diff --git a/bolt/lib/Rewrite/RewriteInstance.cpp b/bolt/lib/Rewrite/RewriteInstance.cpp
@@ -840,6 +840,7 @@ void RewriteInstance::discoverFileObjects() {
       continue;
 
     if (cantFail(Symbol.getType()) == SymbolRef::ST_File) {
+      FileSymbols.emplace_back(Symbol);
       StringRef Name =
           cantFail(std::move(NameOrError), "cannot get symbol name for file");
       // Ignore Clang LTO artificial FILE symbol as it is not always generated,
@@ -1340,6 +1341,7 @@ void RewriteInstance::discoverFileObjects() {
   }
 
   registerFragments();
+  FileSymbols.clear();
 }
 
 Error RewriteInstance::discoverRtFiniAddress() {
@@ -1417,50 +1419,116 @@ void RewriteInstance::registerFragments() {
   if (!BC->HasSplitFunctions)
     return;
 
+  // Process fragments with ambiguous parents separately as they are typically a
+  // vanishing minority of cases and require expensive symbol table lookups.
+  std::vector<std::pair<StringRef, BinaryFunction *>> AmbiguousFragments;
   for (auto &BFI : BC->getBinaryFunctions()) {
     BinaryFunction &Function = BFI.second;
     if (!Function.isFragment())
       continue;
-    unsigned ParentsFound = 0;
     for (StringRef Name : Function.getNames()) {
-      StringRef BaseName, Suffix;
-      std::tie(BaseName, Suffix) = Name.split('/');
+      StringRef BaseName = NR.restore(Name);
+      const bool IsGlobal = BaseName == Name;
       const size_t ColdSuffixPos = BaseName.find(".cold");
       if (ColdSuffixPos == StringRef::npos)
         continue;
-      // For cold function with local (foo.cold/1) symbol, prefer a parent with
-      // local symbol as well (foo/1) over global symbol (foo).
-      std::string ParentName = BaseName.substr(0, ColdSuffixPos).str();
+      StringRef ParentName = BaseName.substr(0, ColdSuffixPos);
       const BinaryData *BD = BC->getBinaryDataByName(ParentName);
-      if (Suffix != "") {
-        ParentName.append(Twine("/", Suffix).str());
-        const BinaryData *BDLocal = BC->getBinaryDataByName(ParentName);
-        if (BDLocal || !BD)
-          BD = BDLocal;
-      }
-      if (!BD) {
-        if (opts::Verbosity >= 1)
-          BC->outs() << "BOLT-INFO: parent function not found for " << Name
-                     << "\n";
+      const uint64_t NumPossibleLocalParents =
+          NR.getUniquifiedNameCount(ParentName);
+      // The most common case: single local parent fragment.
+      if (!BD && NumPossibleLocalParents == 1) {
+        BD = BC->getBinaryDataByName(NR.getUniqueName(ParentName, 1));
+      } else if (BD && (!NumPossibleLocalParents || IsGlobal)) {
+        // Global parent and either no local candidates (second most common), or
+        // the fragment is global as well (uncommon).
+      } else {
+        // Any other case: need to disambiguate using FILE symbols.
+        AmbiguousFragments.emplace_back(ParentName, &Function);
         continue;
       }
-      const uint64_t Address = BD->getAddress();
-      BinaryFunction *BF = BC->getBinaryFunctionAtAddress(Address);
-      if (!BF) {
-        if (opts::Verbosity >= 1)
-          BC->outs() << formatv(
-              "BOLT-INFO: parent function not found at {0:x}\n", Address);
-        continue;
+      if (BD) {
+        BinaryFunction *BF = BC->getFunctionForSymbol(BD->getSymbol());
+        if (BF) {
+          BC->registerFragment(Function, *BF);
+          continue;
+        }
       }
-      BC->registerFragment(Function, *BF);
-      ++ParentsFound;
-    }
-    if (!ParentsFound) {
       BC->errs() << "BOLT-ERROR: parent function not found for " << Function
                  << '\n';
       exit(1);
     }
   }
+
+  if (AmbiguousFragments.empty())
+    return;
+
+  if (!BC->hasSymbolsWithFileName()) {
+    BC->errs() << "BOLT-ERROR: input file has split functions but does not "
+                  "have FILE symbols. If the binary was stripped, preserve "
+                  "FILE symbols with --keep-file-symbols strip option";
+    exit(1);
+  }
+
+  // The first global symbol is identified by the symbol table sh_info value.
+  // Used as local symbol search stopping point.
+  auto *ELF64LEFile = cast<ELF64LEObjectFile>(InputFile);
+  const ELFFile<ELF64LE> &Obj = ELF64LEFile->getELFFile();
+  auto *SymTab = llvm::find_if(cantFail(Obj.sections()), [](const auto &Sec) {
+    return Sec.sh_type == ELF::SHT_SYMTAB;
+  });
+  assert(SymTab);
+  // Symtab sh_info contains the value one greater than the symbol table index
+  // of the last local symbol.
+  ELFSymbolRef LocalSymEnd = ELF64LEFile->toSymbolRef(SymTab, SymTab->sh_info);
+
+  for (auto &[ParentName, BF] : AmbiguousFragments) {
+    const uint64_t Address = BF->getAddress();
+
+    // Get fragment's own symbol
+    const auto SymIt = FileSymRefs.find(Address);
+    if (SymIt == FileSymRefs.end()) {
+      BC->errs()
+          << "BOLT-ERROR: symbol lookup failed for function at address 0x"
+          << Twine::utohexstr(Address) << '\n';
+      exit(1);
+    }
+
+    // Find containing FILE symbol
+    ELFSymbolRef Symbol = SymIt->second;
+    auto FSI = llvm::upper_bound(FileSymbols, Symbol);
+    if (FSI == FileSymbols.begin()) {
+      BC->errs() << "BOLT-ERROR: owning FILE symbol not found for symbol "
+                 << cantFail(Symbol.getName()) << '\n';
+      exit(1);
+    }
+
+    ELFSymbolRef StopSymbol = LocalSymEnd;
+    if (FSI != FileSymbols.end())
+      StopSymbol = *FSI;
+
+    uint64_t ParentAddress{0};
+    // Iterate over local file symbols and check symbol names to match parent.
+    for (ELFSymbolRef Symbol(FSI[-1]); Symbol < StopSymbol; Symbol.moveNext()) {
+      if (cantFail(Symbol.getName()) == ParentName) {
+        ParentAddress = cantFail(Symbol.getAddress());
+        break;
+      }
+    }
+
+    // No local parent is found, use global parent function.
+    if (!ParentAddress)
+      if (BinaryData *ParentBD = BC->getBinaryDataByName(ParentName))
+        ParentAddress = ParentBD->getAddress();
+
+    if (BinaryFunction *ParentBF =
+            BC->getBinaryFunctionAtAddress(ParentAddress)) {
+      BC->registerFragment(*BF, *ParentBF);
+      continue;
+    }
+    BC->errs() << "BOLT-ERROR: parent function not found for " << *BF << '\n';
+    exit(1);
+  }
 }
 
 void RewriteInstance::createPLTBinaryFunction(uint64_t TargetAddress,
@@ -1725,12 +1793,6 @@ void RewriteInstance::adjustFunctionBoundaries() {
       if (!Function.isSymbolValidInScope(Symbol, SymbolSize))
         break;
 
-      // Ignore unnamed symbols. Used, for example, by debugging info on RISC-V.
-      if (BC->isRISCV() && cantFail(Symbol.getName()).empty()) {
-        ++NextSymRefI;
-        continue;
-      }
-
       // Skip basic block labels. This happens on RISC-V with linker relaxation
       // enabled because every branch needs a relocation and corresponding
       // symbol. We don't want to add such symbols as entry points.
@@ -3932,11 +3994,6 @@ void RewriteInstance::patchELFPHDRTable() {
 
   OS.seek(PHDRTableOffset);
 
-  bool ModdedGnuStack = false;
-  (void)ModdedGnuStack;
-  bool AddedSegment = false;
-  (void)AddedSegment;
-
   auto createNewTextPhdr = [&]() {
     ELF64LEPhdrTy NewPhdr;
     NewPhdr.p_type = ELF::PT_LOAD;
@@ -3952,40 +4009,53 @@ void RewriteInstance::patchELFPHDRTable() {
     NewPhdr.p_filesz = NewTextSegmentSize;
     NewPhdr.p_memsz = NewTextSegmentSize;
     NewPhdr.p_flags = ELF::PF_X | ELF::PF_R;
-    // FIXME: Currently instrumentation is experimental and the runtime data
-    // is emitted with code, thus everything needs to be writable
-    if (opts::Instrument)
+    if (opts::Instrument) {
+      // FIXME: Currently instrumentation is experimental and the runtime data
+      // is emitted with code, thus everything needs to be writable.
       NewPhdr.p_flags |= ELF::PF_W;
+    }
     NewPhdr.p_align = BC->PageAlign;
 
     return NewPhdr;
   };
 
-  auto createNewWritableSectionsPhdr = [&]() {
-    ELF64LEPhdrTy NewPhdr;
-    NewPhdr.p_type = ELF::PT_LOAD;
-    NewPhdr.p_offset = getFileOffsetForAddress(NewWritableSegmentAddress);
-    NewPhdr.p_vaddr = NewWritableSegmentAddress;
-    NewPhdr.p_paddr = NewWritableSegmentAddress;
-    NewPhdr.p_filesz = NewWritableSegmentSize;
-    NewPhdr.p_memsz = NewWritableSegmentSize;
-    NewPhdr.p_align = BC->RegularPageSize;
-    NewPhdr.p_flags = ELF::PF_R | ELF::PF_W;
-    return NewPhdr;
+  auto writeNewSegmentPhdrs = [&]() {
+    ELF64LE::Phdr NewTextPhdr = createNewTextPhdr();
+    OS.write(reinterpret_cast<const char *>(&NewTextPhdr), sizeof(NewTextPhdr));
+
+    if (NewWritableSegmentSize) {
+      ELF64LEPhdrTy NewPhdr;
+      NewPhdr.p_type = ELF::PT_LOAD;
+      NewPhdr.p_offset = getFileOffsetForAddress(NewWritableSegmentAddress);
+      NewPhdr.p_vaddr = NewWritableSegmentAddress;
+      NewPhdr.p_paddr = NewWritableSegmentAddress;
+      NewPhdr.p_filesz = NewWritableSegmentSize;
+      NewPhdr.p_memsz = NewWritableSegmentSize;
+      NewPhdr.p_align = BC->RegularPageSize;
+      NewPhdr.p_flags = ELF::PF_R | ELF::PF_W;
+      OS.write(reinterpret_cast<const char *>(&NewPhdr), sizeof(NewPhdr));
+    }
   };
 
+  bool ModdedGnuStack = false;
+  bool AddedSegment = false;
+
   // Copy existing program headers with modifications.
   for (const ELF64LE::Phdr &Phdr : cantFail(Obj.program_headers())) {
     ELF64LE::Phdr NewPhdr = Phdr;
-    if (PHDRTableAddress && Phdr.p_type == ELF::PT_PHDR) {
-      NewPhdr.p_offset = PHDRTableOffset;
-      NewPhdr.p_vaddr = PHDRTableAddress;
-      NewPhdr.p_paddr = PHDRTableAddress;
-      NewPhdr.p_filesz = sizeof(NewPhdr) * Phnum;
-      NewPhdr.p_memsz = sizeof(NewPhdr) * Phnum;
-    } else if (Phdr.p_type == ELF::PT_GNU_EH_FRAME) {
-      ErrorOr<BinarySection &> EHFrameHdrSec =
-          BC->getUniqueSectionByName(getNewSecPrefix() + ".eh_frame_hdr");
+    switch (Phdr.p_type) {
+    case ELF::PT_PHDR:
+      if (PHDRTableAddress) {
+        NewPhdr.p_offset = PHDRTableOffset;
+        NewPhdr.p_vaddr = PHDRTableAddress;
+        NewPhdr.p_paddr = PHDRTableAddress;
+        NewPhdr.p_filesz = sizeof(NewPhdr) * Phnum;
+        NewPhdr.p_memsz = sizeof(NewPhdr) * Phnum;
+      }
+      break;
+    case ELF::PT_GNU_EH_FRAME: {
+      ErrorOr<BinarySection &> EHFrameHdrSec = BC->getUniqueSectionByName(
+          getNewSecPrefix() + getEHFrameHdrSectionName());
       if (EHFrameHdrSec && EHFrameHdrSec->isAllocatable() &&
           EHFrameHdrSec->isFinalized()) {
         NewPhdr.p_offset = EHFrameHdrSec->getOutputFileOffset();
@@ -3994,37 +4064,36 @@ void RewriteInstance::patchELFPHDRTable() {
         NewPhdr.p_filesz = EHFrameHdrSec->getOutputSize();
         NewPhdr.p_memsz = EHFrameHdrSec->getOutputSize();
       }
-    } else if (opts::UseGnuStack && Phdr.p_type == ELF::PT_GNU_STACK) {
-      NewPhdr = createNewTextPhdr();
-      ModdedGnuStack = true;
-    } else if (!opts::UseGnuStack && Phdr.p_type == ELF::PT_DYNAMIC) {
-      // Insert the new header before DYNAMIC.
-      ELF64LE::Phdr NewTextPhdr = createNewTextPhdr();
-      OS.write(reinterpret_cast<const char *>(&NewTextPhdr),
-               sizeof(NewTextPhdr));
-      if (NewWritableSegmentSize) {
-        ELF64LEPhdrTy NewWritablePhdr = createNewWritableSectionsPhdr();
-        OS.write(reinterpret_cast<const char *>(&NewWritablePhdr),
-                 sizeof(NewWritablePhdr));
+      break;
+    }
+    case ELF::PT_GNU_STACK:
+      if (opts::UseGnuStack) {
+        // Overwrite the header with the new text segment header.
+        NewPhdr = createNewTextPhdr();
+        ModdedGnuStack = true;
+      }
+      break;
+    case ELF::PT_DYNAMIC:
+      if (!opts::UseGnuStack) {
+        // Insert new headers before DYNAMIC.
+        writeNewSegmentPhdrs();
+        AddedSegment = true;
       }
-      AddedSegment = true;
+      break;
     }
     OS.write(reinterpret_cast<const char *>(&NewPhdr), sizeof(NewPhdr));
   }
 
   if (!opts::UseGnuStack && !AddedSegment) {
-    // Append the new header to the end of the table.
-    ELF64LE::Phdr NewTextPhdr = createNewTextPhdr();
-    OS.write(reinterpret_cast<const char *>(&NewTextPhdr), sizeof(NewTextPhdr));
-    if (NewWritableSegmentSize) {
-      ELF64LEPhdrTy NewWritablePhdr = createNewWritableSectionsPhdr();
-      OS.write(reinterpret_cast<const char *>(&NewWritablePhdr),
-               sizeof(NewWritablePhdr));
-    }
+    // Append new headers to the end of the table.
+    writeNewSegmentPhdrs();
   }
 
