[BPF] do compile-once run-everywhere relocation for bitfields

[yonghong-song]

Summary

A bpf specific clang intrinsic is introduced:

u32 __builtin_preserve_field_info(member_access, info_kind)

Depending on info_kind, different information will
be returned to the program. A relocation is also
recorded for this builtin so that bpf loader can
patch the instruction on the target host.
This clang intrinsic is used to get certain information
to facilitate struct/union member relocations.

The offset relocation is extended by 4 bytes to
include relocation kind.
Currently supported relocation kinds are
enum {

FIELD_BYTE_OFFSET = 0,
FIELD_BYTE_SIZE,
FIELD_EXISTENCE,
FIELD_SIGNEDNESS,
FIELD_LSHIFT_U64,
FIELD_RSHIFT_U64,

};
for __builtin_preserve_field_info. The old
access offset relocation is covered by

FIELD_BYTE_OFFSET = 0.

An example:
struct s {

int a;
int b1:9;
int b2:4;

};
enum {

FIELD_BYTE_OFFSET = 0,
FIELD_BYTE_SIZE,
FIELD_EXISTENCE,
FIELD_SIGNEDNESS,
FIELD_LSHIFT_U64,
FIELD_RSHIFT_U64,

};

void bpf_probe_read(void *, unsigned, const void *);
int field_read(struct s *arg) {

unsigned long long ull = 0;
unsigned offset = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_OFFSET);
unsigned size = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_SIZE);

#ifdef USE_PROBE_READ

bpf_probe_read(&ull, size, (const void *)arg + offset);
unsigned lshift = __builtin_preserve_field_info(arg->b2, FIELD_LSHIFT_U64);

#if BYTE_ORDER == ORDER_BIG_ENDIAN

lshift = lshift + (size << 3) - 64;

#endif
#else

switch(size) {
case 1:
  ull = *(unsigned char *)((void *)arg + offset); break;
case 2:
  ull = *(unsigned short *)((void *)arg + offset); break;
case 4:
  ull = *(unsigned int *)((void *)arg + offset); break;
case 8:
  ull = *(unsigned long long *)((void *)arg + offset); break;
}
unsigned lshift = __builtin_preserve_field_info(arg->b2, FIELD_LSHIFT_U64);

#endif

ull <<= lshift;
if (__builtin_preserve_field_info(arg->b2, FIELD_SIGNEDNESS))
  return (long long)ull >> __builtin_preserve_field_info(arg->b2, FIELD_RSHIFT_U64);
return ull >> __builtin_preserve_field_info(arg->b2, FIELD_RSHIFT_U64);

}

There is a minor overhead for bpf_probe_read() on big endian.

The code and relocation generated for field_read where bpf_probe_read() is
used to access argument data on little endian mode:

r3 = r1
r1 = 0
r1 = 4  <=== relocation (FIELD_BYTE_OFFSET)
r3 += r1
r1 = r10
r1 += -8
r2 = 4  <=== relocation (FIELD_BYTE_SIZE)
call bpf_probe_read
r2 = 51 <=== relocation (FIELD_LSHIFT_U64)
r1 = *(u64 *)(r10 - 8)
r1 <<= r2
r2 = 60 <=== relocation (FIELD_RSHIFT_U64)
r0 = r1
r0 >>= r2
r3 = 1  <=== relocation (FIELD_SIGNEDNESS)
if r3 == 0 goto LBB0_2
r1 s>>= r2
r0 = r1

LBB0_2:

exit

Compare to the above code between relocations FIELD_LSHIFT_U64 and
FIELD_LSHIFT_U64, the code with big endian mode has four more
instructions.

r1 = 41   <=== relocation (FIELD_LSHIFT_U64)
r6 += r1
r6 += -64
r6 <<= 32
r6 >>= 32
r1 = *(u64 *)(r10 - 8)
r1 <<= r6
r2 = 60   <=== relocation (FIELD_RSHIFT_U64)

The code and relocation generated when using direct load.

r2 = 0
r3 = 4
r4 = 4
if r4 s> 3 goto LBB0_3
if r4 == 1 goto LBB0_5
if r4 == 2 goto LBB0_6
goto LBB0_9

LBB0_6: # %sw.bb1

r1 += r3
r2 = *(u16 *)(r1 + 0)
goto LBB0_9

LBB0_3: # %entry

if r4 == 4 goto LBB0_7
if r4 == 8 goto LBB0_8
goto LBB0_9

LBB0_8: # %sw.bb9

r1 += r3
r2 = *(u64 *)(r1 + 0)
goto LBB0_9

LBB0_5: # %sw.bb

r1 += r3
r2 = *(u8 *)(r1 + 0)
goto LBB0_9

LBB0_7: # %sw.bb5

r1 += r3
r2 = *(u32 *)(r1 + 0)

LBB0_9: # %sw.epilog

r1 = 51
r2 <<= r1
r1 = 60
r0 = r2
r0 >>= r1
r3 = 1
if r3 == 0 goto LBB0_11
r2 s>>= r1
r0 = r2

LBB0_11: # %sw.epilog

exit

Considering verifier is able to do limited constant
propogation following branches. The following is the
code actually traversed.

r2 = 0
r3 = 4   <=== relocation
r4 = 4   <=== relocation
if r4 s> 3 goto LBB0_3

LBB0_3: # %entry

if r4 == 4 goto LBB0_7

LBB0_7: # %sw.bb5

r1 += r3
r2 = *(u32 *)(r1 + 0)

LBB0_9: # %sw.epilog

r1 = 51   <=== relocation
r2 <<= r1
r1 = 60   <=== relocation
r0 = r2
r0 >>= r1
r3 = 1
if r3 == 0 goto LBB0_11
r2 s>>= r1
r0 = r2

LBB0_11: # %sw.epilog

exit

For native load case, the load size is calculated to be the
same as the size of load width LLVM otherwise used to load
the value which is then used to extract the bitfield value.

[yonghong-song]

builtin return u32 instead of u64.

[yonghong-song]

add BPF backend support

[yonghong-song]

use a bpf target builtin __builtin_get_field_info().

[yonghong-song]

return byte_size/offset/lshift/rshift based on size alignment

[anakryiko]

clang/lib/CodeGen/CGBuiltin.cpp

9321–9322

move this under if (!getDebugInfo) above and ditch IsError completely?

llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp

243–244

getConstant returns u64, but AccessIndex is u32, is that a concern?

264

just curious, why did you decide to not follow llvm.preserve.xxx pattern here? E.g., llvm.preserve.field.info would read just fine, I guess?

535

is it possible to allow capturing same bitfield information for non-bitfield integers?

E.g, if my current vmlinux.h has some field as plain integer, but I know that some older kernel (or maybe future kernels?) had this field as a bitfield, I won't have to do anything nasty just to handle this generically. The less artificial restrictions we have, the better, IMO.

538

I think we should be generic here and allow up to 128 bits and let libbpf handle its limitations separately (e.g., if we can't support >64 bits initially, libbpf will reject the program; but if we ever extend the support, at least we won't have to go back to Clang and fix it up).

543–550

I'll need to do some drawing and math to check how this is going to be handled in big-endian and little-endian, I'll get back to you later with that.

701

nit: I can't from the top of my head figure out what takes precedence: shift or multiplication, maybe add parens to make it obvious?

llvm/lib/Target/BPF/BTFDebug.cpp

1163

why int64?

llvm/lib/Target/BPF/BTFDebug.h

227

nit: this is not BTFOffsetReloc anymore, more like BTFFieldReloc

[yonghong-song]

clang/lib/CodeGen/CGBuiltin.cpp

9321–9322

yes. previously I have two case of errors. Now only have one, it makes sense to merge them.

llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp

243–244

it should be okay. the call is generated by clang where the access index will be in the range. Also, llvm ConstantInt class can only return 64bit values.
https://llvm.org/doxygen/classllvm_1_1ConstantInt.html
We just do the cast here. should be okay.

264

previously i am using preserve.field.info and switch to get.field.info as it is indeed to return certain field info to the user. maybe we should get back to preserve.field.info to indicate that relocation is generated. will do.

535

Yes, we can remove this restriction. Let us first get bitfield interface right and then extend them to nonbitfield.

538

We can do this.

543–550

sounds great.

701

sure.

llvm/lib/Target/BPF/BTFDebug.cpp

1163

Will change to u32.

llvm/lib/Target/BPF/BTFDebug.h

227

Yes, it becomes FieldReloc now.

[yonghong-song]

using 64bit buf always, handling non bitfield members, etc.

[ast]

llvm/lib/Target/BPF/BPFCORE.h

17

why ACCESS_OFFSET is necessary?
Isn't it the same as BYTE_OFFSET but for non-bitfield?
May be single kind will do?

22

All these names are not added as builtin enum before compilation starts, right?
So C program cannot just use FIELD_BYTE_OFFSET and needs to define its own enum first?
How about FIELD_LSHIFT_U64 instead?

23

FIELD_RSHIFT_U64 ?

[yonghong-song]

llvm/lib/Target/BPF/BPFCORE.h

17

This is the relocation type in the .BTF.ext. FIELD_ACCESS_OFFSET corresponds to odd offset relocation. The below newly added relocations are for field info.
I am using relocation enum except FIELD_ACCESS_OFFSET to be used for field_info in __builtin_preserve_field_info().

22

Yes, C programs should define its own enum to have corresponding values first.
Do not familiar within builtin enum's. Let me take a look.

FIELD_LSHIFT_U64 is shorter and looks good.

23

Yes, sounds better.

[yonghong-song]

All these names are not added as builtin enum before compilation starts, right?

Do you prefer to have builtin enum? If we do this, we will emit this enum all the time,
regardless of whether people uses this builtin or not. Are you worried about API
stability?

I think defining explicitly in libbpf/btf.h probably a better choice?
Defining commonly used macros like bpf or BPF
makes more sense. Hidden enum's seems really rare.

[yonghong-song]

llvm/lib/Target/BPF/BPFCORE.h

17

Now I understand what you mean. Currently BYTE_OFFSET is calculated from the start of the last enclosing struct/union members while ACCESS_OFFSET could be the offset from outer struct/union like a.b.c.d.
Let me think whether we could consolidate two.

[yonghong-song]

fixed a few bugs from previous revision. Removed FIELD_ACCESS_OFFSET relocation which will be identical to FIELD_BYTE_OFFSET. All of these CORE related test cases are adjusted and passed now. Removed [WIP] prefix.
TODO: write new tests for the new functionality.

[ast]

lgtm. thanks!

[yonghong-song]

add test cases. Also handle filed_info for field array elements properly.

[ast]

thanks for adding the tests

[yonghong-song]

separate old FIELD_LSHIFT_U64 relocation to FIELD_LSHIFT_U64_BUF and FIELD_LSHIFT_U64_VAL. This allows to generate better code for native loads.

[yonghong-song]

use only one relocation for left shift to optimize for direct load. The bpf_probe_read() big endian mode could have 4 more arithmetic instructions compared to little endian mode. The performance impact should be negligible comparing to bpf_probe_read() itself.

[ast]

perfect. ship it

clang/include/clang/Basic/BuiltinsBPF.def

+//===--- BuiltinsBPF.def - BPF Builtin function database --------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the BPF-specific builtin function database.  Users of
+// this file must define the BUILTIN macro to make use of this information.
+//
+//===----------------------------------------------------------------------===//
+
+// The format of this database matches clang/Basic/Builtins.def.
+
+#if defined(BUILTIN) && !defined(TARGET_BUILTIN)
+#   define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE) BUILTIN(ID, TYPE, ATTRS)
+#endif
+
+// Get record field information.
+TARGET_BUILTIN(__builtin_preserve_field_info, "Ui.", "t", "")
+
+#undef BUILTIN
+#undef TARGET_BUILTIN

clang/include/clang/Basic/DiagnosticSemaKinds.td

def warn_noderef_on_non_pointer_or_array : Warning<
   "'noderef' can only be used on an array or pointer type">, InGroup<IgnoredAttributes>;
 def warn_noderef_to_dereferenceable_pointer : Warning<
   "casting to dereferenceable pointer removes 'noderef' attribute">, InGroup<NoDeref>;
 
 def err_builtin_launder_invalid_arg : Error<
   "%select{non-pointer|function pointer|void pointer}0 argument to "
   "'__builtin_launder' is not allowed">;
 
+def err_preserve_field_info_not_field : Error<
+  "__builtin_preserve_field_info argument %0 not a field access">;
+def err_preserve_field_info_not_const: Error<
+  "__builtin_preserve_field_info argument %0 not a constant">;
+
 def err_bit_cast_non_trivially_copyable : Error<
   "__builtin_bit_cast %select{source|destination}0 type must be trivially copyable">;
 def err_bit_cast_type_size_mismatch : Error<
   "__builtin_bit_cast source size does not equal destination size (%0 vs %1)">;
 } // end of sema component.

clang/include/clang/Basic/TargetBuiltins.h

enum {
     LastTIBuiltin = clang::Builtin::FirstTSBuiltin - 1,
     LastNEONBuiltin = NEON::FirstTSBuiltin - 1,
   #define BUILTIN(ID, TYPE, ATTRS) BI##ID,
   #include "clang/Basic/BuiltinsAArch64.def"
     LastTSBuiltin
   };
   }
 
+  /// BPF builtins
+  namespace BPF {
+  enum {
+    LastTIBuiltin = clang::Builtin::FirstTSBuiltin - 1,
+  #define BUILTIN(ID, TYPE, ATTRS) BI##ID,
+  #include "clang/Basic/BuiltinsBPF.def"
+    LastTSBuiltin
+  };
+  }
+
   /// PPC builtins
   namespace PPC {
     enum {
         LastTIBuiltin = clang::Builtin::FirstTSBuiltin-1,
 #define BUILTIN(ID, TYPE, ATTRS) BI##ID,
 #include "clang/Basic/BuiltinsPPC.def"
         LastTSBuiltin
     };

clang/include/clang/Sema/Sema.h

private:
   void checkFortifiedBuiltinMemoryFunction(FunctionDecl *FD, CallExpr *TheCall);
 
   bool CheckARMBuiltinExclusiveCall(unsigned BuiltinID, CallExpr *TheCall,
                                     unsigned MaxWidth);
   bool CheckNeonBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckARMBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
 
   bool CheckAArch64BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
+  bool CheckBPFBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckHexagonBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckHexagonBuiltinCpu(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckHexagonBuiltinArgument(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckMipsBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckSystemZBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckX86BuiltinRoundingOrSAE(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckX86BuiltinGatherScatterScale(unsigned BuiltinID, CallExpr *TheCall);
   bool CheckX86BuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);

clang/include/clang/module.modulemap

 module Clang_Basic {
   requires cplusplus
   umbrella "Basic"
 
   textual header "Basic/AArch64SVEACLETypes.def"
   textual header "Basic/BuiltinsAArch64.def"
   textual header "Basic/BuiltinsAMDGPU.def"
   textual header "Basic/BuiltinsARM.def"
+  textual header "Basic/BuiltinsBPF.def"
   textual header "Basic/Builtins.def"
   textual header "Basic/BuiltinsHexagon.def"
   textual header "Basic/BuiltinsLe64.def"
   textual header "Basic/BuiltinsMips.def"
   textual header "Basic/BuiltinsNEON.def"
   textual header "Basic/BuiltinsNVPTX.def"
   textual header "Basic/BuiltinsPPC.def"
   textual header "Basic/BuiltinsSystemZ.def"

clang/lib/Basic/Targets/BPF.h

 #include "clang/Basic/TargetOptions.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Support/Compiler.h"
 
 namespace clang {
 namespace targets {
 
 class LLVM_LIBRARY_VISIBILITY BPFTargetInfo : public TargetInfo {
+  static const Builtin::Info BuiltinInfo[];
+
 public:
   BPFTargetInfo(const llvm::Triple &Triple, const TargetOptions &)
       : TargetInfo(Triple) {
     LongWidth = LongAlign = PointerWidth = PointerAlign = 64;
     SizeType = UnsignedLong;
     PtrDiffType = SignedLong;
     IntPtrType = SignedLong;
     IntMaxType = SignedLong;
bool hasFeature(StringRef Feature) const override {
     return Feature == "bpf" || Feature == "alu32" || Feature == "dwarfris";
   }
 
   void setFeatureEnabled(llvm::StringMap<bool> &Features, StringRef Name,
                          bool Enabled) const override {
     Features[Name] = Enabled;
   }
 
-  ArrayRef<Builtin::Info> getTargetBuiltins() const override { return None; }
+  ArrayRef<Builtin::Info> getTargetBuiltins() const override;
 
   const char *getClobbers() const override { return ""; }
 
   BuiltinVaListKind getBuiltinVaListKind() const override {
     return TargetInfo::VoidPtrBuiltinVaList;
   }
 
   bool isValidGCCRegisterName(StringRef Name) const override { return true; }

clang/lib/Basic/Targets/BPF.cpp

 //===--- BPF.cpp - Implement BPF target feature support -------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements BPF TargetInfo objects.
 //
 //===----------------------------------------------------------------------===//
 
 #include "BPF.h"
 #include "Targets.h"
 #include "clang/Basic/MacroBuilder.h"
+#include "clang/Basic/TargetBuiltins.h"
 #include "llvm/ADT/StringRef.h"
 
 using namespace clang;
 using namespace clang::targets;
 
+const Builtin::Info BPFTargetInfo::BuiltinInfo[] = {
+#define BUILTIN(ID, TYPE, ATTRS)                                               \
+  {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr},
+#include "clang/Basic/BuiltinsBPF.def"
+};
+
 void BPFTargetInfo::getTargetDefines(const LangOptions &Opts,
                                      MacroBuilder &Builder) const {
   Builder.defineMacro("__bpf__");
   Builder.defineMacro("__BPF__");
 }
 
 static constexpr llvm::StringLiteral ValidCPUNames[] = {"generic", "v1", "v2",
                                                         "v3", "probe"};
 
 bool BPFTargetInfo::isValidCPUName(StringRef Name) const {
   return llvm::find(ValidCPUNames, Name) != std::end(ValidCPUNames);
 }
 
 void BPFTargetInfo::fillValidCPUList(SmallVectorImpl<StringRef> &Values) const {
   Values.append(std::begin(ValidCPUNames), std::end(ValidCPUNames));
 }
+
+ArrayRef<Builtin::Info> BPFTargetInfo::getTargetBuiltins() const {
+  return llvm::makeArrayRef(BuiltinInfo, clang::BPF::LastTSBuiltin -
+                                             Builtin::FirstTSBuiltin);
+}

clang/lib/CodeGen/CGBuiltin.cpp

static Value *EmitTargetArchBuiltinExpr(CodeGenFunction *CGF,
   case llvm::Triple::arm:
   case llvm::Triple::armeb:
   case llvm::Triple::thumb:
   case llvm::Triple::thumbeb:
     return CGF->EmitARMBuiltinExpr(BuiltinID, E, Arch);
   case llvm::Triple::aarch64:
   case llvm::Triple::aarch64_be:
     return CGF->EmitAArch64BuiltinExpr(BuiltinID, E, Arch);
+  case llvm::Triple::bpfeb:
+  case llvm::Triple::bpfel:
+    return CGF->EmitBPFBuiltinExpr(BuiltinID, E);
   case llvm::Triple::x86:
   case llvm::Triple::x86_64:
     return CGF->EmitX86BuiltinExpr(BuiltinID, E);
   case llvm::Triple::ppc:
   case llvm::Triple::ppc64:
   case llvm::Triple::ppc64le:
     return CGF->EmitPPCBuiltinExpr(BuiltinID, E);
   case llvm::Triple::r600:

   case NEON::BI__builtin_neon_vuqadd_v:
   case NEON::BI__builtin_neon_vuqaddq_v: {
     Int = Intrinsic::aarch64_neon_suqadd;
     return EmitNeonCall(CGM.getIntrinsic(Int, Ty), Ops, "vuqadd");
   }
   }
 }
 
+Value *CodeGenFunction::EmitBPFBuiltinExpr(unsigned BuiltinID,
+                                           const CallExpr *E) {
+  assert(BuiltinID == BPF::BI__builtin_preserve_field_info &&
+         "unexpected ARM builtin");
+
+  const Expr *Arg = E->getArg(0);
+  bool IsBitField = Arg->IgnoreParens()->getObjectKind() == OK_BitField;
+
+  if (!getDebugInfo()) {
+    CGM.Error(E->getExprLoc(), "using builtin_preserve_field_info() without -g");
+    return IsBitField ? EmitLValue(Arg).getBitFieldPointer()
+                      : EmitLValue(Arg).getPointer();
+  }
+
+  // Enable underlying preserve_*_access_index() generation.
+  bool OldIsInPreservedAIRegion = IsInPreservedAIRegion;
+  IsInPreservedAIRegion = true;
+  Value *FieldAddr = IsBitField ? EmitLValue(Arg).getBitFieldPointer()
+                                : EmitLValue(Arg).getPointer();
+  IsInPreservedAIRegion = OldIsInPreservedAIRegion;
+
+  ConstantInt *C = cast<ConstantInt>(EmitScalarExpr(E->getArg(1)));
+  Value *InfoKind = ConstantInt::get(Int64Ty, C->getSExtValue());
+
+  // Built the IR for the preserve_field_info intrinsic.
+  llvm::Function *FnGetFieldInfo = llvm::Intrinsic::getDeclaration(
+      &CGM.getModule(), llvm::Intrinsic::bpf_preserve_field_info,
+      {FieldAddr->getType()});
+  return Builder.CreateCall(FnGetFieldInfo, {FieldAddr, InfoKind});
+}
+
 llvm::Value *CodeGenFunction::
 BuildVector(ArrayRef<llvm::Value*> Ops) {
   assert((Ops.size() & (Ops.size() - 1)) == 0 &&
          "Not a power-of-two sized vector!");
   bool AllConstants = true;
   for (unsigned i = 0, e = Ops.size(); i != e && AllConstants; ++i)
     AllConstants &= isa<Constant>(Ops[i]);
 

clang/lib/CodeGen/CGExpr.cpp

LValue CodeGenFunction::EmitLValueForField(LValue base,
   LValueBaseInfo BaseInfo = base.getBaseInfo();
 
   if (field->isBitField()) {
     const CGRecordLayout &RL =
       CGM.getTypes().getCGRecordLayout(field->getParent());
     const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
     Address Addr = base.getAddress();
     unsigned Idx = RL.getLLVMFieldNo(field);
+    if (!IsInPreservedAIRegion) {
       if (Idx != 0)
         // For structs, we GEP to the field that the record layout suggests.
         Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
+    } else {
+      const RecordDecl *rec = field->getParent();
+      llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
+          getContext().getRecordType(rec), rec->getLocation());
+      Addr = Builder.CreatePreserveStructAccessIndex(Addr, Idx,
+          getDebugInfoFIndex(rec, field->getFieldIndex()),
+          DbgInfo);
+    }
+
     // Get the access type.
     llvm::Type *FieldIntTy =
       llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
     if (Addr.getElementType() != FieldIntTy)
       Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
 
