[llvm] r327163 - Use branch funnels for virtual calls when retpoline mitigation is enabled.

Peter Collingbourne via llvm-commits llvm-commits at lists.llvm.org
Fri May 4 17:50:42 PDT 2018


Sorry, this should be fixed by D45901 but I never got around to landing it.
I'll do that now.

Peter

On Fri, May 4, 2018 at 5:45 PM, Galina Kistanova <gkistanova at gmail.com>
wrote:

> ping?
>
> On Thu, May 3, 2018 at 11:16 AM, Galina Kistanova <gkistanova at gmail.com>
> wrote:
>
>> Hi Peter,
>>
>> One of added tests shows inconsistent results on expensive-checks builder.
>> It fails time to time:
>>
>> http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensiv
>> e-checks-win/builds/9404
>> http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensiv
>> e-checks-win/builds/9407
>> etc.
>> the last:
>> http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensiv
>> e-checks-win/builds/9426
>>
>> . . .
>> ********************
>> Failing Tests (1):
>>     LLVM :: Transforms/LowerTypeTests/icall-branch-funnel.ll
>>
>> Please have a look at this?
>>
>> Thanks
>>
>> Galina
>>
>>
>>
>> On Fri, Mar 9, 2018 at 11:11 AM, Peter Collingbourne via llvm-commits <
>> llvm-commits at lists.llvm.org> wrote:
>>
>>> Author: pcc
>>> Date: Fri Mar  9 11:11:44 2018
>>> New Revision: 327163
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=327163&view=rev
>>> Log:
>>> Use branch funnels for virtual calls when retpoline mitigation is
>>> enabled.
>>>
>>> The retpoline mitigation for variant 2 of CVE-2017-5715 inhibits the
>>> branch predictor, and as a result it can lead to a measurable loss of
>>> performance. We can reduce the performance impact of retpolined virtual
>>> calls by replacing them with a special construct known as a branch
>>> funnel, which is an instruction sequence that implements virtual calls
>>> to a set of known targets using a binary tree of direct branches. This
>>> allows the processor to speculately execute valid implementations of the
>>> virtual function without allowing for speculative execution of of calls
>>> to arbitrary addresses.
>>>
>>> This patch extends the whole-program devirtualization pass to replace
>>> certain virtual calls with calls to branch funnels, which are
>>> represented using a new llvm.icall.jumptable intrinsic. It also extends
>>> the LowerTypeTests pass to recognize the new intrinsic, generate code
>>> for the branch funnels (x86_64 only for now) and lay out virtual tables
>>> as required for each branch funnel.
>>>
>>> The implementation supports full LTO as well as ThinLTO, and extends the
>>> ThinLTO summary format used for whole-program devirtualization to
>>> support branch funnels.
>>>
>>> For more details see RFC:
>>> http://lists.llvm.org/pipermail/llvm-dev/2018-January/120672.html
>>>
>>> Differential Revision: https://reviews.llvm.org/D42453
>>>
>>> Added:
>>>     llvm/trunk/test/CodeGen/X86/icall-branch-funnel.ll
>>>     llvm/trunk/test/Transforms/LowerTypeTests/icall-branch-funnel.ll
>>>     llvm/trunk/test/Transforms/WholeProgramDevirt/Inputs/import-
>>> branch-funnel.yaml
>>>     llvm/trunk/test/Transforms/WholeProgramDevirt/Inputs/import-
>>> vcp-branch-funnel.yaml
>>>     llvm/trunk/test/Transforms/WholeProgramDevirt/branch-funnel.ll
>>> Modified:
>>>     llvm/trunk/include/llvm/ADT/PointerUnion.h
>>>     llvm/trunk/include/llvm/CodeGen/TargetOpcodes.def
>>>     llvm/trunk/include/llvm/IR/Intrinsics.td
>>>     llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h
>>>     llvm/trunk/include/llvm/IR/ModuleSummaryIndexYAML.h
>>>     llvm/trunk/include/llvm/Target/Target.td
>>>     llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>>     llvm/trunk/lib/IR/Verifier.cpp
>>>     llvm/trunk/lib/Target/X86/X86ExpandPseudo.cpp
>>>     llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp
>>>     llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp
>>>     llvm/trunk/test/Transforms/WholeProgramDevirt/import.ll
>>>
>>> Modified: llvm/trunk/include/llvm/ADT/PointerUnion.h
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/
>>> ADT/PointerUnion.h?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/include/llvm/ADT/PointerUnion.h (original)
>>> +++ llvm/trunk/include/llvm/ADT/PointerUnion.h Fri Mar  9 11:11:44 2018
>>> @@ -346,6 +346,12 @@ struct PointerLikeTypeTraits<PointerUnio
>>>    };
>>>  };
>>>
>>> +template <typename PT1, typename PT2, typename PT3>
>>> +bool operator<(PointerUnion3<PT1, PT2, PT3> lhs,
>>> +               PointerUnion3<PT1, PT2, PT3> rhs) {
>>> +  return lhs.getOpaqueValue() < rhs.getOpaqueValue();
>>> +}
>>> +
>>>  /// A pointer union of four pointer types. See documentation for
>>> PointerUnion
>>>  /// for usage.
>>>  template <typename PT1, typename PT2, typename PT3, typename PT4>
>>>
>>> Modified: llvm/trunk/include/llvm/CodeGen/TargetOpcodes.def
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/
>>> CodeGen/TargetOpcodes.def?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/include/llvm/CodeGen/TargetOpcodes.def (original)
>>> +++ llvm/trunk/include/llvm/CodeGen/TargetOpcodes.def Fri Mar  9
>>> 11:11:44 2018
>>> @@ -187,6 +187,8 @@ HANDLE_TARGET_OPCODE(PATCHABLE_TAIL_CALL
>>>  /// patched to insert instrumentation instructions.
>>>  HANDLE_TARGET_OPCODE(PATCHABLE_EVENT_CALL)
>>>
>>> +HANDLE_TARGET_OPCODE(ICALL_BRANCH_FUNNEL)
>>> +
>>>  /// The following generic opcodes are not supposed to appear after ISel.
>>>  /// This is something we might want to relax, but for now, this is
>>> convenient
>>>  /// to produce diagnostics.
>>>
>>> Modified: llvm/trunk/include/llvm/IR/Intrinsics.td
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/
>>> IR/Intrinsics.td?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/include/llvm/IR/Intrinsics.td (original)
>>> +++ llvm/trunk/include/llvm/IR/Intrinsics.td Fri Mar  9 11:11:44 2018
>>> @@ -874,6 +874,10 @@ def int_type_checked_load : Intrinsic<[l
>>>                                        [llvm_ptr_ty, llvm_i32_ty,
>>> llvm_metadata_ty],
>>>                                        [IntrNoMem]>;
>>>
>>> +// Create a branch funnel that implements an indirect call to a limited
>>> set of
>>> +// callees. This needs to be a musttail call.
>>> +def int_icall_branch_funnel : Intrinsic<[], [llvm_vararg_ty], []>;
>>> +
>>>  def int_load_relative: Intrinsic<[llvm_ptr_ty], [llvm_ptr_ty,
>>> llvm_anyint_ty],
>>>                                   [IntrReadMem, IntrArgMemOnly]>;
>>>
>>>
>>> Modified: llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/
>>> IR/ModuleSummaryIndex.h?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h (original)
>>> +++ llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h Fri Mar  9 11:11:44
>>> 2018
>>> @@ -656,8 +656,11 @@ struct TypeTestResolution {
>>>
>>>  struct WholeProgramDevirtResolution {
>>>    enum Kind {
>>> -    Indir,      ///< Just do a regular virtual call
>>> -    SingleImpl, ///< Single implementation devirtualization
>>> +    Indir,        ///< Just do a regular virtual call
>>> +    SingleImpl,   ///< Single implementation devirtualization
>>> +    BranchFunnel, ///< When retpoline mitigation is enabled, use a
>>> branch funnel
>>> +                  ///< that is defined in the merged module. Otherwise
>>> same as
>>> +                  ///< Indir.
>>>    } TheKind = Indir;
>>>
>>>    std::string SingleImplName;
>>>
>>> Modified: llvm/trunk/include/llvm/IR/ModuleSummaryIndexYAML.h
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/
>>> IR/ModuleSummaryIndexYAML.h?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/include/llvm/IR/ModuleSummaryIndexYAML.h (original)
>>> +++ llvm/trunk/include/llvm/IR/ModuleSummaryIndexYAML.h Fri Mar  9
>>> 11:11:44 2018
>>> @@ -98,6 +98,8 @@ template <> struct ScalarEnumerationTrai
>>>    static void enumeration(IO &io, WholeProgramDevirtResolution::Kind
>>> &value) {
>>>      io.enumCase(value, "Indir", WholeProgramDevirtResolution::Indir);
>>>      io.enumCase(value, "SingleImpl", WholeProgramDevirtResolution::
>>> SingleImpl);
>>> +    io.enumCase(value, "BranchFunnel",
>>> +                WholeProgramDevirtResolution::BranchFunnel);
>>>    }
>>>  };
>>>
>>>
>>> Modified: llvm/trunk/include/llvm/Target/Target.td
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/
>>> Target/Target.td?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/include/llvm/Target/Target.td (original)
>>> +++ llvm/trunk/include/llvm/Target/Target.td Fri Mar  9 11:11:44 2018
>>> @@ -1140,6 +1140,12 @@ def FENTRY_CALL : StandardPseudoInstruct
>>>    let mayStore = 1;
>>>    let hasSideEffects = 1;
>>>  }
>>> +def ICALL_BRANCH_FUNNEL : StandardPseudoInstruction {
>>> +  let OutOperandList = (outs unknown:$dst);
>>> +  let InOperandList = (ins variable_ops);
>>> +  let AsmString = "";
>>> +  let hasSideEffects = 1;
>>> +}
>>>
>>>  // Generic opcodes used in GlobalISel.
