Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release:

MFC r309142 (by emaste):

Add WITH_LLD_AS_LD build knob

If set it installs LLD as /usr/bin/ld.  LLD (as of version 3.9) is not
capable of linking the world and kernel, but can self-host and link many
substantial applications. GNU ld continues to be used for the world and
kernel build, regardless of how this knob is set.

It is on by default for arm64, and off for all other CPU architectures.

Sponsored by:	The FreeBSD Foundation

MFC r310840:

Reapply 310775, now it also builds correctly if lldb is disabled:

Move llvm-objdump from CLANG_EXTRAS to installed by default

We currently install three tools from binutils 2.17.50: as, ld, and
objdump. Work is underway to migrate to a permissively-licensed
tool-chain, with one goal being the retirement of binutils 2.17.50.

LLVM's llvm-objdump is intended to be compatible with GNU objdump
although it is currently missing some options and may have formatting
differences. Enable it by default for testing and further investigation.
It may later be changed to install as /usr/bin/objdump, it becomes a
fully viable replacement.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D8879

MFC r312855 (by emaste):

Rename LLD_AS_LD to LLD_IS_LD, for consistency with CLANG_IS_CC

Reported by:	Dan McGregor <dan.mcgregor usask.ca>

MFC r313559 | glebius | 2017-02-10 18:34:48 +0100 (Fri, 10 Feb 2017) | 5 lines

Don't check struct rtentry on FreeBSD, it is an internal kernel structure.
On other systems it may be API structure for SIOCADDRT/SIOCDELRT.

Reviewed by:	emaste, dim

MFC r314152 (by jkim):

Remove an assembler flag, which is redundant since r309124.  The upstream
took care of it by introducing a macro NO_EXEC_STACK_DIRECTIVE.

http://llvm.org/viewvc/llvm-project?rev=273500&view=rev

Reviewed by:	dim

MFC r314564:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
4.0.0 (branches/release_40 296509).  The release will follow soon.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Also note that as of 4.0.0, lld should be able to link the base system
on amd64 and aarch64.  See the WITH_LLD_IS_LLD setting in src.conf(5).
Though please be aware that this is work in progress.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/4.0.0/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Jan Beich, Antoine Brodin and Eric Fiselier for
their help.

Relnotes:	yes
Exp-run:	antoine
PR:		215969, 216008

MFC r314708:

For now, revert r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

This commit is the cause of excessive compile times on skein_block.c
(and possibly other files) during kernel builds on amd64.

We never saw the problematic behavior described in this upstream commit,
so for now it is better to revert it.  An upstream bug has been filed
here: https://bugs.llvm.org/show_bug.cgi?id=32142

Reported by:	mjg

MFC r314795:

Reapply r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

Pull in r296992 from upstream llvm trunk (by Sanjoy Das):

  [SCEV] Decrease the recursion threshold for CompareValueComplexity

  Fixes PR32142.

  r287232 accidentally increased the recursion threshold for
  CompareValueComplexity from 2 to 32.  This change reverses that
  change by introducing a separate flag for CompareValueComplexity's
  threshold.

The latter revision fixes the excessive compile times for skein_block.c.

MFC r314907 | mmel | 2017-03-08 12:40:27 +0100 (Wed, 08 Mar 2017) | 7 lines

Unbreak ARMv6 world.

The new compiler_rt library imported with clang 4.0.0 have several fatal
issues (non-functional __udivsi3 for example) with ARM specific instrict
functions. As temporary workaround, until upstream solve these problems,
disable all thumb[1][2] related feature.

MFC r315016:

Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release.
We were already very close to the last release candidate, so this is a
pretty minor update.

Relnotes:	yes

MFC r316005:

Revert r314907, and pull in r298713 from upstream compiler-rt trunk (by
Weiming Zhao):

  builtins: Select correct code fragments when compiling for Thumb1/Thum2/ARM ISA.

  Summary:
  Value of __ARM_ARCH_ISA_THUMB isn't based on the actual compilation
  mode (-mthumb, -marm), it reflect's capability of given CPU.