-  assert((!opts::UseGnuStack || ModdedGnuStack) &&
-         "could not find GNU_STACK program header to modify");
+  if (opts::UseGnuStack && !ModdedGnuStack) {
+    BC->errs()
+        << "BOLT-ERROR: could not find PT_GNU_STACK program header to modify\n";
+    exit(1);
+  }
 }
 
 namespace {
@@ -5698,7 +5767,8 @@ void RewriteInstance::writeEHFrameHeader() {
       BC->AsmInfo->getCodePointerSize()));
   check_error(std::move(Er), "failed to parse EH frame");
 
-  LLVM_DEBUG(dbgs() << "BOLT: writing a new .eh_frame_hdr\n");
+  LLVM_DEBUG(dbgs() << "BOLT: writing a new " << getEHFrameHdrSectionName()
+                    << '\n');
 
   NextAvailableAddress =
       appendPadding(Out->os(), NextAvailableAddress, EHFrameHdrAlign);
@@ -5716,16 +5786,17 @@ void RewriteInstance::writeEHFrameHeader() {
   const unsigned Flags = BinarySection::getFlags(/*IsReadOnly=*/true,
                                                  /*IsText=*/false,
                                                  /*IsAllocatable=*/true);
-  BinarySection *OldEHFrameHdrSection = getSection(".eh_frame_hdr");
+  BinarySection *OldEHFrameHdrSection = getSection(getEHFrameHdrSectionName());
   if (OldEHFrameHdrSection)
-    OldEHFrameHdrSection->setOutputName(getOrgSecPrefix() + ".eh_frame_hdr");
+    OldEHFrameHdrSection->setOutputName(getOrgSecPrefix() +
+                                        getEHFrameHdrSectionName());
 
   BinarySection &EHFrameHdrSec = BC->registerOrUpdateSection(
-      getNewSecPrefix() + ".eh_frame_hdr", ELF::SHT_PROGBITS, Flags, nullptr,
-      NewEHFrameHdr.size(), /*Alignment=*/1);
+      getNewSecPrefix() + getEHFrameHdrSectionName(), ELF::SHT_PROGBITS, Flags,
+      nullptr, NewEHFrameHdr.size(), /*Alignment=*/1);
   EHFrameHdrSec.setOutputFileOffset(EHFrameHdrFileOffset);
   EHFrameHdrSec.setOutputAddress(EHFrameHdrOutputAddress);
-  EHFrameHdrSec.setOutputName(".eh_frame_hdr");
+  EHFrameHdrSec.setOutputName(getEHFrameHdrSectionName());
 
   NextAvailableAddress += EHFrameHdrSec.getOutputSize();
 

diff --git a/bolt/test/RISCV/unnamed-sym-no-entry.c → bolt/test/RISCV/fake-label-no-entry.c b/bolt/test/RISCV/unnamed-sym-no-entry.c → bolt/test/RISCV/fake-label-no-entry.c
@@ -5,12 +5,12 @@
 
 // RUN: %clang %cflags -g -Wl,-q -o %t %s
 
-/// Verify that the binary indeed contains an unnamed symbol at _start
+/// Verify that the binary indeed contains a fake label ".L0 " at _start.
 // RUN: llvm-readelf -s %t | FileCheck %s --check-prefix=CHECK-ELF
 // CHECK-ELF-DAG: [[#%x,START:]] {{.*}} FUNC GLOBAL DEFAULT [[#%d,SECTION:]] _start{{$}}
 // CHECK-ELF-DAG: [[#%x,START]] {{.*}} NOTYPE LOCAL DEFAULT [[#SECTION]] .L0 {{$}}
 
-/// Verify that BOLT did not create an extra entry point for the unnamed symbol
+/// Verify that BOLT did not create an extra entry point for the fake label.
 // RUN: llvm-bolt -o %t.bolt %t --print-cfg | FileCheck %s
 // CHECK: Binary Function "_start" after building cfg {
 // CHECK:  IsMultiEntry: 0

diff --git a/bolt/test/X86/fragment-lite.s b/bolt/test/X86/fragment-lite.s
@@ -3,35 +3,42 @@
 # RUN: split-file %s %t
 # RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %t/main.s -o %t.o
 # RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %t/baz.s -o %t.baz.o
+# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-unknown %t/baz2.s -o %t.baz2.o
 # RUN: link_fdata %s %t.o %t.main.fdata
 # RUN: link_fdata %s %t.baz.o %t.baz.fdata
-# RUN: merge-fdata %t.main.fdata %t.baz.fdata > %t.fdata
-# RUN: %clang %cflags %t.o %t.baz.o -o %t.exe -Wl,-q
+# RUN: link_fdata %s %t.baz2.o %t.baz2.fdata
+# RUN: merge-fdata %t.main.fdata %t.baz.fdata %t.baz2.fdata > %t.fdata
+# RUN: %clang %cflags %t.o %t.baz.o %t.baz2.o -o %t.exe -Wl,-q
 # RUN: llvm-bolt %t.exe -o %t.out --lite=1 --data %t.fdata -v=1 -print-cfg \
 # RUN:   2>&1 | FileCheck %s
 
 # CHECK: BOLT-INFO: processing main.cold.1 as a sibling of non-ignored function
-# CHECK: BOLT-INFO: processing foo.cold.1/1 as a sibling of non-ignored function
-# CHECK: BOLT-INFO: processing bar.cold.1/1 as a sibling of non-ignored function
+# CHECK: BOLT-INFO: processing foo.cold.1/1(*2) as a sibling of non-ignored function
+# CHECK: BOLT-INFO: processing bar.cold.1/1(*2) as a sibling of non-ignored function
 # CHECK: BOLT-INFO: processing baz.cold.1 as a sibling of non-ignored function
-# CHECK: BOLT-INFO: processing baz.cold.1/1 as a sibling of non-ignored function
+# CHECK: BOLT-INFO: processing baz.cold.1/1(*2) as a sibling of non-ignored function
+# CHECK: BOLT-INFO: processing baz.cold.1/2(*2) as a sibling of non-ignored function
 
 # CHECK: Binary Function "main.cold.1" after building cfg
 # CHECK: Parent : main
 
-# CHECK: Binary Function "foo.cold.1/1" after building cfg
+# CHECK: Binary Function "foo.cold.1/1(*2)" after building cfg
 # CHECK: Parent : foo
 
-# CHECK: Binary Function "bar.cold.1/1" after building cfg
-# CHECK: Parent : bar/1
+# CHECK: Binary Function "bar.cold.1/1(*2)" after building cfg
+# CHECK: Parent : bar/1(*2)
 
 # CHECK: Binary Function "baz.cold.1" after building cfg
 # CHECK: Parent : baz{{$}}
 
-# CHECK: Binary Function "baz.cold.1/1" after building cfg
-# CHECK: Parent : baz/1
+# CHECK: Binary Function "baz.cold.1/1(*2)" after building cfg
+# CHECK: Parent : baz/1(*2)
+
+# CHECK: Binary Function "baz.cold.1/2(*2)" after building cfg
+# CHECK: Parent : baz/2(*2)
 
 #--- main.s
+.file "main.s"
   .globl main
   .type main, %function
 main:
@@ -126,6 +133,7 @@ baz.cold.1:
 .size baz.cold.1, .-baz.cold.1
 
 #--- baz.s
+.file "baz.s"
   .local baz
   .type baz, %function
 baz:
@@ -149,3 +157,29 @@ baz.cold.1:
   retq
   .cfi_endproc
 .size baz.cold.1, .-baz.cold.1
+
+#--- baz2.s
+.file "baz2.s"
+  .local baz
+  .type baz, %function
+baz:
+  .cfi_startproc
+# FDATA: 0 [unknown] 0 1 baz/2 0 1 0
+  cmpl	$0x0, %eax
+  je	baz.cold.1
+  retq
+  .cfi_endproc
+.size baz, .-baz
+
+  .section .text.cold
+  .local baz.cold.1
+  .type baz.cold.1, %function
+baz.cold.1:
+  .cfi_startproc
+  pushq	%rbp
+  movq	%rsp, %rbp
+  movl	$0x0, %eax
+  popq	%rbp
+  retq
+  .cfi_endproc
+.size baz.cold.1, .-baz.cold.1
diff --git a/clang-tools-extra/clang-tidy/bugprone/EasilySwappableParametersCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/EasilySwappableParametersCheck.cpp
@@ -967,7 +967,8 @@ approximateStandardConversionSequence(const TheCheck &Check, QualType From,
   // Get out the qualifiers of the original type. This will always be
   // re-applied to the WorkType to ensure it is the same qualification as the
   // original From was.
-  auto QualifiersToApply = From.split().Quals.getAsOpaqueValue();
+  auto FastQualifiersToApply = static_cast<unsigned>(
+      From.split().Quals.getAsOpaqueValue() & Qualifiers::FastMask);
 
   // LValue->RValue is irrelevant for the check, because it is a thing to be
   // done at a call site, and will be performed if need be performed.
@@ -993,7 +994,7 @@ approximateStandardConversionSequence(const TheCheck &Check, QualType From,
     // "const double -> double".
     LLVM_DEBUG(llvm::dbgs()
                << "--- approximateStdConv. Conversion between numerics.\n");
-    WorkType = QualType{ToBuiltin, QualifiersToApply};
+    WorkType = QualType{ToBuiltin, FastQualifiersToApply};
   }
 
   const auto *FromEnum = WorkType->getAs<EnumType>();
@@ -1002,7 +1003,7 @@ approximateStandardConversionSequence(const TheCheck &Check, QualType From,
     // Unscoped enumerations (or enumerations in C) convert to numerics.
     LLVM_DEBUG(llvm::dbgs()
                << "--- approximateStdConv. Unscoped enum to numeric.\n");
-    WorkType = QualType{ToBuiltin, QualifiersToApply};
+    WorkType = QualType{ToBuiltin, FastQualifiersToApply};
   } else if (FromNumeric && ToEnum && ToEnum->isUnscopedEnumerationType()) {
     // Numeric types convert to enumerations only in C.
     if (Ctx.getLangOpts().CPlusPlus) {
@@ -1013,7 +1014,7 @@ approximateStandardConversionSequence(const TheCheck &Check, QualType From,
 
     LLVM_DEBUG(llvm::dbgs()
                << "--- approximateStdConv. Numeric to unscoped enum.\n");
-    WorkType = QualType{ToEnum, QualifiersToApply};
+    WorkType = QualType{ToEnum, FastQualifiersToApply};
   }
 
   // Check for pointer conversions.
@@ -1022,14 +1023,14 @@ approximateStandardConversionSequence(const TheCheck &Check, QualType From,
   if (FromPtr && ToPtr) {
     if (ToPtr->isVoidPointerType()) {
       LLVM_DEBUG(llvm::dbgs() << "--- approximateStdConv. To void pointer.\n");
-      WorkType = QualType{ToPtr, QualifiersToApply};
+      WorkType = QualType{ToPtr, FastQualifiersToApply};
     }
 
     const auto *FromRecordPtr = FromPtr->getPointeeCXXRecordDecl();
     const auto *ToRecordPtr = ToPtr->getPointeeCXXRecordDecl();
     if (isDerivedToBase(FromRecordPtr, ToRecordPtr)) {
       LLVM_DEBUG(llvm::dbgs() << "--- approximateStdConv. Derived* to Base*\n");
-      WorkType = QualType{ToPtr, QualifiersToApply};
+      WorkType = QualType{ToPtr, FastQualifiersToApply};
     }
   }
 
@@ -1039,7 +1040,7 @@ approximateStandardConversionSequence(const TheCheck &Check, QualType From,
   const auto *ToRecord = To->getAsCXXRecordDecl();
   if (isDerivedToBase(FromRecord, ToRecord)) {
     LLVM_DEBUG(llvm::dbgs() << "--- approximateStdConv. Derived To Base.\n");
-    WorkType = QualType{ToRecord->getTypeForDecl(), QualifiersToApply};
+    WorkType = QualType{ToRecord->getTypeForDecl(), FastQualifiersToApply};
   }
 
   if (Ctx.getLangOpts().CPlusPlus17 && FromPtr && ToPtr) {
@@ -1054,7 +1055,7 @@ approximateStandardConversionSequence(const TheCheck &Check, QualType From,
         !ToFunctionPtr->hasNoexceptExceptionSpec()) {
       LLVM_DEBUG(llvm::dbgs() << "--- approximateStdConv. noexcept function "
                                  "pointer to non-noexcept.\n");
-      WorkType = QualType{ToPtr, QualifiersToApply};
+      WorkType = QualType{ToPtr, FastQualifiersToApply};
     }
   }
 

diff --git a/clang-tools-extra/clang-tidy/modernize/UseNullptrCheck.h b/clang-tools-extra/clang-tidy/modernize/UseNullptrCheck.h
@@ -19,7 +19,7 @@ class UseNullptrCheck : public ClangTidyCheck {
   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
     // FIXME this should be CPlusPlus11 but that causes test cases to
     // erroneously fail.
-    return LangOpts.CPlusPlus;
+    return LangOpts.CPlusPlus || LangOpts.C23;
   }
   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;

diff --git a/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp b/clang-tools-extra/clang-tidy/readability/AvoidReturnWithVoidValueCheck.cpp
@@ -64,8 +64,11 @@ void AvoidReturnWithVoidValueCheck::check(
            << BraceInsertionHints.closingBraceFixIt();
   }
   Diag << FixItHint::CreateRemoval(VoidReturn->getReturnLoc());
-  if (!Result.Nodes.getNodeAs<FunctionDecl>("function_parent") ||
-      SurroundingBlock->body_back() != VoidReturn)
+  const auto *FunctionParent =
+      Result.Nodes.getNodeAs<FunctionDecl>("function_parent");
+  if (!FunctionParent ||
+      (SurroundingBlock && SurroundingBlock->body_back() != VoidReturn))
+    // If this is not the last statement in a function body, we add a `return`.
     Diag << FixItHint::CreateInsertion(SemicolonPos.getLocWithOffset(1),
                                        " return;", true);
 }

diff --git a/clang-tools-extra/clangd/CodeCompletionStrings.cpp b/clang-tools-extra/clangd/CodeCompletionStrings.cpp
@@ -253,7 +253,7 @@ void getSignature(const CodeCompletionString &CCS, std::string *Signature,
       if (!IncludeFunctionArguments &&
           ResultKind == CodeCompletionResult::RK_Declaration)
         TruncateSnippetAt.emplace(Snippet->size());
-      LLVM_FALLTHROUGH;
+      [[fallthrough]];
     case CodeCompletionString::CK_RightParen:
     case CodeCompletionString::CK_LeftBracket:
     case CodeCompletionString::CK_RightBracket:

diff --git a/clang-tools-extra/clangd/unittests/FindTargetTests.cpp b/clang-tools-extra/clangd/unittests/FindTargetTests.cpp
@@ -854,7 +854,7 @@ TEST_F(TargetDeclTest, DependentExprs) {
           }
         };
       )cpp";
-  EXPECT_DECLS("MemberExpr", "void foo()");
+  EXPECT_DECLS("CXXDependentScopeMemberExpr", "void foo()");
 