>>>  include "llvm/Target/GenericOpcodes.td"
>>>
>>> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/S
>>> electionDAG/SelectionDAGBuilder.cpp?rev=327163&r1=327162&r2=
>>> 327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>>> (original)
>>> +++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Fri
>>> Mar  9 11:11:44 2018
>>> @@ -6043,6 +6043,60 @@ SelectionDAGBuilder::visitIntrinsicCall(
>>>    case Intrinsic::experimental_vector_reduce_fmin:
>>>      visitVectorReduce(I, Intrinsic);
>>>      return nullptr;
>>> +
>>> +  case Intrinsic::icall_branch_funnel: {
>>> +    SmallVector<SDValue, 16> Ops;
>>> +    Ops.push_back(DAG.getRoot());
>>> +    Ops.push_back(getValue(I.getArgOperand(0)));
>>> +
>>> +    int64_t Offset;
>>> +    auto *Base = dyn_cast<GlobalObject>(GetPoin
>>> terBaseWithConstantOffset(
>>> +        I.getArgOperand(1), Offset, DAG.getDataLayout()));
>>> +    if (!Base)
>>> +      report_fatal_error(
>>> +          "llvm.icall.branch.funnel operand must be a GlobalValue");
>>> +    Ops.push_back(DAG.getTargetGlobalAddress(Base, getCurSDLoc(),
>>> MVT::i64, 0));
>>> +
>>> +    struct BranchFunnelTarget {
>>> +      int64_t Offset;
>>> +      SDValue Target;
>>> +    };
>>> +    SmallVector<BranchFunnelTarget, 8> Targets;
>>> +
>>> +    for (unsigned Op = 1, N = I.getNumArgOperands(); Op != N; Op += 2) {
>>> +      auto *ElemBase = dyn_cast<GlobalObject>(GetPoin
>>> terBaseWithConstantOffset(
>>> +          I.getArgOperand(Op), Offset, DAG.getDataLayout()));
>>> +      if (ElemBase != Base)
>>> +        report_fatal_error("all llvm.icall.branch.funnel operands must
>>> refer "
>>> +                           "to the same GlobalValue");
>>> +
>>> +      SDValue Val = getValue(I.getArgOperand(Op + 1));
>>> +      auto *GA = dyn_cast<GlobalAddressSDNode>(Val);
>>> +      if (!GA)
>>> +        report_fatal_error(
>>> +            "llvm.icall.branch.funnel operand must be a GlobalValue");
>>> +      Targets.push_back({Offset, DAG.getTargetGlobalAddress(
>>> +                                     GA->getGlobal(), getCurSDLoc(),
>>> +                                     Val.getValueType(),
>>> GA->getOffset())});
>>> +    }
>>> +    std::sort(Targets.begin(), Targets.end(),
>>> +              [](const BranchFunnelTarget &T1, const BranchFunnelTarget
>>> &T2) {
>>> +                return T1.Offset < T2.Offset;
>>> +              });
>>> +
>>> +    for (auto &T : Targets) {
>>> +      Ops.push_back(DAG.getTargetConstant(T.Offset, getCurSDLoc(),
>>> MVT::i32));
>>> +      Ops.push_back(T.Target);
>>> +    }
>>> +
>>> +    SDValue N(DAG.getMachineNode(TargetOpcode::ICALL_BRANCH_FUNNEL,
>>> +                                 getCurSDLoc(), MVT::Other, Ops),
>>> +              0);
>>> +    DAG.setRoot(N);
>>> +    setValue(&I, N);
>>> +    HasTailCall = true;
>>> +    return nullptr;
>>> +  }
>>>    }
>>>  }
>>>
>>>
>>> Modified: llvm/trunk/lib/IR/Verifier.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifi
>>> er.cpp?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/lib/IR/Verifier.cpp (original)
>>> +++ llvm/trunk/lib/IR/Verifier.cpp Fri Mar  9 11:11:44 2018
>>> @@ -2864,17 +2864,20 @@ void Verifier::verifyMustTailCall(CallIn
>>>    Function *F = CI.getParent()->getParent();
>>>    FunctionType *CallerTy = F->getFunctionType();
>>>    FunctionType *CalleeTy = CI.getFunctionType();
>>> -  Assert(CallerTy->getNumParams() == CalleeTy->getNumParams(),
>>> -         "cannot guarantee tail call due to mismatched parameter
>>> counts", &CI);
>>> +  if (!CI.getCalledFunction() || !CI.getCalledFunction()->isIntrinsic())
>>> {
>>> +    Assert(CallerTy->getNumParams() == CalleeTy->getNumParams(),
>>> +           "cannot guarantee tail call due to mismatched parameter
>>> counts",
>>> +           &CI);
>>> +    for (int I = 0, E = CallerTy->getNumParams(); I != E; ++I) {
>>> +      Assert(
>>> +          isTypeCongruent(CallerTy->getParamType(I),
>>> CalleeTy->getParamType(I)),
>>> +          "cannot guarantee tail call due to mismatched parameter
>>> types", &CI);
>>> +    }
>>> +  }
>>>    Assert(CallerTy->isVarArg() == CalleeTy->isVarArg(),
>>>           "cannot guarantee tail call due to mismatched varargs", &CI);
>>>    Assert(isTypeCongruent(CallerTy->getReturnType(),
>>> CalleeTy->getReturnType()),
>>>           "cannot guarantee tail call due to mismatched return types",
>>> &CI);
>>> -  for (int I = 0, E = CallerTy->getNumParams(); I != E; ++I) {
>>> -    Assert(
>>> -        isTypeCongruent(CallerTy->getParamType(I),
>>> CalleeTy->getParamType(I)),
>>> -        "cannot guarantee tail call due to mismatched parameter types",
>>> &CI);
>>> -  }
>>>
>>>    // - The calling conventions of the caller and callee must match.
>>>    Assert(F->getCallingConv() == CI.getCallingConv(),
>>>
>>> Modified: llvm/trunk/lib/Target/X86/X86ExpandPseudo.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X8
>>> 6/X86ExpandPseudo.cpp?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/lib/Target/X86/X86ExpandPseudo.cpp (original)
>>> +++ llvm/trunk/lib/Target/X86/X86ExpandPseudo.cpp Fri Mar  9 11:11:44
>>> 2018
>>> @@ -59,12 +59,112 @@ public:
>>>    }
>>>
>>>  private:
>>> +  void ExpandICallBranchFunnel(MachineBasicBlock *MBB,
>>> +                               MachineBasicBlock::iterator MBBI);
>>> +
>>>    bool ExpandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator
>>> MBBI);
>>>    bool ExpandMBB(MachineBasicBlock &MBB);
>>>  };
>>>  char X86ExpandPseudo::ID = 0;
>>>  } // End anonymous namespace.
>>>
>>> +void X86ExpandPseudo::ExpandICallBranchFunnel(
>>> +    MachineBasicBlock *MBB, MachineBasicBlock::iterator MBBI) {
>>> +  MachineBasicBlock *JTMBB = MBB;
>>> +  MachineInstr *JTInst = &*MBBI;
>>> +  MachineFunction *MF = MBB->getParent();
>>> +  const BasicBlock *BB = MBB->getBasicBlock();
>>> +  auto InsPt = MachineFunction::iterator(MBB);
>>> +  ++InsPt;
>>> +
>>> +  std::vector<std::pair<MachineBasicBlock *, unsigned>> TargetMBBs;
>>> +  DebugLoc DL = JTInst->getDebugLoc();
>>> +  MachineOperand Selector = JTInst->getOperand(0);
>>> +  const GlobalValue *CombinedGlobal = JTInst->getOperand(1).getGloba
>>> l();
>>> +
>>> +  auto CmpTarget = [&](unsigned Target) {
>>> +    BuildMI(*MBB, MBBI, DL, TII->get(X86::LEA64r), X86::R11)
>>> +        .addReg(X86::RIP)
>>> +        .addImm(1)
>>> +        .addReg(0)
>>> +        .addGlobalAddress(CombinedGlobal,
>>> +                          JTInst->getOperand(2 + 2 * Target).getImm())
>>> +        .addReg(0);
>>> +    BuildMI(*MBB, MBBI, DL, TII->get(X86::CMP64rr))
>>> +        .add(Selector)
>>> +        .addReg(X86::R11);
>>> +  };
>>> +
>>> +  auto CreateMBB = [&]() {
>>> +    auto *NewMBB = MF->CreateMachineBasicBlock(BB);
>>> +    MBB->addSuccessor(NewMBB);
>>> +    return NewMBB;
>>> +  };
>>> +
>>> +  auto EmitCondJump = [&](unsigned Opcode, MachineBasicBlock *ThenMBB) {
>>> +    BuildMI(*MBB, MBBI, DL, TII->get(Opcode)).addMBB(ThenMBB);
>>> +
>>> +    auto *ElseMBB = CreateMBB();
>>> +    MF->insert(InsPt, ElseMBB);
>>> +    MBB = ElseMBB;
>>> +    MBBI = MBB->end();
>>> +  };
>>> +
>>> +  auto EmitCondJumpTarget = [&](unsigned Opcode, unsigned Target) {
>>> +    auto *ThenMBB = CreateMBB();
>>> +    TargetMBBs.push_back({ThenMBB, Target});
>>> +    EmitCondJump(Opcode, ThenMBB);
>>> +  };
>>> +
>>> +  auto EmitTailCall = [&](unsigned Target) {
>>> +    BuildMI(*MBB, MBBI, DL, TII->get(X86::TAILJMPd64))
>>> +        .add(JTInst->getOperand(3 + 2 * Target));
>>> +  };
>>> +
>>> +  std::function<void(unsigned, unsigned)> EmitBranchFunnel =
>>> +      [&](unsigned FirstTarget, unsigned NumTargets) {
>>> +    if (NumTargets == 1) {
>>> +      EmitTailCall(FirstTarget);
>>> +      return;
>>> +    }
>>> +
>>> +    if (NumTargets == 2) {
>>> +      CmpTarget(FirstTarget + 1);
>>> +      EmitCondJumpTarget(X86::JB_1, FirstTarget);
>>> +      EmitTailCall(FirstTarget + 1);
>>> +      return;
>>> +    }
>>> +
>>> +    if (NumTargets < 6) {
>>> +      CmpTarget(FirstTarget + 1);
>>> +      EmitCondJumpTarget(X86::JB_1, FirstTarget);
>>> +      EmitCondJumpTarget(X86::JE_1, FirstTarget + 1);
>>> +      EmitBranchFunnel(FirstTarget + 2, NumTargets - 2);
>>> +      return;
>>> +    }
>>> +
>>> +    auto *ThenMBB = CreateMBB();
>>> +    CmpTarget(FirstTarget + (NumTargets / 2));
>>> +    EmitCondJump(X86::JB_1, ThenMBB);
>>> +    EmitCondJumpTarget(X86::JE_1, FirstTarget + (NumTargets / 2));
>>> +    EmitBranchFunnel(FirstTarget + (NumTargets / 2) + 1,
>>> +                  NumTargets - (NumTargets / 2) - 1);
>>> +
>>> +    MF->insert(InsPt, ThenMBB);
>>> +    MBB = ThenMBB;
>>> +    MBBI = MBB->end();
>>> +    EmitBranchFunnel(FirstTarget, NumTargets / 2);
>>> +  };
>>> +
>>> +  EmitBranchFunnel(0, (JTInst->getNumOperands() - 2) / 2);
>>> +  for (auto P : TargetMBBs) {
>>> +    MF->insert(InsPt, P.first);
>>> +    BuildMI(P.first, DL, TII->get(X86::TAILJMPd64))
>>> +        .add(JTInst->getOperand(3 + 2 * P.second));
>>> +  }
>>> +  JTMBB->erase(JTInst);
>>> +}
>>> +
>>>  /// If \p MBBI is a pseudo instruction, this method expands
>>>  /// it to the corresponding (sequence of) actual instruction(s).