  Due to this:
   - use  __tbumb__ and __thumb2__ insteand of __ARM_ARCH_ISA_THUMB
   - use '.thumb' directive consistently  in all affected files
   - decorate all thumb functions using
     DEFINE_COMPILERRT_THUMB_FUNCTION()

  ---------
  Note: This patch doesn't fix broken Thumb1 variant of __udivsi3 !

  Reviewers: weimingz, rengolin, compnerd

  Subscribers: aemerson, dim

  Differential Revision: https://reviews.llvm.org/D30938

Discussed with:	mmel

1 files changed, 115 insertions, 63 deletions

diff --git a/contrib/llvm/lib/IR/DebugInfoMetadata.cpp b/contrib/llvm/lib/IR/DebugInfoMetadata.cpp
index c58e368..8e21a90 100644
--- a/contrib/llvm/lib/IR/DebugInfoMetadata.cpp
+++ b/contrib/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -65,29 +65,29 @@ DILocation *DILocation::getImpl(LLVMContext &Context, unsigned Line,
                    Storage, Context.pImpl->DILocations);
 }
 
-unsigned DINode::getFlag(StringRef Flag) {
-  return StringSwitch<unsigned>(Flag)
+DINode::DIFlags DINode::getFlag(StringRef Flag) {
+  return StringSwitch<DIFlags>(Flag)
 #define HANDLE_DI_FLAG(ID, NAME) .Case("DIFlag" #NAME, Flag##NAME)
 #include "llvm/IR/DebugInfoFlags.def"
-      .Default(0);
+      .Default(DINode::FlagZero);
 }
 
-const char *DINode::getFlagString(unsigned Flag) {
+StringRef DINode::getFlagString(DIFlags Flag) {
   switch (Flag) {
-  default:
-    return "";
 #define HANDLE_DI_FLAG(ID, NAME)                                               \
   case Flag##NAME:                                                             \
     return "DIFlag" #NAME;
 #include "llvm/IR/DebugInfoFlags.def"
   }
+  return "";
 }
 
-unsigned DINode::splitFlags(unsigned Flags,
-                            SmallVectorImpl<unsigned> &SplitFlags) {
-  // Accessibility and member pointer flags need to be specially handled, since
-  // they're packed together.
-  if (unsigned A = Flags & FlagAccessibility) {
+DINode::DIFlags DINode::splitFlags(DIFlags Flags,
+                                   SmallVectorImpl<DIFlags> &SplitFlags) {
+  // Flags that are packed together need to be specially handled, so
+  // that, for example, we emit "DIFlagPublic" and not
+  // "DIFlagPrivate | DIFlagProtected".
+  if (DIFlags A = Flags & FlagAccessibility) {
     if (A == FlagPrivate)
       SplitFlags.push_back(FlagPrivate);
     else if (A == FlagProtected)
@@ -96,7 +96,7 @@ unsigned DINode::splitFlags(unsigned Flags,
       SplitFlags.push_back(FlagPublic);
     Flags &= ~A;
   }
-  if (unsigned R = Flags & FlagPtrToMemberRep) {
+  if (DIFlags R = Flags & FlagPtrToMemberRep) {
     if (R == FlagSingleInheritance)
       SplitFlags.push_back(FlagSingleInheritance);
     else if (R == FlagMultipleInheritance)
@@ -105,14 +105,17 @@ unsigned DINode::splitFlags(unsigned Flags,
       SplitFlags.push_back(FlagVirtualInheritance);
     Flags &= ~R;
   }
+  if ((Flags & FlagIndirectVirtualBase) == FlagIndirectVirtualBase) {
+    Flags &= ~FlagIndirectVirtualBase;
+    SplitFlags.push_back(FlagIndirectVirtualBase);
+  }
 