   // Similar to above but base expression involves a function call.
   Code = R"cpp(
@@ -872,7 +872,7 @@ TEST_F(TargetDeclTest, DependentExprs) {
           }
         };
       )cpp";
-  EXPECT_DECLS("MemberExpr", "void foo()");
+  EXPECT_DECLS("CXXDependentScopeMemberExpr", "void foo()");
 
   // Similar to above but uses a function pointer.
   Code = R"cpp(
@@ -891,7 +891,7 @@ TEST_F(TargetDeclTest, DependentExprs) {
           }
         };
       )cpp";
-  EXPECT_DECLS("MemberExpr", "void foo()");
+  EXPECT_DECLS("CXXDependentScopeMemberExpr", "void foo()");
 
   // Base expression involves a member access into this.
   Code = R"cpp(
@@ -962,7 +962,7 @@ TEST_F(TargetDeclTest, DependentExprs) {
           void Foo() { this->[[find]](); }
         };
   )cpp";
-  EXPECT_DECLS("MemberExpr", "void find()");
+  EXPECT_DECLS("CXXDependentScopeMemberExpr", "void find()");
 }
 
 TEST_F(TargetDeclTest, DependentTypes) {

diff --git a/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp b/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
@@ -621,7 +621,7 @@ sizeof...($TemplateParameter[[Elements]]);
       struct $Class_def[[Foo]] {
         int $Field_decl[[Waldo]];
         void $Method_def[[bar]]() {
-          $Class[[Foo]]().$Field[[Waldo]];
+          $Class[[Foo]]().$Field_dependentName[[Waldo]];
         }
         template $Bracket[[<]]typename $TemplateParameter_def[[U]]$Bracket[[>]]
         void $Method_def[[bar1]]() {

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -100,13 +100,15 @@ Improvements to clang-tidy
 - Improved :program:`run-clang-tidy.py` script. Added argument `-source-filter`
   to filter source files from the compilation database, via a RegEx. In a
   similar fashion to what `-header-filter` does for header files.
+
 - Improved :program:`check_clang_tidy.py` script. Added argument `-export-fixes`
   to aid in clang-tidy and test development.
+
 - Fixed bug where big values for unsigned check options overflowed into negative values
-  when being printed with ``--dump-config``.
+  when being printed with `--dump-config`.
 
-- Fixed ``--verify-config`` option not properly parsing checks when using the 
-  literal operator in the ``.clang-tidy`` config.
+- Fixed `--verify-config` option not properly parsing checks when using the
+  literal operator in the `.clang-tidy` config.
 
 New checks
 ^^^^^^^^^^
@@ -236,7 +238,7 @@ Changes in existing checks
 
 - Improved :doc:`google-explicit-constructor
   <clang-tidy/checks/google/explicit-constructor>` check to better handle
-  ``C++-20`` `explicit(bool)`.
+  C++20 `explicit(bool)`.
 
 - Improved :doc:`google-global-names-in-headers
   <clang-tidy/checks/google/global-names-in-headers>` check by replacing the local
@@ -249,6 +251,10 @@ Changes in existing checks
   check by ignoring other functions with same prefixes as the target specific
   functions.
 
+- Improved :doc:`linuxkernel-must-check-errs
+  <clang-tidy/checks/linuxkernel/must-check-errs>` check documentation to
+  consistently use the check's proper name.
+
 - Improved :doc:`llvm-header-guard
   <clang-tidy/checks/llvm/header-guard>` check by replacing the local
   option `HeaderFileExtensions` by the global option of the same name.
@@ -281,6 +287,10 @@ Changes in existing checks
   don't remove parentheses used in ``sizeof`` calls when they have array index
   accesses as arguments.
 
+- Improved :doc:`modernize-use-nullptr
+  <clang-tidy/checks/modernize/use-nullptr>` check to include support for C23,
+  which also has introduced the ``nullptr`` keyword.
+
 - Improved :doc:`modernize-use-override
   <clang-tidy/checks/modernize/use-override>` check to also remove any trailing
   whitespace when deleting the ``virtual`` keyword.
@@ -336,13 +346,9 @@ Miscellaneous
 ^^^^^^^^^^^^^
 
 - Fixed incorrect formatting in :program:`clang-apply-replacements` when no
-  ``--format`` option is specified. Now :program:`clang-apply-replacements`
+  `--format` option is specified. Now :program:`clang-apply-replacements`
   applies formatting only with the option.
 
-- Fixed the :doc:`linuxkernel-must-check-errs
-  <clang-tidy/checks/linuxkernel/must-check-errs>` documentation to consistently
-  use the check's proper name.
-
 Improvements to include-fixer
 -----------------------------
 

diff --git a/clang-tools-extra/docs/clang-tidy/checks/cert/env33-c.rst b/clang-tools-extra/docs/clang-tidy/checks/cert/env33-c.rst
@@ -10,4 +10,4 @@ but does not actually attempt to execute a command.
 
 This check corresponds to the CERT C Coding Standard rule
 `ENV33-C. Do not call system()
-<https://www.securecoding.cert.org/confluence/pages/viewpage.action?pageId=2130132>`_.
+<https://www.securecoding.cert.org/confluence/display/c/ENV33-C.+Do+not+call+system()>`_.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/use-nullptr.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/use-nullptr.rst
@@ -4,7 +4,7 @@ modernize-use-nullptr
 =====================
 
 The check converts the usage of null pointer constants (e.g. ``NULL``, ``0``)
-to use the new C++11 ``nullptr`` keyword.
+to use the new C++11 and C23 ``nullptr`` keyword.
 
 Example
 -------

diff --git a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/owning-memory.cpp b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/owning-memory.cpp
@@ -309,8 +309,6 @@ struct HeapArray {                                          // Ok, since destruc
 
   HeapArray(HeapArray &&other) : _data(other._data), size(other.size) { // Ok
     other._data = nullptr;                                              // Ok
-    // CHECK-NOTES: [[@LINE-1]]:5: warning: expected assignment source to be of type 'gsl::owner<>'; got 'std::nullptr_t'
-    // FIXME: This warning is emitted because an ImplicitCastExpr for the NullToPointer conversion isn't created for dependent types.
     other.size = 0;
   }
 

diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-copy.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-equals-default-copy.cpp
@@ -260,8 +260,6 @@ template <class T>
 struct Template {
   Template() = default;
   Template(const Template &Other) : Field(Other.Field) {}
-  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use '= default'
-  // CHECK-FIXES: Template(const Template &Other)  = default;
   Template &operator=(const Template &Other);
   void foo(const T &t);
   int Field;
@@ -271,12 +269,8 @@ Template<T> &Template<T>::operator=(const Template<T> &Other) {
   Field = Other.Field;
   return *this;
 }
-// CHECK-MESSAGES: :[[@LINE-4]]:27: warning: use '= default'
-// CHECK-FIXES: Template<T> &Template<T>::operator=(const Template<T> &Other) = default;
-
 Template<int> T1;
 
-
 // Dependent types.
 template <class T>
 struct DT1 {
@@ -290,9 +284,6 @@ DT1<T> &DT1<T>::operator=(const DT1<T> &Other) {
   Field = Other.Field;
   return *this;
 }
-// CHECK-MESSAGES: :[[@LINE-4]]:17: warning: use '= default'
-// CHECK-FIXES: DT1<T> &DT1<T>::operator=(const DT1<T> &Other) = default;
-
 DT1<int> Dt1;
 
 template <class T>
@@ -312,9 +303,6 @@ DT2<T> &DT2<T>::operator=(const DT2<T> &Other) {
 struct T {
   typedef int TT;
 };
-// CHECK-MESSAGES: :[[@LINE-8]]:17: warning: use '= default'
-// CHECK-FIXES: DT2<T> &DT2<T>::operator=(const DT2<T> &Other) = default;
-
 DT2<T> Dt2;
 
 // Default arguments.

diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-nullptr-c23.c b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-nullptr-c23.c
@@ -0,0 +1,139 @@
+// RUN: %check_clang_tidy %s modernize-use-nullptr %t -- -- -std=c23
+
+#define NULL 0
+
+void test_assignment() {
+  int *p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr [modernize-use-nullptr]
+  // CHECK-FIXES: int *p1 = nullptr;
+  p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use nullptr
+  // CHECK-FIXES: p1 = nullptr;
+
+  int *p2 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+  // CHECK-FIXES: int *p2 = nullptr;
+
+  p2 = p1;
+  // CHECK-FIXES: p2 = p1;
+
+  const int null = 0;
+  int *p3 = &null;
+
+  p3 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: use nullptr
+  // CHECK-FIXES: p3 = nullptr;
+
+  int *p4 = p3;
+
+  int i1 = 0;
+
+  int i2 = NULL;
+
+  int i3 = null;
+
+  int *p5, *p6, *p7;
+  p5 = p6 = p7 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: use nullptr
+  // CHECK-FIXES: p5 = p6 = p7 = nullptr;
+}
+
+void test_function(int *p) {}
+
+void test_function_no_ptr_param(int i) {}
+
+void test_function_call() {
+  test_function(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use nullptr
+  // CHECK-FIXES: test_function(nullptr);
+
+  test_function(NULL);
+  // CHECK-MESSAGES: :[[@LINE-1]]:17: warning: use nullptr
+  // CHECK-FIXES: test_function(nullptr);
+
+  test_function_no_ptr_param(0);
+}
+
+char *test_function_return1() {
+  return 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+void *test_function_return2() {
+  return NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+int test_function_return4() {
+  return 0;
+}
+
+int test_function_return5() {
+  return NULL;
+}
+
+int *test_function_return_cast1() {
+  return(int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: use nullptr
+  // CHECK-FIXES: return nullptr;
+}
+
+int *test_function_return_cast2() {
+#define RET return
+  RET(int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: use nullptr
+  // CHECK-FIXES: RET nullptr;
+#undef RET
+}
+
+// Test parentheses expressions resulting in a nullptr.
+int *test_parentheses_expression1() {
+  return(0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return(nullptr);
+}
+
+int *test_parentheses_expression2() {
+  return((int)(0.0f));
+  // CHECK-MESSAGES: :[[@LINE-1]]:10: warning: use nullptr
+  // CHECK-FIXES: return(nullptr);
+}
+
+int *test_nested_parentheses_expression() {
+  return((((0))));
+  // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: use nullptr
+  // CHECK-FIXES: return((((nullptr))));
+}
+
+void test_const_pointers() {
+  const int *const_p1 = 0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p1 = nullptr;
+  const int *const_p2 = NULL;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p2 = nullptr;
+  const int *const_p3 = (int)0;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p3 = nullptr;
+  const int *const_p4 = (int)0.0f;
+  // CHECK-MESSAGES: :[[@LINE-1]]:25: warning: use nullptr
+  // CHECK-FIXES: const int *const_p4 = nullptr;
+}
+
+void test_nested_implicit_cast_expr() {
+  int func0(void*, void*);
+  int func1(int, void*, void*);
+
+  (double)func1(0, 0, 0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: use nullptr
+  // CHECK-MESSAGES: :[[@LINE-2]]:23: warning: use nullptr
+  // CHECK-FIXES: (double)func1(0, nullptr, nullptr);
+  (double)func1(func0(0, 0), 0, 0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:23: warning: use nullptr
+  // CHECK-MESSAGES: :[[@LINE-2]]:26: warning: use nullptr
+  // CHECK-MESSAGES: :[[@LINE-3]]:30: warning: use nullptr
+  // CHECK-MESSAGES: :[[@LINE-4]]:33: warning: use nullptr
+  // CHECK-FIXES: (double)func1(func0(nullptr, nullptr), nullptr, nullptr);
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-nullptr.c b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-nullptr.c
@@ -1,4 +1,4 @@
-// RUN: clang-tidy %s -checks=-*,modernize-use-nullptr -- | count 0
+// RUN: clang-tidy %s -checks=-*,modernize-use-nullptr -- -std=c17 | count 0
 
 // Note: this test expects no diagnostics, but FileCheck cannot handle that,
 // hence the use of | count 0.

diff --git a/clang-tools-extra/test/pp-trace/pp-trace-pragma-general.cpp b/clang-tools-extra/test/pp-trace/pp-trace-pragma-general.cpp
@@ -21,6 +21,12 @@ void foo() {
 
 // CHECK: ---
 // CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
 // CHECK-NEXT:   Loc: "{{.*}}{{[/\\]}}pp-trace-pragma-general.cpp:3:1"
 // CHECK-NEXT:   Introducer: PIK_HashPragma
 // CHECK-NEXT: - Callback: PragmaDiagnosticPush

diff --git a/clang-tools-extra/test/pp-trace/pp-trace-pragma-ms.cpp b/clang-tools-extra/test/pp-trace/pp-trace-pragma-ms.cpp
@@ -18,6 +18,12 @@
 
 // CHECK: ---
 // CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
 // CHECK-NEXT:   Loc: "{{.*}}{{[/\\]}}pp-trace-pragma-ms.cpp:3:1"
 // CHECK-NEXT:   Introducer: PIK_HashPragma
 // CHECK-NEXT: - Callback: PragmaComment
@@ -67,7 +73,7 @@
 // CHECK-NEXT:   Introducer: PIK_HashPragma
 // CHECK-NEXT: - Callback: PragmaMessage
 // CHECK-NEXT:   Loc: "{{.*}}{{[/\\]}}pp-trace-pragma-ms.cpp:13:9"
-// CHECK-NEXT:   Namespace: 
+// CHECK-NEXT:   Namespace:
 // CHECK-NEXT:   Kind: PMK_Message
 // CHECK-NEXT:   Str: message argument
 // CHECK-NEXT: - Callback: PragmaDirective

diff --git a/clang-tools-extra/test/pp-trace/pp-trace-pragma-opencl.cpp b/clang-tools-extra/test/pp-trace/pp-trace-pragma-opencl.cpp
@@ -6,6 +6,12 @@
 
 // CHECK: ---
 // CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
+// CHECK-NEXT:   Loc: "<built-in>:{{.+}}:1"
+// CHECK-NEXT:   Introducer: PIK_HashPragma
+// CHECK-NEXT: - Callback: PragmaDirective
 // CHECK-NEXT:   Loc: "{{.*}}{{[/\\]}}pp-trace-pragma-opencl.cpp:3:1"
 // CHECK-NEXT:   Introducer: PIK_HashPragma
 // CHECK-NEXT: - Callback: PragmaOpenCLExtension

diff --git a/clang/cmake/caches/Release.cmake b/clang/cmake/caches/Release.cmake
@@ -82,6 +82,7 @@ set(LLVM_ENABLE_PROJECTS ${STAGE1_PROJECTS} CACHE STRING "")
 # stage2-instrumented and Final Stage Config:
 # Options that need to be set in both the instrumented stage (if we are doing
 # a pgo build) and the final stage.
+set_instrument_and_final_stage_var(CMAKE_POSITION_INDEPENDENT_CODE "ON" STRING)
 set_instrument_and_final_stage_var(LLVM_ENABLE_LTO "${LLVM_RELEASE_ENABLE_LTO}" STRING)
 if (LLVM_RELEASE_ENABLE_LTO)
   set_instrument_and_final_stage_var(LLVM_ENABLE_LLD "ON" BOOL)

diff --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst
@@ -711,6 +711,8 @@ even-odd element pair with indices ``i * 2`` and ``i * 2 + 1`` with
 power of 2, the vector is widened with neutral elements for the reduction
 at the end to the next power of 2.
 