>>>  /// \returns true if \p MBBI has been expanded.
>>> @@ -259,6 +359,9 @@ bool X86ExpandPseudo::ExpandMI(MachineBa
>>>      MBBI->eraseFromParent();
>>>      return true;
>>>    }
>>> +  case TargetOpcode::ICALL_BRANCH_FUNNEL:
>>> +    ExpandICallBranchFunnel(&MBB, MBBI);
>>> +    return true;
>>>    }
>>>    llvm_unreachable("Previous switch has a fallthrough?");
>>>  }
>>>
>>> Modified: llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transform
>>> s/IPO/LowerTypeTests.cpp?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp (original)
>>> +++ llvm/trunk/lib/Transforms/IPO/LowerTypeTests.cpp Fri Mar  9
>>> 11:11:44 2018
>>> @@ -8,6 +8,8 @@
>>>  //===------------------------------------------------------
>>> ----------------===//
>>>  //
>>>  // This pass lowers type metadata and calls to the llvm.type.test
>>> intrinsic.
>>> +// It also ensures that globals are properly laid out for the
>>> +// llvm.icall.branch.funnel intrinsic.
>>>  // See http://llvm.org/docs/TypeMetadata.html for more information.
>>>  //
>>>  //===------------------------------------------------------
>>> ----------------===//
>>> @@ -25,6 +27,7 @@
>>>  #include "llvm/ADT/TinyPtrVector.h"
>>>  #include "llvm/ADT/Triple.h"
>>>  #include "llvm/Analysis/TypeMetadataUtils.h"
>>> +#include "llvm/Analysis/ValueTracking.h"
>>>  #include "llvm/IR/Attributes.h"
>>>  #include "llvm/IR/BasicBlock.h"
>>>  #include "llvm/IR/Constant.h"
>>> @@ -291,6 +294,29 @@ public:
>>>    }
>>>  };
>>>
>>> +struct ICallBranchFunnel final
>>> +    : TrailingObjects<ICallBranchFunnel, GlobalTypeMember *> {
>>> +  static ICallBranchFunnel *create(BumpPtrAllocator &Alloc, CallInst
>>> *CI,
>>> +                                   ArrayRef<GlobalTypeMember *>
>>> Targets) {
>>> +    auto *Call = static_cast<ICallBranchFunnel *>(
>>> +        Alloc.Allocate(totalSizeToAlloc<GlobalTypeMember
>>> *>(Targets.size()),
>>> +                       alignof(ICallBranchFunnel)));
>>> +    Call->CI = CI;
>>> +    Call->NTargets = Targets.size();
>>> +    std::uninitialized_copy(Targets.begin(), Targets.end(),
>>> +                            Call->getTrailingObjects<GlobalTypeMember
>>> *>());
>>> +    return Call;
>>> +  }
>>> +
>>> +  CallInst *CI;
>>> +  ArrayRef<GlobalTypeMember *> targets() const {
>>> +    return makeArrayRef(getTrailingObjects<GlobalTypeMember *>(),
>>> NTargets);
>>> +  }
>>> +
>>> +private:
>>> +  size_t NTargets;
>>> +};
>>> +
>>>  class LowerTypeTestsModule {
>>>    Module &M;
>>>
>>> @@ -372,6 +398,7 @@ class LowerTypeTestsModule {
>>>        const DenseMap<GlobalTypeMember *, uint64_t> &GlobalLayout);
>>>    Value *lowerTypeTestCall(Metadata *TypeId, CallInst *CI,
>>>                             const TypeIdLowering &TIL);
>>> +
>>>    void buildBitSetsFromGlobalVariables(ArrayRef<Metadata *> TypeIds,
>>>                                         ArrayRef<GlobalTypeMember *>
>>> Globals);
>>>    unsigned getJumpTableEntrySize();
>>> @@ -383,11 +410,13 @@ class LowerTypeTestsModule {
>>>    void buildBitSetsFromFunctions(ArrayRef<Metadata *> TypeIds,
>>>                                   ArrayRef<GlobalTypeMember *>
>>> Functions);
>>>    void buildBitSetsFromFunctionsNative(ArrayRef<Metadata *> TypeIds,
>>> -                                    ArrayRef<GlobalTypeMember *>
>>> Functions);
>>> +                                       ArrayRef<GlobalTypeMember *>
>>> Functions);
>>>    void buildBitSetsFromFunctionsWASM(ArrayRef<Metadata *> TypeIds,
>>>                                       ArrayRef<GlobalTypeMember *>
>>> Functions);
>>> -  void buildBitSetsFromDisjointSet(ArrayRef<Metadata *> TypeIds,
>>> -                                   ArrayRef<GlobalTypeMember *>
>>> Globals);
>>> +  void
>>> +  buildBitSetsFromDisjointSet(ArrayRef<Metadata *> TypeIds,
>>> +                              ArrayRef<GlobalTypeMember *> Globals,
>>> +                              ArrayRef<ICallBranchFunnel *>
>>> ICallBranchFunnels);
>>>
>>>    void replaceWeakDeclarationWithJumpTablePtr(Function *F, Constant
>>> *JT);
>>>    void moveInitializerToModuleConstructor(GlobalVariable *GV);
>>> @@ -1462,7 +1491,8 @@ void LowerTypeTestsModule::buildBitSetsF
>>>  }
>>>
>>>  void LowerTypeTestsModule::buildBitSetsFromDisjointSet(
>>> -    ArrayRef<Metadata *> TypeIds, ArrayRef<GlobalTypeMember *> Globals)
>>> {
>>> +    ArrayRef<Metadata *> TypeIds, ArrayRef<GlobalTypeMember *> Globals,
>>> +    ArrayRef<ICallBranchFunnel *> ICallBranchFunnels) {
>>>    DenseMap<Metadata *, uint64_t> TypeIdIndices;
>>>    for (unsigned I = 0; I != TypeIds.size(); ++I)
>>>      TypeIdIndices[TypeIds[I]] = I;
>>> @@ -1471,15 +1501,25 @@ void LowerTypeTestsModule::buildBitSetsF
>>>    // the type identifier.
>>>    std::vector<std::set<uint64_t>> TypeMembers(TypeIds.size());
>>>    unsigned GlobalIndex = 0;
>>> +  DenseMap<GlobalTypeMember *, uint64_t> GlobalIndices;
>>>    for (GlobalTypeMember *GTM : Globals) {
>>>      for (MDNode *Type : GTM->types()) {
>>>        // Type = { offset, type identifier }
>>> -      unsigned TypeIdIndex = TypeIdIndices[Type->getOperand(1)];
>>> -      TypeMembers[TypeIdIndex].insert(GlobalIndex);
>>> +      auto I = TypeIdIndices.find(Type->getOperand(1));
>>> +      if (I != TypeIdIndices.end())
>>> +        TypeMembers[I->second].insert(GlobalIndex);
>>>      }
>>> +    GlobalIndices[GTM] = GlobalIndex;
>>>      GlobalIndex++;
>>>    }
>>>
>>> +  for (ICallBranchFunnel *JT : ICallBranchFunnels) {
>>> +    TypeMembers.emplace_back();
>>> +    std::set<uint64_t> &TMSet = TypeMembers.back();
>>> +    for (GlobalTypeMember *T : JT->targets())
>>> +      TMSet.insert(GlobalIndices[T]);
>>> +  }
>>> +
>>>    // Order the sets of indices by size. The GlobalLayoutBuilder works
>>> best
>>>    // when given small index sets first.
>>>    std::stable_sort(
>>> @@ -1567,8 +1607,11 @@ bool LowerTypeTestsModule::runForTesting
>>>  bool LowerTypeTestsModule::lower() {
>>>    Function *TypeTestFunc =
>>>        M.getFunction(Intrinsic::getName(Intrinsic::type_test));
>>> -  if ((!TypeTestFunc || TypeTestFunc->use_empty()) && !ExportSummary &&
>>> -      !ImportSummary)
>>> +  Function *ICallBranchFunnelFunc =
>>> +      M.getFunction(Intrinsic::getName(Intrinsic::icall_branch_fun
>>> nel));
>>> +  if ((!TypeTestFunc || TypeTestFunc->use_empty()) &&
>>> +      (!ICallBranchFunnelFunc || ICallBranchFunnelFunc->use_empty()) &&
>>> +      !ExportSummary && !ImportSummary)
>>>      return false;
>>>
>>>    if (ImportSummary) {
>>> @@ -1580,6 +1623,10 @@ bool LowerTypeTestsModule::lower() {
>>>        }
>>>      }
>>>
>>> +    if (ICallBranchFunnelFunc && !ICallBranchFunnelFunc->use_empty())
>>> +      report_fatal_error(
>>> +          "unexpected call to llvm.icall.branch.funnel during import
>>> phase");
>>> +
>>>      SmallVector<Function *, 8> Defs;
>>>      SmallVector<Function *, 8> Decls;
>>>      for (auto &F : M) {
>>> @@ -1604,8 +1651,8 @@ bool LowerTypeTestsModule::lower() {
>>>    // Equivalence class set containing type identifiers and the globals
>>> that
>>>    // reference them. This is used to partition the set of type
>>> identifiers in
>>>    // the module into disjoint sets.
