Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 753 deletions

diff --git a/gnu/llvm/lib/Analysis/Lint.cpp b/gnu/llvm/lib/Analysis/Lint.cpp
deleted file mode 100644
index 5d0a627f842..00000000000
--- a/gnu/llvm/lib/Analysis/Lint.cpp
+++ /dev/null
@@ -1,753 +0,0 @@
-//===-- Lint.cpp - Check for common errors in LLVM IR ---------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass statically checks for common and easily-identified constructs
-// which produce undefined or likely unintended behavior in LLVM IR.
-//
-// It is not a guarantee of correctness, in two ways. First, it isn't
-// comprehensive. There are checks which could be done statically which are
-// not yet implemented. Some of these are indicated by TODO comments, but
-// those aren't comprehensive either. Second, many conditions cannot be
-// checked statically. This pass does no dynamic instrumentation, so it
-// can't check for all possible problems.
-//
-// Another limitation is that it assumes all code will be executed. A store
-// through a null pointer in a basic block which is never reached is harmless,
-// but this pass will warn about it anyway. This is the main reason why most
-// of these checks live here instead of in the Verifier pass.
-//
-// Optimization passes may make conditions that this pass checks for more or
-// less obvious. If an optimization pass appears to be introducing a warning,
-// it may be that the optimization pass is merely exposing an existing
-// condition in the code.
-//
-// This code may be run before instcombine. In many cases, instcombine checks
-// for the same kinds of things and turns instructions with undefined behavior
-// into unreachable (or equivalent). Because of this, this pass makes some
-// effort to look through bitcasts and so on.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/Lint.h"
-#include "llvm/ADT/APInt.h"
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/Twine.h"
-#include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/Analysis/AssumptionCache.h"
-#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/Analysis/Loads.h"
-#include "llvm/Analysis/MemoryLocation.h"
-#include "llvm/Analysis/Passes.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/IR/Argument.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/GlobalVariable.h"
-#include "llvm/IR/InstVisitor.h"
-#include "llvm/IR/InstrTypes.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/LegacyPassManager.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/Value.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/KnownBits.h"
-#include "llvm/Support/MathExtras.h"
-#include "llvm/Support/raw_ostream.h"
-#include <cassert>
-#include <cstdint>
-#include <iterator>
-#include <string>
-
-using namespace llvm;
-
-namespace {
-  namespace MemRef {
-    static const unsigned Read     = 1;
-    static const unsigned Write    = 2;
-    static const unsigned Callee   = 4;
-    static const unsigned Branchee = 8;
-  } // end namespace MemRef
-
-  class Lint : public FunctionPass, public InstVisitor<Lint> {
-    friend class InstVisitor<Lint>;
-
-    void visitFunction(Function &F);
-
-    void visitCallSite(CallSite CS);
-    void visitMemoryReference(Instruction &I, Value *Ptr,
-                              uint64_t Size, unsigned Align,
-                              Type *Ty, unsigned Flags);
-    void visitEHBeginCatch(IntrinsicInst *II);
-    void visitEHEndCatch(IntrinsicInst *II);
-
-    void visitCallInst(CallInst &I);
-    void visitInvokeInst(InvokeInst &I);
-    void visitReturnInst(ReturnInst &I);
-    void visitLoadInst(LoadInst &I);
-    void visitStoreInst(StoreInst &I);
-    void visitXor(BinaryOperator &I);
-    void visitSub(BinaryOperator &I);
-    void visitLShr(BinaryOperator &I);
-    void visitAShr(BinaryOperator &I);
-    void visitShl(BinaryOperator &I);
-    void visitSDiv(BinaryOperator &I);
-    void visitUDiv(BinaryOperator &I);
-    void visitSRem(BinaryOperator &I);
-    void visitURem(BinaryOperator &I);
-    void visitAllocaInst(AllocaInst &I);
-    void visitVAArgInst(VAArgInst &I);
-    void visitIndirectBrInst(IndirectBrInst &I);
-    void visitExtractElementInst(ExtractElementInst &I);
-    void visitInsertElementInst(InsertElementInst &I);
-    void visitUnreachableInst(UnreachableInst &I);
-
-    Value *findValue(Value *V, bool OffsetOk) const;