 #define HANDLE_DI_FLAG(ID, NAME)                                               \
-  if (unsigned Bit = Flags & ID) {                                             \
+  if (DIFlags Bit = Flags & Flag##NAME) {                                      \
     SplitFlags.push_back(Bit);                                                 \
     Flags &= ~Bit;                                                             \
   }
 #include "llvm/IR/DebugInfoFlags.def"
-
   return Flags;
 }
 
@@ -229,7 +232,7 @@ DIEnumerator *DIEnumerator::getImpl(LLVMContext &Context, int64_t Value,
 
 DIBasicType *DIBasicType::getImpl(LLVMContext &Context, unsigned Tag,
                                   MDString *Name, uint64_t SizeInBits,
-                                  uint64_t AlignInBits, unsigned Encoding,
+                                  uint32_t AlignInBits, unsigned Encoding,
                                   StorageType Storage, bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
   DEFINE_GETIMPL_LOOKUP(DIBasicType,
@@ -242,7 +245,7 @@ DIBasicType *DIBasicType::getImpl(LLVMContext &Context, unsigned Tag,
 DIDerivedType *DIDerivedType::getImpl(
     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
-    uint64_t AlignInBits, uint64_t OffsetInBits, unsigned Flags,
+    uint32_t AlignInBits, uint64_t OffsetInBits, DIFlags Flags,
     Metadata *ExtraData, StorageType Storage, bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
   DEFINE_GETIMPL_LOOKUP(DIDerivedType,
@@ -257,7 +260,7 @@ DIDerivedType *DIDerivedType::getImpl(
 DICompositeType *DICompositeType::getImpl(
     LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
-    uint64_t AlignInBits, uint64_t OffsetInBits, unsigned Flags,
+    uint32_t AlignInBits, uint64_t OffsetInBits, DIFlags Flags,
     Metadata *Elements, unsigned RuntimeLang, Metadata *VTableHolder,
     Metadata *TemplateParams, MDString *Identifier, StorageType Storage,
     bool ShouldCreate) {
@@ -278,8 +281,8 @@ DICompositeType *DICompositeType::getImpl(
 DICompositeType *DICompositeType::buildODRType(
     LLVMContext &Context, MDString &Identifier, unsigned Tag, MDString *Name,
     Metadata *File, unsigned Line, Metadata *Scope, Metadata *BaseType,
-    uint64_t SizeInBits, uint64_t AlignInBits, uint64_t OffsetInBits,
-    unsigned Flags, Metadata *Elements, unsigned RuntimeLang,
+    uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
+    DIFlags Flags, Metadata *Elements, unsigned RuntimeLang,
     Metadata *VTableHolder, Metadata *TemplateParams) {
   assert(!Identifier.getString().empty() && "Expected valid identifier");
   if (!Context.isODRUniquingDebugTypes())
@@ -312,8 +315,8 @@ DICompositeType *DICompositeType::buildODRType(
 DICompositeType *DICompositeType::getODRType(
     LLVMContext &Context, MDString &Identifier, unsigned Tag, MDString *Name,
     Metadata *File, unsigned Line, Metadata *Scope, Metadata *BaseType,
-    uint64_t SizeInBits, uint64_t AlignInBits, uint64_t OffsetInBits,
-    unsigned Flags, Metadata *Elements, unsigned RuntimeLang,
+    uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
+    DIFlags Flags, Metadata *Elements, unsigned RuntimeLang,
     Metadata *VTableHolder, Metadata *TemplateParams) {
   assert(!Identifier.getString().empty() && "Expected valid identifier");
   if (!Context.isODRUniquingDebugTypes())
@@ -335,9 +338,8 @@ DICompositeType *DICompositeType::getODRTypeIfExists(LLVMContext &Context,
   return Context.pImpl->DITypeMap->lookup(&Identifier);
 }
 