>>> -  using GlobalClassesTy =
>>> -      EquivalenceClasses<PointerUnion<GlobalTypeMember *, Metadata *>>;
>>> +  using GlobalClassesTy = EquivalenceClasses<
>>> +      PointerUnion3<GlobalTypeMember *, Metadata *, ICallBranchFunnel
>>> *>>;
>>>    GlobalClassesTy GlobalClasses;
>>>
>>>    // Verify the type metadata and build a few data structures to let us
>>> @@ -1688,14 +1735,13 @@ bool LowerTypeTestsModule::lower() {
>>>      }
>>>    }
>>>
>>> +  DenseMap<GlobalObject *, GlobalTypeMember *> GlobalTypeMembers;
>>>    for (GlobalObject &GO : M.global_objects()) {
>>>      if (isa<GlobalVariable>(GO) && GO.isDeclarationForLinker())
>>>        continue;
>>>
>>>      Types.clear();
>>>      GO.getMetadata(LLVMContext::MD_type, Types);
>>> -    if (Types.empty())
>>> -      continue;
>>>
>>>      bool IsDefinition = !GO.isDeclarationForLinker();
>>>      bool IsExported = false;
>>> @@ -1706,6 +1752,7 @@ bool LowerTypeTestsModule::lower() {
>>>
>>>      auto *GTM =
>>>          GlobalTypeMember::create(Alloc, &GO, IsDefinition, IsExported,
>>> Types);
>>> +    GlobalTypeMembers[&GO] = GTM;
>>>      for (MDNode *Type : Types) {
>>>        verifyTypeMDNode(&GO, Type);
>>>        auto &Info = TypeIdInfo[Type->getOperand(1)];
>>> @@ -1746,6 +1793,43 @@ bool LowerTypeTestsModule::lower() {
>>>      }
>>>    }
>>>
>>> +  if (ICallBranchFunnelFunc) {
>>> +    for (const Use &U : ICallBranchFunnelFunc->uses()) {
>>> +      if (Arch != Triple::x86_64)
>>> +        report_fatal_error(
>>> +            "llvm.icall.branch.funnel not supported on this target");
>>> +
>>> +      auto CI = cast<CallInst>(U.getUser());
>>> +
>>> +      std::vector<GlobalTypeMember *> Targets;
>>> +      if (CI->getNumArgOperands() % 2 != 1)
>>> +        report_fatal_error("number of arguments should be odd");
>>> +
>>> +      GlobalClassesTy::member_iterator CurSet;
>>> +      for (unsigned I = 1; I != CI->getNumArgOperands(); I += 2) {
>>> +        int64_t Offset;
>>> +        auto *Base = dyn_cast<GlobalObject>(GetPoin
>>> terBaseWithConstantOffset(
>>> +            CI->getOperand(I), Offset, M.getDataLayout()));
>>> +        if (!Base)
>>> +          report_fatal_error(
>>> +              "Expected branch funnel operand to be global value");
>>> +
>>> +        GlobalTypeMember *GTM = GlobalTypeMembers[Base];
>>> +        Targets.push_back(GTM);
>>> +        GlobalClassesTy::member_iterator NewSet =
>>> +            GlobalClasses.findLeader(GlobalClasses.insert(GTM));
>>> +        if (I == 1)
>>> +          CurSet = NewSet;
>>> +        else
>>> +          CurSet = GlobalClasses.unionSets(CurSet, NewSet);
>>> +      }
>>> +
>>> +      GlobalClasses.unionSets(
>>> +          CurSet, GlobalClasses.findLeader(GlobalClasses.insert(
>>> +                      ICallBranchFunnel::create(Alloc, CI, Targets))));
>>> +    }
>>> +  }
>>> +
>>>    if (ExportSummary) {
>>>      DenseMap<GlobalValue::GUID, TinyPtrVector<Metadata *>>
>>> MetadataByGUID;
>>>      for (auto &P : TypeIdInfo) {
>>> @@ -1798,13 +1882,16 @@ bool LowerTypeTestsModule::lower() {
>>>      // Build the list of type identifiers in this disjoint set.
>>>      std::vector<Metadata *> TypeIds;
>>>      std::vector<GlobalTypeMember *> Globals;
>>> +    std::vector<ICallBranchFunnel *> ICallBranchFunnels;
>>>      for (GlobalClassesTy::member_iterator MI =
>>>               GlobalClasses.member_begin(S.first);
>>>           MI != GlobalClasses.member_end(); ++MI) {
>>> -      if ((*MI).is<Metadata *>())
>>> +      if (MI->is<Metadata *>())
>>>          TypeIds.push_back(MI->get<Metadata *>());
>>> -      else
>>> +      else if (MI->is<GlobalTypeMember *>())
>>>          Globals.push_back(MI->get<GlobalTypeMember *>());
>>> +      else
>>> +        ICallBranchFunnels.push_back(MI->get<ICallBranchFunnel *>());
>>>      }
>>>
>>>      // Order type identifiers by global index for determinism. This
>>> ordering is
>>> @@ -1814,7 +1901,7 @@ bool LowerTypeTestsModule::lower() {
>>>      });
>>>
>>>      // Build bitsets for this disjoint set.
>>> -    buildBitSetsFromDisjointSet(TypeIds, Globals);
>>> +    buildBitSetsFromDisjointSet(TypeIds, Globals, ICallBranchFunnels);
>>>    }
>>>
>>>    allocateByteArrays();
>>>
>>> Modified: llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transform
>>> s/IPO/WholeProgramDevirt.cpp?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp (original)
>>> +++ llvm/trunk/lib/Transforms/IPO/WholeProgramDevirt.cpp Fri Mar  9
>>> 11:11:44 2018
>>> @@ -316,12 +316,17 @@ struct CallSiteInfo {
>>>    /// cases we are directly operating on the call sites at the IR level.
>>>    std::vector<VirtualCallSite> CallSites;
>>>
>>> +  /// Whether all call sites represented by this CallSiteInfo,
>>> including those
>>> +  /// in summaries, have been devirtualized. This starts off as true
>>> because a
>>> +  /// default constructed CallSiteInfo represents no call sites.
>>> +  bool AllCallSitesDevirted = true;
>>> +
>>>    // These fields are used during the export phase of ThinLTO and
>>> reflect
>>>    // information collected from function summaries.
>>>
>>>    /// Whether any function summary contains an
>>> llvm.assume(llvm.type.test) for
>>>    /// this slot.
>>> -  bool SummaryHasTypeTestAssumeUsers;
>>> +  bool SummaryHasTypeTestAssumeUsers = false;
>>>
>>>    /// CFI-specific: a vector containing the list of function summaries
>>> that use
>>>    /// the llvm.type.checked.load intrinsic and therefore will require
>>> @@ -337,8 +342,22 @@ struct CallSiteInfo {
>>>             !SummaryTypeCheckedLoadUsers.empty();
>>>    }
>>>
>>> -  /// As explained in the comment for SummaryTypeCheckedLoadUsers.
>>> -  void markDevirt() { SummaryTypeCheckedLoadUsers.clear(); }
>>> +  void markSummaryHasTypeTestAssumeUsers() {
>>> +    SummaryHasTypeTestAssumeUsers = true;
>>> +    AllCallSitesDevirted = false;
>>> +  }
>>> +
>>> +  void addSummaryTypeCheckedLoadUser(FunctionSummary *FS) {
>>> +    SummaryTypeCheckedLoadUsers.push_back(FS);
>>> +    AllCallSitesDevirted = false;
>>> +  }
>>> +
>>> +  void markDevirt() {
>>> +    AllCallSitesDevirted = true;
>>> +
>>> +    // As explained in the comment for SummaryTypeCheckedLoadUsers.
>>> +    SummaryTypeCheckedLoadUsers.clear();
>>> +  }
>>>  };
>>>
>>>  // Call site information collected for a specific VTableSlot.
>>> @@ -373,7 +392,9 @@ CallSiteInfo &VTableSlotInfo::findCallSi
>>>
>>>  void VTableSlotInfo::addCallSite(Value *VTable, CallSite CS,
>>>                                   unsigned *NumUnsafeUses) {
>>> -  findCallSiteInfo(CS).CallSites.push_back({VTable, CS,
>>> NumUnsafeUses});
>>> +  auto &CSI = findCallSiteInfo(CS);
>>> +  CSI.AllCallSitesDevirted = false;
>>> +  CSI.CallSites.push_back({VTable, CS, NumUnsafeUses});
>>>  }
>>>
>>>  struct DevirtModule {
>>> @@ -438,6 +459,12 @@ struct DevirtModule {
>>>                             VTableSlotInfo &SlotInfo,
>>>                             WholeProgramDevirtResolution *Res);
>>>
>>> +  void applyICallBranchFunnel(VTableSlotInfo &SlotInfo, Constant *JT,
>>> +                              bool &IsExported);
>>> +  void tryICallBranchFunnel(MutableArrayRef<VirtualCallTarget>
>>> TargetsForSlot,
>>> +                            VTableSlotInfo &SlotInfo,
>>> +                            WholeProgramDevirtResolution *Res,
>>> VTableSlot Slot);
>>> +
>>>    bool tryEvaluateFunctionsWithArgs(
>>>        MutableArrayRef<VirtualCallTarget> TargetsForSlot,
>>>        ArrayRef<uint64_t> Args);
>>> @@ -471,6 +498,8 @@ struct DevirtModule {
>>>                             StringRef Name, IntegerType *IntTy,
>>>                             uint32_t Storage);
>>>
>>> +  Constant *getMemberAddr(const TypeMemberInfo *M);
>>> +
>>>    void applyUniqueRetValOpt(CallSiteInfo &CSInfo, StringRef FnName,
>>> bool IsOne,
>>>                              Constant *UniqueMemberAddr);
>>>    bool tryUniqueRetValOpt(unsigned BitWidth,
>>> @@ -726,10 +755,9 @@ void DevirtModule::applySingleImplDevirt
>>>        if (VCallSite.NumUnsafeUses)
>>>          --*VCallSite.NumUnsafeUses;
>>>      }
>>> -    if (CSInfo.isExported()) {
>>> +    if (CSInfo.isExported())
>>>        IsExported = true;
>>> -      CSInfo.markDevirt();
>>> -    }
>>> +    CSInfo.markDevirt();
>>>    };
>>>    Apply(SlotInfo.CSInfo);
>>>    for (auto &P : SlotInfo.ConstCSInfo)
>>> @@ -785,6 +813,134 @@ bool DevirtModule::trySingleImplDevirt(
>>>    return true;
>>>  }
>>>
>>> +void DevirtModule::tryICallBranchFunnel(
>>> +    MutableArrayRef<VirtualCallTarget> TargetsForSlot, VTableSlotInfo
>>> &SlotInfo,
>>> +    WholeProgramDevirtResolution *Res, VTableSlot Slot) {
>>> +  Triple T(M.getTargetTriple());
>>> +  if (T.getArch() != Triple::x86_64)
>>> +    return;
>>> +
>>> +  const unsigned kBranchFunnelThreshold = 10;
>>> +  if (TargetsForSlot.size() > kBranchFunnelThreshold)
>>> +    return;
>>> +
>>> +  bool HasNonDevirt = !SlotInfo.CSInfo.AllCallSitesDevirted;
>>> +  if (!HasNonDevirt)
>>> +    for (auto &P : SlotInfo.ConstCSInfo)
>>> +      if (!P.second.AllCallSitesDevirted) {
>>> +        HasNonDevirt = true;
>>> +        break;
>>> +      }
>>> +
>>> +  if (!HasNonDevirt)
>>> +    return;
>>> +
>>> +  FunctionType *FT =
>>> +      FunctionType::get(Type::getVoidTy(M.getContext()), {Int8PtrTy},
>>> true);
>>> +  Function *JT;
>>> +  if (isa<MDString>(Slot.TypeID)) {
>>> +    JT = Function::Create(FT, Function::ExternalLinkage,
>>> +                          getGlobalName(Slot, {}, "branch_funnel"), &M);
>>> +    JT->setVisibility(GlobalValue::HiddenVisibility);
>>> +  } else {
>>> +    JT = Function::Create(FT, Function::InternalLinkage,
>>> "branch_funnel", &M);
>>> +  }
>>> +  JT->addAttribute(1, Attribute::Nest);
>>> +
>>> +  std::vector<Value *> JTArgs;
>>> +  JTArgs.push_back(JT->arg_begin());
>>> +  for (auto &T : TargetsForSlot) {
>>> +    JTArgs.push_back(getMemberAddr(T.TM));
>>> +    JTArgs.push_back(T.Fn);
>>> +  }
>>> +
>>> +  BasicBlock *BB = BasicBlock::Create(M.getContext(), "", JT, nullptr);
>>> +  Constant *Intr =
>>> +      Intrinsic::getDeclaration(&M, llvm::Intrinsic::icall_branch_funnel,
>>> {});
>>> +
>>> +  auto *CI = CallInst::Create(Intr, JTArgs, "", BB);
>>> +  CI->setTailCallKind(CallInst::TCK_MustTail);
>>> +  ReturnInst::Create(M.getContext(), nullptr, BB);
>>> +
>>> +  bool IsExported = false;
>>> +  applyICallBranchFunnel(SlotInfo, JT, IsExported);
>>> +  if (IsExported)
>>> +    Res->TheKind = WholeProgramDevirtResolution::BranchFunnel;
>>> +}
>>> +
>>> +void DevirtModule::applyICallBranchFunnel(VTableSlotInfo &SlotInfo,
>>> +                                          Constant *JT, bool
>>> &IsExported) {
>>> +  auto Apply = [&](CallSiteInfo &CSInfo) {
>>> +    if (CSInfo.isExported())
>>> +      IsExported = true;
>>> +    if (CSInfo.AllCallSitesDevirted)
>>> +      return;
>>> +    for (auto &&VCallSite : CSInfo.CallSites) {
>>> +      CallSite CS = VCallSite.CS;
>>> +
>>> +      // Jump tables are only profitable if the retpoline mitigation is
>>> enabled.
