Index: lib/Target/BPF/BPF.h
===================================================================
--- lib/Target/BPF/BPF.h
+++ lib/Target/BPF/BPF.h
@@ -15,11 +15,16 @@
 namespace llvm {
 class BPFTargetMachine;
 
+ModulePass *createBPFAbstractMemberAccess();
+
 FunctionPass *createBPFISelDag(BPFTargetMachine &TM);
+FunctionPass *createBPFMISimplifyPatchablePass();
 FunctionPass *createBPFMIPeepholePass();
 FunctionPass *createBPFMIPreEmitPeepholePass();
 FunctionPass *createBPFMIPreEmitCheckingPass();
 
+void initializeBPFAbstractMemberAccessPass(PassRegistry&);
+void initializeBPFMISimplifyPatchablePass(PassRegistry&);
 void initializeBPFMIPeepholePass(PassRegistry&);
 void initializeBPFMIPreEmitPeepholePass(PassRegistry&);
 void initializeBPFMIPreEmitCheckingPass(PassRegistry&);
Index: lib/Target/BPF/BPFAbstrctMemberAccess.cpp
===================================================================
--- /dev/null
+++ lib/Target/BPF/BPFAbstrctMemberAccess.cpp
@@ -0,0 +1,482 @@
+//===------ BPFAbstractMemberAccess.cpp - Abstracting Member Accesses -----===//
+//
+// 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 pass abstracted struct/union member accesses in order to support
+// compile-once run-everywhere (CO-RE). The CO-RE intends to compile the program
+// which can run on different kernels. In particular, if bpf program tries to
+// access a particular kernel data structure member, the details of the
+// intermediate member access will be remembered so bpf loader can do
+// necessary adjustment right before program loading.
+//
+// For example,
+//
+//   struct s {
+//     int a;
+//     int b;
+//   };
+//   struct t {
+//     struct s c;
+//     int d;
+//   };
+//   struct t e;
+//
+// For the member access e.c.b, the compiler will generate code
+//   &e + 4
+//
+// The compile-once run-everywhere instead generates the following code
+//   r = 4
+//   &e + r
+// The "4" in "r = 4" can be changed based on a particular kernel version.
+// For example, on a particular kernel version, if struct s is changed to
+//
+//   struct s {
+//     int new_field;
+//     int a;
+//     int b;
+//   }
+//
+// By repeating the member access on the host, the bpf loader can
+// adjust "r = 4" as "r = 8".
+//
+// This feature relies on the following three intrinsic calls:
+//   addr = preserve_array_access_index(base, dimension, index)
+//   addr = preserve_union_access_index(base, di_index)
+//          !llvm.preserve.access.index <union_ditype>
+//   addr = preserve_struct_access_index(base, gep_index, di_index)
+//          !llvm.preserve.access.index <struct_ditype>
+//
+//===----------------------------------------------------------------------===//
+
+#include "BPF.h"
+#include "BPFCORE.h"
+#include "BPFTargetMachine.h"
+#include "llvm/IR/DebugInfoMetadata.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Type.h"
+#include "llvm/IR/User.h"
+#include "llvm/IR/Value.h"
+#include "llvm/Pass.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+
+#define DEBUG_TYPE "bpf-abstract-member-access"
+
+namespace llvm {
+const std::string BPFCoreSharedInfo::AmaAttr = "btf_ama";
+const std::string BPFCoreSharedInfo::PatchableExtSecName =
+    ".BPF.patchable_externs";
+} // namespace llvm
+
+using namespace llvm;
+
+namespace {
+
+class BPFAbstractMemberAccess final : public ModulePass {
+  StringRef getPassName() const override {
+    return "BPF Abstract Member Access";
+  }
+
+  bool runOnModule(Module &M) override;
+
+public:
+  static char ID;
+  BPFAbstractMemberAccess() : ModulePass(ID) {}
+
+private:
+  enum : uint32_t {
+    BPFPreserveArrayAI = 1,
+    BPFPreserveUnionAI = 2,
+    BPFPreserveStructAI = 3,
+  };
+
+  std::map<std::string, GlobalVariable *> GEPGlobals;
+  // A map to link preserve_*_access_index instrinsic calls.
+  std::map<CallInst *, std::pair<CallInst *, uint32_t>> AIChain;
+  // A map to hold all the base preserve_*_access_index instrinsic calls.
+  // The base call is not an input of any other preserve_*_access_index
+  // intrinsics.
+  std::map<CallInst *, uint32_t> BaseAICalls;
+
+  bool doTransformation(Module &M);
+
+  void traceAICall(CallInst *Call, uint32_t Kind);
+  void traceBitCast(BitCastInst *BitCast, CallInst *Parent, uint32_t Kind);
+  void traceGEP(GetElementPtrInst *GEP, CallInst *Parent, uint32_t Kind);
+  void collectAICallChains(Module &M, Function &F);
+
+  bool IsPreserveDIAccessIndexCall(const CallInst *Call, uint32_t &Kind);
+  bool removePreserveAccessIndexIntrinsic(Module &M);
+  void replaceWithGEP(std::vector<CallInst *> &CallList,
+                      uint32_t NumOfZerosIndex, uint32_t DIIndex);
+
+  Value *computeBaseAndAccessStr(CallInst *Call, std::string &AccessStr,
+                                 std::string &AccessKey, uint32_t Kind,
+                                 MDNode *&TypeMeta);
+  bool getAccessIndex(const Value *IndexValue, uint64_t &AccessIndex);
+  bool transformGEPChain(Module &M, CallInst *Call, uint32_t Kind);
+};
+} // End anonymous namespace
+
+char BPFAbstractMemberAccess::ID = 0;
+INITIALIZE_PASS(BPFAbstractMemberAccess, DEBUG_TYPE,
+                "abstracting struct/union member accessees", false, false)
+
+ModulePass *llvm::createBPFAbstractMemberAccess() {
+  return new BPFAbstractMemberAccess();
+}
+
+bool BPFAbstractMemberAccess::runOnModule(Module &M) {
+  LLVM_DEBUG(dbgs() << "********** Abstract Member Accesses **********\n");
+
+  // Bail out if no debug info.
+  if (empty(M.debug_compile_units()))
+    return false;
+
+  return doTransformation(M);
+}
+
+/// Check whether a call is a preserve_*_access_index intrinsic call or not.
+bool BPFAbstractMemberAccess::IsPreserveDIAccessIndexCall(const CallInst *Call,
+                                                          uint32_t &Kind) {
+  if (!Call)
+    return false;
+
+  const auto *GV = dyn_cast<GlobalValue>(Call->getCalledValue());
+  if (!GV)
+    return false;
+  if (GV->getName().startswith("llvm.preserve.array.access.index")) {
+    Kind = BPFPreserveArrayAI;
+    return true;
+  }
+  if (GV->getName().startswith("llvm.preserve.union.access.index")) {
+    Kind = BPFPreserveUnionAI;
+    return true;
+  }
+  if (GV->getName().startswith("llvm.preserve.struct.access.index")) {
+    Kind = BPFPreserveStructAI;
+    return true;
+  }
+
+  return false;
+}
+
+void BPFAbstractMemberAccess::replaceWithGEP(std::vector<CallInst *> &CallList,
+                                             uint32_t DimensionIndex,
+                                             uint32_t GEPIndex) {
+  for (auto Call : CallList) {
+    uint32_t Dimension = 1;
+    if (DimensionIndex > 0)
+      Dimension = cast<ConstantInt>(Call->getArgOperand(DimensionIndex))
+                      ->getZExtValue();
+
+    Constant *Zero =
+        ConstantInt::get(Type::getInt32Ty(Call->getParent()->getContext()), 0);
+    SmallVector<Value *, 4> IdxList;
+    for (unsigned I = 0; I < Dimension; ++I)
+      IdxList.push_back(Zero);
+    IdxList.push_back(Call->getArgOperand(GEPIndex));
+
+    auto *GEP = GetElementPtrInst::CreateInBounds(Call->getArgOperand(0),
+                                                  IdxList, "", Call);
+    Call->replaceAllUsesWith(GEP);
+    Call->eraseFromParent();
+  }
+}
+
+bool BPFAbstractMemberAccess::removePreserveAccessIndexIntrinsic(Module &M) {
+  std::vector<CallInst *> PreserveArrayIndexCalls;
+  std::vector<CallInst *> PreserveUnionIndexCalls;
+  std::vector<CallInst *> PreserveStructIndexCalls;
+  bool Found = false;
+
+  for (Function &F : M)
+    for (auto &BB : F)
+      for (auto &I : BB) {
+        auto *Call = dyn_cast<CallInst>(&I);
+        uint32_t Kind;
+        if (!IsPreserveDIAccessIndexCall(Call, Kind))
+          continue;
+
+        Found = true;
+        if (Kind == BPFPreserveArrayAI)
+          PreserveArrayIndexCalls.push_back(Call);
+        else if (Kind == BPFPreserveUnionAI)
+          PreserveUnionIndexCalls.push_back(Call);
+        else
+          PreserveStructIndexCalls.push_back(Call);
+      }
+
+  // do the following transformation:
+  // . addr = preserve_array_access_index(base, dimension, index)
+  //   is transformed to
+  //     addr = GEP(base, dimenion's zero's, index)
+  // . addr = preserve_union_access_index(base, di_index)
+  //   is transformed to
+  //     addr = base, i.e., all usages of "addr" are replaced by "base".
+  // . addr = preserve_struct_access_index(base, gep_index, di_index)
+  //   is transformed to
+  //     addr = GEP(base, 0, gep_index)
+  replaceWithGEP(PreserveArrayIndexCalls, 1, 2);
+  replaceWithGEP(PreserveStructIndexCalls, 0, 1);
+  for (auto Call : PreserveUnionIndexCalls) {
+    Call->replaceAllUsesWith(Call->getArgOperand(0));
+    Call->eraseFromParent();
+  }
+
+  return Found;
+}
+
+void BPFAbstractMemberAccess::traceAICall(CallInst *Call, uint32_t Kind) {
+  for (User *U : Call->users()) {
+    Instruction *Inst = dyn_cast<Instruction>(U);
+    if (!Inst)
+      continue;
+
+    if (auto *BI = dyn_cast<BitCastInst>(Inst)) {
+      traceBitCast(BI, Call, Kind);
+    } else if (auto *CI = dyn_cast<CallInst>(Inst)) {
+      uint32_t CIKind;
+      if (IsPreserveDIAccessIndexCall(CI, CIKind)) {
+        AIChain[CI] = std::make_pair(Call, Kind);
+        traceAICall(CI, CIKind);
+      } else {
+        BaseAICalls[Call] = Kind;
+      }
+    } else if (auto *GI = dyn_cast<GetElementPtrInst>(Inst)) {
+      if (GI->hasAllZeroIndices())
+        traceGEP(GI, Call, Kind);
+      else
+        BaseAICalls[Call] = Kind;
+    }
+  }
+}
+
+void BPFAbstractMemberAccess::traceBitCast(BitCastInst *BitCast,
+                                           CallInst *Parent, uint32_t Kind) {
+  for (User *U : BitCast->users()) {
+    Instruction *Inst = dyn_cast<Instruction>(U);
+    if (!Inst)
+      continue;
+
+    if (auto *BI = dyn_cast<BitCastInst>(Inst)) {
+      traceBitCast(BI, Parent, Kind);
+    } else if (auto *CI = dyn_cast<CallInst>(Inst)) {
+      uint32_t CIKind;
+      if (IsPreserveDIAccessIndexCall(CI, CIKind)) {
+        AIChain[CI] = std::make_pair(Parent, Kind);
+        traceAICall(CI, CIKind);
+      } else {
+        BaseAICalls[Parent] = Kind;
+      }
+    } else if (auto *GI = dyn_cast<GetElementPtrInst>(Inst)) {
+      if (GI->hasAllZeroIndices())
+        traceGEP(GI, Parent, Kind);
+      else
+        BaseAICalls[Parent] = Kind;
+    }
+  }
+}
+
+void BPFAbstractMemberAccess::traceGEP(GetElementPtrInst *GEP, CallInst *Parent,
+                                       uint32_t Kind) {
+  for (User *U : GEP->users()) {
+    Instruction *Inst = dyn_cast<Instruction>(U);
+    if (!Inst)
+      continue;
+
+    if (auto *BI = dyn_cast<BitCastInst>(Inst)) {
+      traceBitCast(BI, Parent, Kind);
+    } else if (auto *CI = dyn_cast<CallInst>(Inst)) {
+      uint32_t CIKind;
+      if (IsPreserveDIAccessIndexCall(CI, CIKind)) {
+        AIChain[CI] = std::make_pair(Parent, Kind);
+        traceAICall(CI, CIKind);
+      } else {
+        BaseAICalls[Parent] = Kind;
+      }
+    } else if (auto *GI = dyn_cast<GetElementPtrInst>(Inst)) {
+      if (GI->hasAllZeroIndices())
+        traceGEP(GI, Parent, Kind);
+      else
+        BaseAICalls[Parent] = Kind;
+    }
+  }
+}
+
+void BPFAbstractMemberAccess::collectAICallChains(Module &M, Function &F) {
+  AIChain.clear();
+  BaseAICalls.clear();
+
+  for (auto &BB : F)
+    for (auto &I : BB) {
+      uint32_t Kind;
+      auto *Call = dyn_cast<CallInst>(&I);
+      if (!IsPreserveDIAccessIndexCall(Call, Kind) ||
+          AIChain.find(Call) != AIChain.end())
+        continue;
+
+      traceAICall(Call, Kind);
+    }
+}
+
+/// Get access index from the preserve_*_access_index intrinsic calls.
+bool BPFAbstractMemberAccess::getAccessIndex(const Value *IndexValue,
+                                             uint64_t &AccessIndex) {
+  const ConstantInt *CV = dyn_cast<ConstantInt>(IndexValue);
+  if (!CV)
+    return false;
+
+  AccessIndex = CV->getValue().getZExtValue();
+  return true;
+}
+
+/// Compute the base of the whole preserve_*_access_index chains, i.e., the base
+/// pointer of the first preserve_*_access_index call, and construct the access
+/// string, which will be the name of a global variable.
+Value *BPFAbstractMemberAccess::computeBaseAndAccessStr(CallInst *Call,
+                                                        std::string &AccessStr,
+                                                        std::string &AccessKey,
+                                                        uint32_t Kind,
+                                                        MDNode *&TypeMeta) {
+  Value *Base = nullptr;
+  std::vector<uint64_t> AccessIndices;
+  uint64_t TypeNameIndex = 0;
+  std::string LastTypeName;
+
+  while (Call) {
+    // Base of original corresponding GEP
+    Base = Call->getArgOperand(0);
+
+    // Type Name
+    std::string TypeName;
+    MDNode *MDN;
+    if (Kind == BPFPreserveUnionAI || Kind == BPFPreserveStructAI) {
+      MDN = Call->getMetadata(LLVMContext::MD_preserve_access_index);
+      if (!MDN)
+        return nullptr;
+
+      DIType *Ty = dyn_cast<DIType>(MDN);
+      if (!Ty)
+        return nullptr;
+
+      TypeName = Ty->getName();
+    }
+
+    // Access Index
+    uint64_t AccessIndex;
+    uint32_t ArgIndex = (Kind == BPFPreserveUnionAI) ? 1 : 2;
+    if (!getAccessIndex(Call->getArgOperand(ArgIndex), AccessIndex))
+      return nullptr;
+
+    AccessIndices.push_back(AccessIndex);
+    if (TypeName.size()) {
+      TypeNameIndex = AccessIndices.size() - 1;
+      LastTypeName = TypeName;
+      TypeMeta = MDN;
+    }
+
+    Kind = AIChain[Call].second;
+    Call = AIChain[Call].first;
+  }
+
+  // The intial type name is required.
+  // FIXME: if the initial type access is an array index, e.g.,
+  // &a[3].b.c, only one dimentional array is supported.
+  if (!LastTypeName.size() || AccessIndices.size() > TypeNameIndex + 2)
+    return nullptr;
+
+  // Construct the type string AccessStr.
+  for (unsigned I = 0; I < AccessIndices.size(); ++I)
+    AccessStr = std::to_string(AccessIndices[I]) + ":" + AccessStr;
+
+  if (TypeNameIndex == AccessIndices.size() - 1)
+    AccessStr = "0:" + AccessStr;
+
+  // Access key is the type name + access string, uniquely identifying
+  // one kernel memory access.
+  AccessKey = LastTypeName + ":" + AccessStr;
+
+  return Base;
+}
+
+/// Call/Kind is the base preserve_*_access_index() call. Attempts to do
+/// transformation to a chain of relocable GEPs.
+bool BPFAbstractMemberAccess::transformGEPChain(Module &M, CallInst *Call,
+                                                uint32_t Kind) {
+  std::string AccessStr, AccessKey;
+  MDNode *TypeMeta = nullptr;
+  Value *Base =
+      computeBaseAndAccessStr(Call, AccessStr, AccessKey, Kind, TypeMeta);
+  if (!Base)
+    return false;
+
+  // Do the transformation
+  // For any original GEP Call and Base %2 like
+  //   %4 = bitcast %struct.net_device** %dev1 to i64*
+  // it is transformed to:
+  //   %6 = load __BTF_0:sk_buff:0:0:2:0:
+  //   %7 = bitcast %struct.sk_buff* %2 to i8*
+  //   %8 = getelementptr i8, i8* %7, %6
+  //   %9 = bitcast i8* %8 to i64*
+  //   using %9 instead of %4
+  // The original Call inst is removed.
+  BasicBlock *BB = Call->getParent();
+  GlobalVariable *GV;
+
+  if (GEPGlobals.find(AccessKey) == GEPGlobals.end()) {
+    GV = new GlobalVariable(M, Type::getInt64Ty(BB->getContext()), false,
+                            GlobalVariable::ExternalLinkage, NULL, AccessStr);
+    GV->addAttribute(BPFCoreSharedInfo::AmaAttr);
+    // Set the metadata (debuginfo types) for the global.
+    if (TypeMeta)
+      GV->setMetadata(LLVMContext::MD_preserve_access_index, TypeMeta);
+    GEPGlobals[AccessKey] = GV;
+  } else {
+    GV = GEPGlobals[AccessKey];
+  }
+
+  // Load the global variable.
+  auto *LDInst = new LoadInst(Type::getInt64Ty(BB->getContext()), GV);
+  BB->getInstList().insert(Call->getIterator(), LDInst);
+
+  // Generate a BitCast
+  auto *BCInst = new BitCastInst(Base, Type::getInt8PtrTy(BB->getContext()));
+  BB->getInstList().insert(Call->getIterator(), BCInst);
+
+  // Generate a GetElementPtr
+  auto *GEP = GetElementPtrInst::Create(Type::getInt8Ty(BB->getContext()),
+                                        BCInst, LDInst);
+  BB->getInstList().insert(Call->getIterator(), GEP);
+
+  // Generate a BitCast
+  auto *BCInst2 = new BitCastInst(GEP, Call->getType());
+  BB->getInstList().insert(Call->getIterator(), BCInst2);
+
+  Call->replaceAllUsesWith(BCInst2);
+  Call->eraseFromParent();
+
+  return true;
+}
+
+bool BPFAbstractMemberAccess::doTransformation(Module &M) {
+  bool Transformed = false;
+
+  for (Function &F : M) {
+    // Collect PreserveDIAccessIndex Intrinsic call chains.
+    // The call chains will be used to generate the access
+    // patterns similar to GEP.
+    collectAICallChains(M, F);
+
+    for (auto &C : BaseAICalls)
+      Transformed = transformGEPChain(M, C.first, C.second) || Transformed;
+  }
+
+  return removePreserveAccessIndexIntrinsic(M) || Transformed;
+}
Index: lib/Target/BPF/BPFAsmPrinter.cpp
===================================================================
--- lib/Target/BPF/BPFAsmPrinter.cpp
+++ lib/Target/BPF/BPFAsmPrinter.cpp
@@ -38,7 +38,7 @@
 public:
   explicit BPFAsmPrinter(TargetMachine &TM,
                          std::unique_ptr<MCStreamer> Streamer)
-      : AsmPrinter(TM, std::move(Streamer)) {}
+      : AsmPrinter(TM, std::move(Streamer)), BTF(nullptr) {}
 