-DISubroutineType *DISubroutineType::getImpl(LLVMContext &Context,
-                                            unsigned Flags, uint8_t CC,
-                                            Metadata *TypeArray,
+DISubroutineType *DISubroutineType::getImpl(LLVMContext &Context, DIFlags Flags,
+                                            uint8_t CC, Metadata *TypeArray,
                                             StorageType Storage,
                                             bool ShouldCreate) {
   DEFINE_GETIMPL_LOOKUP(DISubroutineType, (Flags, CC, TypeArray));
@@ -345,14 +347,34 @@ DISubroutineType *DISubroutineType::getImpl(LLVMContext &Context,
   DEFINE_GETIMPL_STORE(DISubroutineType, (Flags, CC), Ops);
 }
 
+static const char *ChecksumKindName[DIFile::CSK_Last + 1] = {
+  "CSK_None",
+  "CSK_MD5",
+  "CSK_SHA1"
+};
+
+DIFile::ChecksumKind DIFile::getChecksumKind(StringRef CSKindStr) {
+  return StringSwitch<DIFile::ChecksumKind>(CSKindStr)
+      .Case("CSK_MD5", DIFile::CSK_MD5)
+      .Case("CSK_SHA1", DIFile::CSK_SHA1)
+      .Default(DIFile::CSK_None);
+}
+
+StringRef DIFile::getChecksumKindAsString() const {
+  assert(CSKind <= DIFile::CSK_Last && "Invalid checksum kind");
+  return ChecksumKindName[CSKind];
+}
+
 DIFile *DIFile::getImpl(LLVMContext &Context, MDString *Filename,
-                        MDString *Directory, StorageType Storage,
+                        MDString *Directory, DIFile::ChecksumKind CSKind,
+                        MDString *Checksum, StorageType Storage,
                         bool ShouldCreate) {
   assert(isCanonical(Filename) && "Expected canonical MDString");
   assert(isCanonical(Directory) && "Expected canonical MDString");
-  DEFINE_GETIMPL_LOOKUP(DIFile, (Filename, Directory));
-  Metadata *Ops[] = {Filename, Directory};
-  DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DIFile, Ops);
+  assert(isCanonical(Checksum) && "Expected canonical MDString");
+  DEFINE_GETIMPL_LOOKUP(DIFile, (Filename, Directory, CSKind, Checksum));
+  Metadata *Ops[] = {Filename, Directory, Checksum};
+  DEFINE_GETIMPL_STORE(DIFile, (CSKind), Ops);
 }
 
 DICompileUnit *DICompileUnit::getImpl(
@@ -361,7 +383,8 @@ DICompileUnit *DICompileUnit::getImpl(
     unsigned RuntimeVersion, MDString *SplitDebugFilename,
     unsigned EmissionKind, Metadata *EnumTypes, Metadata *RetainedTypes,
     Metadata *GlobalVariables, Metadata *ImportedEntities, Metadata *Macros,
-    uint64_t DWOId, StorageType Storage, bool ShouldCreate) {
+    uint64_t DWOId, bool SplitDebugInlining, StorageType Storage,
+    bool ShouldCreate) {
   assert(Storage != Uniqued && "Cannot unique DICompileUnit");
   assert(isCanonical(Producer) && "Expected canonical MDString");
   assert(isCanonical(Flags) && "Expected canonical MDString");
@@ -371,9 +394,10 @@ DICompileUnit *DICompileUnit::getImpl(
       File,      Producer,      Flags,           SplitDebugFilename,
       EnumTypes, RetainedTypes, GlobalVariables, ImportedEntities,
       Macros};
-  return storeImpl(new (array_lengthof(Ops)) DICompileUnit(
-                       Context, Storage, SourceLanguage, IsOptimized,
-                       RuntimeVersion, EmissionKind, DWOId, Ops),
+  return storeImpl(new (array_lengthof(Ops))
+                       DICompileUnit(Context, Storage, SourceLanguage,
+                                     IsOptimized, RuntimeVersion, EmissionKind,
+                                     DWOId, SplitDebugInlining, Ops),
                    Storage);
 }
 