>>> +      Attribute FSAttr = CS.getCaller()->getFnAttribute
>>> ("target-features");
>>> +      if (FSAttr.hasAttribute(Attribute::None) ||
>>> +          !FSAttr.getValueAsString().contains("+retpoline"))
>>> +        continue;
>>> +
>>> +      if (RemarksEnabled)
>>> +        VCallSite.emitRemark("branch-funnel", JT->getName(),
>>> OREGetter);
>>> +
>>> +      // Pass the address of the vtable in the nest register, which is
>>> r10 on
>>> +      // x86_64.
>>> +      std::vector<Type *> NewArgs;
>>> +      NewArgs.push_back(Int8PtrTy);
>>> +      for (Type *T : CS.getFunctionType()->params())
>>> +        NewArgs.push_back(T);
>>> +      PointerType *NewFT = PointerType::getUnqual(
>>> +          FunctionType::get(CS.getFunctionType()->getReturnType(),
>>> NewArgs,
>>> +                            CS.getFunctionType()->isVarArg()));
>>> +
>>> +      IRBuilder<> IRB(CS.getInstruction());
>>> +      std::vector<Value *> Args;
>>> +      Args.push_back(IRB.CreateBitCast(VCallSite.VTable, Int8PtrTy));
>>> +      for (unsigned I = 0; I != CS.getNumArgOperands(); ++I)
>>> +        Args.push_back(CS.getArgOperand(I));
>>> +
>>> +      CallSite NewCS;
>>> +      if (CS.isCall())
>>> +        NewCS = IRB.CreateCall(IRB.CreateBitCast(JT, NewFT), Args);
>>> +      else
>>> +        NewCS = IRB.CreateInvoke(
>>> +            IRB.CreateBitCast(JT, NewFT),
>>> +            cast<InvokeInst>(CS.getInstruction())->getNormalDest(),
>>> +            cast<InvokeInst>(CS.getInstruction())->getUnwindDest(),
>>> Args);
>>> +      NewCS.setCallingConv(CS.getCallingConv());
>>> +
>>> +      AttributeList Attrs = CS.getAttributes();
>>> +      std::vector<AttributeSet> NewArgAttrs;
>>> +      NewArgAttrs.push_back(AttributeSet::get(
>>> +          M.getContext(), ArrayRef<Attribute>{Attribute::get(
>>> +                              M.getContext(), Attribute::Nest)}));
>>> +      for (unsigned I = 0; I + 2 <  Attrs.getNumAttrSets(); ++I)
>>> +        NewArgAttrs.push_back(Attrs.getParamAttributes(I));
>>> +      NewCS.setAttributes(
>>> +          AttributeList::get(M.getContext(), Attrs.getFnAttributes(),
>>> +                             Attrs.getRetAttributes(), NewArgAttrs));
>>> +
>>> +      CS->replaceAllUsesWith(NewCS.getInstruction());
>>> +      CS->eraseFromParent();
>>> +
>>> +      // This use is no longer unsafe.
>>> +      if (VCallSite.NumUnsafeUses)
>>> +        --*VCallSite.NumUnsafeUses;
>>> +    }
>>> +    // Don't mark as devirtualized because there may be callers
>>> compiled without
>>> +    // retpoline mitigation, which would mean that they are lowered to
>>> +    // llvm.type.test and therefore require an llvm.type.test
>>> resolution for the
>>> +    // type identifier.
>>> +  };
>>> +  Apply(SlotInfo.CSInfo);
>>> +  for (auto &P : SlotInfo.ConstCSInfo)
>>> +    Apply(P.second);
>>> +}
>>> +
>>>  bool DevirtModule::tryEvaluateFunctionsWithArgs(
>>>      MutableArrayRef<VirtualCallTarget> TargetsForSlot,
>>>      ArrayRef<uint64_t> Args) {
>>> @@ -937,6 +1093,12 @@ void DevirtModule::applyUniqueRetValOpt(
>>>    CSInfo.markDevirt();
>>>  }
>>>
>>> +Constant *DevirtModule::getMemberAddr(const TypeMemberInfo *M) {
>>> +  Constant *C = ConstantExpr::getBitCast(M->Bits->GV, Int8PtrTy);
>>> +  return ConstantExpr::getGetElementPtr(Int8Ty, C,
>>> +                                        ConstantInt::get(Int64Ty,
>>> M->Offset));
>>> +}
>>> +
>>>  bool DevirtModule::tryUniqueRetValOpt(
>>>      unsigned BitWidth, MutableArrayRef<VirtualCallTarget>
>>> TargetsForSlot,
>>>      CallSiteInfo &CSInfo, WholeProgramDevirtResolution::ByArg *Res,
>>> @@ -956,12 +1118,7 @@ bool DevirtModule::tryUniqueRetValOpt(
>>>      // checked for a uniform return value in tryUniformRetValOpt.
>>>      assert(UniqueMember);
>>>
>>> -    Constant *UniqueMemberAddr =
>>> -        ConstantExpr::getBitCast(UniqueMember->Bits->GV, Int8PtrTy);
>>> -    UniqueMemberAddr = ConstantExpr::getGetElementPtr(
>>> -        Int8Ty, UniqueMemberAddr,
>>> -        ConstantInt::get(Int64Ty, UniqueMember->Offset));
>>> -
>>> +    Constant *UniqueMemberAddr = getMemberAddr(UniqueMember);
>>>      if (CSInfo.isExported()) {
>>>        Res->TheKind = WholeProgramDevirtResolution::ByArg::UniqueRetVal;
>>>        Res->Info = IsOne;
>>> @@ -1348,6 +1505,14 @@ void DevirtModule::importResolution(VTab
>>>        break;
>>>      }
>>>    }
>>> +
>>> +  if (Res.TheKind == WholeProgramDevirtResolution::BranchFunnel) {
>>> +    auto *JT = M.getOrInsertFunction(getGlobalName(Slot, {},
>>> "branch_funnel"),
>>> +                                     Type::getVoidTy(M.getContext()));
>>> +    bool IsExported = false;
>>> +    applyICallBranchFunnel(SlotInfo, JT, IsExported);
>>> +    assert(!IsExported);
>>> +  }
>>>  }
>>>
>>>  void DevirtModule::removeRedundantTypeTests() {
>>> @@ -1417,14 +1582,13 @@ bool DevirtModule::run() {
>>>          // FIXME: Only add live functions.
>>>          for (FunctionSummary::VFuncId VF :
>>> FS->type_test_assume_vcalls()) {
>>>            for (Metadata *MD : MetadataByGUID[VF.GUID]) {
>>> -            CallSlots[{MD, VF.Offset}].CSInfo.SummaryHasTypeTestAssumeUsers
>>> =
>>> -                true;
>>> +            CallSlots[{MD, VF.Offset}]
>>> +                .CSInfo.markSummaryHasTypeTestAssumeUsers();
>>>            }
>>>          }
>>>          for (FunctionSummary::VFuncId VF :
>>> FS->type_checked_load_vcalls()) {
>>>            for (Metadata *MD : MetadataByGUID[VF.GUID]) {
>>> -            CallSlots[{MD, VF.Offset}]
>>> -                .CSInfo.SummaryTypeCheckedLoadUsers.push_back(FS);
>>> +            CallSlots[{MD, VF.Offset}].CSInfo.addSummaryT
>>> ypeCheckedLoadUser(FS);
>>>            }
>>>          }
>>>          for (const FunctionSummary::ConstVCall &VC :
>>> @@ -1432,7 +1596,7 @@ bool DevirtModule::run() {
>>>            for (Metadata *MD : MetadataByGUID[VC.VFunc.GUID]) {
>>>              CallSlots[{MD, VC.VFunc.Offset}]
>>>                  .ConstCSInfo[VC.Args]
>>> -                .SummaryHasTypeTestAssumeUsers = true;
>>> +                .markSummaryHasTypeTestAssumeUsers();
>>>            }
>>>          }
>>>          for (const FunctionSummary::ConstVCall &VC :
>>> @@ -1440,7 +1604,7 @@ bool DevirtModule::run() {
>>>            for (Metadata *MD : MetadataByGUID[VC.VFunc.GUID]) {
>>>              CallSlots[{MD, VC.VFunc.Offset}]
>>>                  .ConstCSInfo[VC.Args]
>>> -                .SummaryTypeCheckedLoadUsers.push_back(FS);
>>> +                .addSummaryTypeCheckedLoadUser(FS);
>>>            }
>>>          }
>>>        }
>>> @@ -1464,9 +1628,12 @@ bool DevirtModule::run() {
>>>                         cast<MDString>(S.first.TypeID)->getString())
>>>                     .WPDRes[S.first.ByteOffset];
>>>
>>> -      if (!trySingleImplDevirt(TargetsForSlot, S.second, Res) &&
>>> -          tryVirtualConstProp(TargetsForSlot, S.second, Res, S.first))
>>> -        DidVirtualConstProp = true;
>>> +      if (!trySingleImplDevirt(TargetsForSlot, S.second, Res)) {
>>> +        DidVirtualConstProp |=
>>> +            tryVirtualConstProp(TargetsForSlot, S.second, Res,
>>> S.first);
>>> +
>>> +        tryICallBranchFunnel(TargetsForSlot, S.second, Res, S.first);
>>> +      }
>>>
>>>        // Collect functions devirtualized at least for one call site for
>>> stats.