+These reductions support both fixed-sized and scalable vector types.
+
 Example:
 
 .. code-block:: c++
@@ -1493,6 +1495,7 @@ Conditional ``explicit``                     __cpp_conditional_explicit       C+
 ``if consteval``                             __cpp_if_consteval               C++23         C++20
 ``static operator()``                        __cpp_static_call_operator       C++23         C++03
 Attributes on Lambda-Expressions                                              C++23         C++11
+Attributes on Structured Bindings            __cpp_structured_bindings        C++26         C++03
 ``= delete ("should have a reason");``       __cpp_deleted_function           C++26         C++03
 -------------------------------------------- -------------------------------- ------------- -------------
 Designated initializers (N494)                                                C99           C89
@@ -2928,7 +2931,7 @@ Query for this feature with ``__has_builtin(__builtin_dump_struct)``
 ``__builtin_shufflevector`` is used to express generic vector
 permutation/shuffle/swizzle operations.  This builtin is also very important
 for the implementation of various target-specific header files like
-``<xmmintrin.h>``.
+``<xmmintrin.h>``. This builtin can be used within constant expressions.
 
 **Syntax**:
 
@@ -2955,7 +2958,7 @@ for the implementation of various target-specific header files like
   // Concatenate every other element of 8-element vectors V1 and V2.
   __builtin_shufflevector(V1, V2, 0, 2, 4, 6, 8, 10, 12, 14)
 
-  // Shuffle v1 with some elements being undefined
+  // Shuffle v1 with some elements being undefined. Not allowed in constexpr.
   __builtin_shufflevector(v1, v1, 3, -1, 1, -1)
 
 **Description**:
@@ -2968,6 +2971,7 @@ starting with the first vector, continuing into the second vector.  Thus, if
 ``vec1`` is a 4-element vector, index 5 would refer to the second element of
 ``vec2``. An index of -1 can be used to indicate that the corresponding element
 in the returned vector is a don't care and can be optimized by the backend.
+Values of -1 are not supported in constant expressions.
 
 The result of ``__builtin_shufflevector`` is a vector with the same element
 type as ``vec1``/``vec2`` but that has an element count equal to the number of
@@ -2982,7 +2986,8 @@ Query for this feature with ``__has_builtin(__builtin_shufflevector)``.
 
 ``__builtin_convertvector`` is used to express generic vector
 type-conversion operations. The input vector and the output vector
-type must have the same number of elements.
+type must have the same number of elements. This builtin can be used within
+constant expressions.
 
 **Syntax**:
 
@@ -5572,3 +5577,25 @@ but the expression has no runtime effects.
 Type- and value-dependent expressions are not supported yet.
 
 This facility is designed to aid with testing name lookup machinery.
+
+Predefined Macros
+=================
+
+`__GCC_DESTRUCTIVE_SIZE` and `__GCC_CONSTRUCTIVE_SIZE`
+------------------------------------------------------
+Specify the mimum offset between two objects to avoid false sharing and the
+maximum size of contiguous memory to promote true sharing, respectively. These
+macros are predefined in all C and C++ language modes, but can be redefined on
+the command line with ``-D`` to specify different values as needed or can be
+undefined on the command line with ``-U`` to disable support for the feature.
+
+**Note: the values the macros expand to are not guaranteed to be stable. They
+are are affected by architectures and CPU tuning flags, can change between
+releases of Clang and will not match the values defined by other compilers such
+as GCC.**
+
+Compiling different TUs depending on these flags (including use of
+``std::hardware_constructive_interference`` or
+``std::hardware_destructive_interference``)  with different compilers, macro
+definitions, or architecture flags will lead to ODR violations and should be
+avoided.
diff --git a/clang/docs/LibTooling.rst b/clang/docs/LibTooling.rst
@@ -63,15 +63,22 @@ and automatic location of the compilation database using source files paths.
   #include "llvm/Support/CommandLine.h"
 
   using namespace clang::tooling;
+  using namespace llvm;
 
   // Apply a custom category to all command-line options so that they are the
   // only ones displayed.
-  static llvm::cl::OptionCategory MyToolCategory("my-tool options");
+  static cl::OptionCategory MyToolCategory("my-tool options");
 
   int main(int argc, const char **argv) {
-    // CommonOptionsParser constructor will parse arguments and create a
-    // CompilationDatabase.  In case of error it will terminate the program.
-    CommonOptionsParser OptionsParser(argc, argv, MyToolCategory);
+    // CommonOptionsParser::create will parse arguments and create a
+    // CompilationDatabase.
+    auto ExpectedParser = CommonOptionsParser::create(argc, argv, MyToolCategory);
+    if (!ExpectedParser) {
+      // Fail gracefully for unsupported options.
+      llvm::errs() << ExpectedParser.takeError();
+      return 1;
+    }
+    CommonOptionsParser& OptionsParser = ExpectedParser.get();
 
     // Use OptionsParser.getCompilations() and OptionsParser.getSourcePathList()
     // to retrieve CompilationDatabase and the list of input file paths.
@@ -133,7 +140,12 @@ version of this example tool is also checked into the clang tree at
   static cl::extrahelp MoreHelp("\nMore help text...\n");
 
   int main(int argc, const char **argv) {
-    CommonOptionsParser OptionsParser(argc, argv, MyToolCategory);
+    auto ExpectedParser = CommonOptionsParser::create(argc, argv, MyToolCategory);
+    if (!ExpectedParser) {
+      llvm::errs() << ExpectedParser.takeError();
+      return 1;
+    }
+    CommonOptionsParser& OptionsParser = ExpectedParser.get();
     ClangTool Tool(OptionsParser.getCompilations(),
                    OptionsParser.getSourcePathList());
     return Tool.run(newFrontendActionFactory<clang::SyntaxOnlyAction>().get());

diff --git a/clang/docs/OpenMPSupport.rst b/clang/docs/OpenMPSupport.rst
@@ -310,7 +310,9 @@ implementation.
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc                         | dispatch construct and function variant argument adjustment  | :part:`worked on`        | D99537, D99679                                                        |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
-| misc                         | assume and assumes directives                                | :part:`worked on`        |                                                                       |
+| misc                         | assumes directives                                           | :part:`worked on`        |                                                                       |
++------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
+| misc                         | assume directive                                             | :part:`worked on`        |                                                                       |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+
 | misc                         | nothing directive                                            | :good:`done`             | D123286                                                               |
 +------------------------------+--------------------------------------------------------------+--------------------------+-----------------------------------------------------------------------+

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
@@ -90,6 +90,18 @@ C++ Language Changes
 --------------------
 - Implemented ``_BitInt`` literal suffixes ``__wb`` or ``__WB`` as a Clang extension with ``unsigned`` modifiers also allowed. (#GH85223).
 
+C++17 Feature Support
+^^^^^^^^^^^^^^^^^^^^^
+- Clang now exposes ``__GCC_DESTRUCTIVE_SIZE`` and ``__GCC_CONSTRUCTIVE_SIZE``
+  predefined macros to support standard library implementations of
+  ``std::hardware_destructive_interference_size`` and
+  ``std::hardware_constructive_interference_size``, respectively. These macros
+  are predefined in all C and C++ language modes. The values the macros
+  expand to are not stable between releases of Clang and do not need to match
+  the values produced by GCC, so these macros should not be used from header
+  files because they may not be stable across multiple TUs (the values may vary
+  based on compiler version as well as CPU tuning). #GH60174
+
 C++20 Feature Support
 ^^^^^^^^^^^^^^^^^^^^^
 
@@ -131,6 +143,9 @@ C++2c Feature Support
 
 - Implemented `P2573R2: = delete("should have a reason"); <https://wg21.link/P2573R2>`_
 
+- Implemented `P0609R3: Attributes for Structured Bindings <https://wg21.link/P0609R3>`_
+
+- Implemented `P2748R5 Disallow Binding a Returned Glvalue to a Temporary <https://wg21.link/P2748R5>`_.
 
 Resolutions to C++ Defect Reports
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -207,6 +222,7 @@ Non-comprehensive list of changes in this release
 - ``__typeof_unqual__`` is available in all C modes as an extension, which behaves
   like ``typeof_unqual`` from C23, similar to ``__typeof__`` and ``typeof``.
 
+- ``__builtin_reduce_{add|mul|xor|or|and|min|max}`` builtins now support scalable vectors.
 
 * Shared libraries linked with either the ``-ffast-math``, ``-Ofast``, or
   ``-funsafe-math-optimizations`` flags will no longer enable flush-to-zero
@@ -217,6 +233,9 @@ Non-comprehensive list of changes in this release
 * ``-fdenormal-fp-math=preserve-sign`` is no longer implied by ``-ffast-math``
   on x86 systems.
 
+- Builtins ``__builtin_shufflevector()`` and ``__builtin_convertvector()`` may
+  now be used within constant expressions.
+
 New Compiler Flags
 ------------------
 - ``-fsanitize=implicit-bitfield-conversion`` checks implicit truncation and
@@ -385,18 +404,6 @@ Improvements to Clang's diagnostics
 
 - Clang now diagnoses requires expressions with explicit object parameters.
 
-- Clang now looks up members of the current instantiation in the template definition context
-  if the current instantiation has no dependent base classes.
-
-  .. code-block:: c++
-
-     template<typename T>
-     struct A {
-       int f() {
-         return this->x; // error: no member named 'x' in 'A<T>'
-       }
-     };
-
 Improvements to Clang's time-trace
 ----------------------------------
 
@@ -458,6 +465,10 @@ Bug Fixes in This Version
 
 - Fixed an assertion failure on invalid InitListExpr in C89 mode (#GH88008).
 
+- Fixed missing destructor calls when we branch from middle of an expression.
+  This could happen through a branch in stmt-expr or in an expression containing a coroutine
+  suspension. Fixes (#GH63818) (#GH88478).
+
 - Clang will no longer diagnose an erroneous non-dependent ``switch`` condition
   during instantiation, and instead will only diagnose it once, during checking
   of the function template.
@@ -588,6 +599,8 @@ Bug Fixes to C++ Support
 - Fixed a use-after-free bug in parsing of type constraints with default arguments that involve lambdas. (#GH67235)
 - Fixed bug in which the body of a consteval lambda within a template was not parsed as within an
   immediate function context.
+- Fix CTAD for ``std::initializer_list``. This allows ``std::initializer_list{1, 2, 3}`` to be deduced as
+  ``std::initializer_list<int>`` as intended.
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -640,6 +653,9 @@ Arm and AArch64 Support
     * Arm Cortex-A78AE (cortex-a78ae).
     * Arm Cortex-A520AE (cortex-a520ae).
     * Arm Cortex-A720AE (cortex-a720ae).
+    * Arm Neoverse-N3 (neoverse-n3).
+    * Arm Neoverse-V3 (neoverse-v3).
+    * Arm Neoverse-V3AE (neoverse-v3ae).
 
 Android Support
 ^^^^^^^^^^^^^^^

diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst
@@ -2319,6 +2319,8 @@ are listed below.
    on ELF targets when using the integrated assembler. This flag currently
    only has an effect on ELF targets.
 
+.. _funique_internal_linkage_names:
+
 .. option:: -f[no]-unique-internal-linkage-names
 
    Controls whether Clang emits a unique (best-effort) symbol name for internal
@@ -2448,27 +2450,41 @@ usual build cycle when using sample profilers for optimization:
    usual build flags that you always build your application with. The only
    requirement is that DWARF debug info including source line information is
    generated. This DWARF information is important for the profiler to be able
-   to map instructions back to source line locations.
+   to map instructions back to source line locations. The usefulness of this
+   DWARF information can be improved with the ``-fdebug-info-for-profiling``
+   and ``-funique-internal-linkage-names`` options.
 
-   On Linux, ``-g`` or just ``-gline-tables-only`` is sufficient:
+   On Linux:
 
    .. code-block:: console
 
-     $ clang++ -O2 -gline-tables-only code.cc -o code
+     $ clang++ -O2 -gline-tables-only \
+       -fdebug-info-for-profiling -funique-internal-linkage-names \
+       code.cc -o code
 
    While MSVC-style targets default to CodeView debug information, DWARF debug
    information is required to generate source-level LLVM profiles. Use
    ``-gdwarf`` to include DWARF debug information:
 
-   .. code-block:: console
+   .. code-block:: winbatch
+
+     > clang-cl /O2 -gdwarf -gline-tables-only ^
+       /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
+       code.cc /Fe:code /fuse-ld=lld /link /debug:dwarf
+
+.. note::
 
-     $ clang-cl -O2 -gdwarf -gline-tables-only coff-profile.cpp -fuse-ld=lld -link -debug:dwarf
+   :ref:`-funique-internal-linkage-names <funique_internal_linkage_names>`
+   generates unique names based on given command-line source file paths. If
+   your build system uses absolute source paths and these paths may change
+   between steps 1 and 4, then the uniqued function names may change and result
+   in unused profile data. Consider omitting this option in such cases.
 
 2. Run the executable under a sampling profiler. The specific profiler
    you use does not really matter, as long as its output can be converted
    into the format that the LLVM optimizer understands.
 
-   Two such profilers are the the Linux Perf profiler
+   Two such profilers are the Linux Perf profiler
    (https://perf.wiki.kernel.org/) and Intel's Sampling Enabling Product (SEP),
    available as part of `Intel VTune
    <https://software.intel.com/content/www/us/en/develop/tools/oneapi/components/vtune-profiler.html>`_.
@@ -2482,7 +2498,9 @@ usual build cycle when using sample profilers for optimization:
 
    .. code-block:: console
 
-     $ perf record -b ./code
+     $ perf record -b -e BR_INST_RETIRED.NEAR_TAKEN:uppp ./code
+
+   If the event above is unavailable, ``branches:u`` is probably next-best.
 
