(Options.end() - 1);
+  }
+
   CodeGenFunction CGF(*this);
-  CGF.EmitCPUDispatchMultiVersionResolver(ResolverFunc, Options);
+  CGF.EmitMultiVersionResolver(ResolverFunc, Options);
 }
 
-/// If an ifunc for the specified mangled name is not in the module, create and
-/// return an llvm IFunc Function with the specified type.
-llvm::Constant *
-CodeGenModule::GetOrCreateMultiVersionIFunc(GlobalDecl GD, llvm::Type *DeclTy,
-                                            const FunctionDecl *FD) {
+/// If a dispatcher for the specified mangled name is not in the module, create
+/// and return an llvm Function with the specified type.
+llvm::Constant *CodeGenModule::GetOrCreateMultiVersionResolver(
+    GlobalDecl GD, llvm::Type *DeclTy, const FunctionDecl *FD) {
   std::string MangledName =
       getMangledNameImpl(*this, GD, FD, /*OmitMultiVersionMangling=*/true);
-  std::string IFuncName = MangledName + ".ifunc";
-  if (llvm::GlobalValue *IFuncGV = GetGlobalValue(IFuncName))
-    return IFuncGV;
+
+  // Holds the name of the resolver, in ifunc mode this is the ifunc (which has
+  // a separate resolver).
+  std::string ResolverName = MangledName;
+  if (getTarget().supportsIFunc())
+    ResolverName += ".ifunc";
+  else if (FD->isTargetMultiVersion())
+    ResolverName += ".resolver";
+
+  // If this already exists, just return that one.
+  if (llvm::GlobalValue *ResolverGV = GetGlobalValue(ResolverName))
+    return ResolverGV;
 
   // Since this is the first time we've created this IFunc, make sure
   // that we put this multiversioned function into the list to be
@@ -2503,20 +2668,28 @@ CodeGenModule::GetOrCreateMultiVersionIFunc(GlobalDecl GD, llvm::Type *DeclTy,
   if (!FD->isCPUDispatchMultiVersion() && !FD->isCPUSpecificMultiVersion())
     MultiVersionFuncs.push_back(GD);
 
-  std::string ResolverName = MangledName + ".resolver";
-  llvm::Type *ResolverType = llvm::FunctionType::get(
-      llvm::PointerType::get(DeclTy,
-                             Context.getTargetAddressSpace(FD->getType())),
-      false);
-  llvm::Constant *Resolver =
-      GetOrCreateLLVMFunction(ResolverName, ResolverType, GlobalDecl{},
-                              /*ForVTable=*/false);
-  llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
-      DeclTy, 0, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
-  GIF->setName(IFuncName);
-  SetCommonAttributes(FD, GIF);
+  if (getTarget().supportsIFunc()) {
+    llvm::Type *ResolverType = llvm::FunctionType::get(
+        llvm::PointerType::get(
+            DeclTy, getContext().getTargetAddressSpace(FD->getType())),
+        false);
+    llvm::Constant *Resolver = GetOrCreateLLVMFunction(
+        MangledName + ".resolver", ResolverType, GlobalDecl{},
+        /*ForVTable=*/false);
+    llvm::GlobalIFunc *GIF = llvm::GlobalIFunc::create(
+        DeclTy, 0, llvm::Function::ExternalLinkage, "", Resolver, &getModule());
+    GIF->setName(ResolverName);
+    SetCommonAttributes(FD, GIF);
 
-  return GIF;
+    return GIF;
+  }
+
+  llvm::Constant *Resolver = GetOrCreateLLVMFunction(
+      ResolverName, DeclTy, GlobalDecl{}, /*ForVTable=*/false);
+  assert(isa<llvm::GlobalValue>(Resolver) &&
+         "Resolver should be created for the first time");
+  SetCommonAttributes(FD, cast<llvm::GlobalValue>(Resolver));
+  return Resolver;
 }
 