   StringRef getPassName() const override { return "BPF Assembly Printer"; }
   bool doInitialization(Module &M) override;
@@ -49,6 +49,9 @@
                              const char *ExtraCode, raw_ostream &O) override;
 
   void EmitInstruction(const MachineInstr *MI) override;
+
+private:
+  BTFDebug *BTF;
 };
 } // namespace
 
@@ -57,8 +60,10 @@
 
   // Only emit BTF when debuginfo available.
   if (MAI->doesSupportDebugInformation() && !empty(M.debug_compile_units())) {
-    Handlers.emplace_back(llvm::make_unique<BTFDebug>(this), "emit",
-                          "Debug Info Emission", "BTF", "BTF Emission");
+    BTF = new BTFDebug(this);
+    Handlers.push_back(HandlerInfo(std::unique_ptr<BTFDebug>(BTF), "emit",
+                                   "Debug Info Emission", "BTF",
+                                   "BTF Emission"));
   }
 
   return false;
@@ -133,11 +138,12 @@
 }
 
 void BPFAsmPrinter::EmitInstruction(const MachineInstr *MI) {
-
-  BPFMCInstLower MCInstLowering(OutContext, *this);
-
   MCInst TmpInst;
-  MCInstLowering.Lower(MI, TmpInst);
+
+  if (!BTF || !BTF->InstLower(MI, TmpInst)) {
+    BPFMCInstLower MCInstLowering(OutContext, *this);
+    MCInstLowering.Lower(MI, TmpInst);
+  }
   EmitToStreamer(*OutStreamer, TmpInst);
 }
 
Index: lib/Target/BPF/BPFCORE.h
===================================================================
--- /dev/null
+++ lib/Target/BPF/BPFCORE.h
@@ -0,0 +1,24 @@
+//===- BPFCORE.h - Common info for Compile-Once Run-EveryWhere  -*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_BPF_BPFCORE_H
+#define LLVM_LIB_TARGET_BPF_BPFCORE_H
+
+namespace llvm {
+
+class BPFCoreSharedInfo {
+public:
+  /// The attribute attached to globals representing a member offset
+  static const std::string AmaAttr;
+  /// The section name to identify a patchable external global
+  static const std::string PatchableExtSecName;
+};
+
+} // namespace llvm
+
+#endif
Index: lib/Target/BPF/BPFMISimplifyPatchable.cpp
===================================================================
--- /dev/null
+++ lib/Target/BPF/BPFMISimplifyPatchable.cpp
@@ -0,0 +1,163 @@
+//===----- BPFMISimplifyPatchable.cpp - MI Simplify Patchable Insts -------===//
+//
+// 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 pass targets a subset of instructions like below
+//    ld_imm64 r1, @global
+//    ldd r2, r1, 0
+//    add r3, struct_base_reg, r2
+//
+// Here @global should either present a AMA (abstruct member access) or
+// a patchable extern variable. And these two kinds of accesses
+// are subject to bpf load time patching. After this pass, the
+// code becomes
+//    ld_imm64 r1, @global
+//    add r3, struct_base_reg, r1
+//
+// Eventually, at BTF output stage, a relocation record will be generated
+// for ld_imm64 which should be replaced later by bpf loader:
+//    r1 = <calculated offset> or <to_be_patched_extern_val>
+//    add r3, struct_base_reg, r1
+// or
+//    ld_imm64 r1, <to_be_patched_extern_val>
+//    add r3, struct_base_reg, r1
+//
+//===----------------------------------------------------------------------===//
+
+#include "BPF.h"
+#include "BPFCORE.h"
+#include "BPFInstrInfo.h"
+#include "BPFTargetMachine.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "bpf-mi-simplify-patchable"
+
+namespace {
+
+struct BPFMISimplifyPatchable : public MachineFunctionPass {
+
+  static char ID;
+  const BPFInstrInfo *TII;
+  MachineFunction *MF;
+
+  BPFMISimplifyPatchable() : MachineFunctionPass(ID) {
+    initializeBPFMISimplifyPatchablePass(*PassRegistry::getPassRegistry());
+  }
+
+private:
+  // Initialize class variables.
+  void initialize(MachineFunction &MFParm);
+
+  bool removeLD(void);
+
+public:
+  // Main entry point for this pass.
+  bool runOnMachineFunction(MachineFunction &MF) override {
+    if (!skipFunction(MF.getFunction())) {
+      initialize(MF);
+    }
+    return removeLD();
+  }
+};
+
+// Initialize class variables.
+void BPFMISimplifyPatchable::initialize(MachineFunction &MFParm) {
+  MF = &MFParm;
+  TII = MF->getSubtarget<BPFSubtarget>().getInstrInfo();
+  LLVM_DEBUG(dbgs() << "*** BPF simplify patchable insts pass ***\n\n");
+}
+
+/// Remove unneeded Load instructions.
+bool BPFMISimplifyPatchable::removeLD() {
+  MachineRegisterInfo *MRI = &MF->getRegInfo();
+  MachineInstr *ToErase = nullptr;
+  bool Changed = false;
+
+  for (MachineBasicBlock &MBB : *MF) {
+    for (MachineInstr &MI : MBB) {
+      if (ToErase) {
+        ToErase->eraseFromParent();
+        ToErase = nullptr;
+      }
+
+      // Ensure the register format is LOAD <reg>, <reg>, 0
+      if (MI.getOpcode() != BPF::LDD && MI.getOpcode() != BPF::LDW &&
+          MI.getOpcode() != BPF::LDH && MI.getOpcode() != BPF::LDB &&
+          MI.getOpcode() != BPF::LDW32 && MI.getOpcode() != BPF::LDH32 &&
+          MI.getOpcode() != BPF::LDB32)
+        continue;
+
+      if (!MI.getOperand(0).isReg() || !MI.getOperand(1).isReg())
+        continue;
+
+      if (!MI.getOperand(2).isImm() || MI.getOperand(2).getImm())
+        continue;
+
+      unsigned DstReg = MI.getOperand(0).getReg();
+      unsigned SrcReg = MI.getOperand(1).getReg();
+      int64_t ImmVal = MI.getOperand(2).getImm();
+
+      MachineInstr *DefInst = MRI->getUniqueVRegDef(SrcReg);
+      if (!DefInst)
+        continue;
+
+      bool IsCandidate = false;
+      if (DefInst->getOpcode() == BPF::LD_imm64) {
+        const MachineOperand &MO = DefInst->getOperand(1);
+        if (MO.isGlobal()) {
+          const GlobalValue *GVal = MO.getGlobal();
+          auto *GVar = dyn_cast<GlobalVariable>(GVal);
+          if (GVar) {
+            // Global variables representing structure offset or
+            // patchable extern globals.
+            if (GVar->hasAttribute(BPFCoreSharedInfo::AmaAttr)) {
+              assert(ImmVal == 0);
+              IsCandidate = true;
+            } else if (!GVar->hasInitializer() && GVar->hasExternalLinkage() &&
+                       GVar->getSection() ==
+                           BPFCoreSharedInfo::PatchableExtSecName) {
+              if (ImmVal == 0)
+                IsCandidate = true;
+              else
+                errs() << "WARNING: unhandled patchable extern "
+                       << GVar->getName() << " with load offset " << ImmVal
+                       << "\n";
+            }
+          }
+        }
+      }
+
+      if (!IsCandidate)
+        continue;
+
+      auto Begin = MRI->use_begin(DstReg), End = MRI->use_end();
+      decltype(End) NextI;
+      for (auto I = Begin; I != End; I = NextI) {
+        NextI = std::next(I);
+        I->setReg(SrcReg);
+      }
+
+      ToErase = &MI;
+      Changed = true;
+    }
+  }
+
+  return Changed;
+}
+
+} // namespace
+
+INITIALIZE_PASS(BPFMISimplifyPatchable, DEBUG_TYPE,
+                "BPF PreEmit SimplifyPatchable", false, false)
+
+char BPFMISimplifyPatchable::ID = 0;
+FunctionPass *llvm::createBPFMISimplifyPatchablePass() {
+  return new BPFMISimplifyPatchable();
+}
Index: lib/Target/BPF/BPFTargetMachine.cpp
===================================================================
--- lib/Target/BPF/BPFTargetMachine.cpp
+++ lib/Target/BPF/BPFTargetMachine.cpp
@@ -34,6 +34,7 @@
   RegisterTargetMachine<BPFTargetMachine> Z(getTheBPFTarget());
 
   PassRegistry &PR = *PassRegistry::getPassRegistry();
+  initializeBPFAbstractMemberAccessPass(PR);
   initializeBPFMIPeepholePass(PR);
 }
 
@@ -68,6 +69,7 @@
       static_cast<BPFMCAsmInfo *>(const_cast<MCAsmInfo *>(AsmInfo.get()));
   MAI->setDwarfUsesRelocationsAcrossSections(!Subtarget.getUseDwarfRIS());
 }
+
 namespace {
 // BPF Code Generator Pass Configuration Options.
 class BPFPassConfig : public TargetPassConfig {
@@ -79,6 +81,7 @@
     return getTM<BPFTargetMachine>();
   }
 
+  void addIRPasses() override;
   bool addInstSelector() override;
   void addMachineSSAOptimization() override;
   void addPreEmitPass() override;
@@ -89,6 +92,13 @@
   return new BPFPassConfig(*this, PM);
 }
 
+void BPFPassConfig::addIRPasses() {
+
+  addPass(createBPFAbstractMemberAccess());
+
+  TargetPassConfig::addIRPasses();
+}
+
 // Install an instruction selector pass using
 // the ISelDag to gen BPF code.
 bool BPFPassConfig::addInstSelector() {
@@ -98,6 +108,8 @@
 }
 
 void BPFPassConfig::addMachineSSAOptimization() {
+  addPass(createBPFMISimplifyPatchablePass());
+
   // The default implementation must be called first as we want eBPF
   // Peephole ran at last.
   TargetPassConfig::addMachineSSAOptimization();
Index: lib/Target/BPF/BTF.h
===================================================================
--- lib/Target/BPF/BTF.h
+++ lib/Target/BPF/BTF.h
@@ -17,7 +17,7 @@
 ///
 /// The binary layout for .BTF.ext section:
 ///   struct ExtHeader
-///   FuncInfo and LineInfo subsections
+///   FuncInfo, LineInfo, OffsetReloc and ExternReloc subsections
 /// The FuncInfo subsection is defined as below:
 ///   BTFFuncInfo Size
 ///   struct SecFuncInfo for ELF section #1
@@ -32,6 +32,20 @@
 ///   struct SecLineInfo for ELF section #2
 ///   A number of struct BPFLineInfo for ELF section #2
 ///   ...
+/// The OffsetReloc subsection is defined as below:
+///   BPFOffsetReloc Size
+///   struct SecOffsetReloc for ELF section #1
+///   A number of struct BPFOffsetReloc for ELF section #1
+///   struct SecOffsetReloc for ELF section #2
+///   A number of struct BPFOffsetReloc for ELF section #2
+///   ...
+/// The ExternReloc subsection is defined as below:
+///   BPFExternReloc Size
+///   struct SecExternReloc for ELF section #1
+///   A number of struct BPFExternReloc for ELF section #1
+///   struct SecExternReloc for ELF section #2
+///   A number of struct BPFExternReloc for ELF section #2
+///   ...
 ///
 /// The section formats are also defined at
 ///    https://github.com/torvalds/linux/blob/master/include/uapi/linux/btf.h
@@ -49,7 +63,7 @@
 /// Sizes in bytes of various things in the BTF format.
 enum {
   HeaderSize = 24,
-  ExtHeaderSize = 24,
+  ExtHeaderSize = 40,
   CommonTypeSize = 12,
   BTFArraySize = 12,
   BTFEnumSize = 8,
@@ -58,8 +72,12 @@
   BTFDataSecVarSize = 12,
   SecFuncInfoSize = 8,
   SecLineInfoSize = 8,
+  SecOffsetRelocSize = 8,
+  SecExternRelocSize = 8,
   BPFFuncInfoSize = 8,
-  BPFLineInfoSize = 16
+  BPFLineInfoSize = 16,
+  BPFOffsetRelocSize = 12,
+  BPFExternRelocSize = 8,
 };
 
 /// The .BTF section header definition.
@@ -191,10 +209,14 @@
   uint8_t Flags;
   uint32_t HdrLen;
 
-  uint32_t FuncInfoOff; ///< Offset of func info section
-  uint32_t FuncInfoLen; ///< Length of func info section
-  uint32_t LineInfoOff; ///< Offset of line info section
-  uint32_t LineInfoLen; ///< Length of line info section
+  uint32_t FuncInfoOff;    ///< Offset of func info section
+  uint32_t FuncInfoLen;    ///< Length of func info section
+  uint32_t LineInfoOff;    ///< Offset of line info section
+  uint32_t LineInfoLen;    ///< Length of line info section
+  uint32_t OffsetRelocOff; ///< Offset of offset reloc section
+  uint32_t OffsetRelocLen; ///< Length of offset reloc section
+  uint32_t ExternRelocOff; ///< Offset of extern reloc section
+  uint32_t ExternRelocLen; ///< Length of extern reloc section
 };
 
 /// Specifying one function info.
@@ -220,10 +242,35 @@
 
 /// Specifying line info's in one section.
 struct SecLineInfo {
-  uint32_t SecNameOff;  ///< Section name index in the .BTF string tble
+  uint32_t SecNameOff;  ///< Section name index in the .BTF string table
   uint32_t NumLineInfo; ///< Number of line info's in this section
 };
 
+/// Specifying one offset relocation.
+struct BPFOffsetReloc {
+  uint32_t InsnOffset;    ///< Byte offset in this section
+  uint32_t TypeID;        ///< TypeID for the relocation
+  uint32_t OffsetNameOff; ///< The string to traverse types
+};
+
+/// Specifying offset relocation's in one section.
+struct SecOffsetReloc {
+  uint32_t SecNameOff;     ///< Section name index in the .BTF string table
+  uint32_t NumOffsetReloc; ///< Number of offset reloc's in this section
+};
+
+/// Specifying one offset relocation.
+struct BPFExternReloc {
+  uint32_t InsnOffset;    ///< Byte offset in this section
+  uint32_t ExternNameOff; ///< The string for external variable
+};
+
+/// Specifying extern relocation's in one section.
+struct SecExternReloc {
+  uint32_t SecNameOff;     ///< Section name index in the .BTF string table
+  uint32_t NumExternReloc; ///< Number of extern reloc's in this section
+};
+
 } // End namespace BTF.
 } // End namespace llvm.
 