    Note the use of the ``-b`` flag. This tells Perf to use the Last Branch
    Record (LBR) to record call chains. While this is not strictly required,
@@ -2532,21 +2550,42 @@ usual build cycle when using sample profilers for optimization:
    that executes faster than the original one. Note that you are not
    required to build the code with the exact same arguments that you
    used in the first step. The only requirement is that you build the code
-   with ``-gline-tables-only`` and ``-fprofile-sample-use``.
+   with the same debug info options and ``-fprofile-sample-use``.
+
+   On Linux:
 
    .. code-block:: console
 
-     $ clang++ -O2 -gline-tables-only -fprofile-sample-use=code.prof code.cc -o code
+     $ clang++ -O2 -gline-tables-only \
+       -fdebug-info-for-profiling -funique-internal-linkage-names \
+       -fprofile-sample-use=code.prof code.cc -o code
 
-  [OPTIONAL] Sampling-based profiles can have inaccuracies or missing block/
-  edge counters. The profile inference algorithm (profi) can be used to infer
-  missing blocks and edge counts, and improve the quality of profile data.
-  Enable it with ``-fsample-profile-use-profi``.
+   On Windows:
 
-  .. code-block:: console
+   .. code-block:: winbatch
+
+     > clang-cl /O2 -gdwarf -gline-tables-only ^
+       /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
+       /fprofile-sample-use=code.prof code.cc /Fe:code /fuse-ld=lld /link /debug:dwarf
+
+   [OPTIONAL] Sampling-based profiles can have inaccuracies or missing block/
+   edge counters. The profile inference algorithm (profi) can be used to infer
+   missing blocks and edge counts, and improve the quality of profile data.
+   Enable it with ``-fsample-profile-use-profi``. For example, on Linux:
+
+   .. code-block:: console
+
+     $ clang++ -fsample-profile-use-profi -O2 -gline-tables-only \
+       -fdebug-info-for-profiling -funique-internal-linkage-names \
+       -fprofile-sample-use=code.prof code.cc -o code
+
+   On Windows:
+
+   .. code-block:: winbatch
 
-    $ clang++ -O2 -gline-tables-only -fprofile-sample-use=code.prof \
-      -fsample-profile-use-profi code.cc -o code
+     > clang-cl /clang:-fsample-profile-use-profi /O2 -gdwarf -gline-tables-only ^
+       /clang:-fdebug-info-for-profiling /clang:-funique-internal-linkage-names ^
+       /fprofile-sample-use=code.prof code.cc /Fe:code /fuse-ld=lld /link /debug:dwarf
 
 Sample Profile Formats
 """"""""""""""""""""""

diff --git a/clang/include/clang/APINotes/Types.h b/clang/include/clang/APINotes/Types.h
@@ -675,14 +675,21 @@ class TagInfo : public CommonTypeInfo {
   LLVM_PREFERRED_TYPE(bool)
   unsigned IsFlagEnum : 1;
 
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned SwiftCopyableSpecified : 1;
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned SwiftCopyable : 1;
+
 public:
   std::optional<std::string> SwiftImportAs;
   std::optional<std::string> SwiftRetainOp;
   std::optional<std::string> SwiftReleaseOp;
 
   std::optional<EnumExtensibilityKind> EnumExtensibility;
 
-  TagInfo() : HasFlagEnum(0), IsFlagEnum(0) {}
+  TagInfo()
+      : HasFlagEnum(0), IsFlagEnum(0), SwiftCopyableSpecified(false),
+        SwiftCopyable(false) {}
 
   std::optional<bool> isFlagEnum() const {
     if (HasFlagEnum)
@@ -694,6 +701,15 @@ class TagInfo : public CommonTypeInfo {
     IsFlagEnum = Value.value_or(false);
   }
 
+  std::optional<bool> isSwiftCopyable() const {
+    return SwiftCopyableSpecified ? std::optional<bool>(SwiftCopyable)
+                                  : std::nullopt;
+  }
+  void setSwiftCopyable(std::optional<bool> Value) {
+    SwiftCopyableSpecified = Value.has_value();
+    SwiftCopyable = Value.value_or(false);
+  }
+
   TagInfo &operator|=(const TagInfo &RHS) {
     static_cast<CommonTypeInfo &>(*this) |= RHS;
 
@@ -710,6 +726,9 @@ class TagInfo : public CommonTypeInfo {
     if (!EnumExtensibility)
       EnumExtensibility = RHS.EnumExtensibility;
 
+    if (!SwiftCopyableSpecified)
+      setSwiftCopyable(RHS.isSwiftCopyable());
+
     return *this;
   }
 
@@ -724,6 +743,7 @@ inline bool operator==(const TagInfo &LHS, const TagInfo &RHS) {
          LHS.SwiftRetainOp == RHS.SwiftRetainOp &&
          LHS.SwiftReleaseOp == RHS.SwiftReleaseOp &&
          LHS.isFlagEnum() == RHS.isFlagEnum() &&
+         LHS.isSwiftCopyable() == RHS.isSwiftCopyable() &&
          LHS.EnumExtensibility == RHS.EnumExtensibility;
 }
 

diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
@@ -2197,6 +2197,16 @@ class ASTContext : public RefCountedBase<ASTContext> {
     return getQualifiedType(type.getUnqualifiedType(), Qs);
   }
 
+  /// \brief Return a type with the given __ptrauth qualifier.
+  QualType getPointerAuthType(QualType Ty, PointerAuthQualifier PointerAuth) {
+    assert(!Ty.getPointerAuth());
+    assert(PointerAuth);
+
+    Qualifiers Qs;
+    Qs.setPointerAuth(PointerAuth);
+    return getQualifiedType(Ty, Qs);
+  }
+
   unsigned char getFixedPointScale(QualType Ty) const;
   unsigned char getFixedPointIBits(QualType Ty) const;
   llvm::FixedPointSemantics getFixedPointSemantics(QualType Ty) const;

diff --git a/clang/include/clang/AST/ASTNodeTraverser.h b/clang/include/clang/AST/ASTNodeTraverser.h
@@ -844,6 +844,12 @@ class ASTNodeTraverser
     }
   }
 
+  void VisitUnresolvedLookupExpr(const UnresolvedLookupExpr *E) {
+    if (E->hasExplicitTemplateArgs())
+      for (auto Arg : E->template_arguments())
+        Visit(Arg.getArgument());
+  }
+
   void VisitRequiresExpr(const RequiresExpr *E) {
     for (auto *D : E->getLocalParameters())
       Visit(D);

diff --git a/clang/include/clang/AST/AbstractBasicReader.h b/clang/include/clang/AST/AbstractBasicReader.h
@@ -213,9 +213,9 @@ class DataStreamBasicReader : public BasicReaderBase<Impl> {
   }
 
   Qualifiers readQualifiers() {
-    static_assert(sizeof(Qualifiers().getAsOpaqueValue()) <= sizeof(uint32_t),
+    static_assert(sizeof(Qualifiers().getAsOpaqueValue()) <= sizeof(uint64_t),
                   "update this if the value size changes");
-    uint32_t value = asImpl().readUInt32();
+    uint64_t value = asImpl().readUInt64();
     return Qualifiers::fromOpaqueValue(value);
   }
 

diff --git a/clang/include/clang/AST/AbstractBasicWriter.h b/clang/include/clang/AST/AbstractBasicWriter.h
@@ -196,9 +196,9 @@ class DataStreamBasicWriter : public BasicWriterBase<Impl> {
   }
 
   void writeQualifiers(Qualifiers value) {
-    static_assert(sizeof(value.getAsOpaqueValue()) <= sizeof(uint32_t),
+    static_assert(sizeof(value.getAsOpaqueValue()) <= sizeof(uint64_t),
                   "update this if the value size changes");
-    asImpl().writeUInt32(value.getAsOpaqueValue());
+    asImpl().writeUInt64(value.getAsOpaqueValue());
   }
 
   void writeExceptionSpecInfo(

diff --git a/clang/include/clang/AST/DeclContextInternals.h b/clang/include/clang/AST/DeclContextInternals.h
@@ -42,11 +42,12 @@ class StoredDeclsList {
   /// external declarations.
   DeclsAndHasExternalTy Data;
 
-  template<typename Fn>
-  void erase_if(Fn ShouldErase) {
+  template <typename Fn> DeclListNode::Decls *erase_if(Fn ShouldErase) {
     Decls List = Data.getPointer();
+
     if (!List)
-      return;
+      return nullptr;
+
     ASTContext &C = getASTContext();
     DeclListNode::Decls NewHead = nullptr;
     DeclListNode::Decls *NewLast = nullptr;
@@ -79,6 +80,17 @@ class StoredDeclsList {
     Data.setPointer(NewHead);
 
     assert(llvm::none_of(getLookupResult(), ShouldErase) && "Still exists!");
+
+    if (!Data.getPointer())
+      // All declarations are erased.
+      return nullptr;
+    else if (NewHead.is<NamedDecl *>())
+      // The list only contains a declaration, the header itself.
+      return (DeclListNode::Decls *)&Data;
+    else {
+      assert(NewLast && NewLast->is<NamedDecl *>() && "Not the tail?");
+      return NewLast;
+    }
   }
 
   void erase(NamedDecl *ND) {
@@ -160,12 +172,16 @@ class StoredDeclsList {
 
   void replaceExternalDecls(ArrayRef<NamedDecl*> Decls) {
     // Remove all declarations that are either external or are replaced with
-    // external declarations.
-    erase_if([Decls](NamedDecl *ND) {
+    // external declarations with higher visibilities.
+    DeclListNode::Decls *Tail = erase_if([Decls](NamedDecl *ND) {
       if (ND->isFromASTFile())
         return true;
+      // FIXME: Can we get rid of this loop completely?
       for (NamedDecl *D : Decls)
-        if (D->declarationReplaces(ND, /*IsKnownNewer=*/false))
+        // Only replace the local declaration if the external declaration has
+        // higher visibilities.
+        if (D->getModuleOwnershipKind() <= ND->getModuleOwnershipKind() &&
+            D->declarationReplaces(ND, /*IsKnownNewer=*/false))
           return true;
       return false;
     });
@@ -185,24 +201,15 @@ class StoredDeclsList {
       DeclsAsList = Node;
     }
 
-    DeclListNode::Decls Head = Data.getPointer();
-    if (Head.isNull()) {
+    if (!Data.getPointer()) {
       Data.setPointer(DeclsAsList);
       return;
     }
 
-    // Find the end of the existing list.
-    // FIXME: It would be possible to preserve information from erase_if to
-    // avoid this rescan looking for the end of the list.
-    DeclListNode::Decls *Tail = &Head;
-    while (DeclListNode *Node = Tail->dyn_cast<DeclListNode *>())
-      Tail = &Node->Rest;
-
     // Append the Decls.
     DeclListNode *Node = C.AllocateDeclListNode(Tail->get<NamedDecl *>());
     Node->Rest = DeclsAsList;
     *Tail = Node;
-    Data.setPointer(Head);
   }
 
   /// Return the list of all the decls.

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
@@ -25,8 +25,10 @@
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/ExceptionSpecificationType.h"
 #include "clang/Basic/LLVM.h"
+#include "clang/Basic/LangOptions.h"
 #include "clang/Basic/Linkage.h"
 #include "clang/Basic/PartialDiagnostic.h"
+#include "clang/Basic/PointerAuthOptions.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Basic/Visibility.h"
@@ -139,6 +141,174 @@ using CanQualType = CanQual<Type>;
 #define TYPE(Class, Base) class Class##Type;
 #include "clang/AST/TypeNodes.inc"
 