 /// GetOrCreateLLVMFunction - If the specified mangled name is not in the
@@ -2539,15 +2712,16 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
     if (getLangOpts().OpenMPIsDevice && OpenMPRuntime &&
         !OpenMPRuntime->markAsGlobalTarget(GD) && FD->isDefined() &&
         !DontDefer && !IsForDefinition) {
-      const FunctionDecl *FDDef = FD->getDefinition();
-      GlobalDecl GDDef;
-      if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
-        GDDef = GlobalDecl(CD, GD.getCtorType());
-      else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
-        GDDef = GlobalDecl(DD, GD.getDtorType());
-      else
-        GDDef = GlobalDecl(FDDef);
-      addDeferredDeclToEmit(GDDef);
+      if (const FunctionDecl *FDDef = FD->getDefinition()) {
+        GlobalDecl GDDef;
+        if (const auto *CD = dyn_cast<CXXConstructorDecl>(FDDef))
+          GDDef = GlobalDecl(CD, GD.getCtorType());
+        else if (const auto *DD = dyn_cast<CXXDestructorDecl>(FDDef))
+          GDDef = GlobalDecl(DD, GD.getDtorType());
+        else
+          GDDef = GlobalDecl(FDDef);
+        EmitGlobal(GDDef);
+      }
     }
 
     if (FD->isMultiVersion()) {
@@ -2555,7 +2729,7 @@ llvm::Constant *CodeGenModule::GetOrCreateLLVMFunction(
       if (TA && TA->isDefaultVersion())
         UpdateMultiVersionNames(GD, FD);
       if (!IsForDefinition)
-        return GetOrCreateMultiVersionIFunc(GD, Ty, FD);
+        return GetOrCreateMultiVersionResolver(GD, Ty, FD);
     }
   }
 
@@ -3058,10 +3232,9 @@ CodeGenModule::GetAddrOfGlobal(GlobalDecl GD,
                               IsForDefinition);
 }
 
-llvm::GlobalVariable *
-CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
-                                      llvm::Type *Ty,
-                                      llvm::GlobalValue::LinkageTypes Linkage) {
+llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
+    StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
+    unsigned Alignment) {
   llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
   llvm::GlobalVariable *OldGV = nullptr;
 
@@ -3097,6 +3270,8 @@ CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
       !GV->hasAvailableExternallyLinkage())
     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
 
+  GV->setAlignment(Alignment);
+
   return GV;
 }
 
@@ -3313,8 +3488,15 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
   // CUDA E.2.4.1 "__shared__ variables cannot have an initialization
   // as part of their declaration."  Sema has already checked for
   // error cases, so we just need to set Init to UndefValue.
-  if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
-      D->hasAttr<CUDASharedAttr>())
+  bool IsCUDASharedVar =
+      getLangOpts().CUDAIsDevice && D->hasAttr<CUDASharedAttr>();
+  // Shadows of initialized device-side global variables are also left
+  // undefined.
+  bool IsCUDAShadowVar =
+      !getLangOpts().CUDAIsDevice &&
+      (D->hasAttr<CUDAConstantAttr>() || D->hasAttr<CUDADeviceAttr>() ||
+       D->hasAttr<CUDASharedAttr>());
+  if (getLangOpts().CUDA && (IsCUDASharedVar || IsCUDAShadowVar))
     Init = llvm::UndefValue::get(getTypes().ConvertType(ASTTy));
   else if (!InitExpr) {
     // This is a tentative definition; tentative definitions are
@@ -3434,7 +3616,10 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D,
           Flags |= CGCUDARuntime::ExternDeviceVar;
         if (D->hasAttr<CUDAConstantAttr>())
           Flags |= CGCUDARuntime::ConstantDeviceVar;
-        getCUDARuntime().registerDeviceVar(*GV, Flags);
+        // Extern global variables will be registered in the TU where they are
+        // defined.
+        if (!D->hasExternalStorage())
+          getCUDARuntime().registerDeviceVar(*GV, Flags);
       } else if (D->hasAttr<CUDASharedAttr>())
         // __shared__ variables are odd. Shadows do get created, but
         // they are not registered with the CUDA runtime, so they
@@ -3577,6 +3762,15 @@ static bool isVarDeclStrongDefinition(const ASTContext &Context,
     }
   }
 
+  // Microsoft's link.exe doesn't support alignments greater than 32 for common
+  // symbols, so symbols with greater alignment requirements cannot be common.
+  // Other COFF linkers (ld.bfd and LLD) support arbitrary power-of-two
+  // alignments for common symbols via the aligncomm directive, so this
+  // restriction only applies to MSVC environments.
+  if (Context.getTargetInfo().getTriple().isKnownWindowsMSVCEnvironment() &&
+      Context.getTypeAlignIfKnown(D->getType()) > 32)
+    return true;
+
   return false;
 }
 
@@ -3592,6 +3786,10 @@ llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
       return llvm::GlobalVariable::WeakAnyLinkage;
   }
 