     QualType fieldType =
       field->getType().withCVRQualifiers(base.getVRQualifiers());

clang/lib/CodeGen/CodeGenFunction.h

public:
   llvm::Value *EmitNeonSplat(llvm::Value *V, llvm::Constant *Idx);
   llvm::Value *EmitNeonShiftVector(llvm::Value *V, llvm::Type *Ty,
                                    bool negateForRightShift);
   llvm::Value *EmitNeonRShiftImm(llvm::Value *Vec, llvm::Value *Amt,
                                  llvm::Type *Ty, bool usgn, const char *name);
   llvm::Value *vectorWrapScalar16(llvm::Value *Op);
   llvm::Value *EmitAArch64BuiltinExpr(unsigned BuiltinID, const CallExpr *E,
                                       llvm::Triple::ArchType Arch);
+  llvm::Value *EmitBPFBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
 
   llvm::Value *BuildVector(ArrayRef<llvm::Value*> Ops);
   llvm::Value *EmitX86BuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitPPCBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitAMDGPUBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitSystemZBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,

clang/lib/Sema/SemaChecking.cpp

switch (Context.getTargetInfo().getTriple().getArch()) {
         if (CheckARMBuiltinFunctionCall(BuiltinID, TheCall))
           return ExprError();
         break;
       case llvm::Triple::aarch64:
       case llvm::Triple::aarch64_be:
         if (CheckAArch64BuiltinFunctionCall(BuiltinID, TheCall))
           return ExprError();
         break;
+      case llvm::Triple::bpfeb:
+      case llvm::Triple::bpfel:
+        if (CheckBPFBuiltinFunctionCall(BuiltinID, TheCall))
+          return ExprError();
+        break;
       case llvm::Triple::hexagon:
         if (CheckHexagonBuiltinFunctionCall(BuiltinID, TheCall))
           return ExprError();
         break;
       case llvm::Triple::mips:
       case llvm::Triple::mipsel:
       case llvm::Triple::mips64:
       case llvm::Triple::mips64el:
bool Sema::CheckAArch64BuiltinFunctionCall(unsigned BuiltinID,
   case AArch64::BI__builtin_arm_dsb:
   case AArch64::BI__builtin_arm_isb: l = 0; u = 15; break;
   case AArch64::BI__builtin_arm_tcancel: l = 0; u = 65535; break;
   }
 
   return SemaBuiltinConstantArgRange(TheCall, i, l, u + l);
 }
 
+bool Sema::CheckBPFBuiltinFunctionCall(unsigned BuiltinID,
+                                       CallExpr *TheCall) {
+  assert(BuiltinID == BPF::BI__builtin_preserve_field_info &&
+         "unexpected ARM builtin");
+
+  if (checkArgCount(*this, TheCall, 2))
+    return true;
+
+  // The first argument needs to be a record field access.
+  // If it is an array element access, we delay decision
+  // to BPF backend to check whether the access is a
+  // field access or not.
+  Expr *Arg = TheCall->getArg(0);
+  if (Arg->getType()->getAsPlaceholderType() ||
+      (Arg->IgnoreParens()->getObjectKind() != OK_BitField &&
+       !dyn_cast<MemberExpr>(Arg->IgnoreParens()) &&
+       !dyn_cast<ArraySubscriptExpr>(Arg->IgnoreParens()))) {
+    Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_field)
+        << 1 << Arg->getSourceRange();
+    return true;
+  }
+
+  // The second argument needs to be a constant int
+  llvm::APSInt Value;
+  if (!TheCall->getArg(1)->isIntegerConstantExpr(Value, Context)) {
+    Diag(Arg->getBeginLoc(), diag::err_preserve_field_info_not_const)
+        << 2 << Arg->getSourceRange();
+    return true;
+  }
+
+  TheCall->setType(Context.UnsignedIntTy);
+  return false;
+}
+
 bool Sema::CheckHexagonBuiltinCpu(unsigned BuiltinID, CallExpr *TheCall) {
   struct BuiltinAndString {
     unsigned BuiltinID;
     const char *Str;
   };
 
   static BuiltinAndString ValidCPU[] = {
     { Hexagon::BI__builtin_HEXAGON_A6_vcmpbeq_notany, "v65,v66" },

clang/test/CodeGen/builtins-bpf-preserve-field-info-1.c

+// REQUIRES: bpf-registered-target
+// RUN: %clang -target bpf -emit-llvm -S -g %s -o - | FileCheck %s
+
+#define _(x, y) (__builtin_preserve_field_info((x), (y)))
+
+struct s1 {
+  char a;
+  char b:2;
+};
+
+union u1 {
+  char a;
+  char b:2;
+};
+
+unsigned unit1(struct s1 *arg) {
+  return _(arg->a, 10) + _(arg->b, 10);
+}
+// CHECK: define dso_local i32 @unit1
+// CHECK: call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1* %{{[0-9a-z]+}}, i32 0, i32 0), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[STRUCT_S1:[0-9]+]]
+// CHECK: call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %{{[0-9a-z]+}}, i64 10), !dbg !{{[0-9]+}}
+// CHECK: call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1* %{{[0-9a-z]+}}, i32 1, i32 1), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[STRUCT_S1:[0-9]+]]
+// CHECK: call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %{{[0-9a-z]+}}, i64 10), !dbg !{{[0-9]+}}
+
+unsigned unit2(union u1 *arg) {
+  return _(arg->a, 10) + _(arg->b, 10);
+}
+// CHECK: define dso_local i32 @unit2
+// CHECK: call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %{{[0-9a-z]+}}, i32 0), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[UNION_U1:[0-9]+]]
+// CHECK: call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %{{[0-9a-z]+}}, i64 10), !dbg !{{[0-9]+}}
+// CHECK: call i8* @llvm.preserve.struct.access.index.p0i8.p0s_union.u1s(%union.u1* %{{[0-9a-z]+}}, i32 0, i32 1), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[UNION_U1:[0-9]+]]
+// CHECK: call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %{{[0-9a-z]+}}, i64 10), !dbg !{{[0-9]+}}
+
+// CHECK: ![[STRUCT_S1]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1"
+// CHECK: ![[UNION_U1]] = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1"

clang/test/CodeGen/builtins-bpf-preserve-field-info-2.c

+// REQUIRES: bpf-registered-target
+// RUN: %clang -target bpf -emit-llvm -S -g %s -o - | FileCheck %s
+
+#define _(x, y) (__builtin_preserve_field_info((x), (y)))
+
+struct s1 {
+  char a;
+  char b:2;
+};
+struct s2 {
+  struct s1 s;
+};
+
+unsigned unit1(struct s2 *arg) {
+  return _(arg->s.a, 10) + _(arg->s.b, 10);
+}
+// CHECK: define dso_local i32 @unit1
+// CHECK: call %struct.s1* @llvm.preserve.struct.access.index.p0s_struct.s1s.p0s_struct.s2s(%struct.s2* %{{[0-9a-z]+}}, i32 0, i32 0), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[STRUCT_S2:[0-9]+]]
+// CHECK: call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1* %{{[0-9a-z]+}}, i32 0, i32 0), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[STRUCT_S1:[0-9]+]]
+// CHECK: call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %{{[0-9a-z]+}}, i64 10), !dbg !{{[0-9]+}}
+// CHECK: call %struct.s1* @llvm.preserve.struct.access.index.p0s_struct.s1s.p0s_struct.s2s(%struct.s2* %{{[0-9a-z]+}}, i32 0, i32 0), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[STRUCT_S2:[0-9]+]]
+// CHECK: call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1* %{{[0-9a-z]+}}, i32 1, i32 1), !dbg !{{[0-9]+}}, !llvm.preserve.access.index ![[STRUCT_S1:[0-9]+]]
+// CHECK: call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %{{[0-9a-z]+}}, i64 10), !dbg !{{[0-9]+}}
+
+// CHECK: ![[STRUCT_S2]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s2"
+// CHECK: ![[STRUCT_S1]] = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1"

clang/test/Sema/builtins-bpf.c

+// RUN: %clang_cc1 -x c -triple bpf-pc-linux-gnu -dwarf-version=4 -fsyntax-only -verify %s
+
+struct s { int a; int b[4]; int c:1; };
+union u { int a; int b[4]; int c:1; };
+
+unsigned invalid1(const int *arg) {
+  return __builtin_preserve_field_info(arg, 1); // expected-error {{__builtin_preserve_field_info argument 1 not a field access}}
+}
+
+unsigned invalid2(const int *arg) {
+  return __builtin_preserve_field_info(*arg, 1); // expected-error {{__builtin_preserve_field_info argument 1 not a field access}}
+}
+
+void *invalid3(struct s *arg) {
+  return __builtin_preserve_field_info(arg->a, 1); // expected-warning {{incompatible integer to pointer conversion returning 'unsigned int' from a function with result type 'void *'}}
+}
+
+unsigned valid4(struct s *arg) {
+  return __builtin_preserve_field_info(arg->b[1], 1);
+}
+
+unsigned valid5(union u *arg) {
+  return __builtin_preserve_field_info(arg->b[2], 1);
+}
+
+unsigned valid6(struct s *arg) {
+  return __builtin_preserve_field_info(arg->a, 1);
+}
+
+unsigned valid7(struct s *arg) {
+  return __builtin_preserve_field_info(arg->c, 1ULL);
+}
+
+unsigned valid8(union u *arg) {
+  return __builtin_preserve_field_info(arg->a, 1);
+}
+
+unsigned valid9(union u *arg) {
+  return __builtin_preserve_field_info(arg->c, 'a');
+}
+
+unsigned invalid10(struct s *arg) {
+  return __builtin_preserve_field_info(arg->a, arg); // expected-error {{__builtin_preserve_field_info argument 2 not a constant}}
+}
+
+unsigned invalid11(struct s *arg, int info_kind) {
+  return __builtin_preserve_field_info(arg->a, info_kind); // expected-error {{__builtin_preserve_field_info argument 2 not a constant}}
+}

llvm/include/llvm/IR/IntrinsicsBPF.td

let TargetPrefix = "bpf" in {  // All intrinsics start with "llvm.bpf."
   def int_bpf_load_byte : GCCBuiltin<"__builtin_bpf_load_byte">,
               Intrinsic<[llvm_i64_ty], [llvm_ptr_ty, llvm_i64_ty], [IntrReadMem]>;
   def int_bpf_load_half : GCCBuiltin<"__builtin_bpf_load_half">,
               Intrinsic<[llvm_i64_ty], [llvm_ptr_ty, llvm_i64_ty], [IntrReadMem]>;
   def int_bpf_load_word : GCCBuiltin<"__builtin_bpf_load_word">,
               Intrinsic<[llvm_i64_ty], [llvm_ptr_ty, llvm_i64_ty], [IntrReadMem]>;
   def int_bpf_pseudo : GCCBuiltin<"__builtin_bpf_pseudo">,
               Intrinsic<[llvm_i64_ty], [llvm_i64_ty, llvm_i64_ty]>;
+  def int_bpf_preserve_field_info : GCCBuiltin<"__builtin_bpf_preserve_field_info">,
+              Intrinsic<[llvm_i32_ty], [llvm_anyptr_ty, llvm_i64_ty],
+              [IntrNoMem, ImmArg<1>]>;
 }

llvm/lib/Target/BPF/BPF.h

 #define LLVM_LIB_TARGET_BPF_BPF_H
 
 #include "MCTargetDesc/BPFMCTargetDesc.h"
 #include "llvm/Target/TargetMachine.h"
 
 namespace llvm {
 class BPFTargetMachine;
 
-ModulePass *createBPFAbstractMemberAccess();
+ModulePass *createBPFAbstractMemberAccess(BPFTargetMachine *TM);
 
 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&);
 }
 
 #endif

llvm/lib/Target/BPF/BPFAbstractMemberAccess.cpp

 //
 // 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>
 //
+// Bitfield member access needs special attention. User cannot take the
+// address of a bitfield acceess. To facilitate kernel verifier
+// for easy bitfield code optimization, a new clang intrinsic is introduced:
+//   uint32_t __builtin_preserve_field_info(member_access, info_kind)
+// In IR, a chain with two (or more) intrinsic calls will be generated:
+//   ...
+//   addr = preserve_struct_access_index(base, 1, 1) !struct s
+//   uint32_t result = bpf_preserve_field_info(addr, info_kind)
+//
+// Suppose the info_kind is FIELD_SIGNEDNESS,
+// The above two IR intrinsics will be replaced with
+// a relocatable insn:
+//   signness = /* signness of member_access */
+// and signness can be changed by bpf loader based on the
+// types on the host.
+//
+// User can also test whether a field exists or not with
+//   uint32_t result = bpf_preserve_field_info(member_access, FIELD_EXISTENCE)
+// The field will be always available (result = 1) during initial
+// compilation, but bpf loader can patch with the correct value
+// on the target host where the member_access may or may not be available
+//
 //===----------------------------------------------------------------------===//
 
 #include "BPF.h"
 #include "BPFCORE.h"
 #include "BPFTargetMachine.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instruction.h"
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) {}
+  TargetMachine *TM;
+  // Add optional BPFTargetMachine parameter so that BPF backend can add the phase
+  // with target machine to find out the endianness. The default constructor (without
+  // parameters) is used by the pass manager for managing purposes.
+  BPFAbstractMemberAccess(BPFTargetMachine *TM = nullptr) : ModulePass(ID), TM(TM) {}
 
   struct CallInfo {
     uint32_t Kind;
     uint32_t AccessIndex;
     MDNode *Metadata;
     Value *Base;
   };
+  typedef std::stack<std::pair<CallInst *, CallInfo>> CallInfoStack;
 
 private:
   enum : uint32_t {
     BPFPreserveArrayAI = 1,
     BPFPreserveUnionAI = 2,
     BPFPreserveStructAI = 3,
+    BPFPreserveFieldInfoAI = 4,
   };
 
   std::map<std::string, GlobalVariable *> GEPGlobals;
   // A map to link preserve_*_access_index instrinsic calls.
   std::map<CallInst *, std::pair<CallInst *, CallInfo>> 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
+  // The base call is not an input of any other preserve_*
   // intrinsics.
   std::map<CallInst *, CallInfo> BaseAICalls;
 
   bool doTransformation(Module &M);
 
   void traceAICall(CallInst *Call, CallInfo &ParentInfo);
   void traceBitCast(BitCastInst *BitCast, CallInst *Parent,
                     CallInfo &ParentInfo);
   void traceGEP(GetElementPtrInst *GEP, CallInst *Parent,
                 CallInfo &ParentInfo);
   void collectAICallChains(Module &M, Function &F);
 
   bool IsPreserveDIAccessIndexCall(const CallInst *Call, CallInfo &Cinfo);
   bool IsValidAIChain(const MDNode *ParentMeta, uint32_t ParentAI,
                       const MDNode *ChildMeta);
   bool removePreserveAccessIndexIntrinsic(Module &M);
   void replaceWithGEP(std::vector<CallInst *> &CallList,
                       uint32_t NumOfZerosIndex, uint32_t DIIndex);
+  bool HasPreserveFieldInfoCall(CallInfoStack &CallStack);
+  uint32_t GetFieldInfo(uint32_t InfoKind, DICompositeType *CTy,
+                        uint32_t AccessIndex, uint32_t PatchImm);
 
   Value *computeBaseAndAccessKey(CallInst *Call, CallInfo &CInfo,
                                  std::string &AccessKey, MDNode *&BaseMeta);
   uint64_t getConstant(const Value *IndexValue);
   bool transformGEPChain(Module &M, CallInst *Call, CallInfo &CInfo);
 };
 } // 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();
+ModulePass *llvm::createBPFAbstractMemberAccess(BPFTargetMachine *TM) {
+  return new BPFAbstractMemberAccess(TM);
 }
 
 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;
bool BPFAbstractMemberAccess::IsPreserveDIAccessIndexCall(const CallInst *Call,
   const auto *GV = dyn_cast<GlobalValue>(Call->getCalledValue());
   if (!GV)
     return false;
   if (GV->getName().startswith("llvm.preserve.array.access.index")) {
     CInfo.Kind = BPFPreserveArrayAI;
     CInfo.Metadata = Call->getMetadata(LLVMContext::MD_preserve_access_index);
     if (!CInfo.Metadata)
       report_fatal_error("Missing metadata for llvm.preserve.array.access.index intrinsic");
     CInfo.AccessIndex = getConstant(Call->getArgOperand(2));
     CInfo.Base = Call->getArgOperand(0);
     return true;
   }
   if (GV->getName().startswith("llvm.preserve.union.access.index")) {
     CInfo.Kind = BPFPreserveUnionAI;
     CInfo.Metadata = Call->getMetadata(LLVMContext::MD_preserve_access_index);
     if (!CInfo.Metadata)
       report_fatal_error("Missing metadata for llvm.preserve.union.access.index intrinsic");
     CInfo.AccessIndex = getConstant(Call->getArgOperand(1));
     CInfo.Base = Call->getArgOperand(0);
     return true;
   }
   if (GV->getName().startswith("llvm.preserve.struct.access.index")) {
     CInfo.Kind = BPFPreserveStructAI;
     CInfo.Metadata = Call->getMetadata(LLVMContext::MD_preserve_access_index);
     if (!CInfo.Metadata)
       report_fatal_error("Missing metadata for llvm.preserve.struct.access.index intrinsic");
     CInfo.AccessIndex = getConstant(Call->getArgOperand(2));
     CInfo.Base = Call->getArgOperand(0);
     return true;
   }
+  if (GV->getName().startswith("llvm.bpf.preserve.field.info")) {
+    CInfo.Kind = BPFPreserveFieldInfoAI;
+    CInfo.Metadata = nullptr;
+    // Check validity of info_kind as clang did not check this.
+    uint64_t InfoKind = getConstant(Call->getArgOperand(1));
+    if (InfoKind >= BPFCoreSharedInfo::MAX_FIELD_RELOC_KIND)
+      report_fatal_error("Incorrect info_kind for llvm.bpf.preserve.field.info intrinsic");
+    CInfo.AccessIndex = InfoKind;
+    return true;
+  }
 
   return false;
 }
 
 void BPFAbstractMemberAccess::replaceWithGEP(std::vector<CallInst *> &CallList,
                                              uint32_t DimensionIndex,
                                              uint32_t GEPIndex) {
   for (auto Call : CallList) {

 }
 
 /// Check whether the access index chain is valid. We check
 /// here because there may be type casts between two
 /// access indexes. We want to ensure memory access still valid.
 bool BPFAbstractMemberAccess::IsValidAIChain(const MDNode *ParentType,
                                              uint32_t ParentAI,
                                              const MDNode *ChildType) {
+  if (!ChildType)
+    return true; // preserve_field_info, no type comparison needed.
+
   const DIType *PType = stripQualifiers(cast<DIType>(ParentType));
   const DIType *CType = stripQualifiers(cast<DIType>(ChildType));
 
   // Child is a derived/pointer type, which is due to type casting.
   // Pointer type cannot be in the middle of chain.
   if (isa<DIDerivedType>(CType))
     return false;
 

 }
 
 uint64_t BPFAbstractMemberAccess::getConstant(const Value *IndexValue) {
   const ConstantInt *CV = dyn_cast<ConstantInt>(IndexValue);
   assert(CV);
   return CV->getValue().getZExtValue();
 }
 
-/// Compute the base of the whole preserve_*_access_index chains, i.e., the base
+uint32_t BPFAbstractMemberAccess::GetFieldInfo(uint32_t InfoKind,
+                                               DICompositeType *CTy,
+                                               uint32_t AccessIndex,
+                                               uint32_t PatchImm) {
+  if (InfoKind == BPFCoreSharedInfo::FIELD_EXISTENCE)
+      return 1;
+
+  uint32_t Tag = CTy->getTag();
+  if (InfoKind == BPFCoreSharedInfo::FIELD_BYTE_OFFSET) {
+    if (Tag == dwarf::DW_TAG_array_type) {
+      auto *EltTy = stripQualifiers(CTy->getBaseType());
+      PatchImm += AccessIndex * calcArraySize(CTy, 1) *
+                  (EltTy->getSizeInBits() >> 3);
+    } else if (Tag == dwarf::DW_TAG_structure_type) {
+      auto *MemberTy = cast<DIDerivedType>(CTy->getElements()[AccessIndex]);
+      PatchImm += MemberTy->getOffsetInBits() >> 3;
+    }
+    return PatchImm;
+  }
+
+  if (InfoKind == BPFCoreSharedInfo::FIELD_BYTE_SIZE) {
+    if (Tag == dwarf::DW_TAG_array_type) {
+      auto *EltTy = stripQualifiers(CTy->getBaseType());
+      return calcArraySize(CTy, 1) * (EltTy->getSizeInBits() >> 3);
+    } else {
+      auto *MemberTy = cast<DIDerivedType>(CTy->getElements()[AccessIndex]);
+      uint32_t SizeInBits = MemberTy->getSizeInBits();
+      if (!MemberTy->isBitField())
+        return SizeInBits >> 3;
+
+      uint32_t OffsetInBits = MemberTy->getOffsetInBits();
+      uint32_t Start = OffsetInBits >> 3;
+      uint32_t End = (OffsetInBits + SizeInBits - 1) >> 3;
+      return End - Start + 1;
+    }
+  }
+
+  if (InfoKind == BPFCoreSharedInfo::FIELD_SIGNEDNESS) {
+    const DIType *BaseTy;
+    if (Tag == dwarf::DW_TAG_array_type) {
+      // Signedness only checked when final array elements are accessed.
+      if (CTy->getElements().size() != 1)
+        report_fatal_error("Invalid array expression for llvm.bpf.preserve.field.info");
+      BaseTy = stripQualifiers(CTy->getBaseType());
+    } else {
+      auto *MemberTy = cast<DIDerivedType>(CTy->getElements()[AccessIndex]);
+      BaseTy = stripQualifiers(MemberTy->getBaseType());
+    }
+
+    // Only basic types and enum types have signedness.
+    const auto *BTy = dyn_cast<DIBasicType>(BaseTy);
+    while (!BTy) {
+      const auto *CompTy = dyn_cast<DICompositeType>(BaseTy);
+      // Report an error if the field expression does not have signedness.
+      if (!CompTy || CompTy->getTag() != dwarf::DW_TAG_enumeration_type)
+        report_fatal_error("Invalid field expression for llvm.bpf.preserve.field.info");
+      BaseTy = stripQualifiers(CompTy->getBaseType());
+      BTy = dyn_cast<DIBasicType>(BaseTy);
+    }
+    uint32_t Encoding = BTy->getEncoding();
+    return (Encoding == dwarf::DW_ATE_signed || Encoding == dwarf::DW_ATE_signed_char);
+  }
+
+  if (InfoKind == BPFCoreSharedInfo::FIELD_LSHIFT_U64) {
+    const Triple &Triple = TM->getTargetTriple();
+    DIDerivedType *MemberTy = nullptr;
+    bool IsBitField = false;
+    uint32_t SizeInBits;
+
+    if (Tag == dwarf::DW_TAG_array_type) {
+      auto *EltTy = stripQualifiers(CTy->getBaseType());
+      SizeInBits = calcArraySize(CTy, 1) * EltTy->getSizeInBits();
+    } else {
+      MemberTy = cast<DIDerivedType>(CTy->getElements()[AccessIndex]);
+      SizeInBits = MemberTy->getSizeInBits();
+      IsBitField = MemberTy->isBitField();
+    }
+
+    if (!IsBitField) {
+      if (SizeInBits > 64)
+        report_fatal_error("too big field size for llvm.bpf.preserve.field.info");
+      /* endianness */
+      if (Triple.getArch() == Triple::bpfeb)
+        return 0;
+      else
+        return 64 - SizeInBits;
+    }
+
+    uint32_t OffsetInBits = MemberTy->getOffsetInBits();
+    uint32_t Start = OffsetInBits >> 3;
+    uint32_t End = (OffsetInBits + SizeInBits - 1) >> 3;
+    uint32_t NumOfBytes = End - Start + 1;
+    if (NumOfBytes > 8)
+      report_fatal_error("too big field size for llvm.bpf.preserve.field.info");
+
+    /* endianness */
+    if (Triple.getArch() == Triple::bpfeb)
+      return OffsetInBits - (Start << 3);
+    else
+      return ((Start + 8) << 3) - OffsetInBits - SizeInBits;
+  }
+
+  if (InfoKind == BPFCoreSharedInfo::FIELD_RSHIFT_U64) {
+    DIDerivedType *MemberTy = nullptr;
+    bool IsBitField = false;
+    uint32_t SizeInBits;
+    if (Tag == dwarf::DW_TAG_array_type) {
+      auto *EltTy = stripQualifiers(CTy->getBaseType());
+      SizeInBits = calcArraySize(CTy, 1) * EltTy->getSizeInBits();
+    } else {
+      MemberTy = cast<DIDerivedType>(CTy->getElements()[AccessIndex]);
+      SizeInBits = MemberTy->getSizeInBits();
+      IsBitField = MemberTy->isBitField();
+    }
+
+    if (!IsBitField) {
+      if (SizeInBits > 64)
+        report_fatal_error("too big field size for llvm.bpf.preserve.field.info");
+      return 64 - SizeInBits;
+    }
+
+    uint32_t OffsetInBits = MemberTy->getOffsetInBits();
+    uint32_t Start = OffsetInBits >> 3;
+    uint32_t End = (OffsetInBits + SizeInBits - 1) >> 3;
+    uint32_t NumOfBytes = End - Start + 1;
+    if (NumOfBytes > 8)
+      report_fatal_error("too big field size for llvm.bpf.preserve.field.info");
+
+    return 64 - SizeInBits;
+  }
+
+  llvm_unreachable("Unknown llvm.bpf.preserve.field.info info kind");
+}
+
+bool BPFAbstractMemberAccess::HasPreserveFieldInfoCall(CallInfoStack &CallStack) {
+  // This is called in error return path, no need to maintain CallStack.
+  while (CallStack.size()) {
+    auto StackElem = CallStack.top();
+    if (StackElem.second.Kind == BPFPreserveFieldInfoAI)
+      return true;
+    CallStack.pop();
+  }
+  return false;
+}
+
+/// Compute the base of the whole preserve_* intrinsics 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::computeBaseAndAccessKey(CallInst *Call,
                                                         CallInfo &CInfo,
                                                         std::string &AccessKey,
                                                         MDNode *&TypeMeta) {
   Value *Base = nullptr;
   std::string TypeName;
-  std::stack<std::pair<CallInst *, CallInfo>> CallStack;
+  CallInfoStack CallStack;
 
   // Put the access chain into a stack with the top as the head of the chain.
   while (Call) {
     CallStack.push(std::make_pair(Call, CInfo));
     CInfo = AIChain[Call].second;
     Call = AIChain[Call].first;
   }
 
   // The access offset from the base of the head of chain is also
   // calculated here as all debuginfo types are available.
 