+/// Pointer-authentication qualifiers.
+class PointerAuthQualifier {
+  enum : uint32_t {
+    EnabledShift = 0,
+    EnabledBits = 1,
+    EnabledMask = 1 << EnabledShift,
+    AddressDiscriminatedShift = EnabledShift + EnabledBits,
+    AddressDiscriminatedBits = 1,
+    AddressDiscriminatedMask = 1 << AddressDiscriminatedShift,
+    AuthenticationModeShift =
+        AddressDiscriminatedShift + AddressDiscriminatedBits,
+    AuthenticationModeBits = 2,
+    AuthenticationModeMask = ((1 << AuthenticationModeBits) - 1)
+                             << AuthenticationModeShift,
+    IsaPointerShift = AuthenticationModeShift + AuthenticationModeBits,
+    IsaPointerBits = 1,
+    IsaPointerMask = ((1 << IsaPointerBits) - 1) << IsaPointerShift,
+    AuthenticatesNullValuesShift = IsaPointerShift + IsaPointerBits,
+    AuthenticatesNullValuesBits = 1,
+    AuthenticatesNullValuesMask = ((1 << AuthenticatesNullValuesBits) - 1)
+                                  << AuthenticatesNullValuesShift,
+    KeyShift = AuthenticatesNullValuesShift + AuthenticatesNullValuesBits,
+    KeyBits = 10,
+    KeyMask = ((1 << KeyBits) - 1) << KeyShift,
+    DiscriminatorShift = KeyShift + KeyBits,
+    DiscriminatorBits = 16,
+    DiscriminatorMask = ((1u << DiscriminatorBits) - 1) << DiscriminatorShift,
+  };
+
+  // bits:     |0      |1      |2..3              |4          |
+  //           |Enabled|Address|AuthenticationMode|ISA pointer|
+  // bits:     |5                |6..15|   16...31   |
+  //           |AuthenticatesNull|Key  |Discriminator|
+  uint32_t Data = 0;
+
+  // The following static assertions check that each of the 32 bits is present
+  // exactly in one of the constants.
+  static_assert((EnabledBits + AddressDiscriminatedBits +
+                 AuthenticationModeBits + IsaPointerBits +
+                 AuthenticatesNullValuesBits + KeyBits + DiscriminatorBits) ==
+                    32,
+                "PointerAuthQualifier should be exactly 32 bits");
+  static_assert((EnabledMask + AddressDiscriminatedMask +
+                 AuthenticationModeMask + IsaPointerMask +
+                 AuthenticatesNullValuesMask + KeyMask + DiscriminatorMask) ==
+                    0xFFFFFFFF,
+                "All masks should cover the entire bits");
+  static_assert((EnabledMask ^ AddressDiscriminatedMask ^
+                 AuthenticationModeMask ^ IsaPointerMask ^
+                 AuthenticatesNullValuesMask ^ KeyMask ^ DiscriminatorMask) ==
+                    0xFFFFFFFF,
+                "All masks should cover the entire bits");
+
+  PointerAuthQualifier(unsigned Key, bool IsAddressDiscriminated,
+                       unsigned ExtraDiscriminator,
+                       PointerAuthenticationMode AuthenticationMode,
+                       bool IsIsaPointer, bool AuthenticatesNullValues)
+      : Data(EnabledMask |
+             (IsAddressDiscriminated
+                  ? llvm::to_underlying(AddressDiscriminatedMask)
+                  : 0) |
+             (Key << KeyShift) |
+             (llvm::to_underlying(AuthenticationMode)
+              << AuthenticationModeShift) |
+             (ExtraDiscriminator << DiscriminatorShift) |
+             (IsIsaPointer << IsaPointerShift) |
+             (AuthenticatesNullValues << AuthenticatesNullValuesShift)) {
+    assert(Key <= KeyNoneInternal);
+    assert(ExtraDiscriminator <= MaxDiscriminator);
+    assert((Data == 0) ==
+           (getAuthenticationMode() == PointerAuthenticationMode::None));
+  }
+
+public:
+  enum {
+    KeyNoneInternal = (1u << KeyBits) - 1,
+
+    /// The maximum supported pointer-authentication key.
+    MaxKey = KeyNoneInternal - 1,
+
+    /// The maximum supported pointer-authentication discriminator.
+    MaxDiscriminator = (1u << DiscriminatorBits) - 1
+  };
+
+public:
+  PointerAuthQualifier() = default;
+
+  static PointerAuthQualifier
+  Create(unsigned Key, bool IsAddressDiscriminated, unsigned ExtraDiscriminator,
+         PointerAuthenticationMode AuthenticationMode, bool IsIsaPointer,
+         bool AuthenticatesNullValues) {
+    if (Key == PointerAuthKeyNone)
+      Key = KeyNoneInternal;
+    assert(Key <= KeyNoneInternal && "out-of-range key value");
+    return PointerAuthQualifier(Key, IsAddressDiscriminated, ExtraDiscriminator,
+                                AuthenticationMode, IsIsaPointer,
+                                AuthenticatesNullValues);
+  }
+
+  bool isPresent() const {
+    assert((Data == 0) ==
+           (getAuthenticationMode() == PointerAuthenticationMode::None));
+    return Data != 0;
+  }
+
+  explicit operator bool() const { return isPresent(); }
+
+  unsigned getKey() const {
+    assert(isPresent());
+    return (Data & KeyMask) >> KeyShift;
+  }
+
+  bool hasKeyNone() const { return isPresent() && getKey() == KeyNoneInternal; }
+
+  bool isAddressDiscriminated() const {
+    assert(isPresent());
+    return (Data & AddressDiscriminatedMask) >> AddressDiscriminatedShift;
+  }
+
+  unsigned getExtraDiscriminator() const {
+    assert(isPresent());
+    return (Data >> DiscriminatorShift);
+  }
+
+  PointerAuthenticationMode getAuthenticationMode() const {
+    return PointerAuthenticationMode((Data & AuthenticationModeMask) >>
+                                     AuthenticationModeShift);
+  }
+
+  bool isIsaPointer() const {
+    assert(isPresent());
+    return (Data & IsaPointerMask) >> IsaPointerShift;
+  }
+
+  bool authenticatesNullValues() const {
+    assert(isPresent());
+    return (Data & AuthenticatesNullValuesMask) >> AuthenticatesNullValuesShift;
+  }
+
+  PointerAuthQualifier withoutKeyNone() const {
+    return hasKeyNone() ? PointerAuthQualifier() : *this;
+  }
+
+  friend bool operator==(PointerAuthQualifier Lhs, PointerAuthQualifier Rhs) {
+    return Lhs.Data == Rhs.Data;
+  }
+  friend bool operator!=(PointerAuthQualifier Lhs, PointerAuthQualifier Rhs) {
+    return Lhs.Data != Rhs.Data;
+  }
+
+  bool isEquivalent(PointerAuthQualifier Other) const {
+    return withoutKeyNone() == Other.withoutKeyNone();
+  }
+
+  uint32_t getAsOpaqueValue() const { return Data; }
+
+  // Deserialize pointer-auth qualifiers from an opaque representation.
+  static PointerAuthQualifier fromOpaqueValue(uint32_t Opaque) {
+    PointerAuthQualifier Result;
+    Result.Data = Opaque;
+    assert((Result.Data == 0) ==
+           (Result.getAuthenticationMode() == PointerAuthenticationMode::None));
+    return Result;
+  }
+
+  void Profile(llvm::FoldingSetNodeID &ID) const { ID.AddInteger(Data); }
+};
+
 /// The collection of all-type qualifiers we support.
 /// Clang supports five independent qualifiers:
 /// * C99: const, volatile, and restrict
@@ -147,8 +317,9 @@ using CanQualType = CanQual<Type>;
 /// * Objective C: the GC attributes (none, weak, or strong)
 class Qualifiers {
 public:
-  enum TQ { // NOTE: These flags must be kept in sync with DeclSpec::TQ.
-    Const    = 0x1,
+  enum TQ : uint64_t {
+    // NOTE: These flags must be kept in sync with DeclSpec::TQ.
+    Const = 0x1,
     Restrict = 0x2,
     Volatile = 0x4,
     CVRMask = Const | Volatile | Restrict
@@ -182,7 +353,7 @@ class Qualifiers {
     OCL_Autoreleasing
   };
 
-  enum {
+  enum : uint64_t {
     /// The maximum supported address space number.
     /// 23 bits should be enough for anyone.
     MaxAddressSpace = 0x7fffffu,
@@ -197,16 +368,25 @@ class Qualifiers {
   /// Returns the common set of qualifiers while removing them from
   /// the given sets.
   static Qualifiers removeCommonQualifiers(Qualifiers &L, Qualifiers &R) {
+    Qualifiers Q;
+    PointerAuthQualifier LPtrAuth = L.getPointerAuth();
+    if (LPtrAuth.isPresent() &&
+        LPtrAuth.getKey() != PointerAuthQualifier::KeyNoneInternal &&
+        LPtrAuth == R.getPointerAuth()) {
+      Q.setPointerAuth(LPtrAuth);
+      PointerAuthQualifier Empty;
+      L.setPointerAuth(Empty);
+      R.setPointerAuth(Empty);
+    }
+
     // If both are only CVR-qualified, bit operations are sufficient.
     if (!(L.Mask & ~CVRMask) && !(R.Mask & ~CVRMask)) {
-      Qualifiers Q;
       Q.Mask = L.Mask & R.Mask;
       L.Mask &= ~Q.Mask;
       R.Mask &= ~Q.Mask;
       return Q;
     }
 
-    Qualifiers Q;
     unsigned CommonCRV = L.getCVRQualifiers() & R.getCVRQualifiers();
     Q.addCVRQualifiers(CommonCRV);
     L.removeCVRQualifiers(CommonCRV);
@@ -251,16 +431,14 @@ class Qualifiers {
   }
 
   // Deserialize qualifiers from an opaque representation.
-  static Qualifiers fromOpaqueValue(unsigned opaque) {
+  static Qualifiers fromOpaqueValue(uint64_t opaque) {
     Qualifiers Qs;
     Qs.Mask = opaque;
     return Qs;
   }
 
   // Serialize these qualifiers into an opaque representation.
-  unsigned getAsOpaqueValue() const {
-    return Mask;
-  }
+  uint64_t getAsOpaqueValue() const { return Mask; }
 
   bool hasConst() const { return Mask & Const; }
   bool hasOnlyConst() const { return Mask == Const; }
@@ -302,7 +480,7 @@ class Qualifiers {
   }
   void removeCVRQualifiers(unsigned mask) {
     assert(!(mask & ~CVRMask) && "bitmask contains non-CVR bits");
-    Mask &= ~mask;
+    Mask &= ~static_cast<uint64_t>(mask);
   }
   void removeCVRQualifiers() {
     removeCVRQualifiers(CVRMask);
@@ -407,6 +585,20 @@ class Qualifiers {
     setAddressSpace(space);
   }
 
+  bool hasPointerAuth() const { return Mask & PtrAuthMask; }
+  PointerAuthQualifier getPointerAuth() const {
+    return PointerAuthQualifier::fromOpaqueValue(Mask >> PtrAuthShift);
+  }
+  void setPointerAuth(PointerAuthQualifier Q) {
+    Mask = (Mask & ~PtrAuthMask) |
+           (uint64_t(Q.getAsOpaqueValue()) << PtrAuthShift);
+  }
+  void removePointerAuth() { Mask &= ~PtrAuthMask; }
+  void addPointerAuth(PointerAuthQualifier Q) {
+    assert(Q.isPresent());
+    setPointerAuth(Q);
+  }
+
   // Fast qualifiers are those that can be allocated directly
   // on a QualType object.
   bool hasFastQualifiers() const { return getFastQualifiers(); }
@@ -417,7 +609,7 @@ class Qualifiers {
   }
   void removeFastQualifiers(unsigned mask) {
     assert(!(mask & ~FastMask) && "bitmask contains non-fast qualifier bits");
-    Mask &= ~mask;
+    Mask &= ~static_cast<uint64_t>(mask);
   }
   void removeFastQualifiers() {
     removeFastQualifiers(FastMask);
@@ -454,6 +646,8 @@ class Qualifiers {
         addObjCGCAttr(Q.getObjCGCAttr());
       if (Q.hasObjCLifetime())
         addObjCLifetime(Q.getObjCLifetime());
+      if (Q.hasPointerAuth())
+        addPointerAuth(Q.getPointerAuth());
     }
   }
 
@@ -471,6 +665,8 @@ class Qualifiers {
         removeObjCLifetime();
       if (getAddressSpace() == Q.getAddressSpace())
         removeAddressSpace();
+      if (getPointerAuth() == Q.getPointerAuth())
+        removePointerAuth();
     }
   }
 
@@ -483,6 +679,8 @@ class Qualifiers {
            !hasObjCGCAttr() || !qs.hasObjCGCAttr());
     assert(getObjCLifetime() == qs.getObjCLifetime() ||
            !hasObjCLifetime() || !qs.hasObjCLifetime());
+    assert(!hasPointerAuth() || !qs.hasPointerAuth() ||
+           getPointerAuth() == qs.getPointerAuth());
     Mask |= qs.Mask;
   }
 
@@ -536,6 +734,8 @@ class Qualifiers {
            // be changed.
            (getObjCGCAttr() == other.getObjCGCAttr() || !hasObjCGCAttr() ||
             !other.hasObjCGCAttr()) &&
+           // Pointer-auth qualifiers must match exactly.
+           getPointerAuth() == other.getPointerAuth() &&
            // ObjC lifetime qualifiers must match exactly.
            getObjCLifetime() == other.getObjCLifetime() &&
            // CVR qualifiers may subset.
@@ -605,24 +805,26 @@ class Qualifiers {
   void print(raw_ostream &OS, const PrintingPolicy &Policy,
              bool appendSpaceIfNonEmpty = false) const;
 
-  void Profile(llvm::FoldingSetNodeID &ID) const {
-    ID.AddInteger(Mask);
-  }
+  void Profile(llvm::FoldingSetNodeID &ID) const { ID.AddInteger(Mask); }
 
 private:
-  // bits:     |0 1 2|3|4 .. 5|6  ..  8|9   ...   31|
-  //           |C R V|U|GCAttr|Lifetime|AddressSpace|
-  uint32_t Mask = 0;
-
-  static const uint32_t UMask = 0x8;
-  static const uint32_t UShift = 3;
-  static const uint32_t GCAttrMask = 0x30;
-  static const uint32_t GCAttrShift = 4;
-  static const uint32_t LifetimeMask = 0x1C0;
-  static const uint32_t LifetimeShift = 6;
-  static const uint32_t AddressSpaceMask =
+  // bits:     |0 1 2|3|4 .. 5|6  ..  8|9   ...   31|32 ... 63|
+  //           |C R V|U|GCAttr|Lifetime|AddressSpace| PtrAuth |
+  uint64_t Mask = 0;
+  static_assert(sizeof(PointerAuthQualifier) == sizeof(uint32_t),
+                "PointerAuthQualifier must be 32 bits");
+
+  static constexpr uint64_t UMask = 0x8;
+  static constexpr uint64_t UShift = 3;
+  static constexpr uint64_t GCAttrMask = 0x30;
+  static constexpr uint64_t GCAttrShift = 4;
+  static constexpr uint64_t LifetimeMask = 0x1C0;
+  static constexpr uint64_t LifetimeShift = 6;
+  static constexpr uint64_t AddressSpaceMask =
       ~(CVRMask | UMask | GCAttrMask | LifetimeMask);
-  static const uint32_t AddressSpaceShift = 9;
+  static constexpr uint64_t AddressSpaceShift = 9;
+  static constexpr uint64_t PtrAuthShift = 32;
+  static constexpr uint64_t PtrAuthMask = uint64_t(0xffffffff) << PtrAuthShift;
 };
 
 class QualifiersAndAtomic {
@@ -1242,6 +1444,10 @@ class QualType {
   // true when Type is objc's weak and weak is enabled but ARC isn't.
   bool isNonWeakInMRRWithObjCWeak(const ASTContext &Context) const;
 
+  PointerAuthQualifier getPointerAuth() const {
+    return getQualifiers().getPointerAuth();
+  }
+
   enum PrimitiveDefaultInitializeKind {
     /// The type does not fall into any of the following categories. Note that
     /// this case is zero-valued so that values of this enum can be used as a
@@ -2172,6 +2378,10 @@ class alignas(TypeAlignment) Type : public ExtQualsTypeCommonBase {
   /// 'riscv_rvv_vector_bits' type attribute as VectorType.
   QualType getRVVEltType(const ASTContext &Ctx) const;
 
+  /// Returns the representative type for the element of a sizeless vector
+  /// builtin type.
+  QualType getSizelessVectorEltType(const ASTContext &Ctx) const;
+
   /// Types are partitioned into 3 broad categories (C99 6.2.5p1):
   /// object types, function types, and incomplete types.
 

diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
@@ -3211,7 +3211,7 @@ def ObjCRequiresPropertyDefs : InheritableAttr {
 def Unused : InheritableAttr {
   let Spellings = [CXX11<"", "maybe_unused", 201603>, GCC<"unused">,
                    C23<"", "maybe_unused", 202106>];
-  let Subjects = SubjectList<[Var, ObjCIvar, Type, Enum, EnumConstant, Label,
+  let Subjects = SubjectList<[Var, Binding, ObjCIvar, Type, Enum, EnumConstant, Label,
                               Field, ObjCMethod, FunctionLike]>;
   let Documentation = [WarnMaybeUnusedDocs];
 }

diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -478,6 +478,15 @@ def ext_decomp_decl_empty : ExtWarn<
   "ISO C++17 does not allow a decomposition group to be empty">,
   InGroup<DiagGroup<"empty-decomposition">>;
 