Index: lib/Target/BPF/BTFDebug.h
===================================================================
--- lib/Target/BPF/BTFDebug.h
+++ lib/Target/BPF/BTFDebug.h
@@ -32,10 +32,12 @@
 class BTFTypeBase {
 protected:
   uint8_t Kind;
+  bool IsCompleted;
   uint32_t Id;
   struct BTF::CommonType BTFType;
 
 public:
+  BTFTypeBase() : IsCompleted(false) {}
   virtual ~BTFTypeBase() = default;
   void setId(uint32_t Id) { this->Id = Id; }
   uint32_t getId() { return Id; }
@@ -54,11 +56,13 @@
 /// volatile, typedef and restrict.
 class BTFTypeDerived : public BTFTypeBase {
   const DIDerivedType *DTy;
+  bool NeedsFixup;
 
 public:
-  BTFTypeDerived(const DIDerivedType *Ty, unsigned Tag);
+  BTFTypeDerived(const DIDerivedType *Ty, unsigned Tag, bool NeedsFixup);
   void completeType(BTFDebug &BDebug);
   void emitType(MCStreamer &OS);
+  void setPointeeType(uint32_t PointeeType);
 };
 
 /// Handle struct or union forward declaration.
@@ -100,13 +104,15 @@
 
 /// Handle array type.
 class BTFTypeArray : public BTFTypeBase {
+  uint32_t ElemSize;
   struct BTF::BTFArray ArrayInfo;
 
 public:
-  BTFTypeArray(uint32_t ElemTypeId, uint32_t NumElems);
+  BTFTypeArray(uint32_t ElemTypeId, uint32_t ElemSize, uint32_t NumElems);
   uint32_t getSize() { return BTFTypeBase::getSize() + BTF::BTFArraySize; }
   void completeType(BTFDebug &BDebug);
   void emitType(MCStreamer &OS);
+  void getLocInfo(uint32_t Loc, uint32_t &LocOffset, uint32_t &ElementTypeId);
 };
 
 /// Handle struct/union type.
@@ -123,6 +129,9 @@
   }
   void completeType(BTFDebug &BDebug);
   void emitType(MCStreamer &OS);
+  std::string getName();
+  void getMemberInfo(uint32_t Loc, uint32_t &Offset, uint32_t &MemberType);
+  uint32_t getStructSize();
 };
 
 /// Handle function pointer.
@@ -218,6 +227,19 @@
   uint32_t ColumnNum;   ///< the column number
 };
 
+/// Represent one offset relocation.
+struct BTFOffsetReloc {
+  const MCSymbol *Label;  ///< MCSymbol identifying insn for the reloc
+  uint32_t TypeID;        ///< Type ID
+  uint32_t OffsetNameOff; ///< The string to traverse types
+};
+
+/// Represent one extern relocation.
+struct BTFExternReloc {
+  const MCSymbol *Label;  ///< MCSymbol identifying insn for the reloc
+  uint32_t ExternNameOff; ///< The extern variable name
+};
+
 /// Collect and emit BTF information.
 class BTFDebug : public DebugHandlerBase {
   MCStreamer &OS;
@@ -225,14 +247,21 @@
   bool LineInfoGenerated;
   uint32_t SecNameOff;
   uint32_t ArrayIndexTypeId;
+  bool MapDefNotCollected;
   BTFStringTable StringTable;
   std::vector<std::unique_ptr<BTFTypeBase>> TypeEntries;
   std::unordered_map<const DIType *, uint32_t> DIToIdMap;
   std::map<uint32_t, std::vector<BTFFuncInfo>> FuncInfoTable;
   std::map<uint32_t, std::vector<BTFLineInfo>> LineInfoTable;
+  std::map<uint32_t, std::vector<BTFOffsetReloc>> OffsetRelocTable;
+  std::map<uint32_t, std::vector<BTFExternReloc>> ExternRelocTable;
   StringMap<std::vector<std::string>> FileContent;
-  std::map<std::string, std::unique_ptr<BTFKindDataSec>>
-      DataSecEntries;
+  std::map<std::string, std::unique_ptr<BTFKindDataSec>> DataSecEntries;
+  std::vector<BTFTypeStruct *> StructTypes;
+  std::vector<BTFTypeArray *> ArrayTypes;
+  std::map<std::string, int64_t> AccessOffsets;
+  std::map<std::string, std::pair<bool, std::vector<BTFTypeDerived *>>>
+      FixupDerivedTypes;
 
   /// Add types to TypeEntries.
   /// @{
@@ -245,7 +274,8 @@
   /// IR type visiting functions.
   /// @{
   void visitTypeEntry(const DIType *Ty);
-  void visitTypeEntry(const DIType *Ty, uint32_t &TypeId);
+  void visitTypeEntry(const DIType *Ty, uint32_t &TypeId, bool CheckPointer,
+                      bool SeenPointer);
   void visitBasicType(const DIBasicType *BTy, uint32_t &TypeId);
   void visitSubroutineType(
       const DISubroutineType *STy, bool ForSubprog,
@@ -258,7 +288,9 @@
                        uint32_t &TypeId);
   void visitArrayType(const DICompositeType *ATy, uint32_t &TypeId);
   void visitEnumType(const DICompositeType *ETy, uint32_t &TypeId);
-  void visitDerivedType(const DIDerivedType *DTy, uint32_t &TypeId);
+  void visitDerivedType(const DIDerivedType *DTy, uint32_t &TypeId,
+                        bool CheckPointer, bool SeenPointer);
+  void visitMapDefType(const DIType *Ty, uint32_t &TypeId);
   /// @}
 
   /// Get the file content for the subprogram. Certain lines of the file
@@ -270,7 +302,21 @@
                          uint32_t Column);
 
   /// Generate types and variables for globals.
-  void processGlobals(void);
+  void processGlobals(bool ProcessingMapDef);
+
+  /// Generate one offset relocation record.
+  void generateOffsetReloc(const MachineInstr *MI, const MCSymbol *ORSym,
+                           DIType *RootTy, StringRef AccessPattern);
+
+  /// Set the to-be-traversed Struct/Array Type based on TypeId.
+  void setTypeFromId(uint32_t TypeId, BTFTypeStruct **PrevStructType,
+                     BTFTypeArray **PrevArrayType);
+
+  /// Populating unprocessed struct type.
+  unsigned populateStructType(const DIType *Ty);
+
+  /// Process LD_imm64 instructions.
+  void processLDimm64(const MachineInstr *MI);
 
   /// Emit common header of .BTF and .BTF.ext sections.
   void emitCommonHeader();
@@ -291,6 +337,9 @@
 public:
   BTFDebug(AsmPrinter *AP);
 
+  ///
+  bool InstLower(const MachineInstr *MI, MCInst &OutMI);
+
   /// Get the special array index type id.
   uint32_t getArrayIndexTypeId() {
     assert(ArrayIndexTypeId);
Index: lib/Target/BPF/BTFDebug.cpp
===================================================================
--- lib/Target/BPF/BTFDebug.cpp
+++ lib/Target/BPF/BTFDebug.cpp
@@ -11,6 +11,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "BTFDebug.h"
+#include "BPF.h"
+#include "BPFCORE.h"
+#include "MCTargetDesc/BPFMCTargetDesc.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
@@ -37,8 +40,9 @@
   OS.EmitIntValue(BTFType.Size, 4);
 }
 
-BTFTypeDerived::BTFTypeDerived(const DIDerivedType *DTy, unsigned Tag)
-    : DTy(DTy) {
+BTFTypeDerived::BTFTypeDerived(const DIDerivedType *DTy, unsigned Tag,
+                               bool NeedsFixup)
+    : DTy(DTy), NeedsFixup(NeedsFixup) {
   switch (Tag) {
   case dwarf::DW_TAG_pointer_type:
     Kind = BTF::BTF_KIND_PTR;
@@ -62,8 +66,15 @@
 }
 
 void BTFTypeDerived::completeType(BTFDebug &BDebug) {
+  if (IsCompleted)
+    return;
+  IsCompleted = true;
+
   BTFType.NameOff = BDebug.addString(DTy->getName());
 
+  if (NeedsFixup)
+    return;
+
   // The base type for PTR/CONST/VOLATILE could be void.
   const DIType *ResolvedType = DTy->getBaseType();
   if (!ResolvedType) {
@@ -78,6 +89,10 @@
 
 void BTFTypeDerived::emitType(MCStreamer &OS) { BTFTypeBase::emitType(OS); }
 
+void BTFTypeDerived::setPointeeType(uint32_t PointeeType) {
+  BTFType.Type = PointeeType;
+}
+
 /// Represent a struct/union forward declaration.
 BTFTypeFwd::BTFTypeFwd(StringRef Name, bool IsUnion) : Name(Name) {
   Kind = BTF::BTF_KIND_FWD;
@@ -86,6 +101,10 @@
 }
 
 void BTFTypeFwd::completeType(BTFDebug &BDebug) {
+  if (IsCompleted)
+    return;
+  IsCompleted = true;
+
   BTFType.NameOff = BDebug.addString(Name);
 }
 
@@ -119,6 +138,10 @@
 }
 
 void BTFTypeInt::completeType(BTFDebug &BDebug) {
+  if (IsCompleted)
+    return;
+  IsCompleted = true;
+
   BTFType.NameOff = BDebug.addString(Name);
 }
 
@@ -135,6 +158,10 @@
 }
 
 void BTFTypeEnum::completeType(BTFDebug &BDebug) {
+  if (IsCompleted)
+    return;
+  IsCompleted = true;
+
   BTFType.NameOff = BDebug.addString(ETy->getName());
 
   DINodeArray Elements = ETy->getElements();
@@ -157,7 +184,9 @@
   }
 }
 
-BTFTypeArray::BTFTypeArray(uint32_t ElemTypeId, uint32_t NumElems) {
+BTFTypeArray::BTFTypeArray(uint32_t ElemTypeId, uint32_t ElemSize,
+                           uint32_t NumElems)
+    : ElemSize(ElemSize) {
   Kind = BTF::BTF_KIND_ARRAY;
   BTFType.NameOff = 0;
   BTFType.Info = Kind << 24;
@@ -169,6 +198,9 @@
 
 /// Represent a BTF array.
 void BTFTypeArray::completeType(BTFDebug &BDebug) {
+  if (IsCompleted)
+    return;
+  IsCompleted = true;
 
   // The IR does not really have a type for the index.
   // A special type for array index should have been
@@ -184,6 +216,12 @@
   OS.EmitIntValue(ArrayInfo.Nelems, 4);
 }
 
+void BTFTypeArray::getLocInfo(uint32_t Loc, uint32_t &LocOffset,
+                              uint32_t &ElementTypeId) {
+  ElementTypeId = ArrayInfo.ElemType;
+  LocOffset = Loc * ElemSize;
+}
+
 /// Represent either a struct or a union.
 BTFTypeStruct::BTFTypeStruct(const DICompositeType *STy, bool IsStruct,
                              bool HasBitField, uint32_t Vlen)
@@ -194,6 +232,10 @@
 }
 
 void BTFTypeStruct::completeType(BTFDebug &BDebug) {
+  if (IsCompleted)
+    return;
+  IsCompleted = true;
+
   BTFType.NameOff = BDebug.addString(STy->getName());
 
   // Add struct/union members.
@@ -224,6 +266,17 @@
   }
 }
 
+std::string BTFTypeStruct::getName() { return STy->getName(); }
+
+void BTFTypeStruct::getMemberInfo(uint32_t Loc, uint32_t &MemberOffset,
+                                  uint32_t &MemberType) {
+  MemberType = Members[Loc].Type;
+  MemberOffset =
+      HasBitField ? Members[Loc].Offset & 0xffffff : Members[Loc].Offset;
+}
+
+uint32_t BTFTypeStruct::getStructSize() { return STy->getSizeInBits() >> 3; }
+
 /// The Func kind represents both subprogram and pointee of function
 /// pointers. If the FuncName is empty, it represents a pointee of function
 /// pointer. Otherwise, it represents a subprogram. The func arg names
@@ -238,6 +291,10 @@
 }
 
 void BTFTypeFuncProto::completeType(BTFDebug &BDebug) {
+  if (IsCompleted)
+    return;
+  IsCompleted = true;
+
   DITypeRefArray Elements = STy->getTypeArray();
   auto RetType = Elements[0];
   BTFType.Type = RetType ? BDebug.getTypeId(RetType) : 0;
@@ -275,6 +332,10 @@
 }
 
 void BTFTypeFunc::completeType(BTFDebug &BDebug) {
+  if (IsCompleted)
+    return;
+  IsCompleted = true;
+
   BTFType.NameOff = BDebug.addString(Name);
 }
 
@@ -335,7 +396,8 @@
 
 BTFDebug::BTFDebug(AsmPrinter *AP)
     : DebugHandlerBase(AP), OS(*Asm->OutStreamer), SkipInstruction(false),
-      LineInfoGenerated(false), SecNameOff(0), ArrayIndexTypeId(0) {
+      LineInfoGenerated(false), SecNameOff(0), ArrayIndexTypeId(0),
+      MapDefNotCollected(true) {
   addString("\0");
 }
 
@@ -417,6 +479,7 @@
 
   auto TypeEntry =
       llvm::make_unique<BTFTypeStruct>(CTy, IsStruct, HasBitField, VLen);
+  StructTypes.push_back(TypeEntry.get());
   TypeId = addType(std::move(TypeEntry), CTy);
 
   // Visit all struct members.
@@ -426,11 +489,14 @@
 
 void BTFDebug::visitArrayType(const DICompositeType *CTy, uint32_t &TypeId) {
   // Visit array element type.
-  uint32_t ElemTypeId;
-  visitTypeEntry(CTy->getBaseType(), ElemTypeId);
+  uint32_t ElemTypeId, ElemSize;
+  const DIType *ElemType = CTy->getBaseType();
+  visitTypeEntry(ElemType, ElemTypeId, false, false);
+  ElemSize = ElemType->getSizeInBits() >> 3;
 
   if (!CTy->getSizeInBits()) {
-    auto TypeEntry = llvm::make_unique<BTFTypeArray>(ElemTypeId, 0);
+    auto TypeEntry = llvm::make_unique<BTFTypeArray>(ElemTypeId, 0, 0);
+    ArrayTypes.push_back(TypeEntry.get());
     ElemTypeId = addType(std::move(TypeEntry), CTy);
   } else {
     // Visit array dimensions.
@@ -442,11 +508,14 @@
           auto *CI = SR->getCount().dyn_cast<ConstantInt *>();
           int64_t Count = CI->getSExtValue();
 
-          auto TypeEntry = llvm::make_unique<BTFTypeArray>(ElemTypeId, Count);
+          auto TypeEntry =
+              llvm::make_unique<BTFTypeArray>(ElemTypeId, ElemSize, Count);
+          ArrayTypes.push_back(TypeEntry.get());
           if (I == 0)
             ElemTypeId = addType(std::move(TypeEntry), CTy);
           else
             ElemTypeId = addType(std::move(TypeEntry));
+          ElemSize = ElemSize * Count;
         }
     }
   }
@@ -498,13 +567,42 @@
 }
 
 /// Handle pointer, typedef, const, volatile, restrict and member types.
-void BTFDebug::visitDerivedType(const DIDerivedType *DTy, uint32_t &TypeId) {
+void BTFDebug::visitDerivedType(const DIDerivedType *DTy, uint32_t &TypeId,
+                                bool CheckPointer, bool SeenPointer) {
   unsigned Tag = DTy->getTag();
 