-    Value *findValueImpl(Value *V, bool OffsetOk,
-                         SmallPtrSetImpl<Value *> &Visited) const;
-
-  public:
-    Module *Mod;
-    const DataLayout *DL;
-    AliasAnalysis *AA;
-    AssumptionCache *AC;
-    DominatorTree *DT;
-    TargetLibraryInfo *TLI;
-
-    std::string Messages;
-    raw_string_ostream MessagesStr;
-
-    static char ID; // Pass identification, replacement for typeid
-    Lint() : FunctionPass(ID), MessagesStr(Messages) {
-      initializeLintPass(*PassRegistry::getPassRegistry());
-    }
-
-    bool runOnFunction(Function &F) override;
-
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.setPreservesAll();
-      AU.addRequired<AAResultsWrapperPass>();
-      AU.addRequired<AssumptionCacheTracker>();
-      AU.addRequired<TargetLibraryInfoWrapperPass>();
-      AU.addRequired<DominatorTreeWrapperPass>();
-    }
-    void print(raw_ostream &O, const Module *M) const override {}
-
-    void WriteValues(ArrayRef<const Value *> Vs) {
-      for (const Value *V : Vs) {
-        if (!V)
-          continue;
-        if (isa<Instruction>(V)) {
-          MessagesStr << *V << '\n';
-        } else {
-          V->printAsOperand(MessagesStr, true, Mod);
-          MessagesStr << '\n';
-        }
-      }
-    }
-
-    /// A check failed, so printout out the condition and the message.
-    ///
-    /// This provides a nice place to put a breakpoint if you want to see why
-    /// something is not correct.
-    void CheckFailed(const Twine &Message) { MessagesStr << Message << '\n'; }
-
-    /// A check failed (with values to print).
-    ///
-    /// This calls the Message-only version so that the above is easier to set
-    /// a breakpoint on.
-    template <typename T1, typename... Ts>
-    void CheckFailed(const Twine &Message, const T1 &V1, const Ts &...Vs) {
-      CheckFailed(Message);
-      WriteValues({V1, Vs...});
-    }
-  };
-} // end anonymous namespace
-
-char Lint::ID = 0;
-INITIALIZE_PASS_BEGIN(Lint, "lint", "Statically lint-checks LLVM IR",
-                      false, true)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
-INITIALIZE_PASS_END(Lint, "lint", "Statically lint-checks LLVM IR",
-                    false, true)
-
-// Assert - We know that cond should be true, if not print an error message.
-#define Assert(C, ...) \
-    do { if (!(C)) { CheckFailed(__VA_ARGS__); return; } } while (false)
-
-// Lint::run - This is the main Analysis entry point for a
-// function.
-//
-bool Lint::runOnFunction(Function &F) {
-  Mod = F.getParent();
-  DL = &F.getParent()->getDataLayout();
-  AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
-  AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
-  DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-  TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
-  visit(F);
-  dbgs() << MessagesStr.str();
-  Messages.clear();
-  return false;
-}
-
-void Lint::visitFunction(Function &F) {
-  // This isn't undefined behavior, it's just a little unusual, and it's a
-  // fairly common mistake to neglect to name a function.
-  Assert(F.hasName() || F.hasLocalLinkage(),
-         "Unusual: Unnamed function with non-local linkage", &F);
-
-  // TODO: Check for irreducible control flow.
-}
-
-void Lint::visitCallSite(CallSite CS) {
-  Instruction &I = *CS.getInstruction();
-  Value *Callee = CS.getCalledValue();
-
-  visitMemoryReference(I, Callee, MemoryLocation::UnknownSize, 0, nullptr,
-                       MemRef::Callee);
-
-  if (Function *F = dyn_cast<Function>(findValue(Callee,
-                                                 /*OffsetOk=*/false))) {
-    Assert(CS.getCallingConv() == F->getCallingConv(),
-           "Undefined behavior: Caller and callee calling convention differ",
-           &I);
-
-    FunctionType *FT = F->getFunctionType();
-    unsigned NumActualArgs = CS.arg_size();
-
-    Assert(FT->isVarArg() ? FT->getNumParams() <= NumActualArgs
-                          : FT->getNumParams() == NumActualArgs,
-           "Undefined behavior: Call argument count mismatches callee "
-           "argument count",
-           &I);
-
-    Assert(FT->getReturnType() == I.getType(),
-           "Undefined behavior: Call return type mismatches "
-           "callee return type",
-           &I);
-
-    // Check argument types (in case the callee was casted) and attributes.