   // Get type name and calculate the first index.
   // We only want to get type name from structure or union.
   // If user wants a relocation like
   //    int *p; ... __builtin_preserve_access_index(&p[4]) ...
   // or
   //    int a[10][20]; ... __builtin_preserve_access_index(&a[2][3]) ...
   // we will skip them.
   uint32_t FirstIndex = 0;
-  uint32_t AccessOffset = 0;
+  uint32_t PatchImm = 0; // AccessOffset or the requested field info
+  uint32_t InfoKind = BPFCoreSharedInfo::FIELD_BYTE_OFFSET;
   while (CallStack.size()) {
     auto StackElem = CallStack.top();
     Call = StackElem.first;
     CInfo = StackElem.second;
 
     if (!Base)
       Base = CInfo.Base;
 
     DIType *Ty = stripQualifiers(cast<DIType>(CInfo.Metadata));
     if (CInfo.Kind == BPFPreserveUnionAI ||
         CInfo.Kind == BPFPreserveStructAI) {
       // struct or union type
       TypeName = Ty->getName();
       TypeMeta = Ty;
-      AccessOffset += FirstIndex * Ty->getSizeInBits() >> 3;
+      PatchImm += FirstIndex * (Ty->getSizeInBits() >> 3);
       break;
     }
 
+    assert(CInfo.Kind == BPFPreserveArrayAI);
+
     // Array entries will always be consumed for accumulative initial index.
     CallStack.pop();
 
     // BPFPreserveArrayAI
     uint64_t AccessIndex = CInfo.AccessIndex;
 
     DIType *BaseTy = nullptr;
     bool CheckElemType = false;
if (const auto *CTy = dyn_cast<DICompositeType>(Ty)) {
         CheckElemType = true;
       } else {
         FirstIndex += AccessIndex * calcArraySize(CTy, 0);
       }
     }
 
     if (CheckElemType) {
       auto *CTy = dyn_cast<DICompositeType>(BaseTy);
-      if (!CTy)
+      if (!CTy) {
+        if (HasPreserveFieldInfoCall(CallStack))
+          report_fatal_error("Invalid field access for llvm.preserve.field.info intrinsic");
         return nullptr;
+      }
 
       unsigned CTag = CTy->getTag();
-      if (CTag != dwarf::DW_TAG_structure_type && CTag != dwarf::DW_TAG_union_type)
-        return nullptr;
-      else
+      if (CTag == dwarf::DW_TAG_structure_type || CTag == dwarf::DW_TAG_union_type) {
         TypeName = CTy->getName();
+      } else {
+        if (HasPreserveFieldInfoCall(CallStack))
+          report_fatal_error("Invalid field access for llvm.preserve.field.info intrinsic");
+        return nullptr;
+      }
       TypeMeta = CTy;
-      AccessOffset += FirstIndex * CTy->getSizeInBits() >> 3;
+      PatchImm += FirstIndex * (CTy->getSizeInBits() >> 3);
       break;
     }
   }
   assert(TypeName.size());
   AccessKey += std::to_string(FirstIndex);
 
   // Traverse the rest of access chain to complete offset calculation
   // and access key construction.
   while (CallStack.size()) {
     auto StackElem = CallStack.top();
     CInfo = StackElem.second;
     CallStack.pop();
 
+    if (CInfo.Kind == BPFPreserveFieldInfoAI)
+      break;
+
+    // If the next Call (the top of the stack) is a BPFPreserveFieldInfoAI,
+    // the action will be extracting field info.
+    if (CallStack.size()) {
+      auto StackElem2 = CallStack.top();
+      CallInfo CInfo2 = StackElem2.second;
+      if (CInfo2.Kind == BPFPreserveFieldInfoAI) {
+        InfoKind = CInfo2.AccessIndex;
+        assert(CallStack.size() == 1);
+      }
+    }
+
     // Access Index
     uint64_t AccessIndex = CInfo.AccessIndex;
     AccessKey += ":" + std::to_string(AccessIndex);
 
     MDNode *MDN = CInfo.Metadata;
     // At this stage, it cannot be pointer type.
     auto *CTy = cast<DICompositeType>(stripQualifiers(cast<DIType>(MDN)));
-    uint32_t Tag = CTy->getTag();
-    if (Tag == dwarf::DW_TAG_structure_type) {
-      auto *MemberTy = cast<DIDerivedType>(CTy->getElements()[AccessIndex]);
-      AccessOffset += MemberTy->getOffsetInBits() >> 3;
-    } else if (Tag == dwarf::DW_TAG_array_type) {
-      auto *EltTy = stripQualifiers(CTy->getBaseType());
-      AccessOffset += AccessIndex * calcArraySize(CTy, 1) *
-                      EltTy->getSizeInBits() >> 3;
-    }
+    PatchImm = GetFieldInfo(InfoKind, CTy, AccessIndex, PatchImm);
   }
 
-  // Access key is the type name + access string, uniquely identifying
-  // one kernel memory access.
-  AccessKey = TypeName + ":" + std::to_string(AccessOffset) + "$" + AccessKey;
+  // Access key is the type name + reloc type + patched imm + access string,
+  // uniquely identifying one relocation.
+  AccessKey = TypeName + ":" + std::to_string(InfoKind) + ":" +
+              std::to_string(PatchImm) + "$" + AccessKey;
 
   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,
                                                 CallInfo &CInfo) {
   std::string AccessKey;
   MDNode *TypeMeta;
   Value *Base =
       computeBaseAndAccessKey(Call, CInfo, AccessKey, 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 sk_buff:50:$0:0:0:2:0
-  //   %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, AccessKey);
+    IntegerType *VarType;
+    if (CInfo.Kind == BPFPreserveFieldInfoAI)
+      VarType = Type::getInt32Ty(BB->getContext()); // 32bit return value
+    else
+      VarType = Type::getInt64Ty(BB->getContext()); // 64bit ptr arith
+
+    GV = new GlobalVariable(M, VarType, false, GlobalVariable::ExternalLinkage,
+                            NULL, AccessKey);
     GV->addAttribute(BPFCoreSharedInfo::AmaAttr);
     GV->setMetadata(LLVMContext::MD_preserve_access_index, TypeMeta);
     GEPGlobals[AccessKey] = GV;
   } else {
     GV = GEPGlobals[AccessKey];
   }
 
+  if (CInfo.Kind == BPFPreserveFieldInfoAI) {
+    // Load the global variable which represents the returned field info.
+    auto *LDInst = new LoadInst(Type::getInt32Ty(BB->getContext()), GV);
+    BB->getInstList().insert(Call->getIterator(), LDInst);
+    Call->replaceAllUsesWith(LDInst);
+    Call->eraseFromParent();
+    return true;
+  }
+
+  // For any original GEP Call and Base %2 like
+  //   %4 = bitcast %struct.net_device** %dev1 to i64*
+  // it is transformed to:
+  //   %6 = load sk_buff:50:$0:0:0:2:0
+  //   %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.
+
   // 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);
 

llvm/lib/Target/BPF/BPFCORE.h

 //===- 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:
+  enum OffsetRelocKind : uint32_t {
+    FIELD_BYTE_OFFSET = 0,
+    FIELD_BYTE_SIZE,
+    FIELD_EXISTENCE,
+    FIELD_SIGNEDNESS,
+    FIELD_LSHIFT_U64,
+    FIELD_RSHIFT_U64,
+
+    MAX_FIELD_RELOC_KIND,
+  };
   /// 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

llvm/lib/Target/BPF/BPFTargetMachine.cpp

 }
 
 TargetPassConfig *BPFTargetMachine::createPassConfig(PassManagerBase &PM) {
   return new BPFPassConfig(*this, PM);
 }
 
 void BPFPassConfig::addIRPasses() {
 
-  addPass(createBPFAbstractMemberAccess());
+  addPass(createBPFAbstractMemberAccess(&getBPFTargetMachine()));
 
   TargetPassConfig::addIRPasses();
 }
 
 // Install an instruction selector pass using
 // the ISelDag to gen BPF code.
 bool BPFPassConfig::addInstSelector() {
   addPass(createBPFISelDag(getBPFTargetMachine()));

llvm/lib/Target/BPF/BTF.h

 /// The binary layout for .BTF section:
 ///   struct Header
 ///   Type and Str subsections
 /// The Type subsection is a collection of types with type id starting with 1.
 /// The Str subsection is simply a collection of strings.
 ///
 /// The binary layout for .BTF.ext section:
 ///   struct ExtHeader
-///   FuncInfo, LineInfo, OffsetReloc and ExternReloc subsections
+///   FuncInfo, LineInfo, FieldReloc and ExternReloc subsections
 /// The FuncInfo subsection is defined as below:
 ///   BTFFuncInfo Size
 ///   struct SecFuncInfo for ELF section #1
 ///   A number of struct BPFFuncInfo for ELF section #1
 ///   struct SecFuncInfo for ELF section #2
 ///   A number of struct BPFFuncInfo for ELF section #2
 ///   ...
 /// The LineInfo subsection is defined as below:
 ///   BPFLineInfo Size
 ///   struct SecLineInfo for ELF section #1
 ///   A number of struct BPFLineInfo for ELF section #1
 ///   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 FieldReloc subsection is defined as below:
+///   BPFFieldReloc Size
+///   struct SecFieldReloc for ELF section #1
+///   A number of struct BPFFieldReloc for ELF section #1
+///   struct SecFieldReloc for ELF section #2
+///   A number of struct BPFFieldReloc 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
 ///   ...
enum {
   CommonTypeSize = 12,
   BTFArraySize = 12,
   BTFEnumSize = 8,
   BTFMemberSize = 12,
   BTFParamSize = 8,
   BTFDataSecVarSize = 12,
   SecFuncInfoSize = 8,
   SecLineInfoSize = 8,
-  SecOffsetRelocSize = 8,
+  SecFieldRelocSize = 8,
   SecExternRelocSize = 8,
   BPFFuncInfoSize = 8,
   BPFLineInfoSize = 16,
-  BPFOffsetRelocSize = 12,
+  BPFFieldRelocSize = 16,
   BPFExternRelocSize = 8,
 };
 
 /// The .BTF section header definition.
 struct Header {
   uint16_t Magic;  ///< Magic value
   uint8_t Version; ///< Version number
   uint8_t Flags;   ///< Extra flags
struct ExtHeader {
   uint8_t Version;
   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 OffsetRelocOff; ///< Offset of offset reloc section
-  uint32_t OffsetRelocLen; ///< Length of offset reloc section
+  uint32_t FieldRelocOff; ///< Offset of offset reloc section
+  uint32_t FieldRelocLen; ///< 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.
 struct BPFFuncInfo {
   uint32_t InsnOffset; ///< Byte offset in the section
   uint32_t TypeId;     ///< Type id referring to .BTF type section

 
 /// Specifying line info's in one section.
 struct SecLineInfo {
   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 {
+struct BPFFieldReloc {
   uint32_t InsnOffset;    ///< Byte offset in this section
   uint32_t TypeID;        ///< TypeID for the relocation
   uint32_t OffsetNameOff; ///< The string to traverse types
+  uint32_t RelocKind;     ///< What to patch the instruction
 };
 
 /// Specifying offset relocation's in one section.
-struct SecOffsetReloc {
+struct SecFieldReloc {
   uint32_t SecNameOff;     ///< Section name index in the .BTF string table
-  uint32_t NumOffsetReloc; ///< Number of offset reloc's in this section
+  uint32_t NumFieldReloc; ///< 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
 };
 

llvm/lib/Target/BPF/BTFDebug.h

 
 /// String table.
 class BTFStringTable {
   /// String table size in bytes.
   uint32_t Size;
   /// A mapping from string table offset to the index
   /// of the Table. It is used to avoid putting
   /// duplicated strings in the table.
-  std::unordered_map<uint32_t, uint32_t> OffsetToIdMap;
+  std::map<uint32_t, uint32_t> OffsetToIdMap;
   /// A vector of strings to represent the string table.
   std::vector<std::string> Table;
 
 public:
   BTFStringTable() : Size(0) {}
   uint32_t getSize() { return Size; }
   std::vector<std::string> &getTable() { return Table; }
   /// Add a string to the string table and returns its offset
struct BTFLineInfo {
   MCSymbol *Label;      ///< MCSymbol identifying insn for the lineinfo
   uint32_t FileNameOff; ///< file name offset in the .BTF string table
   uint32_t LineOff;     ///< line offset in the .BTF string table
   uint32_t LineNum;     ///< the line number
   uint32_t ColumnNum;   ///< the column number
 };
 
 /// Represent one offset relocation.
-struct BTFOffsetReloc {
+struct BTFFieldReloc {
   const MCSymbol *Label;  ///< MCSymbol identifying insn for the reloc
   uint32_t TypeID;        ///< Type ID
   uint32_t OffsetNameOff; ///< The string to traverse types
+  uint32_t RelocKind;     ///< What to patch the instruction
 };
 
 /// 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;
   bool SkipInstruction;
   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<BTFFieldReloc>> FieldRelocTable;
   std::map<uint32_t, std::vector<BTFExternReloc>> ExternRelocTable;
   StringMap<std::vector<std::string>> FileContent;
   std::map<std::string, std::unique_ptr<BTFKindDataSec>> DataSecEntries;
   std::vector<BTFTypeStruct *> StructTypes;
-  std::map<std::string, int64_t> AccessOffsets;
+  std::map<std::string, uint32_t> PatchImms;
   std::map<StringRef, std::pair<bool, std::vector<BTFTypeDerived *>>>
       FixupDerivedTypes;
 
   /// Add types to TypeEntries.
   /// @{
   /// Add types to TypeEntries and DIToIdMap.
   uint32_t addType(std::unique_ptr<BTFTypeBase> TypeEntry, const DIType *Ty);
   /// Add types to TypeEntries only and return type id.
class BTFDebug : public DebugHandlerBase {
   /// Construct a line info.
   void constructLineInfo(const DISubprogram *SP, MCSymbol *Label, uint32_t Line,
                          uint32_t Column);
 
   /// Generate types and variables for globals.
   void processGlobals(bool ProcessingMapDef);
 
   /// Generate one offset relocation record.
-  void generateOffsetReloc(const MachineInstr *MI, const MCSymbol *ORSym,
+  void generateFieldReloc(const MachineInstr *MI, const MCSymbol *ORSym,
                            DIType *RootTy, StringRef AccessPattern);
 
   /// Populating unprocessed struct type.
   unsigned populateStructType(const DIType *Ty);
 
   /// Process LD_imm64 instructions.
   void processLDimm64(const MachineInstr *MI);
 

llvm/lib/Target/BPF/BTFDebug.cpp

for (const auto &S : StringTable.getTable()) {
     OS.EmitBytes(StringRef("\0", 1));
     StringOffset += S.size() + 1;
   }
 }
 
 void BTFDebug::emitBTFExtSection() {
   // Do not emit section if empty FuncInfoTable and LineInfoTable.
   if (!FuncInfoTable.size() && !LineInfoTable.size() &&
-      !OffsetRelocTable.size() && !ExternRelocTable.size())
+      !FieldRelocTable.size() && !ExternRelocTable.size())
     return;
 
   MCContext &Ctx = OS.getContext();
   OS.SwitchSection(Ctx.getELFSection(".BTF.ext", ELF::SHT_PROGBITS, 0));
 
   // Emit header.
   emitCommonHeader();
   OS.EmitIntValue(BTF::ExtHeaderSize, 4);
 
   // 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;
+  // Do not account for optional FieldReloc/ExternReloc.
+  uint32_t FieldRelocLen = 0, ExternRelocLen = 0;
   for (const auto &FuncSec : FuncInfoTable) {
     FuncLen += BTF::SecFuncInfoSize;
     FuncLen += FuncSec.second.size() * BTF::BPFFuncInfoSize;
   }
   for (const auto &LineSec : LineInfoTable) {
     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 &FieldRelocSec : FieldRelocTable) {
+    FieldRelocLen += BTF::SecFieldRelocSize;
+    FieldRelocLen += FieldRelocSec.second.size() * BTF::BPFFieldRelocSize;
   }
   for (const auto &ExternRelocSec : ExternRelocTable) {
     ExternRelocLen += BTF::SecExternRelocSize;
     ExternRelocLen += ExternRelocSec.second.size() * BTF::BPFExternRelocSize;
   }
 
-  if (OffsetRelocLen)
-    OffsetRelocLen += 4;
+  if (FieldRelocLen)
+    FieldRelocLen += 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(FieldRelocLen, 4);
+  OS.EmitIntValue(FuncLen + LineLen + FieldRelocLen, 4);
   OS.EmitIntValue(ExternRelocLen, 4);
 
   // Emit func_info table.
   OS.AddComment("FuncInfo");
   OS.EmitIntValue(BTF::BPFFuncInfoSize, 4);
   for (const auto &FuncSec : FuncInfoTable) {
     OS.AddComment("FuncInfo section string offset=" +
                   std::to_string(FuncSec.first));
for (const auto &LineInfo : LineSec.second) {
       OS.EmitIntValue(LineInfo.FileNameOff, 4);
       OS.EmitIntValue(LineInfo.LineOff, 4);
       OS.AddComment("Line " + std::to_string(LineInfo.LineNum) + " Col " +
                     std::to_string(LineInfo.ColumnNum));
       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 field reloc table.
+  if (FieldRelocLen) {
+    OS.AddComment("FieldReloc");
+    OS.EmitIntValue(BTF::BPFFieldRelocSize, 4);
+    for (const auto &FieldRelocSec : FieldRelocTable) {
+      OS.AddComment("Field reloc section string offset=" +
+                    std::to_string(FieldRelocSec.first));
+      OS.EmitIntValue(FieldRelocSec.first, 4);
+      OS.EmitIntValue(FieldRelocSec.second.size(), 4);
+      for (const auto &FieldRelocInfo : FieldRelocSec.second) {
+        Asm->EmitLabelReference(FieldRelocInfo.Label, 4);
+        OS.EmitIntValue(FieldRelocInfo.TypeID, 4);
+        OS.EmitIntValue(FieldRelocInfo.OffsetNameOff, 4);
+        OS.EmitIntValue(FieldRelocInfo.RelocKind, 4);
       }
     }
   }
 
   // Emit extern reloc table.
   if (ExternRelocLen) {
     OS.AddComment("ExternReloc");
     OS.EmitIntValue(BTF::BPFExternRelocSize, 4);

 unsigned BTFDebug::populateStructType(const DIType *Ty) {
   unsigned Id;
   visitTypeEntry(Ty, Id, false, false);
   for (const auto &TypeEntry : TypeEntries)
     TypeEntry->completeType(*this);
   return Id;
 }
 
-/// Generate a struct member offset relocation.
-void BTFDebug::generateOffsetReloc(const MachineInstr *MI,
+/// Generate a struct member field relocation.
+void BTFDebug::generateFieldReloc(const MachineInstr *MI,
                                    const MCSymbol *ORSym, DIType *RootTy,
                                    StringRef AccessPattern) {
   unsigned RootId = populateStructType(RootTy);
   size_t FirstDollar = AccessPattern.find_first_of('$');
   size_t FirstColon = AccessPattern.find_first_of(':');
+  size_t SecondColon = AccessPattern.find_first_of(':', FirstColon + 1);
   StringRef IndexPattern = AccessPattern.substr(FirstDollar + 1);
-  StringRef OffsetStr = AccessPattern.substr(FirstColon + 1,
-      FirstDollar - FirstColon);
-
-  BTFOffsetReloc OffsetReloc;
-  OffsetReloc.Label = ORSym;
-  OffsetReloc.OffsetNameOff = addString(IndexPattern);
-  OffsetReloc.TypeID = RootId;
-  AccessOffsets[AccessPattern.str()] = std::stoi(OffsetStr);
-  OffsetRelocTable[SecNameOff].push_back(OffsetReloc);
+  StringRef RelocKindStr = AccessPattern.substr(FirstColon + 1,
+      SecondColon - FirstColon);
+  StringRef PatchImmStr = AccessPattern.substr(SecondColon + 1,
+      FirstDollar - SecondColon);
+
+  BTFFieldReloc FieldReloc;
+  FieldReloc.Label = ORSym;
+  FieldReloc.OffsetNameOff = addString(IndexPattern);
+  FieldReloc.TypeID = RootId;
+  FieldReloc.RelocKind = std::stoull(RelocKindStr);
+  PatchImms[AccessPattern.str()] = std::stoul(PatchImmStr);
+  FieldRelocTable[SecNameOff].push_back(FieldReloc);
 }
 
 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.
+  // add this insn into the .BTF.ext FieldReloc 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 (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());
+      generateFieldReloc(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());

 /// 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)) {
-        // Emit "mov ri, <imm>" for abstract member accesses.
-        int64_t Imm = AccessOffsets[GVar->getName().str()];
+        // Emit "mov ri, <imm>" for patched immediate.
+        uint32_t Imm = PatchImms[GVar->getName().str()];
         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());

llvm/test/CodeGen/BPF/CORE/intrinsic-array.ll

 ; CHECK-LABEL: test
 ; CHECK:       [[RELOC:.Ltmp[0-9]+]]
 ; CHECK:       r2 = 20
 ; CHECK:       r1 += r2
 ; CHECK:       call get_value
 ; CHECK:       exit
 ;
 ; CHECK:      .section        .BTF.ext,"",@progbits
-; CHECK:      .long   12                      # OffsetReloc
-; CHECK-NEXT: .long   20                      # Offset reloc section string offset=20
+; CHECK:      .long   16                      # FieldReloc
+; CHECK-NEXT: .long   20                      # Field reloc section string offset=20
 ; CHECK-NEXT: .long   1
 ; CHECK-NEXT: .long   [[RELOC]]
 ; CHECK-NEXT: .long   2
 ; CHECK-NEXT: .long   26
+; CHECK-NEXT: .long   0
 
 declare dso_local i32 @get_value(i8*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %struct.s* @llvm.preserve.array.access.index.p0s_struct.ss.p0s_struct.ss(%struct.s*, i32 immarg, i32 immarg) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.ss(%struct.s*, i32 immarg, i32 immarg) #2