+  /// Try to avoid chasing pointees, esp. structure pointees which may
+  /// unnecessary bring in a lot of types.
+  if (CheckPointer && !SeenPointer) {
+    SeenPointer = Tag == dwarf::DW_TAG_pointer_type;
+  }
+
+  if (CheckPointer && SeenPointer) {
+    const DIType *Base = DTy->getBaseType();
+    if (Base) {
+      if (const auto *CTy = dyn_cast<DICompositeType>(Base)) {
+        auto CTag = CTy->getTag();
+        if ((CTag == dwarf::DW_TAG_structure_type ||
+             CTag == dwarf::DW_TAG_union_type) &&
+            !CTy->isForwardDecl()) {
+          /// Find a candidate, generate a fixup. Later on the struct/union
+          /// pointee type will be replaced with either a real type or
+          /// a forward declaration.
+          auto TypeEntry = llvm::make_unique<BTFTypeDerived>(DTy, Tag, true);
+          auto &Fixup = FixupDerivedTypes[CTy->getName()];
+          Fixup.first = CTag == dwarf::DW_TAG_union_type;
+          Fixup.second.push_back(TypeEntry.get());
+          TypeId = addType(std::move(TypeEntry), DTy);
+          return;
+        }
+      }
+    }
+  }
+
   if (Tag == dwarf::DW_TAG_pointer_type || Tag == dwarf::DW_TAG_typedef ||
       Tag == dwarf::DW_TAG_const_type || Tag == dwarf::DW_TAG_volatile_type ||
       Tag == dwarf::DW_TAG_restrict_type) {
-    auto TypeEntry = llvm::make_unique<BTFTypeDerived>(DTy, Tag);
+    auto TypeEntry = llvm::make_unique<BTFTypeDerived>(DTy, Tag, false);
     TypeId = addType(std::move(TypeEntry), DTy);
   } else if (Tag != dwarf::DW_TAG_member) {
     return;
@@ -513,10 +611,14 @@
   // Visit base type of pointer, typedef, const, volatile, restrict or
   // struct/union member.
   uint32_t TempTypeId = 0;
-  visitTypeEntry(DTy->getBaseType(), TempTypeId);
+  if (Tag == dwarf::DW_TAG_member)
+    visitTypeEntry(DTy->getBaseType(), TempTypeId, true, false);
+  else
+    visitTypeEntry(DTy->getBaseType(), TempTypeId, CheckPointer, SeenPointer);
 }
 
-void BTFDebug::visitTypeEntry(const DIType *Ty, uint32_t &TypeId) {
+void BTFDebug::visitTypeEntry(const DIType *Ty, uint32_t &TypeId,
+                              bool CheckPointer, bool SeenPointer) {
   if (!Ty || DIToIdMap.find(Ty) != DIToIdMap.end()) {
     TypeId = DIToIdMap[Ty];
     return;
@@ -530,14 +632,52 @@
   else if (const auto *CTy = dyn_cast<DICompositeType>(Ty))
     visitCompositeType(CTy, TypeId);
   else if (const auto *DTy = dyn_cast<DIDerivedType>(Ty))
-    visitDerivedType(DTy, TypeId);
+    visitDerivedType(DTy, TypeId, CheckPointer, SeenPointer);
   else
     llvm_unreachable("Unknown DIType");
 }
 
 void BTFDebug::visitTypeEntry(const DIType *Ty) {
   uint32_t TypeId;
-  visitTypeEntry(Ty, TypeId);
+  visitTypeEntry(Ty, TypeId, false, false);
+}
+
+void BTFDebug::visitMapDefType(const DIType *Ty, uint32_t &TypeId) {
+  if (!Ty || DIToIdMap.find(Ty) != DIToIdMap.end()) {
+    TypeId = DIToIdMap[Ty];
+    return;
+  }
+
+  // MapDef type is a struct type
+  const auto *CTy = dyn_cast<DICompositeType>(Ty);
+  if (!CTy)
+    return;
+
+  auto Tag = CTy->getTag();
+  if (Tag != dwarf::DW_TAG_structure_type || CTy->isForwardDecl())
+    return;
+
+  // Record this type
+  const DINodeArray Elements = CTy->getElements();
+  bool HasBitField = false;
+  for (const auto *Element : Elements) {
+    auto E = cast<DIDerivedType>(Element);
+    if (E->isBitField()) {
+      HasBitField = true;
+      break;
+    }
+  }
+
+  auto TypeEntry =
+      llvm::make_unique<BTFTypeStruct>(CTy, true, HasBitField, Elements.size());
+  StructTypes.push_back(TypeEntry.get());
+  TypeId = addType(std::move(TypeEntry), CTy);
+
+  // Visit all struct members
+  for (const auto *Element : Elements) {
+    const auto *MemberType = cast<DIDerivedType>(Element);
+    visitTypeEntry(MemberType->getBaseType());
+  }
 }
 
 /// Read file contents from the actual file or from the source
@@ -635,7 +775,8 @@
 
 void BTFDebug::emitBTFExtSection() {
   // Do not emit section if empty FuncInfoTable and LineInfoTable.
-  if (!FuncInfoTable.size() && !LineInfoTable.size())
+  if (!FuncInfoTable.size() && !LineInfoTable.size() &&
+      !OffsetRelocTable.size() && !ExternRelocTable.size())
     return;
 
   MCContext &Ctx = OS.getContext();
@@ -647,6 +788,8 @@
 
   // Account for FuncInfo/LineInfo record size as well.
   uint32_t FuncLen = 4, LineLen = 4;
+  // Do not account for optional OffsetReloc/ExternReloc.
+  uint32_t OffsetRelocLen = 0, ExternRelocLen = 0;
   for (const auto &FuncSec : FuncInfoTable) {
     FuncLen += BTF::SecFuncInfoSize;
     FuncLen += FuncSec.second.size() * BTF::BPFFuncInfoSize;
@@ -655,11 +798,28 @@
     LineLen += BTF::SecLineInfoSize;
     LineLen += LineSec.second.size() * BTF::BPFLineInfoSize;
   }
+  for (const auto &OffsetRelocSec : OffsetRelocTable) {
+    OffsetRelocLen += BTF::SecOffsetRelocSize;
+    OffsetRelocLen += OffsetRelocSec.second.size() * BTF::BPFOffsetRelocSize;
+  }
+  for (const auto &ExternRelocSec : ExternRelocTable) {
+    ExternRelocLen += BTF::SecExternRelocSize;
+    ExternRelocLen += ExternRelocSec.second.size() * BTF::BPFExternRelocSize;
+  }
+
+  if (OffsetRelocLen)
+    OffsetRelocLen += 4;
+  if (ExternRelocLen)
+    ExternRelocLen += 4;
 
   OS.EmitIntValue(0, 4);
   OS.EmitIntValue(FuncLen, 4);
   OS.EmitIntValue(FuncLen, 4);
   OS.EmitIntValue(LineLen, 4);
+  OS.EmitIntValue(FuncLen + LineLen, 4);
+  OS.EmitIntValue(OffsetRelocLen, 4);
+  OS.EmitIntValue(FuncLen + LineLen + OffsetRelocLen, 4);
+  OS.EmitIntValue(ExternRelocLen, 4);
 
   // Emit func_info table.
   OS.AddComment("FuncInfo");
@@ -692,6 +852,39 @@
       OS.EmitIntValue(LineInfo.LineNum << 10 | LineInfo.ColumnNum, 4);
     }
   }
+
+  // Emit offset reloc table.
+  if (OffsetRelocLen) {
+    OS.AddComment("OffsetReloc");
+    OS.EmitIntValue(BTF::BPFOffsetRelocSize, 4);
+    for (const auto &OffsetRelocSec : OffsetRelocTable) {
+      OS.AddComment("Offset reloc section string offset=" +
+                    std::to_string(OffsetRelocSec.first));
+      OS.EmitIntValue(OffsetRelocSec.first, 4);
+      OS.EmitIntValue(OffsetRelocSec.second.size(), 4);
+      for (const auto &OffsetRelocInfo : OffsetRelocSec.second) {
+        Asm->EmitLabelReference(OffsetRelocInfo.Label, 4);
+        OS.EmitIntValue(OffsetRelocInfo.TypeID, 4);
+        OS.EmitIntValue(OffsetRelocInfo.OffsetNameOff, 4);
+      }
+    }
+  }
+
+  // Emit extern reloc table.
+  if (ExternRelocLen) {
+    OS.AddComment("ExternReloc");
+    OS.EmitIntValue(BTF::BPFExternRelocSize, 4);
+    for (const auto &ExternRelocSec : ExternRelocTable) {
+      OS.AddComment("Extern reloc section string offset=" +
+                    std::to_string(ExternRelocSec.first));
+      OS.EmitIntValue(ExternRelocSec.first, 4);
+      OS.EmitIntValue(ExternRelocSec.second.size(), 4);
+      for (const auto &ExternRelocInfo : ExternRelocSec.second) {
+        Asm->EmitLabelReference(ExternRelocInfo.Label, 4);
+        OS.EmitIntValue(ExternRelocInfo.ExternNameOff, 4);
+      }
+    }
+  }
 }
 
 void BTFDebug::beginFunctionImpl(const MachineFunction *MF) {
@@ -704,6 +897,30 @@
   }
   SkipInstruction = false;
 
+  // Collect MapDef types. Map definition needs to collect
+  // pointee types. Do it first. Otherwise, for the following
+  // case:
+  //    struct m { ...};
+  //    struct t {
+  //      struct m *key;
+  //    };
+  //    foo(struct t *arg);
+  //
+  //    struct mapdef {
+  //      ...
+  //      struct m *key;
+  //      ...
+  //    } __attribute__((section(".maps"))) hash_map;
+  //
+  // If subroutine foo is traversed first, a type chain
+  // "ptr->struct m(fwd)" will be created and later on
+  // when traversing mapdef, since "ptr->struct m" exists,
+  // the traversal of "struct m" will be omitted.
+  if (MapDefNotCollected) {
+    processGlobals(true);
+    MapDefNotCollected = false;
+  }
+
   // Collect all types locally referenced in this function.
   // Use RetainedNodes so we can collect all argument names
   // even if the argument is not used.
@@ -728,6 +945,9 @@
       llvm::make_unique<BTFTypeFunc>(SP->getName(), ProtoTypeId);
   uint32_t FuncTypeId = addType(std::move(FuncTypeEntry));
 
+  for (const auto &TypeEntry : TypeEntries)
+    TypeEntry->completeType(*this);
+
   // Construct funcinfo and the first lineinfo for the function.
   MCSymbol *FuncLabel = Asm->getFunctionBegin();
   BTFFuncInfo FuncInfo;
@@ -750,6 +970,133 @@
   SecNameOff = 0;
 }
 
+/// On-demand populate struct types as requested from abstract member
+/// accessing.
+unsigned BTFDebug::populateStructType(const DIType *Ty) {
+  unsigned Id;
+  visitTypeEntry(Ty, Id, false, false);
+  for (const auto &TypeEntry : TypeEntries)
+    TypeEntry->completeType(*this);
+  return Id;
+}
+
+// Find struct/array debuginfo types given a type id.
+void BTFDebug::setTypeFromId(uint32_t TypeId, BTFTypeStruct **PrevStructType,
+                             BTFTypeArray **PrevArrayType) {
+  for (const auto &StructType : StructTypes) {
+    if (StructType->getId() == TypeId) {
+      *PrevStructType = StructType;
+      return;
+    }
+  }
+  for (const auto &ArrayType : ArrayTypes) {
+    if (ArrayType->getId() == TypeId) {
+      *PrevArrayType = ArrayType;
+      return;
+    }
+  }
+}
+
+/// Generate a struct member offset relocation.
+void BTFDebug::generateOffsetReloc(const MachineInstr *MI,
+                                   const MCSymbol *ORSym, DIType *RootTy,
+                                   StringRef AccessPattern) {
+  BTFTypeStruct *PrevStructType = nullptr;
+  BTFTypeArray *PrevArrayType = nullptr;
+  unsigned RootId = populateStructType(RootTy);
+  setTypeFromId(RootId, &PrevStructType, &PrevArrayType);
+  unsigned RootTySize = PrevStructType->getStructSize();
+
+  BTFOffsetReloc OffsetReloc;
+  OffsetReloc.Label = ORSym;
+  OffsetReloc.OffsetNameOff = addString(AccessPattern.drop_back());
+  OffsetReloc.TypeID = RootId;
+
+  uint32_t Start = 0, End = 0, Offset = 0;
+  bool FirstAccess = true;
+  for (auto C : AccessPattern) {
+    if (C != ':') {
+      End++;
+    } else {
+      std::string SubStr = AccessPattern.substr(Start, End - Start);
+      int Loc = std::stoi(SubStr);
+
+      if (FirstAccess) {
+        Offset = Loc * RootTySize;
+        FirstAccess = false;
+      } else if (PrevStructType) {
+        uint32_t MemberOffset, MemberTypeId;
+        PrevStructType->getMemberInfo(Loc, MemberOffset, MemberTypeId);
+
+        Offset += MemberOffset >> 3;
+        PrevStructType = nullptr;
+        setTypeFromId(MemberTypeId, &PrevStructType, &PrevArrayType);
+      } else if (PrevArrayType) {
+        uint32_t LocOffset, ElementTypeId;
+        PrevArrayType->getLocInfo(Loc, LocOffset, ElementTypeId);
+
+        Offset += LocOffset;
+        PrevArrayType = nullptr;
+        setTypeFromId(ElementTypeId, &PrevStructType, &PrevArrayType);
+      }
+      Start = End + 1;
+      End = Start;
+    }
+  }
+  AccessOffsets[RootTy->getName().str() + ":" + AccessPattern.str()] = Offset;
+  OffsetRelocTable[SecNameOff].push_back(OffsetReloc);
+}
+
+void BTFDebug::processLDimm64(const MachineInstr *MI) {
+  // If the insn is an LD_imm64, the following two cases
+  // will generate an .BTF.ext record.
+  //
+  // If the insn is "r2 = LD_imm64 @__BTF_...",
+  // add this insn into the .BTF.ext OffsetReloc subsection.
+  // Relocation looks like:
+  //  . SecName:
+  //    . InstOffset
+  //    . TypeID
+  //    . OffSetNameOff
+  // Later, the insn is replaced with "r2 = <offset>"
+  // where "<offset>" equals to the offset based on current
+  // type definitions.
+  //
+  // If the insn is "r2 = LD_imm64 @VAR" and VAR is
+  // a patchable external global, add this insn into the .BTF.ext
+  // ExternReloc subsection.
+  // Relocation looks like:
+  //  . SecName:
+  //    . InstOffset
+  //    . ExternNameOff
+  // Later, the insn is replaced with "r2 = <value>" or
+  // "LD_imm64 r2, <value>" where "<value>" = 0.
+
+  // check whether this is a candidate or not
+  const MachineOperand &MO = MI->getOperand(1);
+  if (MO.isGlobal()) {
+    const GlobalValue *GVal = MO.getGlobal();
+    auto *GVar = dyn_cast<GlobalVariable>(GVal);
+    if (GVar && GVar->hasAttribute(BPFCoreSharedInfo::AmaAttr)) {
+      MCSymbol *ORSym = OS.getContext().createTempSymbol();
+      OS.EmitLabel(ORSym);
+
+      MDNode *MDN = GVar->getMetadata(LLVMContext::MD_preserve_access_index);
+      DIType *Ty = dyn_cast<DIType>(MDN);
+      generateOffsetReloc(MI, ORSym, Ty, GVar->getName());
+    } else if (GVar && !GVar->hasInitializer() && GVar->hasExternalLinkage() &&
+               GVar->getSection() == BPFCoreSharedInfo::PatchableExtSecName) {
+      MCSymbol *ORSym = OS.getContext().createTempSymbol();
+      OS.EmitLabel(ORSym);
+
+      BTFExternReloc ExternReloc;
+      ExternReloc.Label = ORSym;
+      ExternReloc.ExternNameOff = addString(GVar->getName());
+      ExternRelocTable[SecNameOff].push_back(ExternReloc);
+    }
+  }
+}
+
 void BTFDebug::beginInstruction(const MachineInstr *MI) {
   DebugHandlerBase::beginInstruction(MI);
 
@@ -770,6 +1117,9 @@
       return;
   }
 
+  if (MI->getOpcode() == BPF::LD_imm64)
+    processLDimm64(MI);
+
   // Skip this instruction if no DebugLoc or the DebugLoc
   // is the same as the previous instruction.
   const DebugLoc &DL = MI->getDebugLoc();
@@ -798,7 +1148,7 @@
   PrevInstLoc = DL;
 }
 
-void BTFDebug::processGlobals() {
+void BTFDebug::processGlobals(bool ProcessingMapDef) {
   // Collect all types referenced by globals.
   const Module *M = MMI->getModule();
   for (const GlobalVariable &Global : M->globals()) {
@@ -806,11 +1156,29 @@
     if (!Global.hasInitializer() && Global.hasExternalLinkage())
       continue;
 