+  if (const auto *FD = D->getAsFunction())
+    if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
+      return llvm::GlobalVariable::LinkOnceAnyLinkage;
+
   // We are guaranteed to have a strong definition somewhere else,
   // so we can use available_externally linkage.
   if (Linkage == GVA_AvailableExternally)
@@ -3828,15 +4026,6 @@ void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
     AddGlobalDtor(Fn, DA->getPriority());
   if (D->hasAttr<AnnotateAttr>())
     AddGlobalAnnotations(D, Fn);
-
-  if (D->isCPUSpecificMultiVersion()) {
-    auto *Spec = D->getAttr<CPUSpecificAttr>();
-    // If there is another specific version we need to emit, do so here.
-    if (Spec->ActiveArgIndex + 1 < Spec->cpus_size()) {
-      ++Spec->ActiveArgIndex;
-      EmitGlobalFunctionDefinition(GD, nullptr);
-    }
-  }
 }
 
 void CodeGenModule::EmitAliasDefinition(GlobalDecl GD) {
@@ -4030,39 +4219,81 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
   llvm::Constant *Zeros[] = { Zero, Zero };
 
+  const ASTContext &Context = getContext();
+  const llvm::Triple &Triple = getTriple();
+
+  const auto CFRuntime = getLangOpts().CFRuntime;
+  const bool IsSwiftABI =
+      static_cast<unsigned>(CFRuntime) >=
+      static_cast<unsigned>(LangOptions::CoreFoundationABI::Swift);
+  const bool IsSwift4_1 = CFRuntime == LangOptions::CoreFoundationABI::Swift4_1;
+
   // If we don't already have it, get __CFConstantStringClassReference.
   if (!CFConstantStringClassRef) {
+    const char *CFConstantStringClassName = "__CFConstantStringClassReference";
     llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
     Ty = llvm::ArrayType::get(Ty, 0);
-    llvm::GlobalValue *GV = cast<llvm::GlobalValue>(
-        CreateRuntimeVariable(Ty, "__CFConstantStringClassReference"));
-
-    if (getTriple().isOSBinFormatCOFF()) {
-      IdentifierInfo &II = getContext().Idents.get(GV->getName());
-      TranslationUnitDecl *TUDecl = getContext().getTranslationUnitDecl();
-      DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
-
-      const VarDecl *VD = nullptr;
-      for (const auto &Result : DC->lookup(&II))
-        if ((VD = dyn_cast<VarDecl>(Result)))
-          break;
-
-      if (!VD || !VD->hasAttr<DLLExportAttr>()) {
-        GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
-        GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
-      } else {
-        GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
-        GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
+
+    switch (CFRuntime) {
+    default: break;
+    case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
+    case LangOptions::CoreFoundationABI::Swift5_0:
+      CFConstantStringClassName =
+          Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
+                              : "$s10Foundation19_NSCFConstantStringCN";
+      Ty = IntPtrTy;
+      break;
+    case LangOptions::CoreFoundationABI::Swift4_2:
+      CFConstantStringClassName =
+          Triple.isOSDarwin() ? "$S15SwiftFoundation19_NSCFConstantStringCN"
+                              : "$S10Foundation19_NSCFConstantStringCN";
+      Ty = IntPtrTy;
+      break;
+    case LangOptions::CoreFoundationABI::Swift4_1:
+      CFConstantStringClassName =
+          Triple.isOSDarwin() ? "__T015SwiftFoundation19_NSCFConstantStringCN"
+                              : "__T010Foundation19_NSCFConstantStringCN";
+      Ty = IntPtrTy;
+      break;
+    }
+
+    llvm::Constant *C = CreateRuntimeVariable(Ty, CFConstantStringClassName);
+
+    if (Triple.isOSBinFormatELF() || Triple.isOSBinFormatCOFF()) {
+      llvm::GlobalValue *GV = nullptr;
+
+      if ((GV = dyn_cast<llvm::GlobalValue>(C))) {
+        IdentifierInfo &II = Context.Idents.get(GV->getName());
+        TranslationUnitDecl *TUDecl = Context.getTranslationUnitDecl();
+        DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
+
+        const VarDecl *VD = nullptr;
+        for (const auto &Result : DC->lookup(&II))
+          if ((VD = dyn_cast<VarDecl>(Result)))
+            break;
+
+        if (Triple.isOSBinFormatELF()) {
+          if (!VD)
+            GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
+        } else {
+          GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
+          if (!VD || !VD->hasAttr<DLLExportAttr>())
+            GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
+          else
+            GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
+        }
+
+        setDSOLocal(GV);
       }
     }
-    setDSOLocal(GV);
 