-    // TODO: Verify that caller and callee attributes are compatible.
-    Function::arg_iterator PI = F->arg_begin(), PE = F->arg_end();
-    CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
-    for (; AI != AE; ++AI) {
-      Value *Actual = *AI;
-      if (PI != PE) {
-        Argument *Formal = &*PI++;
-        Assert(Formal->getType() == Actual->getType(),
-               "Undefined behavior: Call argument type mismatches "
-               "callee parameter type",
-               &I);
-
-        // Check that noalias arguments don't alias other arguments. This is
-        // not fully precise because we don't know the sizes of the dereferenced
-        // memory regions.
-        if (Formal->hasNoAliasAttr() && Actual->getType()->isPointerTy()) {
-          AttributeList PAL = CS.getAttributes();
-          unsigned ArgNo = 0;
-          for (CallSite::arg_iterator BI = CS.arg_begin(); BI != AE; ++BI) {
-            // Skip ByVal arguments since they will be memcpy'd to the callee's
-            // stack so we're not really passing the pointer anyway.
-            if (PAL.hasParamAttribute(ArgNo++, Attribute::ByVal))
-              continue;
-            if (AI != BI && (*BI)->getType()->isPointerTy()) {
-              AliasResult Result = AA->alias(*AI, *BI);
-              Assert(Result != MustAlias && Result != PartialAlias,
-                     "Unusual: noalias argument aliases another argument", &I);
-            }
-          }
-        }
-
-        // Check that an sret argument points to valid memory.
-        if (Formal->hasStructRetAttr() && Actual->getType()->isPointerTy()) {
-          Type *Ty =
-            cast<PointerType>(Formal->getType())->getElementType();
-          visitMemoryReference(I, Actual, DL->getTypeStoreSize(Ty),
-                               DL->getABITypeAlignment(Ty), Ty,
-                               MemRef::Read | MemRef::Write);
-        }
-      }
-    }
-  }
-
-  if (CS.isCall()) {
-    const CallInst *CI = cast<CallInst>(CS.getInstruction());
-    if (CI->isTailCall()) {
-      const AttributeList &PAL = CI->getAttributes();
-      unsigned ArgNo = 0;
-      for (Value *Arg : CS.args()) {
-        // Skip ByVal arguments since they will be memcpy'd to the callee's
-        // stack anyway.
-        if (PAL.hasParamAttribute(ArgNo++, Attribute::ByVal))
-          continue;
-        Value *Obj = findValue(Arg, /*OffsetOk=*/true);
-        Assert(!isa<AllocaInst>(Obj),
-               "Undefined behavior: Call with \"tail\" keyword references "
-               "alloca",
-               &I);
-      }
-    }
-  }
-
-
-  if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I))
-    switch (II->getIntrinsicID()) {
-    default: break;
-
-    // TODO: Check more intrinsics
-
-    case Intrinsic::memcpy: {
-      MemCpyInst *MCI = cast<MemCpyInst>(&I);
-      // TODO: If the size is known, use it.
-      visitMemoryReference(I, MCI->getDest(), MemoryLocation::UnknownSize,
-                           MCI->getDestAlignment(), nullptr, MemRef::Write);
-      visitMemoryReference(I, MCI->getSource(), MemoryLocation::UnknownSize,
-                           MCI->getSourceAlignment(), nullptr, MemRef::Read);
-
-      // Check that the memcpy arguments don't overlap. The AliasAnalysis API
-      // isn't expressive enough for what we really want to do. Known partial
-      // overlap is not distinguished from the case where nothing is known.
-      auto Size = LocationSize::unknown();
-      if (const ConstantInt *Len =
-              dyn_cast<ConstantInt>(findValue(MCI->getLength(),
-                                              /*OffsetOk=*/false)))
-        if (Len->getValue().isIntN(32))
-          Size = LocationSize::precise(Len->getValue().getZExtValue());
-      Assert(AA->alias(MCI->getSource(), Size, MCI->getDest(), Size) !=
-                 MustAlias,
-             "Undefined behavior: memcpy source and destination overlap", &I);
-      break;
-    }
-    case Intrinsic::memmove: {
-      MemMoveInst *MMI = cast<MemMoveInst>(&I);
-      // TODO: If the size is known, use it.