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-byte-size-1.ll

+; 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:
+;   typedef struct s1 { int a1:7; int a2:4; int a3:5; int a4:16;} __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_BYTE_SIZE = 1, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1, FIELD_BYTE_SIZE);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a2, FIELD_BYTE_SIZE);
+;     unsigned r3 = __builtin_preserve_field_info(arg->b2.a3, FIELD_BYTE_SIZE);
+;     unsigned r4 = __builtin_preserve_field_info(arg->b2.a4, FIELD_BYTE_SIZE);
+;     /* r1: 1, r2: 2, r3: 1, r4: 2 */
+;     return r1 + r2 + r3 + r4;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { i32 }
+%struct.s1 = type { i32 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !28, metadata !DIExpression()), !dbg !33
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !34, !llvm.preserve.access.index !16
+  %b2 = bitcast %union.u1* %0 to %struct.s1*, !dbg !34
+  %1 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !35, !llvm.preserve.access.index !21
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %1, i64 1), !dbg !36
+  call void @llvm.dbg.value(metadata i32 %2, metadata !29, metadata !DIExpression()), !dbg !33
+  %3 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 1), !dbg !37, !llvm.preserve.access.index !21
+  %4 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %3, i64 1), !dbg !38
+  call void @llvm.dbg.value(metadata i32 %4, metadata !30, metadata !DIExpression()), !dbg !33
+  %5 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 2), !dbg !39, !llvm.preserve.access.index !21
+  %6 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %5, i64 1), !dbg !40
+  call void @llvm.dbg.value(metadata i32 %6, metadata !31, metadata !DIExpression()), !dbg !33
+  %7 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 3), !dbg !41, !llvm.preserve.access.index !21
+  %8 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %7, i64 1), !dbg !42
+  call void @llvm.dbg.value(metadata i32 %8, metadata !32, metadata !DIExpression()), !dbg !33
+  %add = add i32 %4, %2, !dbg !43
+  %add4 = add i32 %add, %6, !dbg !44
+  %add5 = add i32 %add4, %8, !dbg !45
+  ret i32 %add5, !dbg !46
+}
+
+; CHECK:             r1 = 1
+; CHECK:             r0 = 2
+; CHECK:             r0 += r1
+; CHECK:             r1 = 1
+; CHECK:             r0 += r1
+; CHECK:             r1 = 2
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=43
+; CHECK:             .ascii  "0:1:0"                 # string offset=49
+; CHECK:             .ascii  "0:1:1"                 # string offset=92
+; CHECK:             .ascii  "0:1:2"                 # string offset=98
+; CHECK:             .ascii  "0:1:3"                 # string offset=104
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   43                      # Field reloc section string offset=43
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   49
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   92
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   98
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   104
+; CHECK-NEXT:        .long   1
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_BYTE_SIZE", value: 1, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !12, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !27)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 32, elements: !17)
+!17 = !{!18, !19}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !16, file: !1, line: 2, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !16, file: !1, line: 2, baseType: !20, size: 32)
+!20 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !21)
+!21 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 32, elements: !22)
+!22 = !{!23, !24, !25, !26}
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !21, file: !1, line: 1, baseType: !14, size: 7, flags: DIFlagBitField, extraData: i64 0)
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !21, file: !1, line: 1, baseType: !14, size: 4, offset: 7, flags: DIFlagBitField, extraData: i64 0)
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "a3", scope: !21, file: !1, line: 1, baseType: !14, size: 5, offset: 11, flags: DIFlagBitField, extraData: i64 0)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "a4", scope: !21, file: !1, line: 1, baseType: !14, size: 16, offset: 16, flags: DIFlagBitField, extraData: i64 0)
+!27 = !{!28, !29, !30, !31, !32}
+!28 = !DILocalVariable(name: "arg", arg: 1, scope: !11, file: !1, line: 4, type: !15)
+!29 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 5, type: !4)
+!30 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 6, type: !4)
+!31 = !DILocalVariable(name: "r3", scope: !11, file: !1, line: 7, type: !4)
+!32 = !DILocalVariable(name: "r4", scope: !11, file: !1, line: 8, type: !4)
+!33 = !DILocation(line: 0, scope: !11)
+!34 = !DILocation(line: 5, column: 52, scope: !11)
+!35 = !DILocation(line: 5, column: 55, scope: !11)
+!36 = !DILocation(line: 5, column: 17, scope: !11)
+!37 = !DILocation(line: 6, column: 55, scope: !11)
+!38 = !DILocation(line: 6, column: 17, scope: !11)
+!39 = !DILocation(line: 7, column: 55, scope: !11)
+!40 = !DILocation(line: 7, column: 17, scope: !11)
+!41 = !DILocation(line: 8, column: 55, scope: !11)
+!42 = !DILocation(line: 8, column: 17, scope: !11)
+!43 = !DILocation(line: 10, column: 13, scope: !11)
+!44 = !DILocation(line: 10, column: 18, scope: !11)
+!45 = !DILocation(line: 10, column: 23, scope: !11)
+!46 = !DILocation(line: 10, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-byte-size-2.ll

+; 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:
+;   typedef struct s1 { int a1; char a2; } __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_BYTE_SIZE = 1, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_SIZE);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a1, FIELD_BYTE_SIZE);
+;     unsigned r3 = __builtin_preserve_field_info(arg->b2.a2, FIELD_BYTE_SIZE);
+;     /* r1: 8, r2: 4, r3: 1 */
+;     return r1 + r2 + r3;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { %struct.s1 }
+%struct.s1 = type { i32, i8 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !27, metadata !DIExpression()), !dbg !31
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !32, !llvm.preserve.access.index !16
+  %b2 = getelementptr inbounds %union.u1, %union.u1* %0, i64 0, i32 0, !dbg !32
+  %1 = tail call i32 @llvm.bpf.preserve.field.info.p0s_struct.s1s(%struct.s1* %b2, i64 1), !dbg !33
+  call void @llvm.dbg.value(metadata i32 %1, metadata !28, metadata !DIExpression()), !dbg !31
+  %2 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !34, !llvm.preserve.access.index !21
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %2, i64 1), !dbg !35
+  call void @llvm.dbg.value(metadata i32 %3, metadata !29, metadata !DIExpression()), !dbg !31
+  %4 = tail call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1* %b2, i32 1, i32 1), !dbg !36, !llvm.preserve.access.index !21
+  %5 = tail call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %4, i64 1), !dbg !37
+  call void @llvm.dbg.value(metadata i32 %5, metadata !30, metadata !DIExpression()), !dbg !31
+  %add = add i32 %3, %1, !dbg !38
+  %add3 = add i32 %add, %5, !dbg !39
+  ret i32 %add3, !dbg !40
+}
+
+; CHECK:             r1 = 8
+; CHECK:             r0 = 4
+; CHECK:             r0 += r1
+; CHECK:             r1 = 1
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=42
+; CHECK:             .ascii  "0:1"                   # string offset=48
+; CHECK:             .ascii  "0:1:0"                 # string offset=89
+; CHECK:             .ascii  "0:1:1"                 # string offset=95
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   42                      # Field reloc section string offset=42
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   89
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   95
+; CHECK-NEXT:        .long   1
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0s_struct.s1s(%struct.s1*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i8(i8*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_BYTE_SIZE", value: 1, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !12, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !26)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 64, elements: !17)
+!17 = !{!18, !19}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !16, file: !1, line: 2, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !16, file: !1, line: 2, baseType: !20, size: 64)
+!20 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !21)
+!21 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 64, elements: !22)
+!22 = !{!23, !24}
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !21, file: !1, line: 1, baseType: !14, size: 32)
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !21, file: !1, line: 1, baseType: !25, size: 8, offset: 32)
+!25 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!26 = !{!27, !28, !29, !30}
+!27 = !DILocalVariable(name: "arg", arg: 1, scope: !11, file: !1, line: 4, type: !15)
+!28 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 5, type: !4)
+!29 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 6, type: !4)
+!30 = !DILocalVariable(name: "r3", scope: !11, file: !1, line: 7, type: !4)
+!31 = !DILocation(line: 0, scope: !11)
+!32 = !DILocation(line: 5, column: 52, scope: !11)
+!33 = !DILocation(line: 5, column: 17, scope: !11)
+!34 = !DILocation(line: 6, column: 55, scope: !11)
+!35 = !DILocation(line: 6, column: 17, scope: !11)
+!36 = !DILocation(line: 7, column: 55, scope: !11)
+!37 = !DILocation(line: 7, column: 17, scope: !11)
+!38 = !DILocation(line: 9, column: 13, scope: !11)
+!39 = !DILocation(line: 9, column: 18, scope: !11)
+!40 = !DILocation(line: 9, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-byte-size-3.ll

+; 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:
+;   typedef struct s1 { int a1[10][10]; } __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_BYTE_SIZE = 1, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1[5], FIELD_BYTE_SIZE);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a1[5][5], FIELD_BYTE_SIZE);
+;     /* r1: 40, r2: 4 */
+;     return r1 + r2;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { %struct.s1 }
+%struct.s1 = type { [10 x [10 x i32]] }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !18 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !31, metadata !DIExpression()), !dbg !34
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !35, !llvm.preserve.access.index !22
+  %b2 = getelementptr inbounds %union.u1, %union.u1* %0, i64 0, i32 0, !dbg !35
+  %1 = tail call [10 x [10 x i32]]* @llvm.preserve.struct.access.index.p0a10a10i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !36, !llvm.preserve.access.index !27
+  %2 = tail call [10 x i32]* @llvm.preserve.array.access.index.p0a10i32.p0a10a10i32([10 x [10 x i32]]* %1, i32 1, i32 5), !dbg !37, !llvm.preserve.access.index !8
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0a10i32([10 x i32]* %2, i64 1), !dbg !38
+  call void @llvm.dbg.value(metadata i32 %3, metadata !32, metadata !DIExpression()), !dbg !34
+  %4 = tail call i32* @llvm.preserve.array.access.index.p0i32.p0a10i32([10 x i32]* %2, i32 1, i32 5), !dbg !39, !llvm.preserve.access.index !12
+  %5 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %4, i64 1), !dbg !40
+  call void @llvm.dbg.value(metadata i32 %5, metadata !33, metadata !DIExpression()), !dbg !34
+  %add = add i32 %5, %3, !dbg !41
+  ret i32 %add, !dbg !42
+}
+
+; CHECK:             r1 = 40
+; CHECK:             r0 = 4
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=54
+; CHECK:             .ascii  "0:1:0:5"               # string offset=60
+; CHECK:             .ascii  "0:1:0:5:5"             # string offset=105
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   54                      # Field reloc section string offset=54
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   60
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   105
+; CHECK-NEXT:        .long   1
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x [10 x i32]]* @llvm.preserve.struct.access.index.p0a10a10i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x i32]* @llvm.preserve.array.access.index.p0a10i32.p0a10a10i32([10 x [10 x i32]]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0a10i32([10 x i32]*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.array.access.index.p0i32.p0a10i32([10 x i32]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!14, !15, !16}
+!llvm.ident = !{!17}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !7, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_BYTE_SIZE", value: 1, isUnsigned: true)
+!7 = !{!8, !12}
+!8 = !DICompositeType(tag: DW_TAG_array_type, baseType: !9, size: 3200, elements: !10)
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !{!11, !11}
+!11 = !DISubrange(count: 10)
+!12 = !DICompositeType(tag: DW_TAG_array_type, baseType: !9, size: 320, elements: !13)
+!13 = !{!11}
+!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 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)"}
+!18 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !19, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !30)
+!19 = !DISubroutineType(types: !20)
+!20 = !{!9, !21}
+!21 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !22, size: 64)
+!22 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 3200, elements: !23)
+!23 = !{!24, !25}
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !22, file: !1, line: 2, baseType: !9, size: 32)
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !22, file: !1, line: 2, baseType: !26, size: 3200)
+!26 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !27)
+!27 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 3200, elements: !28)
+!28 = !{!29}
+!29 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !27, file: !1, line: 1, baseType: !8, size: 3200)
+!30 = !{!31, !32, !33}
+!31 = !DILocalVariable(name: "arg", arg: 1, scope: !18, file: !1, line: 4, type: !21)
+!32 = !DILocalVariable(name: "r1", scope: !18, file: !1, line: 5, type: !4)
+!33 = !DILocalVariable(name: "r2", scope: !18, file: !1, line: 6, type: !4)
+!34 = !DILocation(line: 0, scope: !18)
+!35 = !DILocation(line: 5, column: 52, scope: !18)
+!36 = !DILocation(line: 5, column: 55, scope: !18)
+!37 = !DILocation(line: 5, column: 47, scope: !18)
+!38 = !DILocation(line: 5, column: 17, scope: !18)
+!39 = !DILocation(line: 6, column: 47, scope: !18)
+!40 = !DILocation(line: 6, column: 17, scope: !18)
+!41 = !DILocation(line: 8, column: 13, scope: !18)
+!42 = !DILocation(line: 8, column: 3, scope: !18)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-existence-1.ll

+; 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:
+;   typedef unsigned __uint;
+;   struct s1 { int a1; __uint a2:9; __uint a3:4; };
+;   union u1 { int b1; __uint b2:9; __uint b3:4; };
+;   enum { FIELD_EXISTENCE = 2, };
+;   int test(struct s1 *arg1, union u1 *arg2) {
+;     unsigned r1 = __builtin_preserve_field_info(arg1->a1, FIELD_EXISTENCE);
+;     unsigned r2 = __builtin_preserve_field_info(arg1->a3, FIELD_EXISTENCE);
+;     unsigned r3 = __builtin_preserve_field_info(arg2->b1, FIELD_EXISTENCE);
+;     unsigned r4 = __builtin_preserve_field_info(arg2->b3, FIELD_EXISTENCE);
+;     return r1 + r2 + r3 + r4;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%struct.s1 = type { i32, i16 }
+%union.u1 = type { i32 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%struct.s1* %arg1, %union.u1* %arg2) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %struct.s1* %arg1, metadata !29, metadata !DIExpression()), !dbg !35
+  call void @llvm.dbg.value(metadata %union.u1* %arg2, metadata !30, metadata !DIExpression()), !dbg !35
+  %0 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %arg1, i32 0, i32 0), !dbg !36, !llvm.preserve.access.index !16
+  %1 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %0, i64 2), !dbg !37
+  call void @llvm.dbg.value(metadata i32 %1, metadata !31, metadata !DIExpression()), !dbg !35
+  %2 = tail call i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1* %arg1, i32 1, i32 2), !dbg !38, !llvm.preserve.access.index !16
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %2, i64 2), !dbg !39
+  call void @llvm.dbg.value(metadata i32 %3, metadata !32, metadata !DIExpression()), !dbg !35
+  %4 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg2, i32 0), !dbg !40, !llvm.preserve.access.index !23
+  %b1 = getelementptr inbounds %union.u1, %union.u1* %4, i64 0, i32 0, !dbg !40
+  %5 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %b1, i64 2), !dbg !41
+  call void @llvm.dbg.value(metadata i32 %5, metadata !33, metadata !DIExpression()), !dbg !35
+  %6 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_union.u1s(%union.u1* %arg2, i32 0, i32 2), !dbg !42, !llvm.preserve.access.index !23
+  %7 = bitcast i32* %6 to i8*, !dbg !42
+  %8 = tail call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %7, i64 2), !dbg !43
+  call void @llvm.dbg.value(metadata i32 %8, metadata !34, metadata !DIExpression()), !dbg !35
+  %add = add i32 %3, %1, !dbg !44
+  %add1 = add i32 %add, %5, !dbg !45
+  %add2 = add i32 %add1, %8, !dbg !46
+  ret i32 %add2, !dbg !47
+}
+
+; CHECK:             r1 = 1
+; CHECK:             r0 = 1
+; CHECK:             r0 += r1
+; CHECK:             r1 = 1
+; CHECK:             r0 += r1
+; CHECK:             r1 = 1
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_STRUCT(id = 2)
+; CHECK:             .long   37                      # BTF_KIND_UNION(id = 7)
+; CHECK:             .ascii  "s1"                    # string offset=1
+; CHECK:             .ascii  "u1"                    # string offset=37
+; CHECK:             .ascii  ".text"                 # string offset=64
+; CHECK:             .ascii  "0:0"                   # string offset=70
+; CHECK:             .ascii  "0:2"                   # string offset=111
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   64                      # Field reloc section string offset=64
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   70
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   111
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   70
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   111
+; CHECK-NEXT:        .long   2
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i16(i16*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_union.u1s(%union.u1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i8(i8*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 4, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_EXISTENCE", value: 2, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 5, type: !12, scopeLine: 5, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !28)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15, !22}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 2, size: 64, elements: !17)
+!17 = !{!18, !19, !21}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !16, file: !1, line: 2, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !16, file: !1, line: 2, baseType: !20, size: 9, offset: 32, flags: DIFlagBitField, extraData: i64 32)
+!20 = !DIDerivedType(tag: DW_TAG_typedef, name: "__uint", file: !1, line: 1, baseType: !4)
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "a3", scope: !16, file: !1, line: 2, baseType: !20, size: 4, offset: 41, flags: DIFlagBitField, extraData: i64 32)
+!22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !23, size: 64)
+!23 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 3, size: 32, elements: !24)
+!24 = !{!25, !26, !27}
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !23, file: !1, line: 3, baseType: !14, size: 32)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !23, file: !1, line: 3, baseType: !20, size: 9, flags: DIFlagBitField, extraData: i64 0)
+!27 = !DIDerivedType(tag: DW_TAG_member, name: "b3", scope: !23, file: !1, line: 3, baseType: !20, size: 4, flags: DIFlagBitField, extraData: i64 0)
+!28 = !{!29, !30, !31, !32, !33, !34}
+!29 = !DILocalVariable(name: "arg1", arg: 1, scope: !11, file: !1, line: 5, type: !15)
+!30 = !DILocalVariable(name: "arg2", arg: 2, scope: !11, file: !1, line: 5, type: !22)
+!31 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 6, type: !4)
+!32 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 7, type: !4)
+!33 = !DILocalVariable(name: "r3", scope: !11, file: !1, line: 8, type: !4)
+!34 = !DILocalVariable(name: "r4", scope: !11, file: !1, line: 9, type: !4)
+!35 = !DILocation(line: 0, scope: !11)
+!36 = !DILocation(line: 6, column: 53, scope: !11)
+!37 = !DILocation(line: 6, column: 17, scope: !11)
+!38 = !DILocation(line: 7, column: 53, scope: !11)
+!39 = !DILocation(line: 7, column: 17, scope: !11)
+!40 = !DILocation(line: 8, column: 53, scope: !11)
+!41 = !DILocation(line: 8, column: 17, scope: !11)
+!42 = !DILocation(line: 9, column: 53, scope: !11)
+!43 = !DILocation(line: 9, column: 17, scope: !11)
+!44 = !DILocation(line: 10, column: 13, scope: !11)
+!45 = !DILocation(line: 10, column: 18, scope: !11)
+!46 = !DILocation(line: 10, column: 23, scope: !11)
+!47 = !DILocation(line: 10, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-existence-2.ll

+; 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:
+;   typedef unsigned __uint;
+;   struct s1 { int a1; __uint a2:9; __uint a3:4; };
+;   union u1 { int b1; struct s1 b2; };
+;   enum { FIELD_EXISTENCE = 2, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1, FIELD_EXISTENCE);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a3, FIELD_EXISTENCE);
+;     return r1 + r2;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { %struct.s1 }
+%struct.s1 = type { i32, i16 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !27, metadata !DIExpression()), !dbg !30
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !31, !llvm.preserve.access.index !16
+  %b2 = getelementptr inbounds %union.u1, %union.u1* %0, i64 0, i32 0, !dbg !31
+  %1 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !32, !llvm.preserve.access.index !20
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %1, i64 2), !dbg !33
+  call void @llvm.dbg.value(metadata i32 %2, metadata !28, metadata !DIExpression()), !dbg !30
+  %3 = tail call i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1* %b2, i32 1, i32 2), !dbg !34, !llvm.preserve.access.index !20
+  %4 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %3, i64 2), !dbg !35
+  call void @llvm.dbg.value(metadata i32 %4, metadata !29, metadata !DIExpression()), !dbg !30
+  %add = add i32 %4, %2, !dbg !36
+  ret i32 %add, !dbg !37
+}
+
+; CHECK:             r1 = 1
+; CHECK:             r0 = 1
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=55
+; CHECK:             .ascii  "0:1:0"                 # string offset=61
+; CHECK:             .ascii  "0:1:2"                 # string offset=104
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   55                      # Field reloc section string offset=55
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   61
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   104
+; CHECK-NEXT:        .long   2
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i16(i16*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 4, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_EXISTENCE", value: 2, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 5, type: !12, scopeLine: 5, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !26)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 3, size: 64, elements: !17)
+!17 = !{!18, !19}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !16, file: !1, line: 3, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !16, file: !1, line: 3, baseType: !20, size: 64)
+!20 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 2, size: 64, elements: !21)
+!21 = !{!22, !23, !25}
+!22 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !20, file: !1, line: 2, baseType: !14, size: 32)
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !20, file: !1, line: 2, baseType: !24, size: 9, offset: 32, flags: DIFlagBitField, extraData: i64 32)
+!24 = !DIDerivedType(tag: DW_TAG_typedef, name: "__uint", file: !1, line: 1, baseType: !4)
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "a3", scope: !20, file: !1, line: 2, baseType: !24, size: 4, offset: 41, flags: DIFlagBitField, extraData: i64 32)
+!26 = !{!27, !28, !29}
+!27 = !DILocalVariable(name: "arg", arg: 1, scope: !11, file: !1, line: 5, type: !15)
+!28 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 6, type: !4)
+!29 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 7, type: !4)
+!30 = !DILocation(line: 0, scope: !11)
+!31 = !DILocation(line: 6, column: 52, scope: !11)
+!32 = !DILocation(line: 6, column: 55, scope: !11)
+!33 = !DILocation(line: 6, column: 17, scope: !11)
+!34 = !DILocation(line: 7, column: 55, scope: !11)
+!35 = !DILocation(line: 7, column: 17, scope: !11)
+!36 = !DILocation(line: 8, column: 13, scope: !11)
+!37 = !DILocation(line: 8, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-existence-3.ll