     // Decay array -> ptr
     CFConstantStringClassRef =
-        llvm::ConstantExpr::getGetElementPtr(Ty, GV, Zeros);
+        IsSwiftABI ? llvm::ConstantExpr::getPtrToInt(C, Ty)
+                   : llvm::ConstantExpr::getGetElementPtr(Ty, C, Zeros);
   }
 
-  QualType CFTy = getContext().getCFConstantStringType();
+  QualType CFTy = Context.getCFConstantStringType();
 
   auto *STy = cast<llvm::StructType>(getTypes().ConvertType(CFTy));
 
@@ -4073,7 +4304,12 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   Fields.add(cast<llvm::ConstantExpr>(CFConstantStringClassRef));
 
   // Flags.
-  Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
+  if (IsSwiftABI) {
+    Fields.addInt(IntPtrTy, IsSwift4_1 ? 0x05 : 0x01);
+    Fields.addInt(Int64Ty, isUTF16 ? 0x07d0 : 0x07c8);
+  } else {
+    Fields.addInt(IntTy, isUTF16 ? 0x07d0 : 0x07C8);
+  }
 
   // String pointer.
   llvm::Constant *C = nullptr;
@@ -4094,17 +4330,20 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
   // Don't enforce the target's minimum global alignment, since the only use
   // of the string is via this class initializer.
-  CharUnits Align = isUTF16
-                        ? getContext().getTypeAlignInChars(getContext().ShortTy)
-                        : getContext().getTypeAlignInChars(getContext().CharTy);
+  CharUnits Align = isUTF16 ? Context.getTypeAlignInChars(Context.ShortTy)
+                            : Context.getTypeAlignInChars(Context.CharTy);
   GV->setAlignment(Align.getQuantity());
 
   // FIXME: We set the section explicitly to avoid a bug in ld64 224.1.
   // Without it LLVM can merge the string with a non unnamed_addr one during
   // LTO.  Doing that changes the section it ends in, which surprises ld64.
-  if (getTriple().isOSBinFormatMachO())
+  if (Triple.isOSBinFormatMachO())
     GV->setSection(isUTF16 ? "__TEXT,__ustring"
                            : "__TEXT,__cstring,cstring_literals");
+  // Make sure the literal ends up in .rodata to allow for safe ICF and for
+  // the static linker to adjust permissions to read-only later on.
+  else if (Triple.isOSBinFormatELF())
+    GV->setSection(".rodata");
 
   // String.
   llvm::Constant *Str =
@@ -4116,8 +4355,17 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   Fields.add(Str);
 
   // String length.
-  auto Ty = getTypes().ConvertType(getContext().LongTy);
-  Fields.addInt(cast<llvm::IntegerType>(Ty), StringLength);
+  llvm::IntegerType *LengthTy =
+      llvm::IntegerType::get(getModule().getContext(),
+                             Context.getTargetInfo().getLongWidth());
+  if (IsSwiftABI) {
+    if (CFRuntime == LangOptions::CoreFoundationABI::Swift4_1 ||
+        CFRuntime == LangOptions::CoreFoundationABI::Swift4_2)
+      LengthTy = Int32Ty;
+    else
+      LengthTy = IntPtrTy;
+  }
+  Fields.addInt(LengthTy, StringLength);
 
   CharUnits Alignment = getPointerAlign();
 
@@ -4125,7 +4373,7 @@ CodeGenModule::GetAddrOfConstantCFString(const StringLiteral *Literal) {
   GV = Fields.finishAndCreateGlobal("_unnamed_cfstring_", Alignment,
                                     /*isConstant=*/false,
                                     llvm::GlobalVariable::PrivateLinkage);
-  switch (getTriple().getObjectFormat()) {
+  switch (Triple.getObjectFormat()) {
   case llvm::Triple::UnknownObjectFormat:
     llvm_unreachable("unknown file format");
   case llvm::Triple::COFF:
@@ -4264,15 +4512,13 @@ CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
   StringRef GlobalVariableName;
   llvm::GlobalValue::LinkageTypes LT;
 