>>>        if (RemarksEnabled)
>>>
>>> Added: llvm/trunk/test/CodeGen/X86/icall-branch-funnel.ll
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/
>>> X86/icall-branch-funnel.ll?rev=327163&view=auto
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/test/CodeGen/X86/icall-branch-funnel.ll (added)
>>> +++ llvm/trunk/test/CodeGen/X86/icall-branch-funnel.ll Fri Mar  9
>>> 11:11:44 2018
>>> @@ -0,0 +1,170 @@
>>> +; RUN: llc -mtriple=x86_64-unknown-linux < %s | FileCheck %s
>>> +
>>> + at g = external global i8
>>> +
>>> +declare void @f0()
>>> +declare void @f1()
>>> +declare void @f2()
>>> +declare void @f3()
>>> +declare void @f4()
>>> +declare void @f5()
>>> +declare void @f6()
>>> +declare void @f7()
>>> +declare void @f8()
>>> +declare void @f9()
>>> +
>>> +declare void @llvm.icall.branch.funnel(...)
>>> +
>>> +define void @jt2(i8* nest, ...) {
>>> +  ; CHECK: jt2:
>>> +  ; CHECK:      leaq g+1(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB0_1
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f0
>>> +  ; CHECK-NEXT: .LBB0_1:
>>> +  ; CHECK-NEXT: jmp f1
>>> +  musttail call void (...) @llvm.icall.branch.funnel(
>>> +      i8* %0,
>>> +      i8* getelementptr (i8, i8* @g, i64 0), void ()* @f0,
>>> +      i8* getelementptr (i8, i8* @g, i64 1), void ()* @f1,
>>> +      ...
>>> +  )
>>> +  ret void
>>> +}
>>> +
>>> +define void @jt3(i8* nest, ...) {
>>> +  ; CHECK: jt3:
>>> +  ; CHECK:      leaq g+1(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB1_1
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f0
>>> +  ; CHECK-NEXT: .LBB1_1:
>>> +  ; CHECK-NEXT: jne .LBB1_2
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f1
>>> +  ; CHECK-NEXT: .LBB1_2:
>>> +  ; CHECK-NEXT: jmp f2
>>> +  musttail call void (...) @llvm.icall.branch.funnel(
>>> +      i8* %0,
>>> +      i8* getelementptr (i8, i8* @g, i64 0), void ()* @f0,
>>> +      i8* getelementptr (i8, i8* @g, i64 2), void ()* @f2,
>>> +      i8* getelementptr (i8, i8* @g, i64 1), void ()* @f1,
>>> +      ...
>>> +  )
>>> +  ret void
>>> +}
>>> +
>>> +define void @jt7(i8* nest, ...) {
>>> +  ; CHECK: jt7:
>>> +  ; CHECK:      leaq g+3(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB2_1
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: leaq g+1(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB2_6
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f0
>>> +  ; CHECK-NEXT: .LBB2_1:
>>> +  ; CHECK-NEXT: jne .LBB2_2
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f3
>>> +  ; CHECK-NEXT: .LBB2_6:
>>> +  ; CHECK-NEXT: jne .LBB2_7
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f1
>>> +  ; CHECK-NEXT: .LBB2_2:
>>> +  ; CHECK-NEXT: leaq g+5(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB2_3
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f4
>>> +  ; CHECK-NEXT: .LBB2_7:
>>> +  ; CHECK-NEXT: jmp f2
>>> +  ; CHECK-NEXT: .LBB2_3:
>>> +  ; CHECK-NEXT: jne .LBB2_4
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f5
>>> +  ; CHECK-NEXT: .LBB2_4:
>>> +  ; CHECK-NEXT: jmp f6
>>> +  musttail call void (...) @llvm.icall.branch.funnel(
>>> +      i8* %0,
>>> +      i8* getelementptr (i8, i8* @g, i64 0), void ()* @f0,
>>> +      i8* getelementptr (i8, i8* @g, i64 1), void ()* @f1,
>>> +      i8* getelementptr (i8, i8* @g, i64 2), void ()* @f2,
>>> +      i8* getelementptr (i8, i8* @g, i64 3), void ()* @f3,
>>> +      i8* getelementptr (i8, i8* @g, i64 4), void ()* @f4,
>>> +      i8* getelementptr (i8, i8* @g, i64 5), void ()* @f5,
>>> +      i8* getelementptr (i8, i8* @g, i64 6), void ()* @f6,
>>> +      ...
>>> +  )
>>> +  ret void
>>> +}
>>> +
>>> +define void @jt10(i8* nest, ...) {
>>> +  ; CHECK: jt10:
>>> +  ; CHECK:      leaq g+5(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB3_1
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: leaq g+1(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB3_7
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f0
>>> +  ; CHECK-NEXT: .LBB3_1:
>>> +  ; CHECK-NEXT: jne .LBB3_2
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f5
>>> +  ; CHECK-NEXT: .LBB3_7:
>>> +  ; CHECK-NEXT: jne .LBB3_8
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f1
>>> +  ; CHECK-NEXT: .LBB3_2:
>>> +  ; CHECK-NEXT: leaq g+7(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB3_3
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f6
>>> +  ; CHECK-NEXT: .LBB3_8:
>>> +  ; CHECK-NEXT: leaq g+3(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB3_9
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f2
>>> +  ; CHECK-NEXT: .LBB3_3:
>>> +  ; CHECK-NEXT: jne .LBB3_4
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f7
>>> +  ; CHECK-NEXT: .LBB3_9:
>>> +  ; CHECK-NEXT: jne .LBB3_10
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f3
>>> +  ; CHECK-NEXT: .LBB3_4:
>>> +  ; CHECK-NEXT: leaq g+9(%rip), %r11
>>> +  ; CHECK-NEXT: cmpq %r11, %r10
>>> +  ; CHECK-NEXT: jae .LBB3_5
>>> +  ; CHECK-NEXT: #
>>> +  ; CHECK-NEXT: jmp f8
>>> +  ; CHECK-NEXT: .LBB3_10:
>>> +  ; CHECK-NEXT: jmp f4
>>> +  ; CHECK-NEXT: .LBB3_5:
>>> +  ; CHECK-NEXT: jmp f9
>>> +  musttail call void (...) @llvm.icall.branch.funnel(
>>> +      i8* %0,
>>> +      i8* getelementptr (i8, i8* @g, i64 0), void ()* @f0,
>>> +      i8* getelementptr (i8, i8* @g, i64 1), void ()* @f1,
>>> +      i8* getelementptr (i8, i8* @g, i64 2), void ()* @f2,
>>> +      i8* getelementptr (i8, i8* @g, i64 3), void ()* @f3,
>>> +      i8* getelementptr (i8, i8* @g, i64 4), void ()* @f4,
>>> +      i8* getelementptr (i8, i8* @g, i64 5), void ()* @f5,
>>> +      i8* getelementptr (i8, i8* @g, i64 6), void ()* @f6,
>>> +      i8* getelementptr (i8, i8* @g, i64 7), void ()* @f7,
>>> +      i8* getelementptr (i8, i8* @g, i64 8), void ()* @f8,
>>> +      i8* getelementptr (i8, i8* @g, i64 9), void ()* @f9,
>>> +      ...
>>> +  )
>>> +  ret void
>>> +}
>>>
>>> Added: llvm/trunk/test/Transforms/LowerTypeTests/icall-branch-funnel.ll
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transfor
>>> ms/LowerTypeTests/icall-branch-funnel.ll?rev=327163&view=auto
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/test/Transforms/LowerTypeTests/icall-branch-funnel.ll
>>> (added)
>>> +++ llvm/trunk/test/Transforms/LowerTypeTests/icall-branch-funnel.ll
>>> Fri Mar  9 11:11:44 2018
>>> @@ -0,0 +1,46 @@
>>> +; RUN: opt -S -lowertypetests < %s | FileCheck %s
>>> +
>>> +target datalayout = "e-p:64:64"
>>> +target triple = "x86_64-unknown-linux"
>>> +
>>> +; CHECK: @0 = private constant { i32, [0 x i8], i32 } { i32 1, [0 x i8]
>>> zeroinitializer, i32 2 }
>>> +; CHECK: @f1 = alias void (), void ()* @.cfi.jumptable
>>> +; CHECK: @f2 = alias void (), bitcast ([8 x i8]* getelementptr inbounds
>>> ([2 x [8 x i8]], [2 x [8 x i8]]* bitcast (void ()* @.cfi.jumptable to [2 x
>>> [8 x i8]]*), i64 0, i64 1) to void ()*)
>>> +; CHECK: @g1 = alias i32, getelementptr inbounds ({ i32, [0 x i8], i32
>>> }, { i32, [0 x i8], i32 }* @0, i32 0, i32 0)
>>> +; CHECK: @g2 = alias i32, getelementptr inbounds ({ i32, [0 x i8], i32
>>> }, { i32, [0 x i8], i32 }* @0, i32 0, i32 2)
>>> +
>>> + at g1 = constant i32 1
>>> + at g2 = constant i32 2
>>> +
>>> +define void @f1() {
>>> +  ret void
>>> +}
>>> +
>>> +define void @f2() {
>>> +  ret void
>>> +}
>>> +
>>> +declare void @g1f()
>>> +declare void @g2f()
>>> +
>>> +define void @jt2(i8* nest, ...) {
>>> +  musttail call void (...) @llvm.icall.branch.funnel(
>>> +      i8* %0,
>>> +      i32* @g1, void ()* @g1f,
>>> +      i32* @g2, void ()* @g2f,
>>> +      ...
>>> +  )
>>> +  ret void
>>> +}
>>> +
>>> +define void @jt3(i8* nest, ...) {
>>> +  musttail call void (...) @llvm.icall.branch.funnel(
>>> +      i8* %0,
>>> +      void ()* @f1, void ()* @f1,
>>> +      void ()* @f2, void ()* @f2,
>>> +      ...
>>> +  )
>>> +  ret void
>>> +}
>>> +
>>> +declare void @llvm.icall.branch.funnel(...)
>>>
>>> Added: llvm/trunk/test/Transforms/WholeProgramDevirt/Inputs/import-
>>> branch-funnel.yaml
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transfor
>>> ms/WholeProgramDevirt/Inputs/import-branch-funnel.yaml?rev=3
>>> 27163&view=auto
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/test/Transforms/WholeProgramDevirt/Inputs/import-branch-funnel.yaml
>>> (added)
>>> +++ llvm/trunk/test/Transforms/WholeProgramDevirt/Inputs/import-branch-funnel.yaml
>>> Fri Mar  9 11:11:44 2018
>>> @@ -0,0 +1,11 @@
>>> +---
>>> +TypeIdMap:
>>> +  typeid1:
>>> +    WPDRes:
>>> +      0:
>>> +        Kind: BranchFunnel
>>> +  typeid2:
>>> +    WPDRes:
>>> +      8:
>>> +        Kind: BranchFunnel
>>> +...