+; 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:
+;   typedef struct s1 { int a1[10][10]; } __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_EXISTENCE = 2, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1[5], FIELD_EXISTENCE);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a1[5][5], FIELD_EXISTENCE);
+;     return r1 + r2;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { %struct.s1 }
+%struct.s1 = type { [10 x [10 x i32]] }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !18 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !31, metadata !DIExpression()), !dbg !34
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !35, !llvm.preserve.access.index !22
+  %b2 = getelementptr inbounds %union.u1, %union.u1* %0, i64 0, i32 0, !dbg !35
+  %1 = tail call [10 x [10 x i32]]* @llvm.preserve.struct.access.index.p0a10a10i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !36, !llvm.preserve.access.index !27
+  %2 = tail call [10 x i32]* @llvm.preserve.array.access.index.p0a10i32.p0a10a10i32([10 x [10 x i32]]* %1, i32 1, i32 5), !dbg !37, !llvm.preserve.access.index !8
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0a10i32([10 x i32]* %2, i64 2), !dbg !38
+  call void @llvm.dbg.value(metadata i32 %3, metadata !32, metadata !DIExpression()), !dbg !34
+  %4 = tail call i32* @llvm.preserve.array.access.index.p0i32.p0a10i32([10 x i32]* %2, i32 1, i32 5), !dbg !39, !llvm.preserve.access.index !12
+  %5 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %4, i64 2), !dbg !40
+  call void @llvm.dbg.value(metadata i32 %5, metadata !33, metadata !DIExpression()), !dbg !34
+  %add = add i32 %5, %3, !dbg !41
+  ret i32 %add, !dbg !42
+}
+
+; CHECK:             r1 = 1
+; CHECK:             r0 = 1
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=54
+; CHECK:             .ascii  "0:1:0:5"               # string offset=60
+; CHECK:             .ascii  "0:1:0:5:5"             # string offset=105
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   54                      # Field reloc section string offset=54
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   60
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   105
+; CHECK-NEXT:        .long   2
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x [10 x i32]]* @llvm.preserve.struct.access.index.p0a10a10i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x i32]* @llvm.preserve.array.access.index.p0a10i32.p0a10a10i32([10 x [10 x i32]]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0a10i32([10 x i32]*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.array.access.index.p0i32.p0a10i32([10 x i32]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!14, !15, !16}
+!llvm.ident = !{!17}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !7, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_EXISTENCE", value: 2, isUnsigned: true)
+!7 = !{!8, !12}
+!8 = !DICompositeType(tag: DW_TAG_array_type, baseType: !9, size: 3200, elements: !10)
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !{!11, !11}
+!11 = !DISubrange(count: 10)
+!12 = !DICompositeType(tag: DW_TAG_array_type, baseType: !9, size: 320, elements: !13)
+!13 = !{!11}
+!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 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)"}
+!18 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !19, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !30)
+!19 = !DISubroutineType(types: !20)
+!20 = !{!9, !21}
+!21 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !22, size: 64)
+!22 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 3200, elements: !23)
+!23 = !{!24, !25}
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !22, file: !1, line: 2, baseType: !9, size: 32)
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !22, file: !1, line: 2, baseType: !26, size: 3200)
+!26 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !27)
+!27 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 3200, elements: !28)
+!28 = !{!29}
+!29 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !27, file: !1, line: 1, baseType: !8, size: 3200)
+!30 = !{!31, !32, !33}
+!31 = !DILocalVariable(name: "arg", arg: 1, scope: !18, file: !1, line: 4, type: !21)
+!32 = !DILocalVariable(name: "r1", scope: !18, file: !1, line: 5, type: !4)
+!33 = !DILocalVariable(name: "r2", scope: !18, file: !1, line: 6, type: !4)
+!34 = !DILocation(line: 0, scope: !18)
+!35 = !DILocation(line: 5, column: 52, scope: !18)
+!36 = !DILocation(line: 5, column: 55, scope: !18)
+!37 = !DILocation(line: 5, column: 47, scope: !18)
+!38 = !DILocation(line: 5, column: 17, scope: !18)
+!39 = !DILocation(line: 6, column: 47, scope: !18)
+!40 = !DILocation(line: 6, column: 17, scope: !18)
+!41 = !DILocation(line: 7, column: 13, scope: !18)
+!42 = !DILocation(line: 7, column: 3, scope: !18)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-lshift-1.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EL %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EB %s
+; Source code:
+;   typedef struct s1 { int a1:7; int a2:4; int a3:5; int a4:16;} __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_LSHIFT_U64 = 4, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1, FIELD_LSHIFT_U64);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a2, FIELD_LSHIFT_U64);
+;     unsigned r3 = __builtin_preserve_field_info(arg->b2.a3, FIELD_LSHIFT_U64);
+;     unsigned r4 = __builtin_preserve_field_info(arg->b2.a4, FIELD_LSHIFT_U64);
+;     /* big endian:    r1: 0, r2: 7, r3: 3, r4: 0 */
+;     /* little endian: r1: 57, r2: 53, r3: 56, r4: 48 */
+;     return r1 + r2 + r3 + r4;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { i32 }
+%struct.s1 = type { i32 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !28, metadata !DIExpression()), !dbg !33
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !34, !llvm.preserve.access.index !16
+  %b2 = bitcast %union.u1* %0 to %struct.s1*, !dbg !34
+  %1 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !35, !llvm.preserve.access.index !21
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %1, i64 4), !dbg !36
+  call void @llvm.dbg.value(metadata i32 %2, metadata !29, metadata !DIExpression()), !dbg !33
+  %3 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 1), !dbg !37, !llvm.preserve.access.index !21
+  %4 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %3, i64 4), !dbg !38
+  call void @llvm.dbg.value(metadata i32 %4, metadata !30, metadata !DIExpression()), !dbg !33
+  %5 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 2), !dbg !39, !llvm.preserve.access.index !21
+  %6 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %5, i64 4), !dbg !40
+  call void @llvm.dbg.value(metadata i32 %6, metadata !31, metadata !DIExpression()), !dbg !33
+  %7 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 3), !dbg !41, !llvm.preserve.access.index !21
+  %8 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %7, i64 4), !dbg !42
+  call void @llvm.dbg.value(metadata i32 %8, metadata !32, metadata !DIExpression()), !dbg !33
+  %add = add i32 %4, %2, !dbg !43
+  %add4 = add i32 %add, %6, !dbg !44
+  %add5 = add i32 %add4, %8, !dbg !45
+  ret i32 %add5, !dbg !46
+}
+
+; CHECK-EL:         r1 = 57
+; CHECK-EL:         r0 = 53
+; CHECK-EB:         r1 = 0
+; CHECK-EB:         r0 = 7
+; CHECK:            r0 += r1
+; CHECK-EL:         r1 = 56
+; CHECK-EB:         r1 = 3
+; CHECK:            r0 += r1
+; CHECK-EL:         r1 = 48
+; CHECK-EB:         r1 = 0
+; CHECK:            r0 += r1
+; CHECK:            exit
+
+; CHECK:            .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:            .ascii  "u1"                    # string offset=1
+; CHECK:            .ascii  ".text"                 # string offset=43
+; CHECK:            .ascii  "0:1:0"                 # string offset=49
+; CHECK:            .ascii  "0:1:1"                 # string offset=92
+; CHECK:            .ascii  "0:1:2"                 # string offset=98
+; CHECK:            .ascii  "0:1:3"                 # string offset=104
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   43                      # Field reloc section string offset=43
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   49
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   92
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   98
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   104
+; CHECK-NEXT:        .long   4
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_LSHIFT_U64", value: 4, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !12, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !27)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 32, elements: !17)
+!17 = !{!18, !19}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !16, file: !1, line: 2, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !16, file: !1, line: 2, baseType: !20, size: 32)
+!20 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !21)
+!21 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 32, elements: !22)
+!22 = !{!23, !24, !25, !26}
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !21, file: !1, line: 1, baseType: !14, size: 7, flags: DIFlagBitField, extraData: i64 0)
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !21, file: !1, line: 1, baseType: !14, size: 4, offset: 7, flags: DIFlagBitField, extraData: i64 0)
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "a3", scope: !21, file: !1, line: 1, baseType: !14, size: 5, offset: 11, flags: DIFlagBitField, extraData: i64 0)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "a4", scope: !21, file: !1, line: 1, baseType: !14, size: 16, offset: 16, flags: DIFlagBitField, extraData: i64 0)
+!27 = !{!28, !29, !30, !31, !32}
+!28 = !DILocalVariable(name: "arg", arg: 1, scope: !11, file: !1, line: 4, type: !15)
+!29 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 5, type: !4)
+!30 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 6, type: !4)
+!31 = !DILocalVariable(name: "r3", scope: !11, file: !1, line: 7, type: !4)
+!32 = !DILocalVariable(name: "r4", scope: !11, file: !1, line: 8, type: !4)
+!33 = !DILocation(line: 0, scope: !11)
+!34 = !DILocation(line: 5, column: 52, scope: !11)
+!35 = !DILocation(line: 5, column: 55, scope: !11)
+!36 = !DILocation(line: 5, column: 17, scope: !11)
+!37 = !DILocation(line: 6, column: 55, scope: !11)
+!38 = !DILocation(line: 6, column: 17, scope: !11)
+!39 = !DILocation(line: 7, column: 55, scope: !11)
+!40 = !DILocation(line: 7, column: 17, scope: !11)
+!41 = !DILocation(line: 8, column: 55, scope: !11)
+!42 = !DILocation(line: 8, column: 17, scope: !11)
+!43 = !DILocation(line: 11, column: 13, scope: !11)
+!44 = !DILocation(line: 11, column: 18, scope: !11)
+!45 = !DILocation(line: 11, column: 23, scope: !11)
+!46 = !DILocation(line: 11, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-lshift-2.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EL %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EB %s
+; Source code:
+;   typedef struct s1 { int a1; char a2; } __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_LSHIFT_U64 = 4, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1, FIELD_LSHIFT_U64);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a2, FIELD_LSHIFT_U64);
+;     /* big endian:    r1: 0, r2: 0 */
+;     /* little endian: r1: 32, r2: 56 */
+;     return r1 + r2;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { %struct.s1 }
+%struct.s1 = type { i32, i8 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !27, metadata !DIExpression()), !dbg !30
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !31, !llvm.preserve.access.index !16
+  %b2 = getelementptr inbounds %union.u1, %union.u1* %0, i64 0, i32 0, !dbg !31
+  %1 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !32, !llvm.preserve.access.index !21
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %1, i64 4), !dbg !33
+  call void @llvm.dbg.value(metadata i32 %2, metadata !28, metadata !DIExpression()), !dbg !30
+  %3 = tail call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1* %b2, i32 1, i32 1), !dbg !34, !llvm.preserve.access.index !21
+  %4 = tail call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %3, i64 4), !dbg !35
+  call void @llvm.dbg.value(metadata i32 %4, metadata !29, metadata !DIExpression()), !dbg !30
+  %add = add i32 %4, %2, !dbg !36
+  ret i32 %add, !dbg !37
+}
+
+; CHECK-EL:          r1 = 32
+; CHECK-EL:          r0 = 56
+; CHECK-EB:          r1 = 0
+; CHECK-EB:          r0 = 0
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=42
+; CHECK:             .ascii  "0:1:0"                 # string offset=48
+; CHECK:             .ascii  "0:1:1"                 # string offset=91
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   42                      # Field reloc section string offset=42
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   91
+; CHECK-NEXT:        .long   4
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i8(i8*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_LSHIFT_U64", value: 4, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !12, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !26)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 64, elements: !17)
+!17 = !{!18, !19}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !16, file: !1, line: 2, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !16, file: !1, line: 2, baseType: !20, size: 64)
+!20 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !21)
+!21 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 64, elements: !22)
+!22 = !{!23, !24}
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !21, file: !1, line: 1, baseType: !14, size: 32)
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !21, file: !1, line: 1, baseType: !25, size: 8, offset: 32)
+!25 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!26 = !{!27, !28, !29}
+!27 = !DILocalVariable(name: "arg", arg: 1, scope: !11, file: !1, line: 4, type: !15)
+!28 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 5, type: !4)
+!29 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 6, type: !4)
+!30 = !DILocation(line: 0, scope: !11)
+!31 = !DILocation(line: 5, column: 52, scope: !11)
+!32 = !DILocation(line: 5, column: 55, scope: !11)
+!33 = !DILocation(line: 5, column: 17, scope: !11)
+!34 = !DILocation(line: 6, column: 55, scope: !11)
+!35 = !DILocation(line: 6, column: 17, scope: !11)
+!36 = !DILocation(line: 9, column: 13, scope: !11)
+!37 = !DILocation(line: 9, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-lshift-3.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EL %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK_EB %s
+; Source code:
+;   typedef struct s1 { char a1 [5][5]; } __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_LSHIFT_U64 = 4, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1[3], FIELD_LSHIFT_U64);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a1[3][3], FIELD_LSHIFT_U64);
+;     /* little endian: r1 : 24, r2 : 56 */
+;     /* big endian: r1 : 0, r2 : 0 */
+;     return r1 + r2;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { i32, [24 x i8] }
+%struct.s1 = type { [5 x [5 x i8]] }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !18 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !32, metadata !DIExpression()), !dbg !35
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !36, !llvm.preserve.access.index !23
+  %b2 = bitcast %union.u1* %0 to %struct.s1*, !dbg !36
+  %1 = tail call [5 x [5 x i8]]* @llvm.preserve.struct.access.index.p0a5a5i8.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !37, !llvm.preserve.access.index !28
+  %2 = tail call [5 x i8]* @llvm.preserve.array.access.index.p0a5i8.p0a5a5i8([5 x [5 x i8]]* %1, i32 1, i32 3), !dbg !38, !llvm.preserve.access.index !8
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0a5i8([5 x i8]* %2, i64 4), !dbg !39
+  call void @llvm.dbg.value(metadata i32 %3, metadata !33, metadata !DIExpression()), !dbg !35
+  %4 = tail call i8* @llvm.preserve.array.access.index.p0i8.p0a5i8([5 x i8]* %2, i32 1, i32 3), !dbg !40, !llvm.preserve.access.index !12
+  %5 = tail call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %4, i64 4), !dbg !41
+  call void @llvm.dbg.value(metadata i32 %5, metadata !34, metadata !DIExpression()), !dbg !35
+  %add = add i32 %5, %3, !dbg !42
+  ret i32 %add, !dbg !43
+}
+
+; CHECK-EL:          r1 = 24
+; CHECK-EL:          r0 = 56
+; CHECK-EB:          r1 = 0
+; CHECK-EB:          r0 = 0
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=59
+; CHECK:             .ascii  "0:1:0:3"               # string offset=65
+; CHECK:             .ascii  "0:1:0:3:3"             # string offset=110
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   59                      # Field reloc section string offset=59
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   65
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   110
+; CHECK-NEXT:        .long   4
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [5 x [5 x i8]]* @llvm.preserve.struct.access.index.p0a5a5i8.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [5 x i8]* @llvm.preserve.array.access.index.p0a5i8.p0a5a5i8([5 x [5 x i8]]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0a5i8([5 x i8]*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i8* @llvm.preserve.array.access.index.p0i8.p0a5i8([5 x i8]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i8(i8*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!14, !15, !16}
+!llvm.ident = !{!17}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !7, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_LSHIFT_U64", value: 4, isUnsigned: true)
+!7 = !{!8, !12}
+!8 = !DICompositeType(tag: DW_TAG_array_type, baseType: !9, size: 200, elements: !10)
+!9 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!10 = !{!11, !11}
+!11 = !DISubrange(count: 5)
+!12 = !DICompositeType(tag: DW_TAG_array_type, baseType: !9, size: 40, elements: !13)
+!13 = !{!11}
+!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 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)"}
+!18 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !19, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !31)
+!19 = !DISubroutineType(types: !20)
+!20 = !{!21, !22}
+!21 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !23, size: 64)
+!23 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 224, elements: !24)
+!24 = !{!25, !26}
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !23, file: !1, line: 2, baseType: !21, size: 32)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !23, file: !1, line: 2, baseType: !27, size: 200)
+!27 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !28)
+!28 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 200, elements: !29)
+!29 = !{!30}
+!30 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !28, file: !1, line: 1, baseType: !8, size: 200)
+!31 = !{!32, !33, !34}
+!32 = !DILocalVariable(name: "arg", arg: 1, scope: !18, file: !1, line: 4, type: !22)
+!33 = !DILocalVariable(name: "r1", scope: !18, file: !1, line: 5, type: !4)
+!34 = !DILocalVariable(name: "r2", scope: !18, file: !1, line: 6, type: !4)
+!35 = !DILocation(line: 0, scope: !18)
+!36 = !DILocation(line: 5, column: 52, scope: !18)
+!37 = !DILocation(line: 5, column: 55, scope: !18)
+!38 = !DILocation(line: 5, column: 47, scope: !18)
+!39 = !DILocation(line: 5, column: 17, scope: !18)
+!40 = !DILocation(line: 6, column: 47, scope: !18)
+!41 = !DILocation(line: 6, column: 17, scope: !18)
+!42 = !DILocation(line: 9, column: 13, scope: !18)
+!43 = !DILocation(line: 9, column: 3, scope: !18)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-rshift-1.ll

+; 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:
+;   typedef struct s1 { int a1:7; int a2:4; int a3:5; int a4:16;} __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_RSHIFT_U64 = 5, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1, FIELD_RSHIFT_U64);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a2, FIELD_RSHIFT_U64);
+;     unsigned r3 = __builtin_preserve_field_info(arg->b2.a3, FIELD_RSHIFT_U64);
+;     unsigned r4 = __builtin_preserve_field_info(arg->b2.a4, FIELD_RSHIFT_U64);
+;     /* r1: 57, r2: 60, r3: 59, r4: 48 */
+;     return r1 + r2 + r3 + r4;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { i32 }
+%struct.s1 = type { i32 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !28, metadata !DIExpression()), !dbg !33
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !34, !llvm.preserve.access.index !16
+  %b2 = bitcast %union.u1* %0 to %struct.s1*, !dbg !34
+  %1 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !35, !llvm.preserve.access.index !21
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %1, i64 5), !dbg !36
+  call void @llvm.dbg.value(metadata i32 %2, metadata !29, metadata !DIExpression()), !dbg !33
+  %3 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 1), !dbg !37, !llvm.preserve.access.index !21
+  %4 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %3, i64 5), !dbg !38
+  call void @llvm.dbg.value(metadata i32 %4, metadata !30, metadata !DIExpression()), !dbg !33
+  %5 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 2), !dbg !39, !llvm.preserve.access.index !21
+  %6 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %5, i64 5), !dbg !40
+  call void @llvm.dbg.value(metadata i32 %6, metadata !31, metadata !DIExpression()), !dbg !33
+  %7 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 3), !dbg !41, !llvm.preserve.access.index !21
+  %8 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %7, i64 5), !dbg !42
+  call void @llvm.dbg.value(metadata i32 %8, metadata !32, metadata !DIExpression()), !dbg !33
+  %add = add i32 %4, %2, !dbg !43
+  %add4 = add i32 %add, %6, !dbg !44
+  %add5 = add i32 %add4, %8, !dbg !45
+  ret i32 %add5, !dbg !46
+}
+
+; CHECK:             r1 = 57
+; CHECK:             r0 = 60
+; CHECK:             r0 += r1
+; CHECK:             r1 = 59
+; CHECK:             r0 += r1
+; CHECK:             r1 = 48
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=43
+; CHECK:             .ascii  "0:1:0"                 # string offset=49
+; CHECK:             .ascii  "0:1:1"                 # string offset=92
+; CHECK:             .ascii  "0:1:2"                 # string offset=98
+; CHECK:             .ascii  "0:1:3"                 # string offset=104
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   43                      # Field reloc section string offset=43
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   49
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   92
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   98
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   104
+; CHECK-NEXT:        .long   5
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_RSHIFT_U64", value: 5, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !12, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !27)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 32, elements: !17)
+!17 = !{!18, !19}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !16, file: !1, line: 2, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !16, file: !1, line: 2, baseType: !20, size: 32)
+!20 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !21)
+!21 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 32, elements: !22)
+!22 = !{!23, !24, !25, !26}
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !21, file: !1, line: 1, baseType: !14, size: 7, flags: DIFlagBitField, extraData: i64 0)
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !21, file: !1, line: 1, baseType: !14, size: 4, offset: 7, flags: DIFlagBitField, extraData: i64 0)
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "a3", scope: !21, file: !1, line: 1, baseType: !14, size: 5, offset: 11, flags: DIFlagBitField, extraData: i64 0)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "a4", scope: !21, file: !1, line: 1, baseType: !14, size: 16, offset: 16, flags: DIFlagBitField, extraData: i64 0)
+!27 = !{!28, !29, !30, !31, !32}
+!28 = !DILocalVariable(name: "arg", arg: 1, scope: !11, file: !1, line: 4, type: !15)
+!29 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 5, type: !4)
+!30 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 6, type: !4)
+!31 = !DILocalVariable(name: "r3", scope: !11, file: !1, line: 7, type: !4)
+!32 = !DILocalVariable(name: "r4", scope: !11, file: !1, line: 8, type: !4)
+!33 = !DILocation(line: 0, scope: !11)
+!34 = !DILocation(line: 5, column: 52, scope: !11)
+!35 = !DILocation(line: 5, column: 55, scope: !11)
+!36 = !DILocation(line: 5, column: 17, scope: !11)
+!37 = !DILocation(line: 6, column: 55, scope: !11)
+!38 = !DILocation(line: 6, column: 17, scope: !11)
+!39 = !DILocation(line: 7, column: 55, scope: !11)
+!40 = !DILocation(line: 7, column: 17, scope: !11)
+!41 = !DILocation(line: 8, column: 55, scope: !11)
+!42 = !DILocation(line: 8, column: 17, scope: !11)
+!43 = !DILocation(line: 10, column: 13, scope: !11)
+!44 = !DILocation(line: 10, column: 18, scope: !11)
+!45 = !DILocation(line: 10, column: 23, scope: !11)
+!46 = !DILocation(line: 10, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-rshift-2.ll

+; 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:
+;   typedef struct s1 { int a1; char a2; } __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_RSHIFT_U64 = 5, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1, FIELD_RSHIFT_U64);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a2, FIELD_RSHIFT_U64);
+;     /* r1: 32, r2: 56 */
+;     return r1 + r2;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { %struct.s1 }
+%struct.s1 = type { i32, i8 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !27, metadata !DIExpression()), !dbg !30
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !31, !llvm.preserve.access.index !16
+  %b2 = getelementptr inbounds %union.u1, %union.u1* %0, i64 0, i32 0, !dbg !31
+  %1 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !32, !llvm.preserve.access.index !21
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %1, i64 5), !dbg !33
+  call void @llvm.dbg.value(metadata i32 %2, metadata !28, metadata !DIExpression()), !dbg !30
+  %3 = tail call i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1* %b2, i32 1, i32 1), !dbg !34, !llvm.preserve.access.index !21
+  %4 = tail call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %3, i64 5), !dbg !35
+  call void @llvm.dbg.value(metadata i32 %4, metadata !29, metadata !DIExpression()), !dbg !30
+  %add = add i32 %4, %2, !dbg !36
+  ret i32 %add, !dbg !37
+}
+
+; CHECK:             r1 = 32
+; CHECK:             r0 = 56
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=42
+; CHECK:             .ascii  "0:1:0"                 # string offset=48
+; CHECK:             .ascii  "0:1:1"                 # string offset=91
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   42                      # Field reloc section string offset=42
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   91
+; CHECK-NEXT:        .long   5
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i8* @llvm.preserve.struct.access.index.p0i8.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i8(i8*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_RSHIFT_U64", value: 5, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !12, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !26)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 64, elements: !17)
+!17 = !{!18, !19}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !16, file: !1, line: 2, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !16, file: !1, line: 2, baseType: !20, size: 64)
+!20 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !21)
+!21 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 64, elements: !22)
+!22 = !{!23, !24}
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !21, file: !1, line: 1, baseType: !14, size: 32)
+!24 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !21, file: !1, line: 1, baseType: !25, size: 8, offset: 32)
+!25 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!26 = !{!27, !28, !29}
+!27 = !DILocalVariable(name: "arg", arg: 1, scope: !11, file: !1, line: 4, type: !15)
+!28 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 5, type: !4)
+!29 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 6, type: !4)
+!30 = !DILocation(line: 0, scope: !11)
+!31 = !DILocation(line: 5, column: 52, scope: !11)
+!32 = !DILocation(line: 5, column: 55, scope: !11)
+!33 = !DILocation(line: 5, column: 17, scope: !11)
+!34 = !DILocation(line: 6, column: 55, scope: !11)
+!35 = !DILocation(line: 6, column: 17, scope: !11)
+!36 = !DILocation(line: 8, column: 13, scope: !11)
+!37 = !DILocation(line: 8, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-rshift-3.ll

+; 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:
+;   typedef struct s1 { char a1 [5][5]; } __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_RSHIFT_U64 = 5, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1[3], FIELD_RSHIFT_U64);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a1[3][3], FIELD_RSHIFT_U64);
+;     /* r1 : 24, r2 : 56 */
+;     return r1 + r2;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { i32, [24 x i8] }
+%struct.s1 = type { [5 x [5 x i8]] }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !18 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !32, metadata !DIExpression()), !dbg !35
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !36, !llvm.preserve.access.index !23
+  %b2 = bitcast %union.u1* %0 to %struct.s1*, !dbg !36
+  %1 = tail call [5 x [5 x i8]]* @llvm.preserve.struct.access.index.p0a5a5i8.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !37, !llvm.preserve.access.index !28
+  %2 = tail call [5 x i8]* @llvm.preserve.array.access.index.p0a5i8.p0a5a5i8([5 x [5 x i8]]* %1, i32 1, i32 3), !dbg !38, !llvm.preserve.access.index !8
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0a5i8([5 x i8]* %2, i64 5), !dbg !39
+  call void @llvm.dbg.value(metadata i32 %3, metadata !33, metadata !DIExpression()), !dbg !35
+  %4 = tail call i8* @llvm.preserve.array.access.index.p0i8.p0a5i8([5 x i8]* %2, i32 1, i32 3), !dbg !40, !llvm.preserve.access.index !12
+  %5 = tail call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %4, i64 5), !dbg !41
+  call void @llvm.dbg.value(metadata i32 %5, metadata !34, metadata !DIExpression()), !dbg !35
+  %add = add i32 %5, %3, !dbg !42
+  ret i32 %add, !dbg !43
+}
+
+; CHECK:             r1 = 24
+; CHECK:             r0 = 56
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=59
+; CHECK:             .ascii  "0:1:0:3"               # string offset=65
+; CHECK:             .ascii  "0:1:0:3:3"             # string offset=110
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   59                      # Field reloc section string offset=59
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   65
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   110
+; CHECK-NEXT:        .long   5
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [5 x [5 x i8]]* @llvm.preserve.struct.access.index.p0a5a5i8.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [5 x i8]* @llvm.preserve.array.access.index.p0a5i8.p0a5a5i8([5 x [5 x i8]]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0a5i8([5 x i8]*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i8* @llvm.preserve.array.access.index.p0i8.p0a5i8([5 x i8]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i8(i8*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!14, !15, !16}
+!llvm.ident = !{!17}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !7, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 3, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_RSHIFT_U64", value: 5, isUnsigned: true)
+!7 = !{!8, !12}
+!8 = !DICompositeType(tag: DW_TAG_array_type, baseType: !9, size: 200, elements: !10)
+!9 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!10 = !{!11, !11}
+!11 = !DISubrange(count: 5)
+!12 = !DICompositeType(tag: DW_TAG_array_type, baseType: !9, size: 40, elements: !13)
+!13 = !{!11}
+!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 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)"}
+!18 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 4, type: !19, scopeLine: 4, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !31)
+!19 = !DISubroutineType(types: !20)
+!20 = !{!21, !22}
+!21 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !23, size: 64)
+!23 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 2, size: 224, elements: !24)
+!24 = !{!25, !26}
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !23, file: !1, line: 2, baseType: !21, size: 32)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !23, file: !1, line: 2, baseType: !27, size: 200)
+!27 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 1, baseType: !28)
+!28 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 200, elements: !29)
+!29 = !{!30}
+!30 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !28, file: !1, line: 1, baseType: !8, size: 200)
+!31 = !{!32, !33, !34}
+!32 = !DILocalVariable(name: "arg", arg: 1, scope: !18, file: !1, line: 4, type: !22)
+!33 = !DILocalVariable(name: "r1", scope: !18, file: !1, line: 5, type: !4)
+!34 = !DILocalVariable(name: "r2", scope: !18, file: !1, line: 6, type: !4)
+!35 = !DILocation(line: 0, scope: !18)
+!36 = !DILocation(line: 5, column: 52, scope: !18)
+!37 = !DILocation(line: 5, column: 55, scope: !18)
+!38 = !DILocation(line: 5, column: 47, scope: !18)
+!39 = !DILocation(line: 5, column: 17, scope: !18)
+!40 = !DILocation(line: 6, column: 47, scope: !18)
+!41 = !DILocation(line: 6, column: 17, scope: !18)
+!42 = !DILocation(line: 8, column: 13, scope: !18)
+!43 = !DILocation(line: 8, column: 3, scope: !18)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-signedness-1.ll