-  // Mangle the string literal if the ABI allows for it.  However, we cannot
-  // do this if  we are compiling with ASan or -fwritable-strings because they
-  // rely on strings having normal linkage.
-  if (!LangOpts.WritableStrings &&
-      !LangOpts.Sanitize.has(SanitizerKind::Address) &&
-      getCXXABI().getMangleContext().shouldMangleStringLiteral(S)) {
+  // Mangle the string literal if that's how the ABI merges duplicate strings.
+  // Don't do it if they are writable, since we don't want writes in one TU to
+  // affect strings in another.
+  if (getCXXABI().getMangleContext().shouldMangleStringLiteral(S) &&
+      !LangOpts.WritableStrings) {
     llvm::raw_svector_ostream Out(MangledNameBuffer);
     getCXXABI().getMangleContext().mangleStringLiteral(S, Out);
-
     LT = llvm::GlobalValue::LinkOnceODRLinkage;
     GlobalVariableName = MangledNameBuffer;
   } else {
@@ -4620,6 +4866,7 @@ void CodeGenModule::EmitTopLevelDecl(Decl *D) {
   case Decl::TypeAliasTemplate:
   case Decl::Block:
   case Decl::Empty:
+  case Decl::Binding:
     break;
   case Decl::Using:          // using X; [C++]
     if (CGDebugInfo *DI = getModuleDebugInfo())
@@ -4787,6 +5034,10 @@ void CodeGenModule::EmitTopLevelDecl(Decl *D) {
     EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
     break;
 
+  case Decl::OMPRequires:
+    EmitOMPRequiresDecl(cast<OMPRequiresDecl>(D));
+    break;
+
   default:
     // Make sure we handled everything we should, every other kind is a
     // non-top-level decl.  FIXME: Would be nice to have an isTopLevelDeclKind
@@ -4810,7 +5061,7 @@ void CodeGenModule::AddDeferredUnusedCoverageMapping(Decl *D) {
     if (!cast<FunctionDecl>(D)->doesThisDeclarationHaveABody())
       return;
     SourceManager &SM = getContext().getSourceManager();
-    if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getLocStart()))
+    if (LimitedCoverage && SM.getMainFileID() != SM.getFileID(D->getBeginLoc()))
       return;
     auto I = DeferredEmptyCoverageMappingDecls.find(D);
     if (I == DeferredEmptyCoverageMappingDecls.end())
@@ -4981,6 +5232,16 @@ void CodeGenModule::EmitVersionIdentMetadata() {
   IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
 }
 
+void CodeGenModule::EmitCommandLineMetadata() {
+  llvm::NamedMDNode *CommandLineMetadata =
+    TheModule.getOrInsertNamedMetadata("llvm.commandline");
+  std::string CommandLine = getCodeGenOpts().RecordCommandLine;
+  llvm::LLVMContext &Ctx = TheModule.getContext();
+
+  llvm::Metadata *CommandLineNode[] = {llvm::MDString::get(Ctx, CommandLine)};
+  CommandLineMetadata->addOperand(llvm::MDNode::get(Ctx, CommandLineNode));
+}
+
 void CodeGenModule::EmitTargetMetadata() {
   // Warning, new MangledDeclNames may be appended within this loop.
   // We rely on MapVector insertions adding new elements to the end
@@ -5073,7 +5334,7 @@ void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
 
     Address Addr(GetAddrOfGlobalVar(VD), getContext().getDeclAlign(VD));
     if (auto InitFunction = getOpenMPRuntime().emitThreadPrivateVarDefinition(
-            VD, Addr, RefExpr->getLocStart(), PerformInit))
+            VD, Addr, RefExpr->getBeginLoc(), PerformInit))
       CXXGlobalInits.push_back(InitFunction);
   }
 }
@@ -5196,8 +5457,9 @@ TargetAttr::ParsedTargetAttr CodeGenModule::filterFunctionTargetAttrs(const Targ
 // Fills in the supplied string map with the set of target features for the
 // passed in function.
 void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
-                                          const FunctionDecl *FD) {
+                                          GlobalDecl GD) {
   StringRef TargetCPU = Target.getTargetOpts().CPU;
+  const FunctionDecl *FD = GD.getDecl()->getAsFunction();
   if (const auto *TD = FD->getAttr<TargetAttr>()) {
     TargetAttr::ParsedTargetAttr ParsedAttr = filterFunctionTargetAttrs(TD);
 
@@ -5219,8 +5481,8 @@ void CodeGenModule::getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
                           ParsedAttr.Features);
   } else if (const auto *SD = FD->getAttr<CPUSpecificAttr>()) {
     llvm::SmallVector<StringRef, 32> FeaturesTmp;
-    Target.getCPUSpecificCPUDispatchFeatures(SD->getCurCPUName()->getName(),
-                                             FeaturesTmp);
+    Target.getCPUSpecificCPUDispatchFeatures(
+        SD->getCPUName(GD.getMultiVersionIndex())->getName(), FeaturesTmp);
     std::vector<std::string> Features(FeaturesTmp.begin(), FeaturesTmp.end());
     Target.initFeatureMap(FeatureMap, getDiags(), TargetCPU, Features);
   } else {