>>>
>>> Added: llvm/trunk/test/Transforms/WholeProgramDevirt/Inputs/import-
>>> vcp-branch-funnel.yaml
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transfor
>>> ms/WholeProgramDevirt/Inputs/import-vcp-branch-funnel.yaml?r
>>> ev=327163&view=auto
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/test/Transforms/WholeProgramDevirt/Inputs/import-vcp-branch-funnel.yaml
>>> (added)
>>> +++ llvm/trunk/test/Transforms/WholeProgramDevirt/Inputs/import-vcp-branch-funnel.yaml
>>> Fri Mar  9 11:11:44 2018
>>> @@ -0,0 +1,23 @@
>>> +---
>>> +TypeIdMap:
>>> +  typeid1:
>>> +    WPDRes:
>>> +      0:
>>> +        Kind: BranchFunnel
>>> +        ResByArg:
>>> +          1:
>>> +            Kind: VirtualConstProp
>>> +            Info: 0
>>> +            Byte: 42
>>> +            Bit: 0
>>> +  typeid2:
>>> +    WPDRes:
>>> +      8:
>>> +        Kind: BranchFunnel
>>> +        ResByArg:
>>> +          3:
>>> +            Kind: VirtualConstProp
>>> +            Info: 0
>>> +            Byte: 43
>>> +            Bit: 128
>>> +...
>>>
>>> Added: llvm/trunk/test/Transforms/WholeProgramDevirt/branch-funnel.ll
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transfor
>>> ms/WholeProgramDevirt/branch-funnel.ll?rev=327163&view=auto
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/test/Transforms/WholeProgramDevirt/branch-funnel.ll
>>> (added)
>>> +++ llvm/trunk/test/Transforms/WholeProgramDevirt/branch-funnel.ll Fri
>>> Mar  9 11:11:44 2018
>>> @@ -0,0 +1,155 @@
>>> +; RUN: opt -S -wholeprogramdevirt %s | FileCheck
>>> --check-prefixes=CHECK,RETP %s
>>> +; RUN: sed -e 's,+retpoline,-retpoline,g' %s | opt -S
>>> -wholeprogramdevirt | FileCheck --check-prefixes=CHECK,NORETP %s
>>> +; RUN: opt -wholeprogramdevirt -wholeprogramdevirt-summary-action=export
>>> -wholeprogramdevirt-read-summary=%S/Inputs/export.yaml
>>> -wholeprogramdevirt-write-summary=%t -S -o - %s | FileCheck
>>> --check-prefixes=CHECK,RETP %s
>>> +; RUN: FileCheck --check-prefix=SUMMARY %s < %t
>>> +
>>> +; SUMMARY:      TypeIdMap:
>>> +; SUMMARY-NEXT:   typeid1:
>>> +; SUMMARY-NEXT:     TTRes:
>>> +; SUMMARY-NEXT:       Kind:            Unsat
>>> +; SUMMARY-NEXT:       SizeM1BitWidth:  0
>>> +; SUMMARY-NEXT:       AlignLog2:       0
>>> +; SUMMARY-NEXT:       SizeM1:          0
>>> +; SUMMARY-NEXT:       BitMask:         0
>>> +; SUMMARY-NEXT:       InlineBits:      0
>>> +; SUMMARY-NEXT:     WPDRes:
>>> +; SUMMARY-NEXT:       0:
>>> +; SUMMARY-NEXT:         Kind:            BranchFunnel
>>> +; SUMMARY-NEXT:         SingleImplName:  ''
>>> +; SUMMARY-NEXT:         ResByArg:
>>> +; SUMMARY-NEXT:   typeid2:
>>> +; SUMMARY-NEXT:     TTRes:
>>> +; SUMMARY-NEXT:       Kind:            Unsat
>>> +; SUMMARY-NEXT:       SizeM1BitWidth:  0
>>> +; SUMMARY-NEXT:       AlignLog2:       0
>>> +; SUMMARY-NEXT:       SizeM1:          0
>>> +; SUMMARY-NEXT:       BitMask:         0
>>> +; SUMMARY-NEXT:       InlineBits:      0
>>> +; SUMMARY-NEXT:     WPDRes:
>>> +; SUMMARY-NEXT:       0:
>>> +; SUMMARY-NEXT:         Kind:            Indir
>>> +; SUMMARY-NEXT:         SingleImplName:  ''
>>> +; SUMMARY-NEXT:         ResByArg:
>>> +; SUMMARY-NEXT:   typeid3:
>>> +; SUMMARY-NEXT:     TTRes:
>>> +; SUMMARY-NEXT:       Kind:            Unsat
>>> +; SUMMARY-NEXT:       SizeM1BitWidth:  0
>>> +; SUMMARY-NEXT:       AlignLog2:       0
>>> +; SUMMARY-NEXT:       SizeM1:          0
>>> +; SUMMARY-NEXT:       BitMask:         0
>>> +; SUMMARY-NEXT:       InlineBits:      0
>>> +; SUMMARY-NEXT:     WPDRes:
>>> +; SUMMARY-NEXT:       0:
>>> +; SUMMARY-NEXT:         Kind:            BranchFunnel
>>> +; SUMMARY-NEXT:         SingleImplName:  ''
>>> +; SUMMARY-NEXT:         ResByArg:
>>> +
>>> +target datalayout = "e-p:64:64"
>>> +target triple = "x86_64-unknown-linux-gnu"
>>> +
>>> + at vt1_1 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf1_1 to
>>> i8*)], !type !0
>>> + at vt1_2 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf1_2 to
>>> i8*)], !type !0
>>> +
>>> +declare i32 @vf1_1(i8* %this, i32 %arg)
>>> +declare i32 @vf1_2(i8* %this, i32 %arg)
>>> +
>>> + at vt2_1 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_1 to
>>> i8*)], !type !1
>>> + at vt2_2 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_2 to
>>> i8*)], !type !1
>>> + at vt2_3 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_3 to
>>> i8*)], !type !1
>>> + at vt2_4 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_4 to
>>> i8*)], !type !1
>>> + at vt2_5 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_5 to
>>> i8*)], !type !1
>>> + at vt2_6 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_6 to
>>> i8*)], !type !1
>>> + at vt2_7 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_7 to
>>> i8*)], !type !1
>>> + at vt2_8 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_8 to
>>> i8*)], !type !1
>>> + at vt2_9 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_9 to
>>> i8*)], !type !1
>>> + at vt2_10 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_10 to
>>> i8*)], !type !1
>>> + at vt2_11 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf2_11 to
>>> i8*)], !type !1
>>> +
>>> +declare i32 @vf2_1(i8* %this, i32 %arg)
>>> +declare i32 @vf2_2(i8* %this, i32 %arg)
>>> +declare i32 @vf2_3(i8* %this, i32 %arg)
>>> +declare i32 @vf2_4(i8* %this, i32 %arg)
>>> +declare i32 @vf2_5(i8* %this, i32 %arg)
>>> +declare i32 @vf2_6(i8* %this, i32 %arg)
>>> +declare i32 @vf2_7(i8* %this, i32 %arg)
>>> +declare i32 @vf2_8(i8* %this, i32 %arg)
>>> +declare i32 @vf2_9(i8* %this, i32 %arg)
>>> +declare i32 @vf2_10(i8* %this, i32 %arg)
>>> +declare i32 @vf2_11(i8* %this, i32 %arg)
>>> +
>>> + at vt3_1 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf3_1 to
>>> i8*)], !type !2
>>> + at vt3_2 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf3_2 to
>>> i8*)], !type !2
>>> +
>>> +declare i32 @vf3_1(i8* %this, i32 %arg)
>>> +declare i32 @vf3_2(i8* %this, i32 %arg)
>>> +
>>> + at vt4_1 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf4_1 to
>>> i8*)], !type !3
>>> + at vt4_2 = constant [1 x i8*] [i8* bitcast (i32 (i8*, i32)* @vf4_2 to
>>> i8*)], !type !3
>>> +
>>> +declare i32 @vf4_1(i8* %this, i32 %arg)
>>> +declare i32 @vf4_2(i8* %this, i32 %arg)
>>> +
>>> +; CHECK: define i32 @fn1
>>> +define i32 @fn1(i8* %obj) #0 {
>>> +  %vtableptr = bitcast i8* %obj to [1 x i8*]**
>>> +  %vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
>>> +  %vtablei8 = bitcast [1 x i8*]* %vtable to i8*
>>> +  %p = call i1 @llvm.type.test(i8* %vtablei8, metadata !"typeid1")
>>> +  call void @llvm.assume(i1 %p)
>>> +  %fptrptr = getelementptr [1 x i8*], [1 x i8*]* %vtable, i32 0, i32 0
>>> +  %fptr = load i8*, i8** %fptrptr
>>> +  %fptr_casted = bitcast i8* %fptr to i32 (i8*, i32)*
>>> +  ; RETP: {{.*}} = bitcast {{.*}} to i8*
>>> +  ; RETP: [[VT1:%.*]] = bitcast {{.*}} to i8*
>>> +  ; RETP: call i32 bitcast (void (i8*, ...)*
>>> @__typeid_typeid1_0_branch_funnel to i32 (i8*, i8*, i32)*)(i8* nest
>>> [[VT1]], i8* %obj, i32 1)
>>> +  %result = call i32 %fptr_casted(i8* %obj, i32 1)
>>> +  ; NORETP: call i32 %
>>> +  ret i32 %result
>>> +}
>>> +
>>> +; CHECK: define i32 @fn2
>>> +define i32 @fn2(i8* %obj) #0 {
>>> +  %vtableptr = bitcast i8* %obj to [1 x i8*]**
>>> +  %vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
>>> +  %vtablei8 = bitcast [1 x i8*]* %vtable to i8*
>>> +  %p = call i1 @llvm.type.test(i8* %vtablei8, metadata !"typeid2")
>>> +  call void @llvm.assume(i1 %p)
>>> +  %fptrptr = getelementptr [1 x i8*], [1 x i8*]* %vtable, i32 0, i32 0
>>> +  %fptr = load i8*, i8** %fptrptr
>>> +  %fptr_casted = bitcast i8* %fptr to i32 (i8*, i32)*
>>> +  ; CHECK: call i32 %
>>> +  %result = call i32 %fptr_casted(i8* %obj, i32 1)
>>> +  ret i32 %result
>>> +}
>>> +
>>> +; CHECK: define i32 @fn3
>>> +define i32 @fn3(i8* %obj) #0 {
>>> +  %vtableptr = bitcast i8* %obj to [1 x i8*]**
>>> +  %vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
>>> +  %vtablei8 = bitcast [1 x i8*]* %vtable to i8*
>>> +  %p = call i1 @llvm.type.test(i8* %vtablei8, metadata !4)
>>> +  call void @llvm.assume(i1 %p)
>>> +  %fptrptr = getelementptr [1 x i8*], [1 x i8*]* %vtable, i32 0, i32 0
>>> +  %fptr = load i8*, i8** %fptrptr
>>> +  %fptr_casted = bitcast i8* %fptr to i32 (i8*, i32)*
>>> +  ; RETP: call i32 bitcast (void (i8*, ...)* @branch_funnel to
>>> +  ; NORETP: call i32 %
>>> +  %result = call i32 %fptr_casted(i8* %obj, i32 1)
>>> +  ret i32 %result
>>> +}
>>> +
>>> +; CHECK: define internal void @branch_funnel(i8* nest, ...)