+; 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:
+;   typedef unsigned __uint;
+;   struct s1 { int a1; __uint a2:9; __uint a3:4; };
+;   union u1 { int b1; __uint b2:9; __uint b3:4; };
+;   enum { FIELD_SIGNEDNESS = 3, };
+;   int test(struct s1 *arg1, union u1 *arg2) {
+;     unsigned r1 = __builtin_preserve_field_info(arg1->a1, FIELD_SIGNEDNESS);
+;     unsigned r2 = __builtin_preserve_field_info(arg1->a3, FIELD_SIGNEDNESS);
+;     unsigned r3 = __builtin_preserve_field_info(arg2->b1, FIELD_SIGNEDNESS);
+;     unsigned r4 = __builtin_preserve_field_info(arg2->b3, FIELD_SIGNEDNESS);
+;     return r1 + r2 + r3 + r4;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%struct.s1 = type { i32, i16 }
+%union.u1 = type { i32 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%struct.s1* %arg1, %union.u1* %arg2) local_unnamed_addr #0 !dbg !11 {
+entry:
+  call void @llvm.dbg.value(metadata %struct.s1* %arg1, metadata !29, metadata !DIExpression()), !dbg !35
+  call void @llvm.dbg.value(metadata %union.u1* %arg2, metadata !30, metadata !DIExpression()), !dbg !35
+  %0 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %arg1, i32 0, i32 0), !dbg !36, !llvm.preserve.access.index !16
+  %1 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %0, i64 3), !dbg !37
+  call void @llvm.dbg.value(metadata i32 %1, metadata !31, metadata !DIExpression()), !dbg !35
+  %2 = tail call i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1* %arg1, i32 1, i32 2), !dbg !38, !llvm.preserve.access.index !16
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %2, i64 3), !dbg !39
+  call void @llvm.dbg.value(metadata i32 %3, metadata !32, metadata !DIExpression()), !dbg !35
+  %4 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg2, i32 0), !dbg !40, !llvm.preserve.access.index !23
+  %b1 = getelementptr inbounds %union.u1, %union.u1* %4, i64 0, i32 0, !dbg !40
+  %5 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %b1, i64 3), !dbg !41
+  call void @llvm.dbg.value(metadata i32 %5, metadata !33, metadata !DIExpression()), !dbg !35
+  %6 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_union.u1s(%union.u1* %arg2, i32 0, i32 2), !dbg !42, !llvm.preserve.access.index !23
+  %7 = bitcast i32* %6 to i8*, !dbg !42
+  %8 = tail call i32 @llvm.bpf.preserve.field.info.p0i8(i8* %7, i64 3), !dbg !43
+  call void @llvm.dbg.value(metadata i32 %8, metadata !34, metadata !DIExpression()), !dbg !35
+  %add = add i32 %3, %1, !dbg !44
+  %add1 = add i32 %add, %5, !dbg !45
+  %add2 = add i32 %add1, %8, !dbg !46
+  ret i32 %add2, !dbg !47
+}
+
+; CHECK:             r1 = 1
+; CHECK:             r0 = 0
+; CHECK:             r0 += r1
+; CHECK:             r1 = 1
+; CHECK:             r0 += r1
+; CHECK:             r1 = 0
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_STRUCT(id = 2)
+; CHECK:             .long   37                      # BTF_KIND_UNION(id = 7)
+; CHECK:             .ascii  "s1"                    # string offset=1
+; CHECK:             .ascii  "u1"                    # string offset=37
+; CHECK:             .ascii  ".text"                 # string offset=64
+; CHECK:             .ascii  "0:0"                   # string offset=70
+; CHECK:             .ascii  "0:2"                   # string offset=111
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   64                      # Field reloc section string offset=64
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   70
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   111
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   70
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   111
+; CHECK-NEXT:        .long   3
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i16(i16*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_union.u1s(%union.u1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i8(i8*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 4, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6}
+!6 = !DIEnumerator(name: "FIELD_SIGNEDNESS", value: 3, isUnsigned: true)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!11 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 5, type: !12, scopeLine: 5, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !28)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!14, !15, !22}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !16, size: 64)
+!16 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 2, size: 64, elements: !17)
+!17 = !{!18, !19, !21}
+!18 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !16, file: !1, line: 2, baseType: !14, size: 32)
+!19 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !16, file: !1, line: 2, baseType: !20, size: 9, offset: 32, flags: DIFlagBitField, extraData: i64 32)
+!20 = !DIDerivedType(tag: DW_TAG_typedef, name: "__uint", file: !1, line: 1, baseType: !4)
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "a3", scope: !16, file: !1, line: 2, baseType: !20, size: 4, offset: 41, flags: DIFlagBitField, extraData: i64 32)
+!22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !23, size: 64)
+!23 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 3, size: 32, elements: !24)
+!24 = !{!25, !26, !27}
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !23, file: !1, line: 3, baseType: !14, size: 32)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !23, file: !1, line: 3, baseType: !20, size: 9, flags: DIFlagBitField, extraData: i64 0)
+!27 = !DIDerivedType(tag: DW_TAG_member, name: "b3", scope: !23, file: !1, line: 3, baseType: !20, size: 4, flags: DIFlagBitField, extraData: i64 0)
+!28 = !{!29, !30, !31, !32, !33, !34}
+!29 = !DILocalVariable(name: "arg1", arg: 1, scope: !11, file: !1, line: 5, type: !15)
+!30 = !DILocalVariable(name: "arg2", arg: 2, scope: !11, file: !1, line: 5, type: !22)
+!31 = !DILocalVariable(name: "r1", scope: !11, file: !1, line: 6, type: !4)
+!32 = !DILocalVariable(name: "r2", scope: !11, file: !1, line: 7, type: !4)
+!33 = !DILocalVariable(name: "r3", scope: !11, file: !1, line: 8, type: !4)
+!34 = !DILocalVariable(name: "r4", scope: !11, file: !1, line: 9, type: !4)
+!35 = !DILocation(line: 0, scope: !11)
+!36 = !DILocation(line: 6, column: 53, scope: !11)
+!37 = !DILocation(line: 6, column: 17, scope: !11)
+!38 = !DILocation(line: 7, column: 53, scope: !11)
+!39 = !DILocation(line: 7, column: 17, scope: !11)
+!40 = !DILocation(line: 8, column: 53, scope: !11)
+!41 = !DILocation(line: 8, column: 17, scope: !11)
+!42 = !DILocation(line: 9, column: 53, scope: !11)
+!43 = !DILocation(line: 9, column: 17, scope: !11)
+!44 = !DILocation(line: 10, column: 13, scope: !11)
+!45 = !DILocation(line: 10, column: 18, scope: !11)
+!46 = !DILocation(line: 10, column: 23, scope: !11)
+!47 = !DILocation(line: 10, column: 3, scope: !11)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-signedness-2.ll

+; 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:
+;   enum A { AA = -1, AB = 0, }; /* signed */
+;   enum B { BA = 0, BB = 1, };  /* unsigned */
+;   typedef enum A __A;
+;   typedef enum B __B;
+;   typedef int __int;           /* signed */
+;   struct s1 { __A a1; __B a2:9; __int a3:4; };
+;   union u1 { int b1; struct s1 b2; };
+;   enum { FIELD_SIGNEDNESS = 3, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1, FIELD_SIGNEDNESS);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a2, FIELD_SIGNEDNESS);
+;     unsigned r3 = __builtin_preserve_field_info(arg->b2.a3, FIELD_SIGNEDNESS);
+;     return r1 + r2 + r3;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { %struct.s1 }
+%struct.s1 = type { i32, i16 }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !20 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !37, metadata !DIExpression()), !dbg !41
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !42, !llvm.preserve.access.index !24
+  %b2 = getelementptr inbounds %union.u1, %union.u1* %0, i64 0, i32 0, !dbg !42
+  %1 = tail call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !43, !llvm.preserve.access.index !28
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %1, i64 3), !dbg !44
+  call void @llvm.dbg.value(metadata i32 %2, metadata !38, metadata !DIExpression()), !dbg !41
+  %3 = tail call i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1* %b2, i32 1, i32 1), !dbg !45, !llvm.preserve.access.index !28
+  %4 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %3, i64 3), !dbg !46
+  call void @llvm.dbg.value(metadata i32 %4, metadata !39, metadata !DIExpression()), !dbg !41
+  %5 = tail call i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1* %b2, i32 1, i32 2), !dbg !47, !llvm.preserve.access.index !28
+  %6 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %5, i64 3), !dbg !48
+  call void @llvm.dbg.value(metadata i32 %6, metadata !40, metadata !DIExpression()), !dbg !41
+  %add = add i32 %4, %2, !dbg !49
+  %add3 = add i32 %add, %6, !dbg !50
+  ret i32 %add3, !dbg !51
+}
+
+; CHECK:             r1 = 1
+; CHECK:             r0 = 0
+; CHECK:             r0 += r1
+; CHECK:             r1 = 1
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=65
+; CHECK:             .ascii  "0:1:0"                 # string offset=71
+; CHECK:             .ascii  "0:1:1"                 # string offset=114
+; CHECK:             .ascii  "0:1:2"                 # string offset=120
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   65                      # Field reloc section string offset=65
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   71
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   114
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   3
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i16(i16*, i64) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!16, !17, !18}
+!llvm.ident = !{!19}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3, !8, !13}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "A", file: !1, line: 1, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!5 = !{!6, !7}
+!6 = !DIEnumerator(name: "AA", value: -1)
+!7 = !DIEnumerator(name: "AB", value: 0)
+!8 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "B", file: !1, line: 2, baseType: !9, size: 32, elements: !10)
+!9 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!10 = !{!11, !12}
+!11 = !DIEnumerator(name: "BA", value: 0, isUnsigned: true)
+!12 = !DIEnumerator(name: "BB", value: 1, isUnsigned: true)
+!13 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 8, baseType: !9, size: 32, elements: !14)
+!14 = !{!15}
+!15 = !DIEnumerator(name: "FIELD_SIGNEDNESS", value: 3, isUnsigned: true)
+!16 = !{i32 2, !"Dwarf Version", i32 4}
+!17 = !{i32 2, !"Debug Info Version", i32 3}
+!18 = !{i32 1, !"wchar_size", i32 4}
+!19 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!20 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 9, type: !21, scopeLine: 9, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !36)
+!21 = !DISubroutineType(types: !22)
+!22 = !{!4, !23}
+!23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !24, size: 64)
+!24 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 7, size: 64, elements: !25)
+!25 = !{!26, !27}
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !24, file: !1, line: 7, baseType: !4, size: 32)
+!27 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !24, file: !1, line: 7, baseType: !28, size: 64)
+!28 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 6, size: 64, elements: !29)
+!29 = !{!30, !32, !34}
+!30 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !28, file: !1, line: 6, baseType: !31, size: 32)
+!31 = !DIDerivedType(tag: DW_TAG_typedef, name: "__A", file: !1, line: 3, baseType: !3)
+!32 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !28, file: !1, line: 6, baseType: !33, size: 9, offset: 32, flags: DIFlagBitField, extraData: i64 32)
+!33 = !DIDerivedType(tag: DW_TAG_typedef, name: "__B", file: !1, line: 4, baseType: !8)
+!34 = !DIDerivedType(tag: DW_TAG_member, name: "a3", scope: !28, file: !1, line: 6, baseType: !35, size: 4, offset: 41, flags: DIFlagBitField, extraData: i64 32)
+!35 = !DIDerivedType(tag: DW_TAG_typedef, name: "__int", file: !1, line: 5, baseType: !4)
+!36 = !{!37, !38, !39, !40}
+!37 = !DILocalVariable(name: "arg", arg: 1, scope: !20, file: !1, line: 9, type: !23)
+!38 = !DILocalVariable(name: "r1", scope: !20, file: !1, line: 10, type: !9)
+!39 = !DILocalVariable(name: "r2", scope: !20, file: !1, line: 11, type: !9)
+!40 = !DILocalVariable(name: "r3", scope: !20, file: !1, line: 12, type: !9)
+!41 = !DILocation(line: 0, scope: !20)
+!42 = !DILocation(line: 10, column: 52, scope: !20)
+!43 = !DILocation(line: 10, column: 55, scope: !20)
+!44 = !DILocation(line: 10, column: 17, scope: !20)
+!45 = !DILocation(line: 11, column: 55, scope: !20)
+!46 = !DILocation(line: 11, column: 17, scope: !20)
+!47 = !DILocation(line: 12, column: 55, scope: !20)
+!48 = !DILocation(line: 12, column: 17, scope: !20)
+!49 = !DILocation(line: 13, column: 13, scope: !20)
+!50 = !DILocation(line: 13, column: 18, scope: !20)
+!51 = !DILocation(line: 13, column: 3, scope: !20)

llvm/test/CodeGen/BPF/CORE/intrinsic-fieldinfo-signedness-3.ll

+; 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:
+;   enum A { AA = -1, AB = 0, };
+;   enum B { BA = 0, BB = 1, };
+;   typedef enum A __A;
+;   typedef enum B __B;
+;   typedef struct s1 { __A a1[10]; __B a2[10][10]; } __s1;
+;   union u1 { int b1; __s1 b2; };
+;   enum { FIELD_SIGNEDNESS = 3, };
+;   int test(union u1 *arg) {
+;     unsigned r1 = __builtin_preserve_field_info(arg->b2.a1[5], FIELD_SIGNEDNESS);
+;     unsigned r2 = __builtin_preserve_field_info(arg->b2.a2[5][5], FIELD_SIGNEDNESS);
+;     /* r1 : 1, r2 : 0 */
+;     return r1 + r2;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%union.u1 = type { %struct.s1 }
+%struct.s1 = type { [10 x i32], [10 x [10 x i32]] }
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @test(%union.u1* %arg) local_unnamed_addr #0 !dbg !29 {
+entry:
+  call void @llvm.dbg.value(metadata %union.u1* %arg, metadata !43, metadata !DIExpression()), !dbg !46
+  %0 = tail call %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1* %arg, i32 1), !dbg !47, !llvm.preserve.access.index !33
+  %b2 = getelementptr inbounds %union.u1, %union.u1* %0, i64 0, i32 0, !dbg !47
+  %1 = tail call [10 x i32]* @llvm.preserve.struct.access.index.p0a10i32.p0s_struct.s1s(%struct.s1* %b2, i32 0, i32 0), !dbg !48, !llvm.preserve.access.index !38
+  %2 = tail call i32* @llvm.preserve.array.access.index.p0i32.p0a10i32([10 x i32]* %1, i32 1, i32 5), !dbg !49, !llvm.preserve.access.index !17
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %2, i64 3), !dbg !50
+  call void @llvm.dbg.value(metadata i32 %3, metadata !44, metadata !DIExpression()), !dbg !46
+  %4 = tail call [10 x [10 x i32]]* @llvm.preserve.struct.access.index.p0a10a10i32.p0s_struct.s1s(%struct.s1* %b2, i32 1, i32 1), !dbg !51, !llvm.preserve.access.index !38
+  %5 = tail call [10 x i32]* @llvm.preserve.array.access.index.p0a10i32.p0a10a10i32([10 x [10 x i32]]* %4, i32 1, i32 5), !dbg !52, !llvm.preserve.access.index !21
+  %6 = tail call i32* @llvm.preserve.array.access.index.p0i32.p0a10i32([10 x i32]* %5, i32 1, i32 5), !dbg !52, !llvm.preserve.access.index !24
+  %7 = tail call i32 @llvm.bpf.preserve.field.info.p0i32(i32* %6, i64 3), !dbg !53
+  call void @llvm.dbg.value(metadata i32 %7, metadata !45, metadata !DIExpression()), !dbg !46
+  %add = add i32 %7, %3, !dbg !54
+  ret i32 %add, !dbg !55
+}
+
+; CHECK:             r1 = 1
+; CHECK:             r0 = 0
+; CHECK:             r0 += r1
+; CHECK:             exit
+
+; CHECK:             .long   1                       # BTF_KIND_UNION(id = 2)
+; CHECK:             .ascii  "u1"                    # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=81
+; CHECK:             .ascii  "0:1:0:5"               # string offset=87
+; CHECK:             .ascii  "0:1:1:5:5"             # string offset=132
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   81                      # Field reloc section string offset=81
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   87
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   132
+; CHECK-NEXT:        .long   3
+
+; Function Attrs: nounwind readnone
+declare %union.u1* @llvm.preserve.union.access.index.p0s_union.u1s.p0s_union.u1s(%union.u1*, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x i32]* @llvm.preserve.struct.access.index.p0a10i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32* @llvm.preserve.array.access.index.p0i32.p0a10i32([10 x i32]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i32(i32*, i64) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x [10 x i32]]* @llvm.preserve.struct.access.index.p0a10a10i32.p0s_struct.s1s(%struct.s1*, i32, i32) #1
+
+; Function Attrs: nounwind readnone
+declare [10 x i32]* @llvm.preserve.array.access.index.p0a10i32.p0a10a10i32([10 x [10 x i32]]*, i32, i32) #1
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone }
+attributes #2 = { nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!25, !26, !27}
+!llvm.ident = !{!28}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !16, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3, !8, !13}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "A", file: !1, line: 1, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!5 = !{!6, !7}
+!6 = !DIEnumerator(name: "AA", value: -1)
+!7 = !DIEnumerator(name: "AB", value: 0)
+!8 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "B", file: !1, line: 2, baseType: !9, size: 32, elements: !10)
+!9 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!10 = !{!11, !12}
+!11 = !DIEnumerator(name: "BA", value: 0, isUnsigned: true)
+!12 = !DIEnumerator(name: "BB", value: 1, isUnsigned: true)
+!13 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 7, baseType: !9, size: 32, elements: !14)
+!14 = !{!15}
+!15 = !DIEnumerator(name: "FIELD_SIGNEDNESS", value: 3, isUnsigned: true)
+!16 = !{!17, !21, !24}
+!17 = !DICompositeType(tag: DW_TAG_array_type, baseType: !18, size: 320, elements: !19)
+!18 = !DIDerivedType(tag: DW_TAG_typedef, name: "__A", file: !1, line: 3, baseType: !3)
+!19 = !{!20}
+!20 = !DISubrange(count: 10)
+!21 = !DICompositeType(tag: DW_TAG_array_type, baseType: !22, size: 3200, elements: !23)
+!22 = !DIDerivedType(tag: DW_TAG_typedef, name: "__B", file: !1, line: 4, baseType: !8)
+!23 = !{!20, !20}
+!24 = !DICompositeType(tag: DW_TAG_array_type, baseType: !22, size: 320, elements: !19)
+!25 = !{i32 2, !"Dwarf Version", i32 4}
+!26 = !{i32 2, !"Debug Info Version", i32 3}
+!27 = !{i32 1, !"wchar_size", i32 4}
+!28 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git c1e02f16f1105ffaf1c35ee8bc38b7d6db5c6ea9)"}
+!29 = distinct !DISubprogram(name: "test", scope: !1, file: !1, line: 8, type: !30, scopeLine: 8, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !42)
+!30 = !DISubroutineType(types: !31)
+!31 = !{!4, !32}
+!32 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !33, size: 64)
+!33 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "u1", file: !1, line: 6, size: 3520, elements: !34)
+!34 = !{!35, !36}
+!35 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !33, file: !1, line: 6, baseType: !4, size: 32)
+!36 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !33, file: !1, line: 6, baseType: !37, size: 3520)
+!37 = !DIDerivedType(tag: DW_TAG_typedef, name: "__s1", file: !1, line: 5, baseType: !38)
+!38 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 5, size: 3520, elements: !39)
+!39 = !{!40, !41}
+!40 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !38, file: !1, line: 5, baseType: !17, size: 320)
+!41 = !DIDerivedType(tag: DW_TAG_member, name: "a2", scope: !38, file: !1, line: 5, baseType: !21, size: 3200, offset: 320)
+!42 = !{!43, !44, !45}
+!43 = !DILocalVariable(name: "arg", arg: 1, scope: !29, file: !1, line: 8, type: !32)
+!44 = !DILocalVariable(name: "r1", scope: !29, file: !1, line: 9, type: !9)
+!45 = !DILocalVariable(name: "r2", scope: !29, file: !1, line: 10, type: !9)
+!46 = !DILocation(line: 0, scope: !29)
+!47 = !DILocation(line: 9, column: 52, scope: !29)
+!48 = !DILocation(line: 9, column: 55, scope: !29)
+!49 = !DILocation(line: 9, column: 47, scope: !29)
+!50 = !DILocation(line: 9, column: 17, scope: !29)
+!51 = !DILocation(line: 10, column: 55, scope: !29)
+!52 = !DILocation(line: 10, column: 47, scope: !29)
+!53 = !DILocation(line: 10, column: 17, scope: !29)
+!54 = !DILocation(line: 12, column: 13, scope: !29)
+!55 = !DILocation(line: 12, column: 3, scope: !29)

llvm/test/CodeGen/BPF/CORE/intrinsic-struct.ll

 ; CHECK-LABEL: test
 ; CHECK:       [[RELOC:.Ltmp[0-9]+]]
 ; CHECK:       r2 = 4
 ; CHECK:       r1 += r2
 ; CHECK:       call get_value
 ; CHECK:       exit
 ;
 ; CHECK:      .section        .BTF.ext,"",@progbits
-; CHECK:      .long   12                      # OffsetReloc
-; CHECK-NEXT: .long   20                      # Offset reloc section string offset=20
+; CHECK:      .long   16                      # FieldReloc
+; CHECK-NEXT: .long   20                      # Field reloc section string offset=20
 ; CHECK-NEXT: .long   1
 ; CHECK-NEXT: .long   [[RELOC]]
 ; CHECK-NEXT: .long   2
 ; CHECK-NEXT: .long   26
+; CHECK-NEXT: .long   0
 
 declare dso_local i32 @get_value(i8*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.ss(%struct.s*, i32 immarg, i32 immarg) #2
 
 ; Function Attrs: nounwind readnone speculatable
 declare void @llvm.dbg.value(metadata, metadata, metadata) #3

llvm/test/CodeGen/BPF/CORE/intrinsic-union.ll

 ; CHECK-LABEL: test
 ; CHECK:       [[RELOC:.Ltmp[0-9]+]]
 ; CHECK:       r2 = 0
 ; CHECK:       r1 += r2
 ; CHECK:       call get_value
 ; CHECK:       exit
 
 ; CHECK:      .section        .BTF.ext,"",@progbits
-; CHECK:      .long   12                      # OffsetReloc
-; CHECK-NEXT: .long   20                      # Offset reloc section string offset=20
+; CHECK:      .long   16                      # FieldReloc
+; CHECK-NEXT: .long   20                      # Field reloc section string offset=20
 ; CHECK-NEXT: .long   1
 ; CHECK-NEXT: .long   [[RELOC]]
 ; CHECK-NEXT: .long   2
 ; CHECK-NEXT: .long   26
+; CHECK-NEXT: .long   0
 
 declare dso_local i32 @get_value(i8*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %union.u* @llvm.preserve.union.access.index.p0s_union.us.p0s_union.us(%union.u*, i32 immarg) #2
 
 ; Function Attrs: nounwind readnone speculatable
 declare void @llvm.dbg.value(metadata, metadata, metadata) #3

llvm/test/CodeGen/BPF/CORE/offset-reloc-access-str.ll

 }
 
 ; CHECK:             .section        .BTF,"",@progbits
 ; CHECK:             .ascii  ".text"                 # string offset=[[SEC_INDEX:[0-9]+]]
 ; CHECK-NEXT:        .byte   0
 ; CHECK:             .ascii  "0:1"                   # string offset=[[ACCESS_STR:[0-9]+]]
 ; CHECK-NEXT:        .byte   0
 ; CHECK:             .section        .BTF.ext,"",@progbits
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   [[SEC_INDEX]]           # Offset reloc section string offset=[[SEC_INDEX]]
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   [[SEC_INDEX]]           # Field reloc section string offset=[[SEC_INDEX]]
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   {{[0-9]+}}
 ; CHECK-NEXT:        .long   [[ACCESS_STR]]
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   {{[0-9]+}}
 ; CHECK-NEXT:        .long   [[ACCESS_STR]]
+; CHECK-NEXT:        .long   0
 
 declare dso_local i32 @get_value(i8*, i8*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.ss(%struct.s*, i32 immarg, i32 immarg) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.ts(%struct.t*, i32 immarg, i32 immarg) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-basic.ll

 ; 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   28
+; CHECK-NEXT:        .long   172
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   43                      # Offset reloc section string offset=43
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   43                      # Field reloc section string offset=43
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp2
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   86
+; CHECK-NEXT:        .long   0
 
 ; 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

llvm/test/CodeGen/BPF/CORE/offset-reloc-cast-array-1.ll

 ; CHECK:              .long   1                       # BTF_KIND_STRUCT(id = [[TID1:[0-9]+]])
 ; CHECK:              .long   100                     # BTF_KIND_STRUCT(id = [[TID2:[0-9]+]])
 