@@ -412,7 +436,7 @@ DISubprogram *DISubprogram::getImpl(
     MDString *LinkageName, Metadata *File, unsigned Line, Metadata *Type,
     bool IsLocalToUnit, bool IsDefinition, unsigned ScopeLine,
     Metadata *ContainingType, unsigned Virtuality, unsigned VirtualIndex,
-    int ThisAdjustment, unsigned Flags, bool IsOptimized, Metadata *Unit,
+    int ThisAdjustment, DIFlags Flags, bool IsOptimized, Metadata *Unit,
     Metadata *TemplateParams, Metadata *Declaration, Metadata *Variables,
     StorageType Storage, bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
@@ -467,11 +491,12 @@ DILexicalBlockFile *DILexicalBlockFile::getImpl(LLVMContext &Context,
 
 DINamespace *DINamespace::getImpl(LLVMContext &Context, Metadata *Scope,
                                   Metadata *File, MDString *Name, unsigned Line,
-                                  StorageType Storage, bool ShouldCreate) {
+                                  bool ExportSymbols, StorageType Storage,
+                                  bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
-  DEFINE_GETIMPL_LOOKUP(DINamespace, (Scope, File, Name, Line));
+  DEFINE_GETIMPL_LOOKUP(DINamespace, (Scope, File, Name, Line, ExportSymbols));
   Metadata *Ops[] = {File, Scope, Name};
-  DEFINE_GETIMPL_STORE(DINamespace, (Line), Ops);
+  DEFINE_GETIMPL_STORE(DINamespace, (Line, ExportSymbols), Ops);
 }
 
 DIModule *DIModule::getImpl(LLVMContext &Context, Metadata *Scope,
@@ -509,25 +534,27 @@ DIGlobalVariable *
 DIGlobalVariable::getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
                           MDString *LinkageName, Metadata *File, unsigned Line,
                           Metadata *Type, bool IsLocalToUnit, bool IsDefinition,
-                          Metadata *Variable,
                           Metadata *StaticDataMemberDeclaration,
-                          StorageType Storage, bool ShouldCreate) {
+                          uint32_t AlignInBits, StorageType Storage,
+                          bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
   assert(isCanonical(LinkageName) && "Expected canonical MDString");
   DEFINE_GETIMPL_LOOKUP(DIGlobalVariable,
                         (Scope, Name, LinkageName, File, Line, Type,
-                         IsLocalToUnit, IsDefinition, Variable,
-                         StaticDataMemberDeclaration));
-  Metadata *Ops[] = {Scope, Name,        File,     Type,
-                     Name,  LinkageName, Variable, StaticDataMemberDeclaration};
-  DEFINE_GETIMPL_STORE(DIGlobalVariable, (Line, IsLocalToUnit, IsDefinition),
+                         IsLocalToUnit, IsDefinition,
+                         StaticDataMemberDeclaration, AlignInBits));
+  Metadata *Ops[] = {
+      Scope, Name, File, Type, Name, LinkageName, StaticDataMemberDeclaration};
+  DEFINE_GETIMPL_STORE(DIGlobalVariable,
+                       (Line, IsLocalToUnit, IsDefinition, AlignInBits),
                        Ops);
 }
 
 DILocalVariable *DILocalVariable::getImpl(LLVMContext &Context, Metadata *Scope,
                                           MDString *Name, Metadata *File,
                                           unsigned Line, Metadata *Type,
-                                          unsigned Arg, unsigned Flags,
+                                          unsigned Arg, DIFlags Flags,
+                                          uint32_t AlignInBits,
                                           StorageType Storage,
                                           bool ShouldCreate) {
   // 64K ought to be enough for any frontend.
@@ -536,9 +563,10 @@ DILocalVariable *DILocalVariable::getImpl(LLVMContext &Context, Metadata *Scope,
   assert(Scope && "Expected scope");
   assert(isCanonical(Name) && "Expected canonical MDString");
   DEFINE_GETIMPL_LOOKUP(DILocalVariable,
-                        (Scope, Name, File, Line, Type, Arg, Flags));
+                        (Scope, Name, File, Line, Type, Arg, Flags,
+                         AlignInBits));
   Metadata *Ops[] = {Scope, Name, File, Type};
-  DEFINE_GETIMPL_STORE(DILocalVariable, (Line, Arg, Flags), Ops);
+  DEFINE_GETIMPL_STORE(DILocalVariable, (Line, Arg, Flags, AlignInBits), Ops);
 }
 