+    // Decide the section name.
+    std::string SecName;
+    if (Global.hasSection()) {
+      SecName = Global.getSection().str();
+    } else {
+      // data, bss, or readonly sections
+      if (Global.isConstant())
+        SecName = ".rodata";
+      else
+        SecName = Global.getInitializer()->isZeroValue() ? ".bss" : ".data";
+    }
+
+    if (ProcessingMapDef != (SecName == ".maps"))
+      continue;
+
     SmallVector<DIGlobalVariableExpression *, 1> GVs;
     Global.getDebugInfo(GVs);
     uint32_t GVTypeId = 0;
     for (auto *GVE : GVs) {
-      visitTypeEntry(GVE->getVariable()->getType(), GVTypeId);
+      if (SecName == ".maps")
+        visitMapDefType(GVE->getVariable()->getType(), GVTypeId);
+      else
+        visitTypeEntry(GVE->getVariable()->getType(), GVTypeId, false, false);
       break;
     }
 
@@ -835,18 +1203,6 @@
         llvm::make_unique<BTFKindVar>(Global.getName(), GVTypeId, GVarInfo);
     uint32_t VarId = addType(std::move(VarEntry));
 
-    // Decide the section name.
-    std::string SecName;
-    if (Global.hasSection()) {
-      SecName = Global.getSection().str();
-    } else {
-      // data, bss, or readonly sections
-      if (Global.isConstant())
-        SecName += ".rodata";
-      else
-        SecName += Global.getInitializer()->isZeroValue() ? ".bss" : ".data";
-    }
-
     // Find or create a DataSec
     if (DataSecEntries.find(SecName) == DataSecEntries.end()) {
       DataSecEntries[SecName] = llvm::make_unique<BTFKindDataSec>(Asm, SecName);
@@ -858,14 +1214,81 @@
 
     DataSecEntries[SecName]->addVar(VarId, Asm->getSymbol(&Global), Size);
   }
+}
 
-  for (auto &DataSec : DataSecEntries)
-    addType(std::move(DataSec.second));
+/// Emit proper patchable instructions.
+bool BTFDebug::InstLower(const MachineInstr *MI, MCInst &OutMI) {
+  if (MI->getOpcode() == BPF::LD_imm64) {
+    const MachineOperand &MO = MI->getOperand(1);
+    if (MO.isGlobal()) {
+      const GlobalValue *GVal = MO.getGlobal();
+      auto *GVar = dyn_cast<GlobalVariable>(GVal);
+      if (GVar && GVar->hasAttribute(BPFCoreSharedInfo::AmaAttr)) {
+        MDNode *MDN = GVar->getMetadata(LLVMContext::MD_preserve_access_index);
+        DIType *Ty = dyn_cast<DIType>(MDN);
+        std::string TypeName = Ty->getName();
+        int64_t Imm = AccessOffsets[TypeName + ":" + GVar->getName().str()];
+
+        // Emit "mov ri, <imm>" for abstract member accesses.
+        OutMI.setOpcode(BPF::MOV_ri);
+        OutMI.addOperand(MCOperand::createReg(MI->getOperand(0).getReg()));
+        OutMI.addOperand(MCOperand::createImm(Imm));
+        return true;
+      } else if (GVar && !GVar->hasInitializer() &&
+                 GVar->hasExternalLinkage() &&
+                 GVar->getSection() == BPFCoreSharedInfo::PatchableExtSecName) {
+        const IntegerType *IntTy = dyn_cast<IntegerType>(GVar->getValueType());
+        assert(IntTy);
+        // For patchable externals, emit "LD_imm64, ri, 0" if the external
+        // variable is 64bit width, emit "mov ri, 0" otherwise.
+        if (IntTy->getBitWidth() == 64)
+          OutMI.setOpcode(BPF::LD_imm64);
+        else
+          OutMI.setOpcode(BPF::MOV_ri);
+        OutMI.addOperand(MCOperand::createReg(MI->getOperand(0).getReg()));
+        OutMI.addOperand(MCOperand::createImm(0));
+        return true;
+      }
+    }
+  }
+  return false;
 }
 
 void BTFDebug::endModule() {
-  // Collect all global types/variables.
-  processGlobals();
+  // Collect MapDef globals if not collected yet.
+  if (MapDefNotCollected) {
+    processGlobals(true);
+    MapDefNotCollected = false;
+  }
+
+  // Collect global types/variables except MapDef globals.
+  processGlobals(false);
+  for (auto &DataSec : DataSecEntries)
+    addType(std::move(DataSec.second));
+
+  // Fixups
+  for (auto &Fixup : FixupDerivedTypes) {
+    std::string TypeName = Fixup.first;
+    bool IsUnion = Fixup.second.first;
+
+    // Search through struct types
+    uint32_t StructTypeId = 0;
+    for (const auto &StructType : StructTypes) {
+      if (StructType->getName() == TypeName) {
+        StructTypeId = StructType->getId();
+        break;
+      }
+    }
+
+    if (StructTypeId == 0) {
+      auto FwdTypeEntry = llvm::make_unique<BTFTypeFwd>(TypeName, IsUnion);
+      StructTypeId = addType(std::move(FwdTypeEntry));
+    }
+
+    for (auto &DType : Fixup.second.second) {
+      DType->setPointeeType(StructTypeId);
+    }
+  }
 
   // Complete BTF type cross refereences.
   for (const auto &TypeEntry : TypeEntries)
Index: lib/Target/BPF/CMakeLists.txt
===================================================================
--- lib/Target/BPF/CMakeLists.txt
+++ lib/Target/BPF/CMakeLists.txt
@@ -13,6 +13,7 @@
 add_public_tablegen_target(BPFCommonTableGen)
 
 add_llvm_target(BPFCodeGen
+  BPFAbstrctMemberAccess.cpp
   BPFAsmPrinter.cpp
   BPFFrameLowering.cpp
   BPFInstrInfo.cpp
@@ -25,6 +26,7 @@
   BPFTargetMachine.cpp
   BPFMIPeephole.cpp
   BPFMIChecking.cpp
+  BPFMISimplifyPatchable.cpp
   BTFDebug.cpp
   )
 
Index: test/CodeGen/BPF/BTF/binary-format.ll
===================================================================
--- test/CodeGen/BPF/BTF/binary-format.ll
+++ test/CodeGen/BPF/BTF/binary-format.ll
@@ -15,31 +15,33 @@
 
 ; CHECK:    '.BTF'
 ; CHECK-EL: 0x00000000 9feb0100 18000000 00000000 30000000
-; CHECK-EL: 0x00000010 30000000 33000000 2b000000 00000001
+; CHECK-EL: 0x00000010 30000000 33000000 01000000 00000001
 ; CHECK-EL: 0x00000020 04000000 20000001 00000000 0100000d
-; CHECK-EL: 0x00000030 01000000 2f000000 01000000 31000000
-; CHECK-EL: 0x00000040 0000000c 02000000 002e7465 7874002f
+; CHECK-EL: 0x00000030 01000000 05000000 01000000 07000000
+; CHECK-EL: 0x00000040 0000000c 02000000 00696e74 00610066
 ; CHECK-EB: 0x00000000 eb9f0100 00000018 00000000 00000030
-; CHECK-EB: 0x00000010 00000030 00000033 0000002b 01000000
+; CHECK-EB: 0x00000010 00000030 00000033 00000001 01000000
 ; CHECK-EB: 0x00000020 00000004 01000020 00000000 0d000001
-; CHECK-EB: 0x00000030 00000001 0000002f 00000001 00000031
-; CHECK-EB: 0x00000040 0c000000 00000002 002e7465 7874002f
-; CHECK:    0x00000050 746d702f 742e6300 696e7420 6628696e
-; CHECK:    0x00000060 74206129 207b2072 65747572 6e20613b
-; CHECK:    0x00000070 207d0069 6e740061 006600
+; CHECK-EB: 0x00000030 00000001 00000005 00000001 00000007
+; CHECK-EB: 0x00000040 0c000000 00000002 00696e74 00610066
+; CHECK:    0x00000050 002e7465 7874002f 746d702f 742e6300
+; CHECK:    0x00000060 696e7420 6628696e 74206129 207b2072
+; CHECK:    0x00000070 65747572 6e20613b 207d00
 ; CHECK:    '.BTF.ext'
-; CHECK-EL: 0x00000000 9feb0100 18000000 00000000 14000000
-; CHECK-EL: 0x00000010 14000000 2c000000 08000000 01000000
-; CHECK-EL: 0x00000020 01000000 00000000 03000000 10000000
-; CHECK-EL: 0x00000030 01000000 02000000 00000000 07000000
-; CHECK-EL: 0x00000040 10000000 00040000 08000000 07000000
-; CHECK-EL: 0x00000050 10000000 10040000
-; CHECK-EB: 0x00000000 eb9f0100 00000018 00000000 00000014
-; CHECK-EB: 0x00000010 00000014 0000002c 00000008 00000001
-; CHECK-EB: 0x00000020 00000001 00000000 00000003 00000010
-; CHECK-EB: 0x00000030 00000001 00000002 00000000 00000007
-; CHECK-EB: 0x00000040 00000010 00000400 00000008 00000007
-; CHECK-EB: 0x00000050 00000010 00000410
+; CHECK-EL: 0x00000000 9feb0100 28000000 00000000 14000000
+; CHECK-EL: 0x00000010 14000000 2c000000 40000000 00000000
+; CHECK-EL: 0x00000020 40000000 00000000 08000000 09000000
+; CHECK-EL: 0x00000030 01000000 00000000 03000000 10000000
+; CHECK-EL: 0x00000040 09000000 02000000 00000000 0f000000
+; CHECK-EL: 0x00000050 18000000 00040000 08000000 0f000000
+; CHECK-EL: 0x00000060 18000000 10040000
+; CHECK-EB: 0x00000000 eb9f0100 00000028 00000000 00000014
+; CHECK-EB: 0x00000010 00000014 0000002c 00000040 00000000
+; CHECK-EB: 0x00000020 00000040 00000000 00000008 00000009
+; CHECK-EB: 0x00000030 00000001 00000000 00000003 00000010
+; CHECK-EB: 0x00000040 00000009 00000002 00000000 0000000f
+; CHECK-EB: 0x00000050 00000018 00000400 00000008 0000000f
+; CHECK-EB: 0x00000060 00000018 00000410
 
 ; Function Attrs: nounwind readnone speculatable
 declare void @llvm.dbg.value(metadata, metadata, metadata) #1
Index: test/CodeGen/BPF/BTF/extern-global-var.ll
===================================================================
--- test/CodeGen/BPF/BTF/extern-global-var.ll
+++ test/CodeGen/BPF/BTF/extern-global-var.ll
@@ -28,21 +28,21 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=44
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=48
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=15
 ; CHECK-NEXT:        .byte   0
 
 attributes #0 = { norecurse nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
Index: test/CodeGen/BPF/BTF/filename.ll
===================================================================
--- test/CodeGen/BPF/BTF/filename.ll
+++ test/CodeGen/BPF/BTF/filename.ll
@@ -23,41 +23,45 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   26                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   30                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/ttmp/t.c"    # string offset=7
+; CHECK-NEXT:        .ascii  "test"                  # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=26
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=10
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "test"                  # string offset=30
+; CHECK-NEXT:        .ascii  "/home/yhs/ttmp/t.c"    # string offset=16
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
 ; CHECK-NEXT:        .short  60319                   # 0xeb9f
 ; CHECK-NEXT:        .byte   1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   40
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
-; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   10                      # FuncInfo section string offset=10
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Lfunc_begin{{[0-9]+}}
 ; CHECK-NEXT:        .long   3
 ; CHECK-NEXT:        .long   16                      # LineInfo
-; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   10                      # LineInfo section string offset=10
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   16
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   1038                    # Line 1 Col 14
 
Index: test/CodeGen/BPF/BTF/func-func-ptr.ll
===================================================================
--- test/CodeGen/BPF/BTF/func-func-ptr.ll
+++ test/CodeGen/BPF/BTF/func-func-ptr.ll
@@ -29,16 +29,16 @@
 ; CHECK-NEXT:        .long   104
 ; CHECK-NEXT:        .long   104
 ; CHECK-NEXT:        .long   32
-; CHECK-NEXT:        .long   16                      # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
 ; CHECK-NEXT:        .long   218103809               # 0xd000001
 ; CHECK-NEXT:        .long   0
-; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   5
 ; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   23                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   8                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 4)
@@ -54,17 +54,17 @@
 ; CHECK-NEXT:        .long   8
 ; CHECK-NEXT:        .long   29
 ; CHECK-NEXT:        .long   4
-; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   0                       # 0x0
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .ascii  "p2"                    # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=16
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=8
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "p2"                    # string offset=20
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=11
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "f1"                    # string offset=23
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=17
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .ascii  "t1"                    # string offset=26
 ; CHECK-NEXT:        .byte   0
@@ -74,21 +74,25 @@
 ; CHECK-NEXT:        .short  60319                   # 0xeb9f
 ; CHECK-NEXT:        .byte   1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   40
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
-; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   11                      # FuncInfo section string offset=11
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Lfunc_begin0
 ; CHECK-NEXT:        .long   3
 ; CHECK-NEXT:        .long   16                      # LineInfo
-; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   11                      # LineInfo section string offset=11
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   17
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   3091                    # Line 3 Col 19
 
Index: test/CodeGen/BPF/BTF/func-non-void.ll
===================================================================
--- test/CodeGen/BPF/BTF/func-non-void.ll
+++ test/CodeGen/BPF/BTF/func-non-void.ll
@@ -21,52 +21,56 @@
 ; CHECK-NEXT:        .long   48
 ; CHECK-NEXT:        .long   48
 ; CHECK-NEXT:        .long   26
-; CHECK-NEXT:        .long   16                      # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
 ; CHECK-NEXT:        .long   218103809               # 0xd000001
 ; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   5
 ; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   23                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   8                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .ascii  "a1"                    # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=16
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=8
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "a1"                    # string offset=20
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=11
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "f1"                    # string offset=23
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=17
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
 ; CHECK-NEXT:        .short  60319                   # 0xeb9f
 ; CHECK-NEXT:        .byte   1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   40
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   44
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
-; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   11                      # FuncInfo section string offset=11
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Lfunc_begin0
 ; CHECK-NEXT:        .long   3
 ; CHECK-NEXT:        .long   16                      # LineInfo
-; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   11                      # LineInfo section string offset=11
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   .Lfunc_begin0
-; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   17
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   1024                    # Line 1 Col 0
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   17
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   1042                    # Line 1 Col 18
 
Index: test/CodeGen/BPF/BTF/func-source.ll
===================================================================
--- test/CodeGen/BPF/BTF/func-source.ll
+++ test/CodeGen/BPF/BTF/func-source.ll
@@ -27,38 +27,42 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   0
-; CHECK-NEXT:        .long   33                      # BTF_KIND_FUNC(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_FUNC(id = 2)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .byte   102                     # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=3
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "void f(void) { }"      # string offset=16
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=9
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .byte   102                     # string offset=33
+; CHECK-NEXT:        .ascii  "void f(void) { }"      # string offset=18
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
 ; CHECK-NEXT:        .short  60319                   # 0xeb9f
 ; CHECK-NEXT:        .byte   1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   40
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
-; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   3                       # FuncInfo section string offset=3
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Lfunc_begin0
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   16                      # LineInfo
-; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   3                       # LineInfo section string offset=3
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   7
-; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   9
+; CHECK-NEXT:        .long   18
 ; CHECK-NEXT:        .long   1040                    # Line 1 Col 16
 
 attributes #0 = { norecurse nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
Index: test/CodeGen/BPF/BTF/func-typedef.ll
===================================================================
--- test/CodeGen/BPF/BTF/func-typedef.ll
+++ test/CodeGen/BPF/BTF/func-typedef.ll
@@ -24,65 +24,70 @@
 ; CHECK-NEXT:        .long   72
 ; CHECK-NEXT:        .long   72
 ; CHECK-NEXT:        .long   35
-; CHECK-NEXT:        .long   16                      # BTF_KIND_TYPEDEF(id = 1)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_TYPEDEF(id = 1)
 ; CHECK-NEXT:        .long   134217728               # 0x8000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   22                      # BTF_KIND_TYPEDEF(id = 2)
+; CHECK-NEXT:        .long   7                       # BTF_KIND_TYPEDEF(id = 2)
 ; CHECK-NEXT:        .long   134217728               # 0x8000000
 ; CHECK-NEXT:        .long   3
-; CHECK-NEXT:        .long   27                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   12                      # BTF_KIND_INT(id = 3)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 4)
 ; CHECK-NEXT:        .long   218103809               # 0xd000001
 ; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   31
+; CHECK-NEXT:        .long   16
 ; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   33                      # BTF_KIND_FUNC(id = 5)
+; CHECK-NEXT:        .long   18                      # BTF_KIND_FUNC(id = 5)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "__int"                 # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .ascii  "_int"                  # string offset=7
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "__int"                 # string offset=16
+; CHECK-NEXT:        .ascii  "int"                   # string offset=12
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "_int"                  # string offset=22
+; CHECK-NEXT:        .byte   97                      # string offset=16
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=27
+; CHECK-NEXT:        .byte   102                     # string offset=18
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .byte   97                      # string offset=31
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=20
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .byte   102                     # string offset=33
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=26
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
 ; CHECK-NEXT:        .short  60319                   # 0xeb9f
 ; CHECK-NEXT:        .byte   1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   40
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   44
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
-; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   20                      # FuncInfo section string offset=20
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Lfunc_begin0
 ; CHECK-NEXT:        .long   5
 ; CHECK-NEXT:        .long   16                      # LineInfo
-; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   20                      # LineInfo section string offset=20
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   .Lfunc_begin0
-; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   26
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   3072                    # Line 3 Col 0
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   26
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   3092                    # Line 3 Col 20
 