>>> +
>>> +; CHECK: define hidden void @__typeid_typeid1_0_branch_funnel(i8*
>>> nest, ...)
>>> +; CHECK-NEXT: call void (...) @llvm.icall.branch.funnel(i8* %0, i8*
>>> bitcast ([1 x i8*]* @vt1_1 to i8*), i32 (i8*, i32)* @vf1_1, i8* bitcast ([1
>>> x i8*]* @vt1_2 to i8*), i32 (i8*, i32)* @vf1_2, ...)
>>> +
>>> +declare i1 @llvm.type.test(i8*, metadata)
>>> +declare void @llvm.assume(i1)
>>> +
>>> +!0 = !{i32 0, !"typeid1"}
>>> +!1 = !{i32 0, !"typeid2"}
>>> +!2 = !{i32 0, !"typeid3"}
>>> +!3 = !{i32 0, !4}
>>> +!4 = distinct !{}
>>> +
>>> +attributes #0 = { "target-features"="+retpoline" }
>>>
>>> Modified: llvm/trunk/test/Transforms/WholeProgramDevirt/import.ll
>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transfor
>>> ms/WholeProgramDevirt/import.ll?rev=327163&r1=327162&r2=327163&view=diff
>>> ============================================================
>>> ==================
>>> --- llvm/trunk/test/Transforms/WholeProgramDevirt/import.ll (original)
>>> +++ llvm/trunk/test/Transforms/WholeProgramDevirt/import.ll Fri Mar  9
>>> 11:11:44 2018
>>> @@ -1,10 +1,12 @@
>>>  ; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-single-impl.yaml < %s
>>> | FileCheck --check-prefixes=CHECK,SINGLE-IMPL %s
>>> -; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-uniform-ret-val.yaml
>>> < %s | FileCheck --check-prefixes=CHECK,UNIFORM-RET-VAL %s
>>> -; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-unique-ret-val0.yaml
>>> < %s | FileCheck --check-prefixes=CHECK,UNIQUE-RET-VAL0 %s
>>> -; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-unique-ret-val1.yaml
>>> < %s | FileCheck --check-prefixes=CHECK,UNIQUE-RET-VAL1 %s
>>> -; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-vcp.yaml < %s |
>>> FileCheck --check-prefixes=CHECK,VCP,VCP-X86,VCP64 %s
>>> +; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-uniform-ret-val.yaml
>>> < %s | FileCheck --check-prefixes=CHECK,INDIR,UNIFORM-RET-VAL %s
>>> +; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-unique-ret-val0.yaml
>>> < %s | FileCheck --check-prefixes=CHECK,INDIR,UNIQUE-RET-VAL0 %s
>>> +; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-unique-ret-val1.yaml
>>> < %s | FileCheck --check-prefixes=CHECK,INDIR,UNIQUE-RET-VAL1 %s
>>> +; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-vcp.yaml < %s |
>>> FileCheck --check-prefixes=CHECK,VCP,VCP-X86,VCP64,INDIR %s
>>>  ; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-vcp.yaml
>>> -mtriple=i686-unknown-linux -data-layout=e-p:32:32 < %s | FileCheck
>>> --check-prefixes=CHECK,VCP,VCP-X86,VCP32 %s
>>>  ; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-vcp.yaml
>>> -mtriple=armv7-unknown-linux -data-layout=e-p:32:32 < %s | FileCheck
>>> --check-prefixes=CHECK,VCP,VCP-ARM %s
>>> +; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-vcp-branch-funnel.yaml
>>> < %s | FileCheck --check-prefixes=CHECK,VCP,VCP-X86,VCP64,BRANCH-FUNNEL
>>> %s
>>> +; RUN: opt -S -wholeprogramdevirt -wholeprogramdevirt-summary-action=import
>>> -wholeprogramdevirt-read-summary=%S/Inputs/import-branch-funnel.yaml <
>>> %s | FileCheck --check-prefixes=CHECK,BRANCH-FUNNEL,BRANCH-FUNNEL-NOVCP
>>> %s
>>>
>>>  target datalayout = "e-p:64:64"
>>>  target triple = "x86_64-unknown-linux-gnu"
>>> @@ -18,7 +20,7 @@ target triple = "x86_64-unknown-linux-gn
>>>  ; constant propagation.
>>>
>>>  ; CHECK: define i32 @call1
>>> -define i32 @call1(i8* %obj) {
>>> +define i32 @call1(i8* %obj) #0 {
>>>    %vtableptr = bitcast i8* %obj to [3 x i8*]**
>>>    %vtable = load [3 x i8*]*, [3 x i8*]** %vtableptr
>>>    %vtablei8 = bitcast [3 x i8*]* %vtable to i8*
>>> @@ -27,16 +29,18 @@ define i32 @call1(i8* %obj) {
>>>    %fptrptr = getelementptr [3 x i8*], [3 x i8*]* %vtable, i32 0, i32 0
>>>    %fptr = load i8*, i8** %fptrptr
>>>    %fptr_casted = bitcast i8* %fptr to i32 (i8*, i32)*
>>> +  ; CHECK: {{.*}} = bitcast {{.*}} to i8*
>>> +  ; VCP: [[VT1:%.*]] = bitcast {{.*}} to i8*
>>>    ; SINGLE-IMPL: call i32 bitcast (void ()* @singleimpl1 to i32 (i8*,
>>> i32)*)
>>>    %result = call i32 %fptr_casted(i8* %obj, i32 1)
>>>    ; UNIFORM-RET-VAL: ret i32 42
>>> -  ; VCP: {{.*}} = bitcast {{.*}} to i8*
>>> -  ; VCP: [[VT1:%.*]] = bitcast {{.*}} to i8*
>>>    ; VCP-X86: [[GEP1:%.*]] = getelementptr i8, i8* [[VT1]], i32 ptrtoint
>>> (i8* @__typeid_typeid1_0_1_byte to i32)
>>>    ; VCP-ARM: [[GEP1:%.*]] = getelementptr i8, i8* [[VT1]], i32 42
>>>    ; VCP: [[BC1:%.*]] = bitcast i8* [[GEP1]] to i32*
>>>    ; VCP: [[LOAD1:%.*]] = load i32, i32* [[BC1]]
>>>    ; VCP: ret i32 [[LOAD1]]
>>> +  ; BRANCH-FUNNEL-NOVCP: [[VT1:%.*]] = bitcast {{.*}} to i8*
>>> +  ; BRANCH-FUNNEL-NOVCP: call i32 bitcast (void ()*
>>> @__typeid_typeid1_0_branch_funnel to i32 (i8*, i8*, i32)*)(i8* nest
>>> [[VT1]], i8* %obj, i32 1)
>>>    ret i32 %result
>>>  }
>>>
>>> @@ -44,7 +48,8 @@ define i32 @call1(i8* %obj) {
>>>  ; constant propagation.
>>>
>>>  ; CHECK: define i1 @call2
>>> -define i1 @call2(i8* %obj) {
>>> +define i1 @call2(i8* %obj) #0 {
>>> +  ; BRANCH-FUNNEL: [[VT1:%.*]] = bitcast {{.*}} to i8*
>>>    %vtableptr = bitcast i8* %obj to [1 x i8*]**
>>>    %vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
>>>    %vtablei8 = bitcast [1 x i8*]* %vtable to i8*
>>> @@ -57,9 +62,8 @@ define i1 @call2(i8* %obj) {
>>>  cont:
>>>    %fptr_casted = bitcast i8* %fptr to i1 (i8*, i32)*
>>>    ; SINGLE-IMPL: call i1 bitcast (void ()* @singleimpl2 to i1 (i8*,
>>> i32)*)
>>> -  ; UNIFORM-RET-VAL: call i1 %
>>> -  ; UNIQUE-RET-VAL0: call i1 %
>>> -  ; UNIQUE-RET-VAL1: call i1 %
>>> +  ; INDIR: call i1 %
>>> +  ; BRANCH-FUNNEL: call i1 bitcast (void ()*
>>> @__typeid_typeid2_8_branch_funnel to i1 (i8*, i8*, i32)*)(i8* nest
>>> [[VT1]], i8* %obj, i32 undef)
>>>    %result = call i1 %fptr_casted(i8* %obj, i32 undef)
>>>    ret i1 %result
>>>
>>> @@ -69,7 +73,7 @@ trap:
>>>  }
>>>
>>>  ; CHECK: define i1 @call3
>>> -define i1 @call3(i8* %obj) {
>>> +define i1 @call3(i8* %obj) #0 {
>>>    %vtableptr = bitcast i8* %obj to [1 x i8*]**
>>>    %vtable = load [1 x i8*]*, [1 x i8*]** %vtableptr
>>>    %vtablei8 = bitcast [1 x i8*]* %vtable to i8*
>>> @@ -91,6 +95,8 @@ cont:
>>>    ; VCP-ARM: [[AND2:%.*]] = and i8 [[LOAD2]], -128
>>>    ; VCP: [[ICMP2:%.*]] = icmp ne i8 [[AND2]], 0
>>>    ; VCP: ret i1 [[ICMP2]]
>>> +  ; BRANCH-FUNNEL-NOVCP: [[VT2:%.*]] = bitcast {{.*}} to i8*
>>> +  ; BRANCH-FUNNEL-NOVCP: call i1 bitcast (void ()*
>>> @__typeid_typeid2_8_branch_funnel to i1 (i8*, i8*, i32)*)(i8* nest
>>> [[VT2]], i8* %obj, i32 3)
>>>    ret i1 %result
>>>
>>>  trap:
>>> @@ -111,3 +117,5 @@ declare void @llvm.assume(i1)
>>>  declare void @llvm.trap()
>>>  declare {i8*, i1} @llvm.type.checked.load(i8*, i32, metadata)
>>>  declare i1 @llvm.type.test(i8*, metadata)
>>> +
>>> +attributes #0 = { "target-features"="+retpoline" }
>>>
>>>
>>> _______________________________________________
>>> llvm-commits mailing list
>>> llvm-commits at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>>
>>
>>
>


-- 
-- 
Peter
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