 ; CHECK:              .ascii  "v3"                    # string offset=1
 ; CHECK:              .ascii  ".text"                 # string offset=46
 ; CHECK:              .ascii  "0:1:0"                 # string offset=52
 ; CHECK:              .ascii  "2:1"                   # string offset=107
 
-; CHECK:              .long   12                      # OffsetReloc
-; CHECK-NEXT:         .long   46                      # Offset reloc section string offset=46
+; CHECK:              .long   16                      # FieldReloc
+; CHECK-NEXT:         .long   46                      # Field reloc section string offset=46
 ; CHECK-NEXT:         .long   2
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID1]]
 ; CHECK-NEXT:         .long   52
+; CHECK-NEXT:         .long   0
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID2]]
 ; CHECK-NEXT:         .long   107
+; CHECK-NEXT:         .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare [100 x i32]* @llvm.preserve.struct.access.index.p0a100i32.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.array.access.index.p0i32.p0a100i32([100 x i32]*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-cast-array-2.ll

 ; CHECK:              .long   100                     # BTF_KIND_STRUCT(id = [[TID2:[0-9]+]])
 
 ; CHECK:              .ascii  "v3"                    # string offset=1
 ; CHECK:              .ascii  ".text"                 # string offset=46
 ; CHECK:              .ascii  "0:1:0"                 # string offset=52
 ; CHECK:              .ascii  "v1"                    # string offset=100
 ; CHECK:              .ascii  "11:1"                  # string offset=107
 
-; CHECK:              .long   12                      # OffsetReloc
-; CHECK-NEXT:         .long   46                      # Offset reloc section string offset=46
+; CHECK:              .long   16                      # FieldReloc
+; CHECK-NEXT:         .long   46                      # Field reloc section string offset=46
 ; CHECK-NEXT:         .long   2
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID1]]
 ; CHECK-NEXT:         .long   52
+; CHECK-NEXT:         .long   0
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID2]]
 ; CHECK-NEXT:         .long   107
+; CHECK-NEXT:         .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare [100 x i32]* @llvm.preserve.struct.access.index.p0a100i32.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.array.access.index.p0i32.p0a100i32([100 x i32]*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-cast-struct-1.ll

 ; CHECK-NEXT:        .byte   0
 ; CHECK:             .ascii  ".text"                 # string offset=[[SEC_STR:[0-9]+]]
 ; CHECK-NEXT:        .byte   0
 ; CHECK:             .ascii  "0:1"                   # string offset=[[ACCESS_STR:[0-9]+]]
 ; CHECK-NEXT:        .byte   0
 ; CHECK:             .ascii  "v1"                    # string offset=81
 ; CHECK-NEXT:        .byte   0
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   [[SEC_STR]]             # Offset reloc section string offset=[[SEC_STR]]
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   [[SEC_STR]]             # Field reloc section string offset=[[SEC_STR]]
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[V3_TID]]
 ; CHECK-NEXT:        .long   [[ACCESS_STR]]
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[V1_TID]]
 ; CHECK-NEXT:        .long   [[ACCESS_STR]]
+; CHECK-NEXT:        .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %struct.v2* @llvm.preserve.struct.access.index.p0s_struct.v2s.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.v1s(%struct.v1*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-cast-struct-2.ll

 ; CHECK:             .long   91                      # BTF_KIND_STRUCT(id = [[TID2:[0-9]+]])
 
 ; CHECK:             .ascii  "v3"                    # string offset=6
 ; CHECK:             .ascii  ".text"                 # string offset=39
 ; CHECK:             .ascii  "0:1"                   # string offset=45
 ; CHECK:             .ascii  "v1"                    # string offset=91
 
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   39                      # Offset reloc section string offset=39
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   39                      # Field reloc section string offset=39
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID1]]
 ; CHECK-NEXT:        .long   45
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID2]]
 ; CHECK-NEXT:        .long   45
+; CHECK-NEXT:        .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %struct.v2* @llvm.preserve.struct.access.index.p0s_struct.v2s.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.v1s(%struct.v1*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-cast-struct-3.ll

 ; CHECK:             .long   111                     # BTF_KIND_STRUCT(id = [[TID2:[0-9]+]])
 
 ; CHECK:             .ascii  "v3"                    # string offset=6
 ; CHECK:             .ascii  ".text"                 # string offset=57
 ; CHECK:             .ascii  "0:1:4"                 # string offset=63
 ; CHECK:             .ascii  "v1"                    # string offset=111
 ; CHECK:             .ascii  "0:1"                   # string offset=118
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   57                      # Offset reloc section string offset=57
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   57                      # Field reloc section string offset=57
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID1]]
 ; CHECK-NEXT:        .long   63
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID2]]
 ; CHECK-NEXT:        .long   118
+; CHECK-NEXT:        .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare [40 x i32]* @llvm.preserve.struct.access.index.p0a40i32.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.array.access.index.p0i32.p0a40i32([40 x i32]*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-cast-union-1.ll

 ; CHECK:             .long   6                       # BTF_KIND_UNION(id = [[TID1:[0-9]+]])
 ; CHECK:             .long   91                      # BTF_KIND_UNION(id = [[TID2:[0-9]+]])
 
 ; CHECK:             .ascii  "v3"                    # string offset=6
 ; CHECK:             .ascii  ".text"                 # string offset=39
 ; CHECK:             .ascii  "0:1"                   # string offset=45
 ; CHECK:             .ascii  "v1"                    # string offset=91
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   39                      # Offset reloc section string offset=39
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   39                      # Field reloc section string offset=39
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID1]]
 ; CHECK-NEXT:        .long   45
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID2]]
 ; CHECK-NEXT:        .long   45
+; CHECK-NEXT:        .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %union.v3* @llvm.preserve.union.access.index.p0s_union.v3s.p0s_union.v3s(%union.v3*, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare %union.v1* @llvm.preserve.union.access.index.p0s_union.v1s.p0s_union.v1s(%union.v1*, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-cast-union-2.ll

 ; CHECK:             .long   111                     # BTF_KIND_UNION(id = [[TID2:[0-9]+]])
 
 ; CHECK:             .ascii  "v3"                    # string offset=6
 ; CHECK:             .ascii  ".text"                 # string offset=57
 ; CHECK:             .ascii  "0:1:4"                 # string offset=63
 ; CHECK:             .ascii  "v1"                    # string offset=111
 ; CHECK:             .ascii  "0:1"                   # string offset=118
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   57                      # Offset reloc section string offset=57
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   57                      # Field reloc section string offset=57
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID1]]
 ; CHECK-NEXT:        .long   63
+; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID2]]
 ; CHECK-NEXT:        .long   118
+; CHECK-NEXT:        .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %union.v3* @llvm.preserve.union.access.index.p0s_union.v3s.p0s_union.v3s(%union.v3*, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.array.access.index.p0i32.p0a40i32([40 x i32]*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-end-load.ll

 ; CHECK:       exit
 ;
 ; CHECK:       .long   1                       # BTF_KIND_STRUCT(id = 2)
 ;
 ; CHECK:       .byte   115                     # string offset=1
 ; CHECK:       .ascii  ".text"                 # string offset=20
 ; CHECK:       .ascii  "0:1"                   # string offset=26
 ;
-; CHECK:       .long   12                      # OffsetReloc
-; CHECK-NEXT:  .long   20                      # Offset reloc section string offset=20
+; CHECK:       .long   16                      # FieldReloc
+; CHECK-NEXT:  .long   20                      # Field reloc section string offset=20
 ; CHECK-NEXT:  .long   1
 ; CHECK-NEXT:  .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:  .long   2
 ; CHECK-NEXT:  .long   26
+; CHECK-NEXT:  .long   0
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.ss(%struct.s*, i32, i32) #1
 
 ; Function Attrs: nounwind readnone speculatable willreturn
 declare void @llvm.dbg.value(metadata, metadata, metadata) #2
 
 attributes #0 = { nounwind readonly "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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/test/CodeGen/BPF/CORE/offset-reloc-end-ret.ll

 ; CHECK:       exit
 ;
 ; CHECK:       .long   1                       # BTF_KIND_STRUCT(id = 2)
 ;
 ; CHECK:       .byte   115                     # string offset=1
 ; CHECK:       .ascii  ".text"                 # string offset=20
 ; CHECK:       .ascii  "0:1"                   # string offset=63
 ;
-; CHECK:       .long   12                      # OffsetReloc
-; CHECK-NEXT:  .long   20                      # Offset reloc section string offset=20
+; CHECK:       .long   16                      # FieldReloc
+; CHECK-NEXT:  .long   20                      # Field reloc section string offset=20
 ; CHECK-NEXT:  .long   1
 ; CHECK-NEXT:  .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:  .long   2
 ; CHECK-NEXT:  .long   63
+; CHECK-NEXT:  .long   0
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.ss(%struct.s*, i32, i32) #1
 
 ; Function Attrs: nounwind readnone speculatable willreturn
 declare void @llvm.dbg.value(metadata, metadata, metadata) #2
 
 attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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/test/CodeGen/BPF/CORE/offset-reloc-fieldinfo-1.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EL %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EB %s
+; Source code:
+;   struct s {
+;       int a;
+;       int b1:9;
+;       int b2:4;
+;   };
+;   enum {
+;       FIELD_BYTE_OFFSET = 0,
+;       FIELD_BYTE_SIZE,
+;       FIELD_EXISTENCE,
+;       FIELD_SIGNEDNESS,
+;       FIELD_LSHIFT_U64,
+;       FIELD_RSHIFT_U64,
+;   };
+;   void bpf_probe_read(void *, unsigned, const void *);
+;   int field_read(struct s *arg) {
+;     union {
+;       unsigned long long ull;
+;       long long ll;
+;     } res;
+;     unsigned offset = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_OFFSET);
+;     unsigned i, size = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_SIZE);
+;
+;     bpf_probe_read(&res, size, (const void *)arg + offset);
+;     res.ull <<= __builtin_preserve_field_info(arg->b2, FIELD_LSHIFT_U64);
+;     if (__builtin_preserve_field_info(arg->b2, FIELD_SIGNEDNESS))
+;       res.ll >>= __builtin_preserve_field_info(arg->b2, FIELD_RSHIFT_U64);
+;     else
+;       res.ull >>= __builtin_preserve_field_info(arg->b2, FIELD_RSHIFT_U64);
+;     return res.ull;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%struct.s = type { i32, i16 }
+%union.anon = type { i64 }
+
+; Function Attrs: nounwind
+define dso_local i32 @field_read(%struct.s* %arg) local_unnamed_addr #0 !dbg !19 {
+entry:
+  %res = alloca %union.anon, align 8
+  call void @llvm.dbg.value(metadata %struct.s* %arg, metadata !30, metadata !DIExpression()), !dbg !41
+  %0 = bitcast %union.anon* %res to i8*, !dbg !42
+  call void @llvm.lifetime.start.p0i8(i64 8, i8* nonnull %0) #5, !dbg !42
+  call void @llvm.dbg.declare(metadata %union.anon* %res, metadata !31, metadata !DIExpression()), !dbg !43
+  %1 = tail call i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.ss(%struct.s* %arg, i32 1, i32 2), !dbg !44, !llvm.preserve.access.index !24
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 0), !dbg !45
+  call void @llvm.dbg.value(metadata i32 %2, metadata !38, metadata !DIExpression()), !dbg !41
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 1), !dbg !46
+  call void @llvm.dbg.value(metadata i32 %3, metadata !40, metadata !DIExpression()), !dbg !41
+  %4 = bitcast %struct.s* %arg to i8*, !dbg !47
+  %idx.ext = zext i32 %2 to i64, !dbg !48
+  %add.ptr = getelementptr i8, i8* %4, i64 %idx.ext, !dbg !48
+  call void @bpf_probe_read(i8* nonnull %0, i32 %3, i8* %add.ptr) #5, !dbg !49
+  %5 = call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 4), !dbg !50
+  %ull = getelementptr inbounds %union.anon, %union.anon* %res, i64 0, i32 0, !dbg !51
+  %6 = load i64, i64* %ull, align 8, !dbg !52, !tbaa !53
+  %sh_prom = zext i32 %5 to i64, !dbg !52
+  %shl = shl i64 %6, %sh_prom, !dbg !52
+  %7 = call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 3), !dbg !56
+  %tobool = icmp eq i32 %7, 0, !dbg !56
+  %8 = call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 5), !dbg !58
+  %sh_prom1 = zext i32 %8 to i64, !dbg !58
+  %shr4 = lshr i64 %shl, %sh_prom1, !dbg !59
+  %shr = ashr i64 %shl, %sh_prom1, !dbg !59
+  %storemerge = select i1 %tobool, i64 %shr4, i64 %shr, !dbg !59
+  %conv = trunc i64 %storemerge to i32, !dbg !60
+  call void @llvm.lifetime.end.p0i8(i64 8, i8* nonnull %0) #5, !dbg !61
+  ret i32 %conv, !dbg !62
+}
+
+; CHECK:             r{{[0-9]+}} = 5
+; CHECK:             r{{[0-9]+}} = 1
+; CHECK-EL:          r{{[0-9]+}} = 59
+; CHECK-EB:          r{{[0-9]+}} = 1
+; CHECK:             r{{[0-9]+}} = 60
+; CHECK:             r{{[0-9]+}} = 1
+
+; CHECK:             .long   1                       # BTF_KIND_STRUCT(id = 2)
+
+; CHECK:             .byte   115                     # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=30
+; CHECK:             .ascii  "0:2"                   # string offset=73
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   30                      # Field reloc section string offset=30
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   73
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   73
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   73
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   73
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   73
+; CHECK-NEXT:        .long   3
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) #2
+
+; Function Attrs: nounwind readnone
+declare i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.ss(%struct.s*, i32, i32) #3
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i16(i16*, i64) #3
+
+declare dso_local void @bpf_probe_read(i8*, i32, i8*) local_unnamed_addr #4
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) #2
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone speculatable willreturn }
+attributes #2 = { argmemonly nounwind willreturn }
+attributes #3 = { nounwind readnone }
+attributes #4 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "no-infs-fp-math"="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 #5 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!15, !16, !17}
+!llvm.ident = !{!18}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !12, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 6, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6, !7, !8, !9, !10, !11}
+!6 = !DIEnumerator(name: "FIELD_BYTE_OFFSET", value: 0, isUnsigned: true)
+!7 = !DIEnumerator(name: "FIELD_BYTE_SIZE", value: 1, isUnsigned: true)
+!8 = !DIEnumerator(name: "FIELD_EXISTENCE", value: 2, isUnsigned: true)
+!9 = !DIEnumerator(name: "FIELD_SIGNEDNESS", value: 3, isUnsigned: true)
+!10 = !DIEnumerator(name: "FIELD_LSHIFT_U64", value: 4, isUnsigned: true)
+!11 = !DIEnumerator(name: "FIELD_RSHIFT_U64", value: 5, isUnsigned: true)
+!12 = !{!13}
+!13 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !14, size: 64)
+!14 = !DIDerivedType(tag: DW_TAG_const_type, baseType: null)
+!15 = !{i32 2, !"Dwarf Version", i32 4}
+!16 = !{i32 2, !"Debug Info Version", i32 3}
+!17 = !{i32 1, !"wchar_size", i32 4}
+!18 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!19 = distinct !DISubprogram(name: "field_read", scope: !1, file: !1, line: 15, type: !20, scopeLine: 15, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !29)
+!20 = !DISubroutineType(types: !21)
+!21 = !{!22, !23}
+!22 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !24, size: 64)
+!24 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s", file: !1, line: 1, size: 64, elements: !25)
+!25 = !{!26, !27, !28}
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !24, file: !1, line: 2, baseType: !22, size: 32)
+!27 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !24, file: !1, line: 3, baseType: !22, size: 9, offset: 32, flags: DIFlagBitField, extraData: i64 32)
+!28 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !24, file: !1, line: 4, baseType: !22, size: 4, offset: 41, flags: DIFlagBitField, extraData: i64 32)
+!29 = !{!30, !31, !38, !39, !40}
+!30 = !DILocalVariable(name: "arg", arg: 1, scope: !19, file: !1, line: 15, type: !23)
+!31 = !DILocalVariable(name: "res", scope: !19, file: !1, line: 19, type: !32)
+!32 = distinct !DICompositeType(tag: DW_TAG_union_type, scope: !19, file: !1, line: 16, size: 64, elements: !33)
+!33 = !{!34, !36}
+!34 = !DIDerivedType(tag: DW_TAG_member, name: "ull", scope: !32, file: !1, line: 17, baseType: !35, size: 64)
+!35 = !DIBasicType(name: "long long unsigned int", size: 64, encoding: DW_ATE_unsigned)
+!36 = !DIDerivedType(tag: DW_TAG_member, name: "ll", scope: !32, file: !1, line: 18, baseType: !37, size: 64)
+!37 = !DIBasicType(name: "long long int", size: 64, encoding: DW_ATE_signed)
+!38 = !DILocalVariable(name: "offset", scope: !19, file: !1, line: 20, type: !4)
+!39 = !DILocalVariable(name: "i", scope: !19, file: !1, line: 21, type: !4)
+!40 = !DILocalVariable(name: "size", scope: !19, file: !1, line: 21, type: !4)
+!41 = !DILocation(line: 0, scope: !19)
+!42 = !DILocation(line: 16, column: 3, scope: !19)
+!43 = !DILocation(line: 19, column: 5, scope: !19)
+!44 = !DILocation(line: 20, column: 56, scope: !19)
+!45 = !DILocation(line: 20, column: 21, scope: !19)
+!46 = !DILocation(line: 21, column: 22, scope: !19)
+!47 = !DILocation(line: 23, column: 30, scope: !19)
+!48 = !DILocation(line: 23, column: 48, scope: !19)
+!49 = !DILocation(line: 23, column: 3, scope: !19)
+!50 = !DILocation(line: 24, column: 15, scope: !19)
+!51 = !DILocation(line: 24, column: 7, scope: !19)
+!52 = !DILocation(line: 24, column: 11, scope: !19)
+!53 = !{!54, !54, i64 0}
+!54 = !{!"omnipotent char", !55, i64 0}
+!55 = !{!"Simple C/C++ TBAA"}
+!56 = !DILocation(line: 25, column: 7, scope: !57)
+!57 = distinct !DILexicalBlock(scope: !19, file: !1, line: 25, column: 7)
+!58 = !DILocation(line: 0, scope: !57)
+!59 = !DILocation(line: 25, column: 7, scope: !19)
+!60 = !DILocation(line: 29, column: 10, scope: !19)
+!61 = !DILocation(line: 30, column: 1, scope: !19)
+!62 = !DILocation(line: 29, column: 3, scope: !19)