+
 ; Function Attrs: nounwind readnone speculatable
 declare void @llvm.dbg.value(metadata, metadata, metadata) #1
 
Index: test/CodeGen/BPF/BTF/func-unused-arg.ll
===================================================================
--- test/CodeGen/BPF/BTF/func-unused-arg.ll
+++ test/CodeGen/BPF/BTF/func-unused-arg.ll
@@ -21,48 +21,52 @@
 ; CHECK-NEXT:        .long   48
 ; CHECK-NEXT:        .long   48
 ; CHECK-NEXT:        .long   26
-; CHECK-NEXT:        .long   16                      # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
 ; CHECK-NEXT:        .long   218103809               # 0xd000001
 ; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   5
 ; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   23                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   8                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .ascii  "a1"                    # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=16
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=8
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "a1"                    # string offset=20
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=11
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "f1"                    # string offset=23
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=17
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
 ; CHECK-NEXT:        .short  60319                   # 0xeb9f
 ; CHECK-NEXT:        .byte   1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   40
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
-; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   11                      # FuncInfo section string offset=11
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Lfunc_begin0
 ; CHECK-NEXT:        .long   3
 ; CHECK-NEXT:        .long   16                      # LineInfo
-; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   11                      # LineInfo section string offset=11
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   17
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   1042                    # Line 1 Col 18
 
Index: test/CodeGen/BPF/BTF/func-void.ll
===================================================================
--- test/CodeGen/BPF/BTF/func-void.ll
+++ test/CodeGen/BPF/BTF/func-void.ll
@@ -23,35 +23,39 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   0
-; CHECK-NEXT:        .long   16                      # BTF_KIND_FUNC(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_FUNC(id = 2)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=4
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "f1"                    # string offset=16
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=10
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
 ; CHECK-NEXT:        .short  60319                   # 0xeb9f
 ; CHECK-NEXT:        .byte   1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   40
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
-; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   4                       # FuncInfo section string offset=4
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Lfunc_begin0
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   16                      # LineInfo
-; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   4                       # LineInfo section string offset=4
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
-; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   10
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   1040                    # Line 1 Col 16
 
Index: test/CodeGen/BPF/BTF/local-var.ll
===================================================================
--- test/CodeGen/BPF/BTF/local-var.ll
+++ test/CodeGen/BPF/BTF/local-var.ll
@@ -29,34 +29,34 @@
 ; CHECK-NEXT:        .long   64
 ; CHECK-NEXT:        .long   64
 ; CHECK-NEXT:        .long   59
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   16777224                # 0x1000008
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
 ; CHECK-NEXT:        .long   218103809               # 0xd000001
 ; CHECK-NEXT:        .long   3
-; CHECK-NEXT:        .long   49
+; CHECK-NEXT:        .long   6
 ; CHECK-NEXT:        .long   1
-; CHECK-NEXT:        .long   51                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   8                       # BTF_KIND_INT(id = 3)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   55                      # BTF_KIND_FUNC(id = 4)
+; CHECK-NEXT:        .long   12                      # BTF_KIND_FUNC(id = 4)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "char"                  # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .byte   97                      # string offset=6
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "char"                  # string offset=44
+; CHECK-NEXT:        .ascii  "int"                   # string offset=8
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .byte   97                      # string offset=49
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=12
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=51
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=16
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=55
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=22
 ; CHECK-NEXT:        .byte   0
 