+// C++26 structured bindings
+def ext_decl_attrs_on_binding : ExtWarn<
+  "an attribute specifier sequence attached to a structured binding declaration "
+  "is a C++2c extension">, InGroup<CXX26>;
+def warn_cxx23_compat_decl_attrs_on_binding : Warning<
+  "an attribute specifier sequence attached to a structured binding declaration "
+  "is incompatible with C++ standards before C++2c">,
+  InGroup<CXXPre26Compat>, DefaultIgnore;
+
 /// Objective-C parser diagnostics
 def err_expected_minus_or_plus : Error<
   "method type specifier must start with '-' or '+'">;

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -9901,6 +9901,9 @@ def warn_format_invalid_annotation : Warning<
 def warn_format_P_no_precision : Warning<
   "using '%%P' format specifier without precision">,
   InGroup<Format>;
+def warn_format_P_with_objc_pointer : Warning<
+  "using '%%P' format specifier with an Objective-C pointer results in dumping runtime object structure, not object value">,
+  InGroup<Format>;
 def warn_printf_ignored_flag: Warning<
   "flag '%0' is ignored when flag '%1' is present">,
   InGroup<Format>;
@@ -9950,6 +9953,8 @@ def warn_ret_stack_addr_ref : Warning<
 def warn_ret_local_temp_addr_ref : Warning<
   "returning %select{address of|reference to}0 local temporary object">,
   InGroup<ReturnStackAddress>;
+def err_ret_local_temp_ref : Error<
+  "returning reference to local temporary object">;
 def warn_ret_addr_label : Warning<
   "returning address of label, which is local">,
   InGroup<ReturnStackAddress>;
@@ -10328,9 +10333,13 @@ def err_shufflevector_nonconstant_argument : Error<
 def err_shufflevector_argument_too_large : Error<
   "index for __builtin_shufflevector must be less than the total number "
   "of vector elements">;
+def err_shufflevector_minus_one_is_undefined_behavior_constexpr : Error<
+  "index for __builtin_shufflevector not within the bounds of the input vectors; index of -1 found at position %0 not permitted in a constexpr context.">;
 
 def err_convertvector_non_vector : Error<
   "first argument to __builtin_convertvector must be a vector">;
+def err_convertvector_constexpr_unsupported_vector_cast : Error<
+  "unsupported vector cast from %0 to %1 in a constant expression.">;
 def err_builtin_non_vector_type : Error<
   "%0 argument to %1 must be of vector type">;
 def err_convertvector_incompatible_vector : Error<

diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
@@ -57,6 +57,13 @@ enum class ShaderStage {
   Invalid,
 };
 
+enum class PointerAuthenticationMode : unsigned {
+  None,
+  Strip,
+  SignAndStrip,
+  SignAndAuth
+};
+
 /// Bitfields of LangOptions, split out from LangOptions in order to ensure that
 /// this large collection of bitfields is a trivial class type.
 class LangOptionsBase {

diff --git a/clang/include/clang/Basic/PointerAuthOptions.h b/clang/include/clang/Basic/PointerAuthOptions.h
@@ -0,0 +1,23 @@
+//===--- PointerAuthOptions.h -----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines options for configuring pointer-auth technologies
+//  like ARMv8.3.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_BASIC_POINTERAUTHOPTIONS_H
+#define LLVM_CLANG_BASIC_POINTERAUTHOPTIONS_H
+
+namespace clang {
+
+constexpr unsigned PointerAuthKeyNone = -1;
+
+} // end namespace clang
+
+#endif
diff --git a/clang/include/clang/Basic/TargetInfo.h b/clang/include/clang/Basic/TargetInfo.h
@@ -40,6 +40,7 @@
 #include <cassert>
 #include <optional>
 #include <string>
+#include <utility>
 #include <vector>
 
 namespace llvm {
@@ -1792,6 +1793,15 @@ class TargetInfo : public TransferrableTargetInfo,
   /// Whether to support HIP image/texture API's.
   virtual bool hasHIPImageSupport() const { return true; }
 
+  /// The first value in the pair is the minimum offset between two objects to
+  /// avoid false sharing (destructive interference). The second value in the
+  /// pair is maximum size of contiguous memory to promote true sharing
+  /// (constructive interference). Neither of these values are considered part
+  /// of the ABI and can be changed by targets at any time.
+  virtual std::pair<unsigned, unsigned> hardwareInterferenceSizes() const {
+    return std::make_pair(64, 64);
+  }
+
 protected:
   /// Copy type and layout related info.
   void copyAuxTarget(const TargetInfo *Aux);

diff --git a/clang/include/clang/Basic/arm_neon.td b/clang/include/clang/Basic/arm_neon.td
@@ -275,7 +275,7 @@ def OP_VCVT_BF16_F32_HI_A32
                            (call "vget_low", $p0))>;
 
 def OP_CVT_F32_BF16
-    : Op<(bitcast "R", (op "<<", (bitcast "int32_t", $p0),
+    : Op<(bitcast "R", (op "<<", (cast "int32_t", (bitcast "int16_t", $p0)),
                                  (literal "int32_t", "16")))>;
 
 //===----------------------------------------------------------------------===//

diff --git a/clang/include/clang/Basic/arm_sve.td b/clang/include/clang/Basic/arm_sve.td
@@ -1961,19 +1961,20 @@ def SVPSEL_D : SInst<"svpsel_lane_b64", "PPPm", "Pl", MergeNone, "", [IsStreamin
 
 // Standalone sve2.1 builtins
 let TargetGuard = "sve2p1" in {
-def SVORQV   : SInst<"svorqv[_{d}]", "{Pd", "csilUcUsUiUl", MergeNone, "aarch64_sve_orqv", [IsReductionQV]>;
-def SVEORQV  : SInst<"sveorqv[_{d}]", "{Pd", "csilUcUsUiUl", MergeNone, "aarch64_sve_eorqv", [IsReductionQV]>;
-def SVADDQV  : SInst<"svaddqv[_{d}]", "{Pd", "hfdcsilUcUsUiUl", MergeNone, "aarch64_sve_addqv", [IsReductionQV]>;
-def SVANDQV  : SInst<"svandqv[_{d}]", "{Pd", "csilUcUsUiUl", MergeNone, "aarch64_sve_andqv", [IsReductionQV]>;
-def SVSMAXQV : SInst<"svmaxqv[_{d}]", "{Pd", "csil", MergeNone, "aarch64_sve_smaxqv", [IsReductionQV]>;
-def SVUMAXQV : SInst<"svmaxqv[_{d}]", "{Pd", "UcUsUiUl", MergeNone, "aarch64_sve_umaxqv", [IsReductionQV]>;
-def SVSMINQV : SInst<"svminqv[_{d}]", "{Pd", "csil", MergeNone, "aarch64_sve_sminqv", [IsReductionQV]>;
-def SVUMINQV : SInst<"svminqv[_{d}]", "{Pd", "UcUsUiUl", MergeNone, "aarch64_sve_uminqv", [IsReductionQV]>;
-
-def SVFMAXNMQV: SInst<"svmaxnmqv[_{d}]", "{Pd", "hfd", MergeNone, "aarch64_sve_fmaxnmqv", [IsReductionQV]>;
-def SVFMINNMQV: SInst<"svminnmqv[_{d}]", "{Pd", "hfd", MergeNone, "aarch64_sve_fminnmqv", [IsReductionQV]>;
-def SVFMAXQV: SInst<"svmaxqv[_{d}]", "{Pd", "hfd", MergeNone, "aarch64_sve_fmaxqv", [IsReductionQV]>;
-def SVFMINQV: SInst<"svminqv[_{d}]", "{Pd", "hfd", MergeNone, "aarch64_sve_fminqv", [IsReductionQV]>;
+def SVORQV   : SInst<"svorqv[_{d}]",  "{Pd", "csilUcUsUiUl", MergeNone, "aarch64_sve_orqv",   [IsReductionQV]>;
+def SVEORQV  : SInst<"sveorqv[_{d}]", "{Pd", "csilUcUsUiUl", MergeNone, "aarch64_sve_eorqv",  [IsReductionQV]>;
+def SVADDQV  : SInst<"svaddqv[_{d}]", "{Pd", "csilUcUsUiUl", MergeNone, "aarch64_sve_addqv",  [IsReductionQV]>;
+def SVANDQV  : SInst<"svandqv[_{d}]", "{Pd", "csilUcUsUiUl", MergeNone, "aarch64_sve_andqv",  [IsReductionQV]>;
+def SVSMAXQV : SInst<"svmaxqv[_{d}]", "{Pd", "csil",         MergeNone, "aarch64_sve_smaxqv", [IsReductionQV]>;
+def SVUMAXQV : SInst<"svmaxqv[_{d}]", "{Pd", "UcUsUiUl",     MergeNone, "aarch64_sve_umaxqv", [IsReductionQV]>;
+def SVSMINQV : SInst<"svminqv[_{d}]", "{Pd", "csil",         MergeNone, "aarch64_sve_sminqv", [IsReductionQV]>;
+def SVUMINQV : SInst<"svminqv[_{d}]", "{Pd", "UcUsUiUl",     MergeNone, "aarch64_sve_uminqv", [IsReductionQV]>;
+
+def SVFADDQV   : SInst<"svaddqv[_{d}]",   "{Pd", "hfd", MergeNone, "aarch64_sve_faddqv",   [IsReductionQV]>;
+def SVFMAXNMQV : SInst<"svmaxnmqv[_{d}]", "{Pd", "hfd", MergeNone, "aarch64_sve_fmaxnmqv", [IsReductionQV]>;
+def SVFMINNMQV : SInst<"svminnmqv[_{d}]", "{Pd", "hfd", MergeNone, "aarch64_sve_fminnmqv", [IsReductionQV]>;
+def SVFMAXQV   : SInst<"svmaxqv[_{d}]",   "{Pd", "hfd", MergeNone, "aarch64_sve_fmaxqv",   [IsReductionQV]>;
+def SVFMINQV   : SInst<"svminqv[_{d}]",   "{Pd", "hfd", MergeNone, "aarch64_sve_fminqv",   [IsReductionQV]>;
 }
 
 let TargetGuard = "sve2p1|sme2" in {

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -4881,6 +4881,8 @@ def msimd128 : Flag<["-"], "msimd128">, Group<m_wasm_Features_Group>;
 def mno_simd128 : Flag<["-"], "mno-simd128">, Group<m_wasm_Features_Group>;
 def mrelaxed_simd : Flag<["-"], "mrelaxed-simd">, Group<m_wasm_Features_Group>;
 def mno_relaxed_simd : Flag<["-"], "mno-relaxed-simd">, Group<m_wasm_Features_Group>;
+def mhalf_precision : Flag<["-"], "mhalf-precision">, Group<m_wasm_Features_Group>;
+def mno_half_precision : Flag<["-"], "mno-half-precision">, Group<m_wasm_Features_Group>;
 def mnontrapping_fptoint : Flag<["-"], "mnontrapping-fptoint">, Group<m_wasm_Features_Group>;
 def mno_nontrapping_fptoint : Flag<["-"], "mno-nontrapping-fptoint">, Group<m_wasm_Features_Group>;
 def msign_ext : Flag<["-"], "msign-ext">, Group<m_wasm_Features_Group>;
@@ -6587,12 +6589,6 @@ def J : JoinedOrSeparate<["-"], "J">,
   Group<gfortran_Group>,
   Alias<module_dir>;
 
-let Visibility = [FlangOption] in {
-def no_fortran_main : Flag<["-"], "fno-fortran-main">,
-  Visibility<[FlangOption]>, Group<f_Group>,
-  HelpText<"Do not include Fortran_main.a (provided by Flang) when linking">;
-} // let Visibility = [ FlangOption ]
-
 //===----------------------------------------------------------------------===//
 // FC1 Options
 //===----------------------------------------------------------------------===//

diff --git a/clang/include/clang/Sema/DeclSpec.h b/clang/include/clang/Sema/DeclSpec.h
@@ -36,6 +36,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <optional>
 
 namespace clang {
   class ASTContext;
@@ -1790,6 +1791,7 @@ class DecompositionDeclarator {
   struct Binding {
     IdentifierInfo *Name;
     SourceLocation NameLoc;
+    std::optional<ParsedAttributes> Attrs;
   };
 
 private:
@@ -2339,10 +2341,10 @@ class Declarator {
   }
 
   /// Set the decomposition bindings for this declarator.
-  void
-  setDecompositionBindings(SourceLocation LSquareLoc,
-                           ArrayRef<DecompositionDeclarator::Binding> Bindings,
-                           SourceLocation RSquareLoc);
+  void setDecompositionBindings(
+      SourceLocation LSquareLoc,
+      MutableArrayRef<DecompositionDeclarator::Binding> Bindings,
+      SourceLocation RSquareLoc);
 
   /// AddTypeInfo - Add a chunk to this declarator. Also extend the range to
   /// EndLoc, which should be the last token of the chunk.

diff --git a/clang/include/clang/Sema/Lookup.h b/clang/include/clang/Sema/Lookup.h
@@ -499,9 +499,7 @@ class LookupResult {
   /// Note that while no result was found in the current instantiation,
   /// there were dependent base classes that could not be searched.
   void setNotFoundInCurrentInstantiation() {
-    assert((ResultKind == NotFound ||
-            ResultKind == NotFoundInCurrentInstantiation) &&
-           Decls.empty());
+    assert(ResultKind == NotFound && Decls.empty());
     ResultKind = NotFoundInCurrentInstantiation;
   }
 

diff --git a/clang/include/clang/Sema/ParsedAttr.h b/clang/include/clang/Sema/ParsedAttr.h
@@ -948,6 +948,7 @@ class ParsedAttributes : public ParsedAttributesView {
   ParsedAttributes(AttributeFactory &factory) : pool(factory) {}
   ParsedAttributes(const ParsedAttributes &) = delete;
   ParsedAttributes &operator=(const ParsedAttributes &) = delete;
+  ParsedAttributes(ParsedAttributes &&G) = default;
 
   AttributePool &getPool() const { return pool; }
 

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
@@ -7472,7 +7472,7 @@ class Sema final : public SemaBase {
   bool LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
                            CXXScopeSpec &SS);
   bool LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
-                        QualType ObjectType, bool AllowBuiltinCreation = false,
+                        bool AllowBuiltinCreation = false,
                         bool EnteringContext = false);
   ObjCProtocolDecl *LookupProtocol(
       IdentifierInfo *II, SourceLocation IdLoc,
@@ -8881,13 +8881,11 @@ class Sema final : public SemaBase {
     /// functions (but no function templates).
     FoundFunctions,
   };
-
-  bool
-  LookupTemplateName(LookupResult &R, Scope *S, CXXScopeSpec &SS,
-                     QualType ObjectType, bool EnteringContext,
-                     RequiredTemplateKind RequiredTemplate = SourceLocation(),
-                     AssumedTemplateKind *ATK = nullptr,
-                     bool AllowTypoCorrection = true);
+  bool LookupTemplateName(
+      LookupResult &R, Scope *S, CXXScopeSpec &SS, QualType ObjectType,
+      bool EnteringContext, bool &MemberOfUnknownSpecialization,
+      RequiredTemplateKind RequiredTemplate = SourceLocation(),
+      AssumedTemplateKind *ATK = nullptr, bool AllowTypoCorrection = true);
 