llvm/test/CodeGen/BPF/CORE/offset-reloc-fieldinfo-2.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EL %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK,CHECK-EB %s
+; Source code:
+;   struct s {
+;       int a;
+;       int b1:9;
+;       int b2:4;
+;   };
+;   enum {
+;       FIELD_BYTE_OFFSET = 0,
+;       FIELD_BYTE_SIZE,
+;       FIELD_EXISTENCE,
+;       FIELD_SIGNEDNESS,
+;       FIELD_LSHIFT_U64,
+;       FIELD_RSHIFT_U64,
+;   };
+;   void bpf_probe_read(void *, unsigned, const void *);
+;   int field_read(struct s *arg) {
+;     union {
+;       unsigned long long ull;
+;       long long ll;
+;     } res;
+;     unsigned offset = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_OFFSET);
+;     unsigned i, size = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_SIZE);
+;
+;     for (i = 0; i < size; i++)
+;       *((unsigned char *)&res + i) = *((volatile unsigned char *)arg + offset + i);
+;     res.ull <<= __builtin_preserve_field_info(arg->b2, FIELD_LSHIFT_U64);
+;     if (__builtin_preserve_field_info(arg->b2, FIELD_SIGNEDNESS))
+;       res.ll >>= __builtin_preserve_field_info(arg->b2, FIELD_RSHIFT_U64);
+;     else
+;       res.ull >>= __builtin_preserve_field_info(arg->b2, FIELD_RSHIFT_U64);
+;     return res.ull;
+;   }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm test.c
+
+%struct.s = type { i32, i16 }
+%union.anon = type { i64 }
+
+; Function Attrs: nounwind
+define dso_local i32 @field_read(%struct.s* %arg) local_unnamed_addr #0 !dbg !21 {
+entry:
+  %res = alloca %union.anon, align 8
+  call void @llvm.dbg.value(metadata %struct.s* %arg, metadata !32, metadata !DIExpression()), !dbg !43
+  %0 = bitcast %union.anon* %res to i8*, !dbg !44
+  call void @llvm.lifetime.start.p0i8(i64 8, i8* nonnull %0) #4, !dbg !44
+  call void @llvm.dbg.declare(metadata %union.anon* %res, metadata !33, metadata !DIExpression()), !dbg !45
+  %1 = tail call i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.ss(%struct.s* %arg, i32 1, i32 2), !dbg !46, !llvm.preserve.access.index !26
+  call void @llvm.dbg.value(metadata i32 undef, metadata !40, metadata !DIExpression()), !dbg !43
+  %2 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 1), !dbg !47
+  call void @llvm.dbg.value(metadata i32 %2, metadata !42, metadata !DIExpression()), !dbg !43
+  call void @llvm.dbg.value(metadata i32 0, metadata !41, metadata !DIExpression()), !dbg !43
+  %cmp20 = icmp eq i32 %2, 0, !dbg !48
+  br i1 %cmp20, label %for.end, label %for.body.lr.ph, !dbg !51
+
+for.body.lr.ph:                                   ; preds = %entry
+  %3 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 0), !dbg !52
+  call void @llvm.dbg.value(metadata i32 %3, metadata !40, metadata !DIExpression()), !dbg !43
+  %4 = bitcast %struct.s* %arg to i8*, !dbg !53
+  %idx.ext = zext i32 %3 to i64, !dbg !53
+  %add.ptr = getelementptr inbounds i8, i8* %4, i64 %idx.ext, !dbg !53
+  %wide.trip.count = zext i32 %2 to i64, !dbg !48
+  br label %for.body, !dbg !51
+
+for.body:                                         ; preds = %for.body, %for.body.lr.ph
+  %indvars.iv = phi i64 [ 0, %for.body.lr.ph ], [ %indvars.iv.next, %for.body ]
+  call void @llvm.dbg.value(metadata i64 %indvars.iv, metadata !41, metadata !DIExpression()), !dbg !43
+  %add.ptr2 = getelementptr inbounds i8, i8* %add.ptr, i64 %indvars.iv, !dbg !54
+  %5 = load volatile i8, i8* %add.ptr2, align 1, !dbg !55, !tbaa !56
+  %add.ptr4 = getelementptr inbounds i8, i8* %0, i64 %indvars.iv, !dbg !59
+  store i8 %5, i8* %add.ptr4, align 1, !dbg !60, !tbaa !56
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1, !dbg !61
+  call void @llvm.dbg.value(metadata i64 %indvars.iv.next, metadata !41, metadata !DIExpression()), !dbg !43
+  %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count, !dbg !48
+  br i1 %exitcond, label %for.end.loopexit, label %for.body, !dbg !51, !llvm.loop !62
+
+for.end.loopexit:                                 ; preds = %for.body
+  %ull.phi.trans.insert = getelementptr inbounds %union.anon, %union.anon* %res, i64 0, i32 0, !dbg !43
+  %.pre = load i64, i64* %ull.phi.trans.insert, align 8, !dbg !64, !tbaa !56
+  br label %for.end, !dbg !65
+
+for.end:                                          ; preds = %for.end.loopexit, %entry
+  %6 = phi i64 [ %.pre, %for.end.loopexit ], [ undef, %entry ], !dbg !64
+  %7 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 4), !dbg !65
+  %sh_prom = zext i32 %7 to i64, !dbg !64
+  %shl = shl i64 %6, %sh_prom, !dbg !64
+  %8 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 3), !dbg !66
+  %tobool = icmp eq i32 %8, 0, !dbg !66
+  %9 = tail call i32 @llvm.bpf.preserve.field.info.p0i16(i16* %1, i64 5), !dbg !68
+  %sh_prom5 = zext i32 %9 to i64, !dbg !68
+  %shr8 = lshr i64 %shl, %sh_prom5, !dbg !69
+  %shr = ashr i64 %shl, %sh_prom5, !dbg !69
+  %storemerge = select i1 %tobool, i64 %shr8, i64 %shr, !dbg !69
+  %conv = trunc i64 %storemerge to i32, !dbg !70
+  call void @llvm.lifetime.end.p0i8(i64 8, i8* nonnull %0) #4, !dbg !71
+  ret i32 %conv, !dbg !72
+}
+
+; CHECK:             r{{[0-9]+}} = 1
+; CHECK:             r{{[0-9]+}} = 5
+; CHECK-EL:          r{{[0-9]+}} = 59
+; CHECK-EB:          r{{[0-9]+}} = 1
+; CHECK:             r{{[0-9]+}} = 60
+; CHECK:             r{{[0-9]+}} = 1
+
+; CHECK:             .long   1                       # BTF_KIND_STRUCT(id = 2)
+; CHECK:             .byte   115                     # string offset=1
+; CHECK:             .ascii  ".text"                 # string offset=30
+; CHECK:             .ascii  "0:2"                   # string offset=36
+
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   30                      # Field reloc section string offset=30
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   3
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) #2
+
+; Function Attrs: nounwind readnone
+declare i16* @llvm.preserve.struct.access.index.p0i16.p0s_struct.ss(%struct.s*, i32, i32) #3
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.bpf.preserve.field.info.p0i16(i16*, i64) #3
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) #2
+
+; Function Attrs: nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { nounwind readnone speculatable willreturn }
+attributes #2 = { argmemonly nounwind willreturn }
+attributes #3 = { nounwind readnone }
+attributes #4 = { nounwind }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!17, !18, !19}
+!llvm.ident = !{!20}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !12, nameTableKind: None)
+!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
+!2 = !{!3}
+!3 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !1, line: 6, baseType: !4, size: 32, elements: !5)
+!4 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!5 = !{!6, !7, !8, !9, !10, !11}
+!6 = !DIEnumerator(name: "FIELD_BYTE_OFFSET", value: 0, isUnsigned: true)
+!7 = !DIEnumerator(name: "FIELD_BYTE_SIZE", value: 1, isUnsigned: true)
+!8 = !DIEnumerator(name: "FIELD_EXISTENCE", value: 2, isUnsigned: true)
+!9 = !DIEnumerator(name: "FIELD_SIGNEDNESS", value: 3, isUnsigned: true)
+!10 = !DIEnumerator(name: "FIELD_LSHIFT_U64", value: 4, isUnsigned: true)
+!11 = !DIEnumerator(name: "FIELD_RSHIFT_U64", value: 5, isUnsigned: true)
+!12 = !{!13, !16}
+!13 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !14, size: 64)
+!14 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !15)
+!15 = !DIBasicType(name: "unsigned char", size: 8, encoding: DW_ATE_unsigned_char)
+!16 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !15, size: 64)
+!17 = !{i32 2, !"Dwarf Version", i32 4}
+!18 = !{i32 2, !"Debug Info Version", i32 3}
+!19 = !{i32 1, !"wchar_size", i32 4}
+!20 = !{!"clang version 10.0.0 (https://github.com/llvm/llvm-project.git 4a60741b74384f14b21fdc0131ede326438840ab)"}
+!21 = distinct !DISubprogram(name: "field_read", scope: !1, file: !1, line: 15, type: !22, scopeLine: 15, flags: DIFlagPrototyped, isDefinition: true, isOptimized: true, unit: !0, retainedNodes: !31)
+!22 = !DISubroutineType(types: !23)
+!23 = !{!24, !25}
+!24 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!25 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !26, size: 64)
+!26 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s", file: !1, line: 1, size: 64, elements: !27)
+!27 = !{!28, !29, !30}
+!28 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !26, file: !1, line: 2, baseType: !24, size: 32)
+!29 = !DIDerivedType(tag: DW_TAG_member, name: "b1", scope: !26, file: !1, line: 3, baseType: !24, size: 9, offset: 32, flags: DIFlagBitField, extraData: i64 32)
+!30 = !DIDerivedType(tag: DW_TAG_member, name: "b2", scope: !26, file: !1, line: 4, baseType: !24, size: 4, offset: 41, flags: DIFlagBitField, extraData: i64 32)
+!31 = !{!32, !33, !40, !41, !42}
+!32 = !DILocalVariable(name: "arg", arg: 1, scope: !21, file: !1, line: 15, type: !25)
+!33 = !DILocalVariable(name: "res", scope: !21, file: !1, line: 19, type: !34)
+!34 = distinct !DICompositeType(tag: DW_TAG_union_type, scope: !21, file: !1, line: 16, size: 64, elements: !35)
+!35 = !{!36, !38}
+!36 = !DIDerivedType(tag: DW_TAG_member, name: "ull", scope: !34, file: !1, line: 17, baseType: !37, size: 64)
+!37 = !DIBasicType(name: "long long unsigned int", size: 64, encoding: DW_ATE_unsigned)
+!38 = !DIDerivedType(tag: DW_TAG_member, name: "ll", scope: !34, file: !1, line: 18, baseType: !39, size: 64)
+!39 = !DIBasicType(name: "long long int", size: 64, encoding: DW_ATE_signed)
+!40 = !DILocalVariable(name: "offset", scope: !21, file: !1, line: 20, type: !4)
+!41 = !DILocalVariable(name: "i", scope: !21, file: !1, line: 21, type: !4)
+!42 = !DILocalVariable(name: "size", scope: !21, file: !1, line: 21, type: !4)
+!43 = !DILocation(line: 0, scope: !21)
+!44 = !DILocation(line: 16, column: 3, scope: !21)
+!45 = !DILocation(line: 19, column: 5, scope: !21)
+!46 = !DILocation(line: 20, column: 56, scope: !21)
+!47 = !DILocation(line: 21, column: 22, scope: !21)
+!48 = !DILocation(line: 23, column: 17, scope: !49)
+!49 = distinct !DILexicalBlock(scope: !50, file: !1, line: 23, column: 3)
+!50 = distinct !DILexicalBlock(scope: !21, file: !1, line: 23, column: 3)
+!51 = !DILocation(line: 23, column: 3, scope: !50)
+!52 = !DILocation(line: 20, column: 21, scope: !21)
+!53 = !DILocation(line: 0, scope: !49)
+!54 = !DILocation(line: 24, column: 77, scope: !49)
+!55 = !DILocation(line: 24, column: 36, scope: !49)
+!56 = !{!57, !57, i64 0}
+!57 = !{!"omnipotent char", !58, i64 0}
+!58 = !{!"Simple C/C++ TBAA"}
+!59 = !DILocation(line: 24, column: 29, scope: !49)
+!60 = !DILocation(line: 24, column: 34, scope: !49)
+!61 = !DILocation(line: 23, column: 26, scope: !49)
+!62 = distinct !{!62, !51, !63}
+!63 = !DILocation(line: 24, column: 80, scope: !50)
+!64 = !DILocation(line: 25, column: 11, scope: !21)
+!65 = !DILocation(line: 25, column: 15, scope: !21)
+!66 = !DILocation(line: 26, column: 7, scope: !67)
+!67 = distinct !DILexicalBlock(scope: !21, file: !1, line: 26, column: 7)
+!68 = !DILocation(line: 0, scope: !67)
+!69 = !DILocation(line: 26, column: 7, scope: !21)
+!70 = !DILocation(line: 30, column: 10, scope: !21)
+!71 = !DILocation(line: 31, column: 1, scope: !21)
+!72 = !DILocation(line: 30, column: 3, scope: !21)

llvm/test/CodeGen/BPF/CORE/offset-reloc-global-1.ll

 ; CHECK:              call get_value
 
 ; CHECK:              .long   16                      # BTF_KIND_STRUCT(id = [[TID1:[0-9]+]])
 
 ; CHECK:              .ascii  ".text"                 # string offset=10
 ; CHECK:              .ascii  "v3"                    # string offset=16
 ; CHECK:              .ascii  "0:1"                   # string offset=23
 
-; CHECK:              .long   12                      # OffsetReloc
-; CHECK-NEXT:         .long   10                      # Offset reloc section string offset=10
+; CHECK:              .long   16                      # FieldReloc
+; CHECK-NEXT:         .long   10                      # Field reloc section string offset=10
 ; CHECK-NEXT:         .long   1
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID1]]
 ; CHECK-NEXT:         .long   23
+; CHECK-NEXT:         .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "no-infs-fp-math"="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/test/CodeGen/BPF/CORE/offset-reloc-global-2.ll

 ; CHECK:              call get_value
 
 ; CHECK:              .long   16                      # BTF_KIND_STRUCT(id = [[TID1:[0-9]+]])
 
 ; CHECK:              .ascii  ".text"                 # string offset=10
 ; CHECK:              .ascii  "v3"                    # string offset=16
 ; CHECK:              .ascii  "7:1"                   # string offset=23
 
-; CHECK:              .long   12                      # OffsetReloc
-; CHECK-NEXT:         .long   10                      # Offset reloc section string offset=10
+; CHECK:              .long   16                      # FieldReloc
+; CHECK-NEXT:         .long   10                      # Field reloc section string offset=10
 ; CHECK-NEXT:         .long   1
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID1]]
 ; CHECK-NEXT:         .long   23
+; CHECK-NEXT:         .long   0
 
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare [5 x %struct.v3]* @llvm.preserve.array.access.index.p0a5s_struct.v3s.p0a4a5s_struct.v3s([4 x [5 x %struct.v3]]*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone

llvm/test/CodeGen/BPF/CORE/offset-reloc-global-3.ll

 ; CHECK:              call get_value
 
 ; CHECK:              .long   16                      # BTF_KIND_STRUCT(id = [[TID1:[0-9]+]])
 
 ; CHECK:              .ascii  ".text"                 # string offset=10
 ; CHECK:              .ascii  "v3"                    # string offset=16
 ; CHECK:              .ascii  "0:1"                   # string offset=23
 
-; CHECK:              .long   12                      # OffsetReloc
-; CHECK-NEXT:         .long   10                      # Offset reloc section string offset=10
+; CHECK:              .long   16                      # FieldReloc
+; CHECK-NEXT:         .long   10                      # Field reloc section string offset=10
 ; CHECK-NEXT:         .long   1
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID1]]
 ; CHECK-NEXT:         .long   23
+; CHECK-NEXT:         .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "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 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "no-infs-fp-math"="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/test/CodeGen/BPF/CORE/offset-reloc-ignore.ll

entry:
   %0 = tail call i32* @llvm.preserve.array.access.index.p0i32.p0i32(i32* %arg, i32 0, i32 4), !dbg !16, !llvm.preserve.access.index !4
   %call = tail call i32 @get_value(i32* %0) #4, !dbg !17
   ret i32 %call, !dbg !18
 }
 
 ; CHECK:             r1 += 16
 ; CHECK:             call get_value
 ; CHECK:             .section        .BTF.ext,"",@progbits
-; CHECK-NOT:         .long   12                      # OffsetReloc
+; CHECK-NOT:         .long   16                      # FieldReloc
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.array.access.index.p0i32.p0i32(i32*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone speculatable willreturn
 declare void @llvm.dbg.value(metadata, metadata, metadata) #3

llvm/test/CodeGen/BPF/CORE/offset-reloc-middle-chain.ll

 ; CHECK:             .long   1                       # BTF_KIND_STRUCT(id = 2)
 
 ; CHECK:             .ascii  "r1"                    # string offset=1
 ; CHECK:             .ascii  ".text"                 # string offset=29
 ; CHECK:             .ascii  "0:0"                   # string offset=72
 ; CHECK:             .ascii  "0:0:0"                 # string offset=76
 ; CHECK:             .ascii  "0:0:0:0"               # string offset=82
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   29                      # Offset reloc section string offset=29
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   29                      # Field reloc section string offset=29
 ; CHECK-NEXT:        .long   3
 ; CHECK_NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK_NEXT:        .long   2
 ; CHECK_NEXT:        .long   72
+; CHECK_NEXT:        .long   0
 ; CHECK_NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK_NEXT:        .long   2
 ; CHECK_NEXT:        .long   76
+; CHECK_NEXT:        .long   0
 ; CHECK_NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK_NEXT:        .long   2
 ; CHECK_NEXT:        .long   82
+; CHECK_NEXT:        .long   0
 
 ; Function Attrs: nounwind readnone
 declare %struct.s1* @llvm.preserve.struct.access.index.p0s_struct.s1s.p0s_struct.r1s(%struct.r1*, i32, i32) #1
 
 ; Function Attrs: nounwind readnone
 declare %struct.t1* @llvm.preserve.struct.access.index.p0s_struct.t1s.p0s_struct.s1s(%struct.s1*, i32, i32) #1
 
 ; Function Attrs: nounwind readnone

llvm/test/CodeGen/BPF/CORE/offset-reloc-multi-array-1.ll

 ; CHECK:              call get_value
 
 ; CHECK:              .long   6                       # BTF_KIND_STRUCT(id = [[TID1:[0-9]+]])
 
 ; CHECK:              .ascii  "v3"                    # string offset=6
 ; CHECK:              .ascii  ".text"                 # string offset=52
 ; CHECK:              .ascii  "1:1:2:3"               # string offset=58
 
-; CHECK:              .long   12                      # OffsetReloc
-; CHECK-NEXT:         .long   52                      # Offset reloc section string offset=52
+; CHECK:              .long   16                      # FieldReloc
+; CHECK-NEXT:         .long   52                      # Field reloc section string offset=52
 ; CHECK-NEXT:         .long   1
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID1]]
 ; CHECK-NEXT:         .long   58
+; CHECK-NEXT:         .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %struct.v3* @llvm.preserve.array.access.index.p0s_struct.v3s.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare [4 x [4 x i32]]* @llvm.preserve.struct.access.index.p0a4a4i32.p0s_struct.v3s(%struct.v3*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-multi-array-2.ll

 ; CHECK:             call get_value
 
 ; CHECK:             .long   6                       # BTF_KIND_STRUCT(id = [[TID1:[0-9]+]])
 
 ; CHECK:             .ascii  "v3"                    # string offset=6
 ; CHECK:             .ascii  ".text"                 # string offset=52
 ; CHECK:             .ascii  "1:1:2:3:2"             # string offset=58
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   52                      # Offset reloc section string offset=52
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   52                      # Field reloc section string offset=52
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:        .long   [[TID1]]
 ; CHECK-NEXT:        .long   58
+; CHECK-NEXT:        .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %struct.v3* @llvm.preserve.array.access.index.p0s_struct.v3s.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare [4 x [4 x [4 x i32]]]* @llvm.preserve.struct.access.index.p0a4a4a4i32.p0s_struct.v3s(%struct.v3*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-multilevel.ll

 ; 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   28
+; CHECK-NEXT:        .long   124
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   57                      # Offset reloc section string offset=57
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   57                      # Field reloc section string offset=57
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp2
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   100
+; CHECK-NEXT:        .long   0
 
 ; 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

llvm/test/CodeGen/BPF/CORE/offset-reloc-pointer-1.ll

 ; CHECK:              call get_value
 
 ; CHECK:              .long   6                       # BTF_KIND_STRUCT(id = [[TID1:[0-9]+]])
 
 ; CHECK:              .ascii  "v3"                    # string offset=6
 ; CHECK:              .ascii  ".text"                 # string offset=26
 ; CHECK:              .byte   49                      # string offset=32
 
-; CHECK:              .long   12                      # OffsetReloc
-; CHECK-NEXT:         .long   26                      # Offset reloc section string offset=26
+; CHECK:              .long   16                      # FieldReloc
+; CHECK-NEXT:         .long   26                      # Field reloc section string offset=26
 ; CHECK-NEXT:         .long   1
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID1]]
 ; CHECK-NEXT:         .long   32
+; CHECK-NEXT:         .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %struct.v3* @llvm.preserve.array.access.index.p0s_struct.v3s.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone speculatable willreturn
 declare void @llvm.dbg.value(metadata, metadata, metadata) #3

llvm/test/CodeGen/BPF/CORE/offset-reloc-pointer-2.ll

 ; CHECK-NEXT:         r1 += r2
 ; CHECK:              call get_value
 
 ; CHECK:              .long   6                       # BTF_KIND_STRUCT(id = [[TID1:[0-9]+]])
 ; CHECK:              .ascii  "v3"                    # string offset=6
 ; CHECK:              .ascii  ".text"                 # string offset=26
 ; CHECK:              .ascii  "1:1"                   # string offset=32
 
-; CHECK:              .long   12                      # OffsetReloc
-; CHECK-NEXT:         .long   26                      # Offset reloc section string offset=26
+; CHECK:              .long   16                      # FieldReloc
+; CHECK-NEXT:         .long   26                      # Field reloc section string offset=26
 ; CHECK-NEXT:         .long   1
 ; CHECK-NEXT:         .long   .Ltmp{{[0-9]+}}
 ; CHECK-NEXT:         .long   [[TID1]]
 ; CHECK-NEXT:         .long   32
+; CHECK-NEXT:         .long   0
 
 declare dso_local i32 @get_value(i32*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %struct.v3* @llvm.preserve.array.access.index.p0s_struct.v3s.p0s_struct.v3s(%struct.v3*, i32, i32) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.v3s(%struct.v3*, i32, i32) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-struct-anonymous.ll

 ; 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   28
+; CHECK-NEXT:        .long   124
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   66                      # Offset reloc section string offset=66
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   66                      # Field reloc section string offset=66
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp2
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   109
+; CHECK-NEXT:        .long   0
 
 ; 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

llvm/test/CodeGen/BPF/CORE/offset-reloc-struct-array.ll

 ; 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   28
+; CHECK-NEXT:        .long   124
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   77                      # Offset reloc section string offset=77
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   77                      # Field reloc section string offset=77
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp2
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   0
 
 ; 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

llvm/test/CodeGen/BPF/CORE/offset-reloc-typedef-array.ll

 ; CHECK:         r1 += r2
 ; CHECK:         call get_value
 
 ; CHECK:         .long   {{[0-9]+}}              # BTF_KIND_STRUCT(id = [[TYPE_ID:[0-9]+]])
 ; CHECK:         .ascii  ".text"                 # string offset=[[SEC_INDEX:[0-9]+]]
 ; CHECK-NEXT:    .byte   0
 ; CHECK:         .ascii  "0:0:1"                 # string offset=[[ACCESS_STR:[0-9]+]]
 ; CHECK-NEXT:    .byte   0
-; CHECK:         .long   12                      # OffsetReloc
-; CHECK-NEXT:    .long   [[SEC_INDEX]]           # Offset reloc section string offset=[[SEC_INDEX]]
+; CHECK:         .long   16                      # FieldReloc
+; CHECK-NEXT:    .long   [[SEC_INDEX]]           # Field reloc section string offset=[[SEC_INDEX]]
 ; CHECK-NEXT:    .long   1
 ; CHECK-NEXT:    .long   [[RELOC]]
 ; CHECK-NEXT:    .long   [[TYPE_ID]]
 ; CHECK-NEXT:    .long   [[ACCESS_STR]]
+; CHECK-NEXT:    .long   0
 
 declare dso_local i32 @get_value(i8*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare [7 x i32]* @llvm.preserve.struct.access.index.p0a7i32.p0s_struct.__ss(%struct.__s*, i32 immarg, i32 immarg) #2
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.array.access.index.p0i32.p0a7i32([7 x i32]*, i32 immarg, i32 immarg) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-typedef-struct.ll

 ; CHECK:        r1 += r2
 ; CHECK:        call get_value
 
 ; CHECK:        .long   {{[0-9]+}}              # BTF_KIND_STRUCT(id = [[TYPE_ID:[0-9]+]])
 ; CHECK:        .ascii  ".text"                 # string offset=[[SEC_STR:[0-9]+]]
 ; CHECK-NEXT:   .byte   0
 ; CHECK:        .ascii  "0:1"                   # string offset=[[ACCESS_STR:[0-9]+]]
 ; CHECK-NEXT:   .byte   0
-; CHECK:        .long   12                      # OffsetReloc
-; CHECK-NEXT:   .long   [[SEC_STR]]             # Offset reloc section string offset={{[0-9]+}}
+; CHECK:        .long   16                      # FieldReloc
+; CHECK-NEXT:   .long   [[SEC_STR]]             # Field reloc section string offset={{[0-9]+}}
 ; CHECK-NEXT:   .long   1
 ; CHECK-NEXT:   .long   [[RELOC]]
 ; CHECK-NEXT:   .long   [[TYPE_ID]]
 ; CHECK-NEXT:   .long   [[ACCESS_STR]]
+; CHECK-NEXT:   .long   0
 
 declare dso_local i32 @get_value(i8*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.__ss(%struct.__s*, i32 immarg, i32 immarg) #2
 
 ; Function Attrs: nounwind readnone speculatable
 declare void @llvm.dbg.value(metadata, metadata, metadata) #3

llvm/test/CodeGen/BPF/CORE/offset-reloc-typedef-union.ll

 ; CHECK:         r1 += r2
 ; CHECK:         call get_value
 
 ; CHECK:         .long   {{[0-9]+}}              # BTF_KIND_UNION(id = [[TYPE_ID:[0-9]+]])
 ; CHECK:         .ascii  ".text"                 # string offset=[[SEC_INDEX:[0-9]+]]
 ; CHECK-NEXT:    .byte   0
 ; CHECK:         .ascii  "0:1"                   # string offset=[[ACCESS_STR:[0-9]+]]
 ; CHECK-NEXT:    .byte   0
-; CHECK:         .long   12                      # OffsetReloc
-; CHECK-NEXT:    .long   [[SEC_INDEX]]           # Offset reloc section string offset=[[SEC_INDEX]]
+; CHECK:         .long   16                      # FieldReloc
+; CHECK-NEXT:    .long   [[SEC_INDEX]]           # Field reloc section string offset=[[SEC_INDEX]]
 ; CHECK-NEXT:    .long   1
 ; CHECK-NEXT:    .long   [[RELOC]]
 ; CHECK-NEXT:    .long   [[TYPE_ID]]
 ; CHECK-NEXT:    .long   [[ACCESS_STR]]
+; CHECK-NEXT:    .long   0
 
 declare dso_local i32 @get_value(i8*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare %union.__s* @llvm.preserve.union.access.index.p0s_union.__ss.p0s_union.__ss(%union.__s*, i32 immarg) #2
 
 ; Function Attrs: nounwind readnone speculatable
 declare void @llvm.dbg.value(metadata, metadata, metadata) #3

llvm/test/CodeGen/BPF/CORE/offset-reloc-typedef.ll

 ; CHECK:         r1 += r2
 ; CHECK:         call get_value
 
 ; CHECK:         .long   {{[0-9]+}}              # BTF_KIND_UNION(id = [[TYPE_ID:[0-9]+]])
 ; CHECK:         .ascii  ".text"                 # string offset=[[SEC_STR:[0-9]+]]
 ; CHECK-NEXT:    .byte   0
 ; CHECK:         .ascii  "1:1:1"                 # string offset=[[ACCESS_STR:[0-9]+]]
 ; CHECK-NEXT:    .byte   0
-; CHECK:         .long   12                      # OffsetReloc
-; CHECK-NEXT:    .long   [[SEC_STR:[0-9]+]]      # Offset reloc section string offset=[[SEC_STR:[0-9]+]]
+; CHECK:         .long   16                      # FieldReloc
+; CHECK-NEXT:    .long   [[SEC_STR:[0-9]+]]      # Field reloc section string offset=[[SEC_STR:[0-9]+]]
 ; CHECK-NEXT:    .long   1
 ; CHECK-NEXT:    .long   [[RELOC:.Ltmp[0-9]+]]
 ; CHECK-NEXT:    .long   [[TYPE_ID:[0-9]+]]
 ; CHECK-NEXT:    .long   [[ACCESS_STR:[0-9]+]]
+; CHECK-NEXT:    .long   0
 
 declare dso_local i32 @get_value(i8*) local_unnamed_addr #1
 
 ; Function Attrs: nounwind readnone
 declare [7 x %union.u]* @llvm.preserve.array.access.index.p0a7s_union.us.p0a7s_union.us([7 x %union.u]*, i32 immarg, i32 immarg) #2
 
 ; Function Attrs: nounwind readnone
 declare %union.u* @llvm.preserve.union.access.index.p0s_union.us.p0s_union.us(%union.u*, i32 immarg) #2

llvm/test/CodeGen/BPF/CORE/offset-reloc-union.ll

 ; 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   28
+; CHECK-NEXT:        .long   124
 ; CHECK-NEXT:        .long   0
 ; CHECK-NEXT:        .long   8                       # FuncInfo
 
-; CHECK:             .long   12                      # OffsetReloc
-; CHECK-NEXT:        .long   54                      # Offset reloc section string offset=54
+; CHECK:             .long   16                      # FieldReloc
+; CHECK-NEXT:        .long   54                      # Field reloc section string offset=54
 ; CHECK-NEXT:        .long   1
 ; CHECK-NEXT:        .long   .Ltmp2
 ; CHECK-NEXT:        .long   2
 ; CHECK-NEXT:        .long   97
+; CHECK-NEXT:        .long   0
 
 ; 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