 ; Function Attrs: nounwind readnone speculatable
Index: test/CodeGen/BPF/BTF/map-def.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/BTF/map-def.ll
@@ -0,0 +1,120 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   struct key_type {
+;     int a;
+;     int b;
+;   };
+;   struct map_type {
+;     struct key_type *key;
+;     unsigned *value;
+;   };
+;   struct map_type __attribute__((section(".maps"))) hash_map;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.map_type = type { %struct.key_type*, i32* }
+%struct.key_type = type { i32, i32 }
+
+@hash_map = dso_local local_unnamed_addr global %struct.map_type zeroinitializer, section ".maps", align 8, !dbg !0
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   168
+; CHECK-NEXT:        .long   168
+; CHECK-NEXT:        .long   65
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 1)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   10
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   14
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   64                      # 0x40
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 2)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   20                      # BTF_KIND_STRUCT(id = 3)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   29
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   31
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   33                      # BTF_KIND_INT(id = 4)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 5)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .long   37                      # BTF_KIND_INT(id = 6)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   50                      # BTF_KIND_VAR(id = 7)
+; CHECK-NEXT:        .long   234881024               # 0xe000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   59                      # BTF_KIND_DATASEC(id = 8)
+; CHECK-NEXT:        .long   251658241               # 0xf000001
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   hash_map
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "map_type"              # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "key"                   # string offset=10
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "value"                 # string offset=14
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "key_type"              # string offset=20
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   97                      # string offset=29
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   98                      # string offset=31
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=33
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "unsigned int"          # string offset=37
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "hash_map"              # string offset=50
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".maps"                 # string offset=59
+; CHECK-NEXT:        .byte   0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!18, !19, !20}
+!llvm.ident = !{!21}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "hash_map", scope: !2, file: !3, line: 9, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 9.0.0 (trunk 364157) (llvm/trunk 364156)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "map_type", file: !3, line: 5, size: 128, elements: !7)
+!7 = !{!8, !15}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "key", scope: !6, file: !3, line: 6, baseType: !9, size: 64)
+!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size: 64)
+!10 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "key_type", file: !3, line: 1, size: 64, elements: !11)
+!11 = !{!12, !14}
+!12 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !10, file: !3, line: 2, baseType: !13, size: 32)
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !10, file: !3, line: 3, baseType: !13, size: 32, offset: 32)
+!15 = !DIDerivedType(tag: DW_TAG_member, name: "value", scope: !6, file: !3, line: 7, baseType: !16, size: 64, offset: 64)
+!16 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !17, size: 64)
+!17 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!18 = !{i32 2, !"Dwarf Version", i32 4}
+!19 = !{i32 2, !"Debug Info Version", i32 3}
+!20 = !{i32 1, !"wchar_size", i32 4}
+!21 = !{!"clang version 9.0.0 (trunk 364157) (llvm/trunk 364156)"}
Index: test/CodeGen/BPF/BTF/ptr-prune-type.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/BTF/ptr-prune-type.ll
@@ -0,0 +1,84 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   struct t {
+;     int a;
+;   };
+;   struct t2 {
+;     struct t *f1;
+;   };
+;   struct t2 __attribute__((section("prune_types"))) g;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.t2 = type { %struct.t* }
+%struct.t = type { i32 }
+
+@g = dso_local local_unnamed_addr global %struct.t2 zeroinitializer, section "prune_types", align 8, !dbg !0
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   88
+; CHECK-NEXT:        .long   88
+; CHECK-NEXT:        .long   23
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 1)
+; CHECK-NEXT:        .long   67108865                # 0x4000001
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 2)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   7                       # BTF_KIND_VAR(id = 3)
+; CHECK-NEXT:        .long   234881024               # 0xe000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   9                       # BTF_KIND_DATASEC(id = 4)
+; CHECK-NEXT:        .long   251658241               # 0xf000001
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   g
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   21                      # BTF_KIND_FWD(id = 5)
+; CHECK-NEXT:        .long   117440512               # 0x7000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "t2"                    # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=4
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   103                     # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "prune_types"           # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   116                     # string offset=21
+; CHECK-NEXT:        .byte   0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!14, !15, !16}
+!llvm.ident = !{!17}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "g", scope: !2, file: !3, line: 7, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 9.0.0 (trunk 364157) (llvm/trunk 364156)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t2", file: !3, line: 4, size: 64, elements: !7)
+!7 = !{!8}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "f1", scope: !6, file: !3, line: 5, baseType: !9, size: 64)
+!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size: 64)
+!10 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t", file: !3, line: 1, size: 32, elements: !11)
+!11 = !{!12}
+!12 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !10, file: !3, line: 2, baseType: !13, size: 32)
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !{i32 2, !"Dwarf Version", i32 4}
+!15 = !{i32 2, !"Debug Info Version", i32 3}
+!16 = !{i32 1, !"wchar_size", i32 4}
+!17 = !{!"clang version 9.0.0 (trunk 364157) (llvm/trunk 364156)"}
Index: test/CodeGen/BPF/BTF/static-var-derived-type.ll
===================================================================
--- test/CodeGen/BPF/BTF/static-var-derived-type.ll
+++ test/CodeGen/BPF/BTF/static-var-derived-type.ll
@@ -46,11 +46,11 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   45                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   8
 ; CHECK-NEXT:        .long   16777280                # 0x1000040
-; CHECK-NEXT:        .long   54                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   10                      # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_VOLATILE(id = 4)
@@ -116,13 +116,13 @@
 ; CHECK-NEXT:        .long   v4
 ; CHECK-NEXT:        .long   8
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "long int"              # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bugs/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=10
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "long int"              # string offset=45
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=14
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=54
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bugs/test.c" # string offset=20
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .ascii  "int"                   # string offset=58
 ; CHECK-NEXT:        .byte   0
Index: test/CodeGen/BPF/BTF/static-var-inited-sec.ll
===================================================================
--- test/CodeGen/BPF/BTF/static-var-inited-sec.ll
+++ test/CodeGen/BPF/BTF/static-var-inited-sec.ll
@@ -35,11 +35,11 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_VOLATILE(id = 4)
@@ -74,13 +74,13 @@
 ; CHECK-NEXT:        .long   a
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=44
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=48
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=15
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .ascii  "short"                 # string offset=52
 ; CHECK-NEXT:        .byte   0
Index: test/CodeGen/BPF/BTF/static-var-inited.ll
===================================================================
--- test/CodeGen/BPF/BTF/static-var-inited.ll
+++ test/CodeGen/BPF/BTF/static-var-inited.ll
@@ -35,11 +35,11 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_VOLATILE(id = 4)
@@ -74,13 +74,13 @@
 ; CHECK-NEXT:        .long   a
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=44
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=48
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=15
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .ascii  "short"                 # string offset=52
 ; CHECK-NEXT:        .byte   0
Index: test/CodeGen/BPF/BTF/static-var-readonly-sec.ll
===================================================================
--- test/CodeGen/BPF/BTF/static-var-readonly-sec.ll
+++ test/CodeGen/BPF/BTF/static-var-readonly-sec.ll
@@ -35,11 +35,11 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_CONST(id = 4)
@@ -80,13 +80,13 @@
 ; CHECK-NEXT:        .long   a
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=44
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=48
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=15
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .ascii  "short"                 # string offset=52
 ; CHECK-NEXT:        .byte   0
Index: test/CodeGen/BPF/BTF/static-var-readonly.ll
===================================================================
--- test/CodeGen/BPF/BTF/static-var-readonly.ll
+++ test/CodeGen/BPF/BTF/static-var-readonly.ll
@@ -35,11 +35,11 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_CONST(id = 4)
@@ -80,13 +80,13 @@
 ; CHECK-NEXT:        .long   a
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=44
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=48
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=15
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .ascii  "short"                 # string offset=52
 ; CHECK-NEXT:        .byte   0
Index: test/CodeGen/BPF/BTF/static-var-sec.ll
===================================================================
--- test/CodeGen/BPF/BTF/static-var-sec.ll
+++ test/CodeGen/BPF/BTF/static-var-sec.ll
@@ -35,11 +35,11 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_VOLATILE(id = 4)
@@ -74,13 +74,13 @@
 ; CHECK-NEXT:        .long   a
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=44
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=48
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=15
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .ascii  "short"                 # string offset=52
 ; CHECK-NEXT:        .byte   0
Index: test/CodeGen/BPF/BTF/static-var-zerolen-array.ll
===================================================================
--- test/CodeGen/BPF/BTF/static-var-zerolen-array.ll
+++ test/CodeGen/BPF/BTF/static-var-zerolen-array.ll
@@ -32,11 +32,11 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_VOLATILE(id = 4)
@@ -79,13 +79,13 @@
 ; CHECK-NEXT:        .long   sv
 ; CHECK-NEXT:        .long   20
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "test"                  # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=44
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=10
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "test"                  # string offset=48
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=16
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .byte   116                     # string offset=53
 ; CHECK-NEXT:        .byte   0
Index: test/CodeGen/BPF/BTF/static-var.ll
===================================================================
--- test/CodeGen/BPF/BTF/static-var.ll
+++ test/CodeGen/BPF/BTF/static-var.ll
@@ -35,11 +35,11 @@
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
 ; CHECK-NEXT:        .long   218103808               # 0xd000000
 ; CHECK-NEXT:        .long   2
-; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
 ; CHECK-NEXT:        .long   16777216                # 0x1000000
 ; CHECK-NEXT:        .long   4
 ; CHECK-NEXT:        .long   16777248                # 0x1000020
-; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
 ; CHECK-NEXT:        .long   201326592               # 0xc000000
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   0                       # BTF_KIND_VOLATILE(id = 4)
@@ -74,13 +74,13 @@
 ; CHECK-NEXT:        .long   a
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .byte   0                       # string offset=0
-; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=7
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "int"                   # string offset=44
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
 ; CHECK-NEXT:        .byte   0
-; CHECK-NEXT:        .ascii  "foo"                   # string offset=48
+; CHECK-NEXT:        .ascii  "/home/yhs/work/tests/llvm/bug/test.c" # string offset=15
 ; CHECK-NEXT:        .byte   0
 ; CHECK-NEXT:        .ascii  "short"                 # string offset=52
 ; CHECK-NEXT:        .byte   0
Index: test/CodeGen/BPF/CORE/offset-reloc-basic.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/CORE/offset-reloc-basic.ll
@@ -0,0 +1,186 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; Source code:
+;    struct sk_buff {
+;      int i;
+;      struct net_device *dev;
+;    };
+;    #define _(x) (__builtin_preserve_access_index(x))
+;    static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr)
+;        = (void *) 4;
+;
+;    int bpf_prog(struct sk_buff *ctx) {
+;      struct net_device *dev = 0;
+;      bpf_probe_read(&dev, sizeof(dev), _(&ctx->dev));
+;      return dev != 0;
+;    }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%struct.sk_buff = type { i32, %struct.net_device* }
+%struct.net_device = type opaque
+
+; Function Attrs: nounwind
+define dso_local i32 @bpf_prog(%struct.sk_buff*) local_unnamed_addr #0 !dbg !15 {
+  %2 = alloca %struct.net_device*, align 8
+  call void @llvm.dbg.value(metadata %struct.sk_buff* %0, metadata !26, metadata !DIExpression()), !dbg !28
+  %3 = bitcast %struct.net_device** %2 to i8*, !dbg !29
+  call void @llvm.lifetime.start.p0i8(i64 8, i8* nonnull %3) #4, !dbg !29
+  call void @llvm.dbg.value(metadata %struct.net_device* null, metadata !27, metadata !DIExpression()), !dbg !28
+  store %struct.net_device* null, %struct.net_device** %2, align 8, !dbg !30, !tbaa !31
+  %4 = tail call %struct.net_device** @llvm.preserve.struct.access.index.p0p0s_struct.net_devices.p0s_struct.sk_buffs(%struct.sk_buff* %0, i32 1, i32 1), !dbg !35, !llvm.preserve.access.index !19
+  %5 = bitcast %struct.net_device** %4 to i8*, !dbg !35
+  %6 = call i32 inttoptr (i64 4 to i32 (i8*, i32, i8*)*)(i8* nonnull %3, i32 8, i8* %5) #4, !dbg !36
+  %7 = load %struct.net_device*, %struct.net_device** %2, align 8, !dbg !37, !tbaa !31
+  call void @llvm.dbg.value(metadata %struct.net_device* %7, metadata !27, metadata !DIExpression()), !dbg !28
+  %8 = icmp ne %struct.net_device* %7, null, !dbg !38
+  %9 = zext i1 %8 to i32, !dbg !38
+  call void @llvm.lifetime.end.p0i8(i64 8, i8* nonnull %3) #4, !dbg !39
+  ret i32 %9, !dbg !40
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   90
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 2)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   9
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   11
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   64                      # 0x40
+; CHECK-NEXT:        .long   15                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 4)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   19                      # BTF_KIND_FWD(id = 5)
+; CHECK-NEXT:        .long   117440512               # 0x7000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 6)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   30
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   34                      # BTF_KIND_FUNC(id = 7)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "sk_buff"               # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   105                     # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev"                   # string offset=11
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=15
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "net_device"            # string offset=19
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "ctx"                   # string offset=30
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "bpf_prog"              # string offset=34
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=43
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/home/yhs/work/tests/llvm/test.c" # string offset=49
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "0:1"                   # string offset=86
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   124
+; CHECK-NEXT:        .long   144
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   168
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   8                       # FuncInfo
+
+; CHECK:             .long   12                      # OffsetReloc
+; CHECK-NEXT:        .long   43                      # Offset reloc section string offset=43
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp2
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   86
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone
+declare %struct.net_device** @llvm.preserve.struct.access.index.p0p0s_struct.net_devices.p0s_struct.sk_buffs(%struct.sk_buff*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #3
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { argmemonly nounwind }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind readnone speculatable }
+attributes #4 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+!5 = distinct !DIGlobalVariable(name: "bpf_probe_read", scope: !0, file: !1, line: 6, type: !6, isLocal: true, isDefinition: true)
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !10, !9, !10}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)"}
+!15 = distinct !DISubprogram(name: "bpf_prog", scope: !1, file: !1, line: 9, type: !16, scopeLine: 9, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !25)
+!16 = !DISubroutineType(types: !17)
+!17 = !{!9, !18}
+!18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !19, size: 64)
+!19 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "sk_buff", file: !1, line: 1, size: 128, elements: !20)
+!20 = !{!21, !22}
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !19, file: !1, line: 2, baseType: !9, size: 32)
+!22 = !DIDerivedType(tag: DW_TAG_member, name: "dev", scope: !19, file: !1, line: 3, baseType: !23, size: 64, offset: 64)
+!23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !24, size: 64)
+!24 = !DICompositeType(tag: DW_TAG_structure_type, name: "net_device", file: !1, line: 3, flags: DIFlagFwdDecl)
+!25 = !{!26, !27}
+!26 = !DILocalVariable(name: "ctx", arg: 1, scope: !15, file: !1, line: 9, type: !18)
+!27 = !DILocalVariable(name: "dev", scope: !15, file: !1, line: 10, type: !23)
+!28 = !DILocation(line: 0, scope: !15)
+!29 = !DILocation(line: 10, column: 3, scope: !15)
+!30 = !DILocation(line: 10, column: 22, scope: !15)
+!31 = !{!32, !32, i64 0}
+!32 = !{!"any pointer", !33, i64 0}
+!33 = !{!"omnipotent char", !34, i64 0}
+!34 = !{!"Simple C/C++ TBAA"}
+!35 = !DILocation(line: 11, column: 37, scope: !15)
+!36 = !DILocation(line: 11, column: 3, scope: !15)
+!37 = !DILocation(line: 12, column: 10, scope: !15)
+!38 = !DILocation(line: 12, column: 14, scope: !15)
+!39 = !DILocation(line: 13, column: 1, scope: !15)
+!40 = !DILocation(line: 12, column: 3, scope: !15)
Index: test/CodeGen/BPF/CORE/offset-reloc-multilevel.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/CORE/offset-reloc-multilevel.ll
@@ -0,0 +1,197 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; Source code:
+;   struct net_device {
+;     int dev_id;
+;     int others;
+;   };
+;   struct sk_buff {
+;     int i;
+;     struct net_device dev;
+;   };
+;   #define _(x) (__builtin_preserve_access_index(x))
+;   static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr)
+;       = (void *) 4;
+;
+;   int bpf_prog(struct sk_buff *ctx) {
+;     int dev_id;
+;     bpf_probe_read(&dev_id, sizeof(int), _(&ctx->dev.dev_id));
+;     return dev_id;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%struct.sk_buff = type { i32, %struct.net_device }
+%struct.net_device = type { i32, i32 }
+
+; Function Attrs: nounwind
+define dso_local i32 @bpf_prog(%struct.sk_buff*) local_unnamed_addr #0 !dbg !15 {
+  %2 = alloca i32, align 4
+  call void @llvm.dbg.value(metadata %struct.sk_buff* %0, metadata !28, metadata !DIExpression()), !dbg !30
+  %3 = bitcast i32* %2 to i8*, !dbg !31
+  call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %3) #4, !dbg !31
+  %4 = tail call %struct.net_device* @llvm.preserve.struct.access.index.p0s_struct.net_devices.p0s_struct.sk_buffs(%struct.sk_buff* %0, i32 1, i32 1), !dbg !32, !llvm.preserve.access.index !19
+  %5 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.net_devices(%struct.net_device* %4, i32 0, i32 0), !dbg !32, !llvm.preserve.access.index !23
+  %6 = bitcast i32* %5 to i8*, !dbg !32
+  %7 = call i32 inttoptr (i64 4 to i32 (i8*, i32, i8*)*)(i8* nonnull %3, i32 4, i8* %6) #4, !dbg !33
+  %8 = load i32, i32* %2, align 4, !dbg !34, !tbaa !35
+  call void @llvm.dbg.value(metadata i32 %8, metadata !29, metadata !DIExpression()), !dbg !30
+  call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %3) #4, !dbg !39
+  ret i32 %8, !dbg !40
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   132
+; CHECK-NEXT:        .long   132
+; CHECK-NEXT:        .long   106
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 2)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   12
+; CHECK-NEXT:        .long   9
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   11
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   15                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   19                      # BTF_KIND_STRUCT(id = 4)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   30
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   37
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 5)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   44
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   48                      # BTF_KIND_FUNC(id = 6)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "sk_buff"               # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   105                     # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev"                   # string offset=11
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=15
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "net_device"            # string offset=19
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev_id"                # string offset=30
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "others"                # string offset=37
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "ctx"                   # string offset=44
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "bpf_prog"              # string offset=48
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=57
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/home/yhs/work/tests/llvm/test.c" # string offset=63
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "0:1:0"                 # string offset=100
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   76
+; CHECK-NEXT:        .long   96
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   8                       # FuncInfo
+
+; CHECK:             .long   12                      # OffsetReloc
+; CHECK-NEXT:        .long   57                      # Offset reloc section string offset=57
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp2
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   100
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone
+declare %struct.net_device* @llvm.preserve.struct.access.index.p0s_struct.net_devices.p0s_struct.sk_buffs(%struct.sk_buff*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.net_devices(%struct.net_device*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #3
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { argmemonly nounwind }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind readnone speculatable }
+attributes #4 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+!5 = distinct !DIGlobalVariable(name: "bpf_probe_read", scope: !0, file: !1, line: 10, type: !6, isLocal: true, isDefinition: true)
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !10, !9, !10}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)"}
+!15 = distinct !DISubprogram(name: "bpf_prog", scope: !1, file: !1, line: 13, type: !16, scopeLine: 13, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !27)
+!16 = !DISubroutineType(types: !17)
+!17 = !{!9, !18}
+!18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !19, size: 64)
+!19 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "sk_buff", file: !1, line: 5, size: 96, elements: !20)
+!20 = !{!21, !22}
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !19, file: !1, line: 6, baseType: !9, size: 32)
+!22 = !DIDerivedType(tag: DW_TAG_member, name: "dev", scope: !19, file: !1, line: 7, baseType: !23, size: 64, offset: 32)
+!23 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "net_device", file: !1, line: 1, size: 64, elements: !24)
+!24 = !{!25, !26}
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "dev_id", scope: !23, file: !1, line: 2, baseType: !9, size: 32)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "others", scope: !23, file: !1, line: 3, baseType: !9, size: 32, offset: 32)
+!27 = !{!28, !29}
+!28 = !DILocalVariable(name: "ctx", arg: 1, scope: !15, file: !1, line: 13, type: !18)
+!29 = !DILocalVariable(name: "dev_id", scope: !15, file: !1, line: 14, type: !9)
+!30 = !DILocation(line: 0, scope: !15)
+!31 = !DILocation(line: 14, column: 3, scope: !15)
+!32 = !DILocation(line: 15, column: 40, scope: !15)
+!33 = !DILocation(line: 15, column: 3, scope: !15)
+!34 = !DILocation(line: 16, column: 10, scope: !15)
+!35 = !{!36, !36, i64 0}
+!36 = !{!"int", !37, i64 0}
+!37 = !{!"omnipotent char", !38, i64 0}
+!38 = !{!"Simple C/C++ TBAA"}
+!39 = !DILocation(line: 17, column: 1, scope: !15)
+!40 = !DILocation(line: 16, column: 3, scope: !15)
Index: test/CodeGen/BPF/CORE/offset-reloc-struct-anonymous.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/CORE/offset-reloc-struct-anonymous.ll
@@ -0,0 +1,213 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; Source code:
+;   struct sk_buff {
+;     int i;
+;     struct {
+;       int dev_id;
+;       int others;
+;     } dev[10];
+;   };
+;   #define _(x) (__builtin_preserve_access_index(x))
+;   static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr)
+;       = (void *) 4;
+;
+;   int bpf_prog(struct sk_buff *ctx) {
+;     int dev_id;
+;     bpf_probe_read(&dev_id, sizeof(int), _(&ctx->dev[5].dev_id));
+;     return dev_id;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%struct.sk_buff = type { i32, [10 x %struct.anon] }
+%struct.anon = type { i32, i32 }
+
+; Function Attrs: nounwind
+define dso_local i32 @bpf_prog(%struct.sk_buff*) local_unnamed_addr #0 !dbg !15 {
+  %2 = alloca i32, align 4
+  call void @llvm.dbg.value(metadata %struct.sk_buff* %0, metadata !31, metadata !DIExpression()), !dbg !33
+  %3 = bitcast i32* %2 to i8*, !dbg !34
+  call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %3) #4, !dbg !34
+  %4 = tail call [10 x %struct.anon]* @llvm.preserve.struct.access.index.p0a10s_struct.anons.p0s_struct.sk_buffs(%struct.sk_buff* %0, i32 1, i32 1), !dbg !35, !llvm.preserve.access.index !19
+  %5 = tail call %struct.anon* @llvm.preserve.array.access.index.p0s_struct.anons.p0a10s_struct.anons([10 x %struct.anon]* %4, i32 1, i32 5), !dbg !35
+  %6 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.anons(%struct.anon* %5, i32 0, i32 0), !dbg !35, !llvm.preserve.access.index !24