   TemplateNameKind isTemplateName(Scope *S, CXXScopeSpec &SS,
                                   bool hasTemplateKeyword,

diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h
@@ -225,15 +225,11 @@ class StoreManager {
   ///   invalidated. This should include any regions explicitly invalidated
   ///   even if they do not currently have bindings. Pass \c NULL if this
   ///   information will not be used.
-  virtual StoreRef invalidateRegions(Store store,
-                                  ArrayRef<SVal> Values,
-                                  const Expr *E, unsigned Count,
-                                  const LocationContext *LCtx,
-                                  const CallEvent *Call,
-                                  InvalidatedSymbols &IS,
-                                  RegionAndSymbolInvalidationTraits &ITraits,
-                                  InvalidatedRegions *InvalidatedTopLevel,
-                                  InvalidatedRegions *Invalidated) = 0;
+  virtual StoreRef invalidateRegions(
+      Store store, ArrayRef<SVal> Values, const Expr *Ex, unsigned Count,
+      const LocationContext *LCtx, const CallEvent *Call,
+      InvalidatedSymbols &IS, RegionAndSymbolInvalidationTraits &ITraits,
+      InvalidatedRegions *TopLevelRegions, InvalidatedRegions *Invalidated) = 0;
 
   /// enterStackFrame - Let the StoreManager to do something when execution
   /// engine is about to execute into a callee.

diff --git a/clang/lib/APINotes/APINotesFormat.h b/clang/lib/APINotes/APINotesFormat.h
@@ -24,7 +24,10 @@ const uint16_t VERSION_MAJOR = 0;
 /// API notes file minor version number.
 ///
 /// When the format changes IN ANY WAY, this number should be incremented.
-const uint16_t VERSION_MINOR = 25; // SwiftImportAs
+const uint16_t VERSION_MINOR = 26; // SwiftCopyable
+
+const uint8_t kSwiftCopyable = 1;
+const uint8_t kSwiftNonCopyable = 2;
 
 using IdentifierID = llvm::PointerEmbeddedInt<unsigned, 31>;
 using IdentifierIDField = llvm::BCVBR<16>;

diff --git a/clang/lib/APINotes/APINotesReader.cpp b/clang/lib/APINotes/APINotesReader.cpp
@@ -527,6 +527,13 @@ class TagTableInfo
       Info.EnumExtensibility =
           static_cast<EnumExtensibilityKind>((Payload & 0x3) - 1);
 
+    uint8_t Copyable =
+        endian::readNext<uint8_t, llvm::endianness::little>(Data);
+    if (Copyable == kSwiftNonCopyable)
+      Info.setSwiftCopyable(std::optional(false));
+    else if (Copyable == kSwiftCopyable)
+      Info.setSwiftCopyable(std::optional(true));
+
     unsigned ImportAsLength =
         endian::readNext<uint16_t, llvm::endianness::little>(Data);
     if (ImportAsLength > 0) {

diff --git a/clang/lib/APINotes/APINotesWriter.cpp b/clang/lib/APINotes/APINotesWriter.cpp
@@ -1128,7 +1128,7 @@ class TagTableInfo : public CommonTypeTableInfo<TagTableInfo, TagInfo> {
     return 2 + (TI.SwiftImportAs ? TI.SwiftImportAs->size() : 0) +
            2 + (TI.SwiftRetainOp ? TI.SwiftRetainOp->size() : 0) +
            2 + (TI.SwiftReleaseOp ? TI.SwiftReleaseOp->size() : 0) +
-           1 + getCommonTypeInfoSize(TI);
+           2 + getCommonTypeInfoSize(TI);
   }
 
   void emitUnversionedInfo(raw_ostream &OS, const TagInfo &TI) {
@@ -1146,6 +1146,11 @@ class TagTableInfo : public CommonTypeTableInfo<TagTableInfo, TagInfo> {
 
     writer.write<uint8_t>(Flags);
 
+    if (auto Copyable = TI.isSwiftCopyable())
+      writer.write<uint8_t>(*Copyable ? kSwiftCopyable : kSwiftNonCopyable);
+    else
+      writer.write<uint8_t>(0);
+
     if (auto ImportAs = TI.SwiftImportAs) {
       writer.write<uint16_t>(ImportAs->size() + 1);
       OS.write(ImportAs->c_str(), ImportAs->size());

diff --git a/clang/lib/APINotes/APINotesYAMLCompiler.cpp b/clang/lib/APINotes/APINotesYAMLCompiler.cpp
@@ -419,6 +419,7 @@ struct Tag {
   std::optional<EnumExtensibilityKind> EnumExtensibility;
   std::optional<bool> FlagEnum;
   std::optional<EnumConvenienceAliasKind> EnumConvenienceKind;
+  std::optional<bool> SwiftCopyable;
 };
 
 typedef std::vector<Tag> TagsSeq;
@@ -452,6 +453,7 @@ template <> struct MappingTraits<Tag> {
     IO.mapOptional("EnumExtensibility", T.EnumExtensibility);
     IO.mapOptional("FlagEnum", T.FlagEnum);
     IO.mapOptional("EnumKind", T.EnumConvenienceKind);
+    IO.mapOptional("SwiftCopyable", T.SwiftCopyable);
   }
 };
 } // namespace yaml
@@ -1009,6 +1011,9 @@ class YAMLConverter {
       if (Tag.SwiftReleaseOp)
         TI.SwiftReleaseOp = Tag.SwiftReleaseOp;
 
+      if (Tag.SwiftCopyable)
+        TI.setSwiftCopyable(Tag.SwiftCopyable);
+
       if (Tag.EnumConvenienceKind) {
         if (Tag.EnumExtensibility) {
           emitError(

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
@@ -1115,7 +1115,9 @@ int64_t Decl::getID() const {
 
 const FunctionType *Decl::getFunctionType(bool BlocksToo) const {
   QualType Ty;
-  if (const auto *D = dyn_cast<ValueDecl>(this))
+  if (const auto *D = dyn_cast<BindingDecl>(this))
+    return nullptr;
+  else if (const auto *D = dyn_cast<ValueDecl>(this))
     Ty = D->getType();
   else if (const auto *D = dyn_cast<TypedefNameDecl>(this))
     Ty = D->getUnderlyingType();

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
@@ -103,7 +103,7 @@ const Expr *Expr::skipRValueSubobjectAdjustments(
       }
     } else if (const auto *ME = dyn_cast<MemberExpr>(E)) {
       if (!ME->isArrow()) {
-        assert(ME->getBase()->getType()->getAsRecordDecl());
+        assert(ME->getBase()->getType()->isRecordType());
         if (const auto *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
           if (!Field->isBitField() && !Field->getType()->isReferenceType()) {
             E = ME->getBase();

diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
@@ -2706,7 +2706,11 @@ static bool checkFloatingPointResult(EvalInfo &Info, const Expr *E,
 static bool HandleFloatToFloatCast(EvalInfo &Info, const Expr *E,
                                    QualType SrcType, QualType DestType,
                                    APFloat &Result) {
-  assert(isa<CastExpr>(E) || isa<CompoundAssignOperator>(E));
+  assert((isa<CastExpr>(E) || isa<CompoundAssignOperator>(E) ||
+          isa<ConvertVectorExpr>(E)) &&
+         "HandleFloatToFloatCast has been checked with only CastExpr, "
+         "CompoundAssignOperator and ConvertVectorExpr. Please either validate "
+         "the new expression or address the root cause of this usage.");
   llvm::RoundingMode RM = getActiveRoundingMode(Info, E);
   APFloat::opStatus St;
   APFloat Value = Result;
@@ -9237,9 +9241,10 @@ bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) {
       bool HasValidResult = !Result.InvalidBase && !Result.Designator.Invalid &&
                             !Result.IsNullPtr;
       bool VoidPtrCastMaybeOK =
-          HasValidResult &&
-          Info.Ctx.hasSameUnqualifiedType(Result.Designator.getType(Info.Ctx),
-                                          E->getType()->getPointeeType());
+          Result.IsNullPtr ||
+          (HasValidResult &&
+           Info.Ctx.hasSimilarType(Result.Designator.getType(Info.Ctx),
+                                   E->getType()->getPointeeType()));
       // 1. We'll allow it in std::allocator::allocate, and anything which that
       //    calls.
       // 2. HACK 2022-03-28: Work around an issue with libstdc++'s
@@ -10709,8 +10714,11 @@ namespace {
     bool VisitUnaryImag(const UnaryOperator *E);
     bool VisitBinaryOperator(const BinaryOperator *E);
     bool VisitUnaryOperator(const UnaryOperator *E);
+    bool VisitConvertVectorExpr(const ConvertVectorExpr *E);
+    bool VisitShuffleVectorExpr(const ShuffleVectorExpr *E);
+
     // FIXME: Missing: conditional operator (for GNU
-    //                 conditional select), shufflevector, ExtVectorElementExpr
+    //                 conditional select), ExtVectorElementExpr
   };
 } // end anonymous namespace
 
@@ -10961,6 +10969,122 @@ bool VectorExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
   return Success(APValue(ResultElements.data(), ResultElements.size()), E);
 }
 
+static bool handleVectorElementCast(EvalInfo &Info, const FPOptions FPO,
+                                    const Expr *E, QualType SourceTy,
+                                    QualType DestTy, APValue const &Original,
+                                    APValue &Result) {
+  if (SourceTy->isIntegerType()) {
+    if (DestTy->isRealFloatingType()) {
+      Result = APValue(APFloat(0.0));
+      return HandleIntToFloatCast(Info, E, FPO, SourceTy, Original.getInt(),
+                                  DestTy, Result.getFloat());
+    }
+    if (DestTy->isIntegerType()) {
+      Result = APValue(
+          HandleIntToIntCast(Info, E, DestTy, SourceTy, Original.getInt()));
+      return true;
+    }
+  } else if (SourceTy->isRealFloatingType()) {
+    if (DestTy->isRealFloatingType()) {
+      Result = Original;
+      return HandleFloatToFloatCast(Info, E, SourceTy, DestTy,
+                                    Result.getFloat());
+    }
+    if (DestTy->isIntegerType()) {
+      Result = APValue(APSInt());
+      return HandleFloatToIntCast(Info, E, SourceTy, Original.getFloat(),
+                                  DestTy, Result.getInt());
+    }
+  }
+
+  Info.FFDiag(E, diag::err_convertvector_constexpr_unsupported_vector_cast)
+      << SourceTy << DestTy;
+  return false;
+}
+
+bool VectorExprEvaluator::VisitConvertVectorExpr(const ConvertVectorExpr *E) {
+  APValue Source;
+  QualType SourceVecType = E->getSrcExpr()->getType();
+  if (!EvaluateAsRValue(Info, E->getSrcExpr(), Source))
+    return false;
+
+  QualType DestTy = E->getType()->castAs<VectorType>()->getElementType();
+  QualType SourceTy = SourceVecType->castAs<VectorType>()->getElementType();
+
+  const FPOptions FPO = E->getFPFeaturesInEffect(Info.Ctx.getLangOpts());
+
+  auto SourceLen = Source.getVectorLength();
+  SmallVector<APValue, 4> ResultElements;
+  ResultElements.reserve(SourceLen);
+  for (unsigned EltNum = 0; EltNum < SourceLen; ++EltNum) {
+    APValue Elt;
+    if (!handleVectorElementCast(Info, FPO, E, SourceTy, DestTy,
+                                 Source.getVectorElt(EltNum), Elt))
+      return false;
+    ResultElements.push_back(std::move(Elt));
+  }
+
+  return Success(APValue(ResultElements.data(), ResultElements.size()), E);
+}
+
+static bool handleVectorShuffle(EvalInfo &Info, const ShuffleVectorExpr *E,
+                                QualType ElemType, APValue const &VecVal1,
+                                APValue const &VecVal2, unsigned EltNum,
+                                APValue &Result) {
+  unsigned const TotalElementsInInputVector1 = VecVal1.getVectorLength();
+  unsigned const TotalElementsInInputVector2 = VecVal2.getVectorLength();
+
+  APSInt IndexVal = E->getShuffleMaskIdx(Info.Ctx, EltNum);
+  int64_t index = IndexVal.getExtValue();
+  // The spec says that -1 should be treated as undef for optimizations,
+  // but in constexpr we'd have to produce an APValue::Indeterminate,
+  // which is prohibited from being a top-level constant value. Emit a
+  // diagnostic instead.
+  if (index == -1) {
+    Info.FFDiag(
+        E, diag::err_shufflevector_minus_one_is_undefined_behavior_constexpr)
+        << EltNum;
+    return false;
+  }
+
+  if (index < 0 ||
+      index >= TotalElementsInInputVector1 + TotalElementsInInputVector2)
+    llvm_unreachable("Out of bounds shuffle index");
+
+  if (index >= TotalElementsInInputVector1)
+    Result = VecVal2.getVectorElt(index - TotalElementsInInputVector1);
+  else
+    Result = VecVal1.getVectorElt(index);
+  return true;
+}
+
+bool VectorExprEvaluator::VisitShuffleVectorExpr(const ShuffleVectorExpr *E) {
+  APValue VecVal1;
+  const Expr *Vec1 = E->getExpr(0);
+  if (!EvaluateAsRValue(Info, Vec1, VecVal1))
+    return false;
+  APValue VecVal2;
+  const Expr *Vec2 = E->getExpr(1);
+  if (!EvaluateAsRValue(Info, Vec2, VecVal2))
+    return false;
+
+  VectorType const *DestVecTy = E->getType()->castAs<VectorType>();
+  QualType DestElTy = DestVecTy->getElementType();
+
+  auto TotalElementsInOutputVector = DestVecTy->getNumElements();
+
+  SmallVector<APValue, 4> ResultElements;
+  ResultElements.reserve(TotalElementsInOutputVector);
+  for (unsigned EltNum = 0; EltNum < TotalElementsInOutputVector; ++EltNum) {
+    APValue Elt;
+    if (!handleVectorShuffle(Info, E, DestElTy, VecVal1, VecVal2, EltNum, Elt))
+      return false;
+    ResultElements.push_back(std::move(Elt));
+  }
+
+  return Success(APValue(ResultElements.data(), ResultElements.size()), E);
+}
+
 //===----------------------------------------------------------------------===//
 // Array Evaluation
 //===----------------------------------------------------------------------===//