 DIExpression *DIExpression::getImpl(LLVMContext &Context,
@@ -550,8 +578,9 @@ DIExpression *DIExpression::getImpl(LLVMContext &Context,
 
 unsigned DIExpression::ExprOperand::getSize() const {
   switch (getOp()) {
-  case dwarf::DW_OP_bit_piece:
+  case dwarf::DW_OP_LLVM_fragment:
     return 3;
+  case dwarf::DW_OP_constu:
   case dwarf::DW_OP_plus:
   case dwarf::DW_OP_minus:
     return 2;
@@ -570,9 +599,19 @@ bool DIExpression::isValid() const {
     switch (I->getOp()) {
     default:
       return false;
-    case dwarf::DW_OP_bit_piece:
-      // Piece expressions must be at the end.
+    case dwarf::DW_OP_LLVM_fragment:
+      // A fragment operator must appear at the end.
       return I->get() + I->getSize() == E->get();
+    case dwarf::DW_OP_stack_value: {
+      // Must be the last one or followed by a DW_OP_LLVM_fragment.
+      if (I->get() + I->getSize() == E->get())
+        break;
+      auto J = I;
+      if ((++J)->getOp() != dwarf::DW_OP_LLVM_fragment)
+        return false;
+      break;
+    }
+    case dwarf::DW_OP_constu:
     case dwarf::DW_OP_plus:
     case dwarf::DW_OP_minus:
     case dwarf::DW_OP_deref:
@@ -582,22 +621,35 @@ bool DIExpression::isValid() const {
   return true;
 }
 
-bool DIExpression::isBitPiece() const {
-  assert(isValid() && "Expected valid expression");
-  if (unsigned N = getNumElements())
-    if (N >= 3)
-      return getElement(N - 3) == dwarf::DW_OP_bit_piece;
-  return false;
-}
-
-uint64_t DIExpression::getBitPieceOffset() const {
-  assert(isBitPiece() && "Expected bit piece");
-  return getElement(getNumElements() - 2);
+Optional<DIExpression::FragmentInfo>
+DIExpression::getFragmentInfo(expr_op_iterator Start, expr_op_iterator End) {
+  for (auto I = Start; I != End; ++I)
+    if (I->getOp() == dwarf::DW_OP_LLVM_fragment) {
+      DIExpression::FragmentInfo Info = {I->getArg(1), I->getArg(0)};
+      return Info;
+    }
+  return None;
+}
+
+bool DIExpression::isConstant() const {
+  // Recognize DW_OP_constu C DW_OP_stack_value (DW_OP_LLVM_fragment Len Ofs)?.
+  if (getNumElements() != 3 && getNumElements() != 6)
+    return false;
+  if (getElement(0) != dwarf::DW_OP_constu ||
+      getElement(2) != dwarf::DW_OP_stack_value)
+    return false;
+  if (getNumElements() == 6 && getElement(3) != dwarf::DW_OP_LLVM_fragment)
+    return false;
+  return true;
 }
 
-uint64_t DIExpression::getBitPieceSize() const {
-  assert(isBitPiece() && "Expected bit piece");
-  return getElement(getNumElements() - 1);
+DIGlobalVariableExpression *
+DIGlobalVariableExpression::getImpl(LLVMContext &Context, Metadata *Variable,
+                                    Metadata *Expression, StorageType Storage,
+                                    bool ShouldCreate) {
+  DEFINE_GETIMPL_LOOKUP(DIGlobalVariableExpression, (Variable, Expression));
+  Metadata *Ops[] = {Variable, Expression};
+  DEFINE_GETIMPL_STORE_NO_CONSTRUCTOR_ARGS(DIGlobalVariableExpression, Ops);
 }
 
 DIObjCProperty *DIObjCProperty::getImpl(