+  %7 = bitcast i32* %6 to i8*, !dbg !35
+  %8 = call i32 inttoptr (i64 4 to i32 (i8*, i32, i8*)*)(i8* nonnull %3, i32 4, i8* %7) #4, !dbg !36
+  %9 = load i32, i32* %2, align 4, !dbg !37, !tbaa !38
+  call void @llvm.dbg.value(metadata i32 %9, metadata !32, metadata !DIExpression()), !dbg !33
+  call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %3) #4, !dbg !42
+  ret i32 %9, !dbg !43
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   172
+; CHECK-NEXT:        .long   172
+; CHECK-NEXT:        .long   117
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 2)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   84
+; CHECK-NEXT:        .long   9
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   11
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   15                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   0                       # BTF_KIND_STRUCT(id = 4)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   19
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   26
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ARRAY(id = 5)
+; CHECK-NEXT:        .long   50331648                # 0x3000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .long   10
+; CHECK-NEXT:        .long   33                      # BTF_KIND_INT(id = 6)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 7)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   53
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   57                      # BTF_KIND_FUNC(id = 8)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "sk_buff"               # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   105                     # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev"                   # string offset=11
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=15
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev_id"                # string offset=19
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "others"                # string offset=26
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "__ARRAY_SIZE_TYPE__"   # string offset=33
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "ctx"                   # string offset=53
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "bpf_prog"              # string offset=57
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=66
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/home/yhs/work/tests/llvm/test.c" # string offset=72
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "0:1:5:0"               # string offset=109
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   76
+; CHECK-NEXT:        .long   96
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   8                       # FuncInfo
+
+; CHECK:             .long   12                      # OffsetReloc
+; CHECK-NEXT:        .long   66                      # Offset reloc section string offset=66
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp2
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   109
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x %struct.anon]* @llvm.preserve.struct.access.index.p0a10s_struct.anons.p0s_struct.sk_buffs(%struct.sk_buff*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: nounwind readnone
+declare %struct.anon* @llvm.preserve.array.access.index.p0s_struct.anons.p0a10s_struct.anons([10 x %struct.anon]*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.anons(%struct.anon*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #3
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { argmemonly nounwind }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind readnone speculatable }
+attributes #4 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+!5 = distinct !DIGlobalVariable(name: "bpf_probe_read", scope: !0, file: !1, line: 9, type: !6, isLocal: true, isDefinition: true)
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !10, !9, !10}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)"}
+!15 = distinct !DISubprogram(name: "bpf_prog", scope: !1, file: !1, line: 12, type: !16, scopeLine: 12, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !30)
+!16 = !DISubroutineType(types: !17)
+!17 = !{!9, !18}
+!18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !19, size: 64)
+!19 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "sk_buff", file: !1, line: 1, size: 672, elements: !20)
+!20 = !{!21, !22}
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !19, file: !1, line: 2, baseType: !9, size: 32)
+!22 = !DIDerivedType(tag: DW_TAG_member, name: "dev", scope: !19, file: !1, line: 6, baseType: !23, size: 640, offset: 32)
+!23 = !DICompositeType(tag: DW_TAG_array_type, baseType: !24, size: 640, elements: !28)
+!24 = distinct !DICompositeType(tag: DW_TAG_structure_type, scope: !19, file: !1, line: 3, size: 64, elements: !25)
+!25 = !{!26, !27}
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "dev_id", scope: !24, file: !1, line: 4, baseType: !9, size: 32)
+!27 = !DIDerivedType(tag: DW_TAG_member, name: "others", scope: !24, file: !1, line: 5, baseType: !9, size: 32, offset: 32)
+!28 = !{!29}
+!29 = !DISubrange(count: 10)
+!30 = !{!31, !32}
+!31 = !DILocalVariable(name: "ctx", arg: 1, scope: !15, file: !1, line: 12, type: !18)
+!32 = !DILocalVariable(name: "dev_id", scope: !15, file: !1, line: 13, type: !9)
+!33 = !DILocation(line: 0, scope: !15)
+!34 = !DILocation(line: 13, column: 3, scope: !15)
+!35 = !DILocation(line: 14, column: 40, scope: !15)
+!36 = !DILocation(line: 14, column: 3, scope: !15)
+!37 = !DILocation(line: 15, column: 10, scope: !15)
+!38 = !{!39, !39, i64 0}
+!39 = !{!"int", !40, i64 0}
+!40 = !{!"omnipotent char", !41, i64 0}
+!41 = !{!"Simple C/C++ TBAA"}
+!42 = !DILocation(line: 16, column: 1, scope: !15)
+!43 = !DILocation(line: 15, column: 3, scope: !15)
Index: test/CodeGen/BPF/CORE/offset-reloc-struct-array.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/CORE/offset-reloc-struct-array.ll
@@ -0,0 +1,216 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; Source code:
+;   struct net_device {
+;     int dev_id;
+;     int others;
+;   };
+;   struct sk_buff {
+;     int i;
+;     struct net_device dev[10];
+;   };
+;   #define _(x) (__builtin_preserve_access_index(x))
+;   static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr)
+;       = (void *) 4;
+;
+;   int bpf_prog(struct sk_buff *ctx) {
+;     int dev_id;
+;     bpf_probe_read(&dev_id, sizeof(int), _(&ctx->dev[5].dev_id));
+;     return dev_id;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%struct.sk_buff = type { i32, [10 x %struct.net_device] }
+%struct.net_device = type { i32, i32 }
+
+; Function Attrs: nounwind
+define dso_local i32 @bpf_prog(%struct.sk_buff*) local_unnamed_addr #0 !dbg !15 {
+  %2 = alloca i32, align 4
+  call void @llvm.dbg.value(metadata %struct.sk_buff* %0, metadata !31, metadata !DIExpression()), !dbg !33
+  %3 = bitcast i32* %2 to i8*, !dbg !34
+  call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %3) #4, !dbg !34
+  %4 = tail call [10 x %struct.net_device]* @llvm.preserve.struct.access.index.p0a10s_struct.net_devices.p0s_struct.sk_buffs(%struct.sk_buff* %0, i32 1, i32 1), !dbg !35, !llvm.preserve.access.index !19
+  %5 = tail call %struct.net_device* @llvm.preserve.array.access.index.p0s_struct.net_devices.p0a10s_struct.net_devices([10 x %struct.net_device]* %4, i32 1, i32 5), !dbg !35
+  %6 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.net_devices(%struct.net_device* %5, i32 0, i32 0), !dbg !35, !llvm.preserve.access.index !24
+  %7 = bitcast i32* %6 to i8*, !dbg !35
+  %8 = call i32 inttoptr (i64 4 to i32 (i8*, i32, i8*)*)(i8* nonnull %3, i32 4, i8* %7) #4, !dbg !36
+  %9 = load i32, i32* %2, align 4, !dbg !37, !tbaa !38
+  call void @llvm.dbg.value(metadata i32 %9, metadata !32, metadata !DIExpression()), !dbg !33
+  call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %3) #4, !dbg !42
+  ret i32 %9, !dbg !43
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   172
+; CHECK-NEXT:        .long   172
+; CHECK-NEXT:        .long   128
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 2)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   84
+; CHECK-NEXT:        .long   9
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   11
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   15                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   19                      # BTF_KIND_STRUCT(id = 4)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   30
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   37
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ARRAY(id = 5)
+; CHECK-NEXT:        .long   50331648                # 0x3000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .long   10
+; CHECK-NEXT:        .long   44                      # BTF_KIND_INT(id = 6)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 7)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   68                      # BTF_KIND_FUNC(id = 8)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "sk_buff"               # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   105                     # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev"                   # string offset=11
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=15
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "net_device"            # string offset=19
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev_id"                # string offset=30
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "others"                # string offset=37
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "__ARRAY_SIZE_TYPE__"   # string offset=44
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "ctx"                   # string offset=64
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "bpf_prog"              # string offset=68
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=77
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/home/yhs/work/tests/llvm/test.c" # string offset=83
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "0:1:5:0"               # string offset=120
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   76
+; CHECK-NEXT:        .long   96
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   8                       # FuncInfo
+
+; CHECK:             .long   12                      # OffsetReloc
+; CHECK-NEXT:        .long   77                      # Offset reloc section string offset=77
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp2
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   120
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x %struct.net_device]* @llvm.preserve.struct.access.index.p0a10s_struct.net_devices.p0s_struct.sk_buffs(%struct.sk_buff*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: nounwind readnone
+declare %struct.net_device* @llvm.preserve.array.access.index.p0s_struct.net_devices.p0a10s_struct.net_devices([10 x %struct.net_device]*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.net_devices(%struct.net_device*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #3
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { argmemonly nounwind }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind readnone speculatable }
+attributes #4 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+!5 = distinct !DIGlobalVariable(name: "bpf_probe_read", scope: !0, file: !1, line: 10, type: !6, isLocal: true, isDefinition: true)
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !10, !9, !10}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)"}
+!15 = distinct !DISubprogram(name: "bpf_prog", scope: !1, file: !1, line: 13, type: !16, scopeLine: 13, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !30)
+!16 = !DISubroutineType(types: !17)
+!17 = !{!9, !18}
+!18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !19, size: 64)
+!19 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "sk_buff", file: !1, line: 5, size: 672, elements: !20)
+!20 = !{!21, !22}
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !19, file: !1, line: 6, baseType: !9, size: 32)
+!22 = !DIDerivedType(tag: DW_TAG_member, name: "dev", scope: !19, file: !1, line: 7, baseType: !23, size: 640, offset: 32)
+!23 = !DICompositeType(tag: DW_TAG_array_type, baseType: !24, size: 640, elements: !28)
+!24 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "net_device", file: !1, line: 1, size: 64, elements: !25)
+!25 = !{!26, !27}
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "dev_id", scope: !24, file: !1, line: 2, baseType: !9, size: 32)
+!27 = !DIDerivedType(tag: DW_TAG_member, name: "others", scope: !24, file: !1, line: 3, baseType: !9, size: 32, offset: 32)
+!28 = !{!29}
+!29 = !DISubrange(count: 10)
+!30 = !{!31, !32}
+!31 = !DILocalVariable(name: "ctx", arg: 1, scope: !15, file: !1, line: 13, type: !18)
+!32 = !DILocalVariable(name: "dev_id", scope: !15, file: !1, line: 14, type: !9)
+!33 = !DILocation(line: 0, scope: !15)
+!34 = !DILocation(line: 14, column: 3, scope: !15)
+!35 = !DILocation(line: 15, column: 40, scope: !15)
+!36 = !DILocation(line: 15, column: 3, scope: !15)
+!37 = !DILocation(line: 16, column: 10, scope: !15)
+!38 = !{!39, !39, i64 0}
+!39 = !{!"int", !40, i64 0}
+!40 = !{!"omnipotent char", !41, i64 0}
+!41 = !{!"Simple C/C++ TBAA"}
+!42 = !DILocation(line: 17, column: 1, scope: !15)
+!43 = !DILocation(line: 16, column: 3, scope: !15)
Index: test/CodeGen/BPF/CORE/offset-reloc-union.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/CORE/offset-reloc-union.ll
@@ -0,0 +1,220 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; Source code:
+;   union sk_buff {
+;     int i;
+;     struct {
+;       int netid;
+;       union {
+;         int dev_id;
+;         int others;
+;       } dev;
+;     } u;
+;   };
+;   #define _(x) (__builtin_preserve_access_index(x))
+;   static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr)
+;       = (void *) 4;
+;
+;   int bpf_prog(union sk_buff *ctx) {
+;     int dev_id;
+;     bpf_probe_read(&dev_id, sizeof(int), _(&ctx->u.dev.dev_id));
+;     return dev_id;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.sk_buff = type { %struct.anon }
+%struct.anon = type { i32, %union.anon }
+%union.anon = type { i32 }
+
+; Function Attrs: nounwind
+define dso_local i32 @bpf_prog(%union.sk_buff*) local_unnamed_addr #0 !dbg !15 {
+  %2 = alloca i32, align 4
+  call void @llvm.dbg.value(metadata %union.sk_buff* %0, metadata !32, metadata !DIExpression()), !dbg !34
+  %3 = bitcast i32* %2 to i8*, !dbg !35
+  call void @llvm.lifetime.start.p0i8(i64 4, i8* nonnull %3) #4, !dbg !35
+  %4 = tail call %union.sk_buff* @llvm.preserve.union.access.index.p0s_union.sk_buffs.p0s_union.sk_buffs(%union.sk_buff* %0, i32 1), !dbg !36, !llvm.preserve.access.index !19
+  %5 = getelementptr inbounds %union.sk_buff, %union.sk_buff* %4, i64 0, i32 0, !dbg !36
+  %6 = tail call %union.anon* @llvm.preserve.struct.access.index.p0s_union.anons.p0s_struct.anons(%struct.anon* %5, i32 1, i32 1), !dbg !36, !llvm.preserve.access.index !23
+  %7 = tail call %union.anon* @llvm.preserve.union.access.index.p0s_union.anons.p0s_union.anons(%union.anon* %6, i32 0), !dbg !36, !llvm.preserve.access.index !27
+  %8 = bitcast %union.anon* %7 to i8*, !dbg !36
+  %9 = call i32 inttoptr (i64 4 to i32 (i8*, i32, i8*)*)(i8* nonnull %3, i32 4, i8* %8) #4, !dbg !37
+  %10 = load i32, i32* %2, align 4, !dbg !38, !tbaa !39
+  call void @llvm.dbg.value(metadata i32 %10, metadata !33, metadata !DIExpression()), !dbg !34
+  call void @llvm.lifetime.end.p0i8(i64 4, i8* nonnull %3) #4, !dbg !43
+  ret i32 %10, !dbg !44
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   168
+; CHECK-NEXT:        .long   168
+; CHECK-NEXT:        .long   105
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK-NEXT:        .long   83886082                # 0x5000002
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   9
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   11
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   13                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   0                       # BTF_KIND_STRUCT(id = 4)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   17
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   23
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   0                       # BTF_KIND_UNION(id = 5)
+; CHECK-NEXT:        .long   83886082                # 0x5000002
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   27
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   34
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # 0x0
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 6)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   41
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   45                      # BTF_KIND_FUNC(id = 7)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "sk_buff"               # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   105                     # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   117                     # string offset=11
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=13
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "netid"                 # string offset=17
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev"                   # string offset=23
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "dev_id"                # string offset=27
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "others"                # string offset=34
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "ctx"                   # string offset=41
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "bpf_prog"              # string offset=45
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=54
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/home/yhs/work/tests/llvm/test.c" # string offset=60
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "0:1:1:0"               # string offset=97
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   76
+; CHECK-NEXT:        .long   96
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   8                       # FuncInfo
+
+; CHECK:             .long   12                      # OffsetReloc
+; CHECK-NEXT:        .long   54                      # Offset reloc section string offset=54
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp2
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   97
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone
+declare %union.sk_buff* @llvm.preserve.union.access.index.p0s_union.sk_buffs.p0s_union.sk_buffs(%union.sk_buff*, i32 immarg) #2
+
+; Function Attrs: nounwind readnone
+declare %union.anon* @llvm.preserve.struct.access.index.p0s_union.anons.p0s_struct.anons(%struct.anon*, i32 immarg, i32 immarg) #2
+
+; Function Attrs: nounwind readnone
+declare %union.anon* @llvm.preserve.union.access.index.p0s_union.anons.p0s_union.anons(%union.anon*, i32 immarg) #2
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #1
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #3
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { argmemonly nounwind }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind readnone speculatable }
+attributes #4 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!2 = !{}
+!3 = !{!4}
+!4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+!5 = distinct !DIGlobalVariable(name: "bpf_probe_read", scope: !0, file: !1, line: 12, type: !6, isLocal: true, isDefinition: true)
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !10, !9, !10}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 9.0.0 (trunk 360739) (llvm/trunk 360747)"}
+!15 = distinct !DISubprogram(name: "bpf_prog", scope: !1, file: !1, line: 15, type: !16, scopeLine: 15, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !31)
+!16 = !DISubroutineType(types: !17)
+!17 = !{!9, !18}
+!18 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !19, size: 64)
+!19 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "sk_buff", file: !1, line: 1, size: 64, elements: !20)
+!20 = !{!21, !22}
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !19, file: !1, line: 2, baseType: !9, size: 32)
+!22 = !DIDerivedType(tag: DW_TAG_member, name: "u", scope: !19, file: !1, line: 9, baseType: !23, size: 64)
+!23 = distinct !DICompositeType(tag: DW_TAG_structure_type, scope: !19, file: !1, line: 3, size: 64, elements: !24)
+!24 = !{!25, !26}
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "netid", scope: !23, file: !1, line: 4, baseType: !9, size: 32)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "dev", scope: !23, file: !1, line: 8, baseType: !27, size: 32, offset: 32)
+!27 = distinct !DICompositeType(tag: DW_TAG_union_type, scope: !23, file: !1, line: 5, size: 32, elements: !28)
+!28 = !{!29, !30}
+!29 = !DIDerivedType(tag: DW_TAG_member, name: "dev_id", scope: !27, file: !1, line: 6, baseType: !9, size: 32)
+!30 = !DIDerivedType(tag: DW_TAG_member, name: "others", scope: !27, file: !1, line: 7, baseType: !9, size: 32)
+!31 = !{!32, !33}
+!32 = !DILocalVariable(name: "ctx", arg: 1, scope: !15, file: !1, line: 15, type: !18)
+!33 = !DILocalVariable(name: "dev_id", scope: !15, file: !1, line: 16, type: !9)
+!34 = !DILocation(line: 0, scope: !15)
+!35 = !DILocation(line: 16, column: 3, scope: !15)
+!36 = !DILocation(line: 17, column: 40, scope: !15)
+!37 = !DILocation(line: 17, column: 3, scope: !15)
+!38 = !DILocation(line: 18, column: 10, scope: !15)
+!39 = !{!40, !40, i64 0}
+!40 = !{!"int", !41, i64 0}
+!41 = !{!"omnipotent char", !42, i64 0}
+!42 = !{!"Simple C/C++ TBAA"}
+!43 = !DILocation(line: 19, column: 1, scope: !15)
+!44 = !DILocation(line: 18, column: 3, scope: !15)
Index: test/CodeGen/BPF/CORE/patchable-extern-char.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/CORE/patchable-extern-char.ll
@@ -0,0 +1,107 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; Source code:
+;   extern __attribute__((section(".BPF.patchable_externs"))) char a;
+;   int foo() { return a; }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+@a = external dso_local local_unnamed_addr global i8, section ".BPF.patchable_externs", align 1
+
+; Function Attrs: norecurse nounwind readonly
+define dso_local i32 @foo() local_unnamed_addr #0 !dbg !7 {
+  %1 = load i8, i8* @a, align 1, !dbg !11, !tbaa !12
+  %2 = sext i8 %1 to i32, !dbg !11
+; CHECK:             r0 = 0
+; CHECK-NEXT:        r0 <<= 56
+; CHECK-NEXT:        r0 s>>= 56
+  ret i32 %2, !dbg !15
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   54
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
+; CHECK-NEXT:        .long   218103808               # 0xd000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   97                      # string offset=15
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/home/yhs/work/tests/llvm/test.c" # string offset=17
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   44
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   9                       # FuncInfo section string offset=9
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   9                       # LineInfo section string offset=9
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   17
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   2068                    # Line 2 Col 20
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   17
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   2061                    # Line 2 Col 13
+; CHECK-NEXT:        .long   8                       # ExternReloc
+; CHECK-NEXT:        .long   9                       # Extern reloc section string offset=9
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   15
+
+attributes #0 = { norecurse nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.20181009 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.20181009 "}
+!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !8, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: true, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !DILocation(line: 2, column: 20, scope: !7)
+!12 = !{!13, !13, i64 0}
+!13 = !{!"omnipotent char", !14, i64 0}
+!14 = !{!"Simple C/C++ TBAA"}
+!15 = !DILocation(line: 2, column: 13, scope: !7)
Index: test/CodeGen/BPF/CORE/patchable-extern-uint.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/CORE/patchable-extern-uint.ll
@@ -0,0 +1,102 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; Source code:
+;   extern __attribute__((section(".BPF.patchable_externs"))) unsigned a;
+;   int foo() { return a; }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+@a = external dso_local local_unnamed_addr global i32, section ".BPF.patchable_externs", align 4
+
+; Function Attrs: norecurse nounwind readonly
+define dso_local i32 @foo() local_unnamed_addr #0 !dbg !7 {
+  %1 = load i32, i32* @a, align 4, !dbg !11, !tbaa !12
+; CHECK:             r0 = 0
+; CHECK-NEXT:        exit
+  ret i32 %1, !dbg !16
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   49
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
+; CHECK-NEXT:        .long   218103808               # 0xd000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   97                      # string offset=15
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/yhs/work/tests/llvm/test.c" # string offset=17
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   9                       # FuncInfo section string offset=9
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   9                       # LineInfo section string offset=9
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   17
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   2061                    # Line 2 Col 13
+; CHECK-NEXT:        .long   8                       # ExternReloc
+; CHECK-NEXT:        .long   9                       # Extern reloc section string offset=9
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   15
+
+attributes #0 = { norecurse nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.20181009 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/yhs/work/tests/llvm")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.20181009 "}
+!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !8, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: true, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !DILocation(line: 2, column: 20, scope: !7)
+!12 = !{!13, !13, i64 0}
+!13 = !{!"int", !14, i64 0}
+!14 = !{!"omnipotent char", !15, i64 0}
+!15 = !{!"Simple C/C++ TBAA"}
+!16 = !DILocation(line: 2, column: 13, scope: !7)
Index: test/CodeGen/BPF/CORE/patchable-extern-ulonglong.ll
===================================================================
--- /dev/null
+++ test/CodeGen/BPF/CORE/patchable-extern-ulonglong.ll
@@ -0,0 +1,103 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; Source code:
+;   extern __attribute__((section(".BPF.patchable_externs"))) unsigned long long a;
+;   int foo() { return a; }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+@a = external dso_local local_unnamed_addr global i64, section ".BPF.patchable_externs", align 8
+
+; Function Attrs: norecurse nounwind readonly
+define dso_local i32 @foo() local_unnamed_addr #0 !dbg !7 {
+  %1 = load i64, i64* @a, align 8, !dbg !11, !tbaa !12
+  %2 = trunc i64 %1 to i32, !dbg !11
+; CHECK:             r0 = 0 ll
+; CHECK-NEXT:        exit
+  ret i32 %2, !dbg !16
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   54
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
+; CHECK-NEXT:        .long   218103808               # 0xd000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   5                       # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "foo"                   # string offset=5
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=9
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   97                      # string offset=15
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/home/yhs/work/tests/llvm/test.c" # string offset=17
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   9                       # FuncInfo section string offset=9
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   9                       # LineInfo section string offset=9
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   17
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   2061                    # Line 2 Col 13
+; CHECK-NEXT:        .long   8                       # ExternReloc
+; CHECK-NEXT:        .long   9                       # Extern reloc section string offset=9
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   15
+
+attributes #0 = { norecurse nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.20181009 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/llvm")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.20181009 "}
+!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !8, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: true, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !DILocation(line: 2, column: 20, scope: !7)
+!12 = !{!13, !13, i64 0}
+!13 = !{!"long long", !14, i64 0}
+!14 = !{!"omnipotent char", !15, i64 0}
+!15 = !{!"Simple C/C++ TBAA"}
+!16 = !DILocation(line: 2, column: 13, scope: !7)