-      visitMemoryReference(I, MMI->getDest(), MemoryLocation::UnknownSize,
-                           MMI->getDestAlignment(), nullptr, MemRef::Write);
-      visitMemoryReference(I, MMI->getSource(), MemoryLocation::UnknownSize,
-                           MMI->getSourceAlignment(), nullptr, MemRef::Read);
-      break;
-    }
-    case Intrinsic::memset: {
-      MemSetInst *MSI = cast<MemSetInst>(&I);
-      // TODO: If the size is known, use it.
-      visitMemoryReference(I, MSI->getDest(), MemoryLocation::UnknownSize,
-                           MSI->getDestAlignment(), nullptr, MemRef::Write);
-      break;
-    }
-
-    case Intrinsic::vastart:
-      Assert(I.getParent()->getParent()->isVarArg(),
-             "Undefined behavior: va_start called in a non-varargs function",
-             &I);
-
-      visitMemoryReference(I, CS.getArgument(0), MemoryLocation::UnknownSize, 0,
-                           nullptr, MemRef::Read | MemRef::Write);
-      break;
-    case Intrinsic::vacopy:
-      visitMemoryReference(I, CS.getArgument(0), MemoryLocation::UnknownSize, 0,
-                           nullptr, MemRef::Write);
-      visitMemoryReference(I, CS.getArgument(1), MemoryLocation::UnknownSize, 0,
-                           nullptr, MemRef::Read);
-      break;
-    case Intrinsic::vaend:
-      visitMemoryReference(I, CS.getArgument(0), MemoryLocation::UnknownSize, 0,
-                           nullptr, MemRef::Read | MemRef::Write);
-      break;
-
-    case Intrinsic::stackrestore:
-      // Stackrestore doesn't read or write memory, but it sets the
-      // stack pointer, which the compiler may read from or write to
-      // at any time, so check it for both readability and writeability.
-      visitMemoryReference(I, CS.getArgument(0), MemoryLocation::UnknownSize, 0,
-                           nullptr, MemRef::Read | MemRef::Write);
-      break;
-    }
-}
-
-void Lint::visitCallInst(CallInst &I) {
-  return visitCallSite(&I);
-}
-
-void Lint::visitInvokeInst(InvokeInst &I) {
-  return visitCallSite(&I);
-}
-
-void Lint::visitReturnInst(ReturnInst &I) {
-  Function *F = I.getParent()->getParent();
-  Assert(!F->doesNotReturn(),
-         "Unusual: Return statement in function with noreturn attribute", &I);
-
-  if (Value *V = I.getReturnValue()) {
-    Value *Obj = findValue(V, /*OffsetOk=*/true);
-    Assert(!isa<AllocaInst>(Obj), "Unusual: Returning alloca value", &I);
-  }
-}
-
-// TODO: Check that the reference is in bounds.
-// TODO: Check readnone/readonly function attributes.
-void Lint::visitMemoryReference(Instruction &I,
-                                Value *Ptr, uint64_t Size, unsigned Align,
-                                Type *Ty, unsigned Flags) {
-  // If no memory is being referenced, it doesn't matter if the pointer
-  // is valid.
-  if (Size == 0)
-    return;
-
-  Value *UnderlyingObject = findValue(Ptr, /*OffsetOk=*/true);
-  Assert(!isa<ConstantPointerNull>(UnderlyingObject),
-         "Undefined behavior: Null pointer dereference", &I);
-  Assert(!isa<UndefValue>(UnderlyingObject),
-         "Undefined behavior: Undef pointer dereference", &I);
-  Assert(!isa<ConstantInt>(UnderlyingObject) ||
-             !cast<ConstantInt>(UnderlyingObject)->isMinusOne(),
-         "Unusual: All-ones pointer dereference", &I);
-  Assert(!isa<ConstantInt>(UnderlyingObject) ||
-             !cast<ConstantInt>(UnderlyingObject)->isOne(),
-         "Unusual: Address one pointer dereference", &I);
-
-  if (Flags & MemRef::Write) {
-    if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(UnderlyingObject))
-      Assert(!GV->isConstant(), "Undefined behavior: Write to read-only memory",
-             &I);
-    Assert(!isa<Function>(UnderlyingObject) &&
-               !isa<BlockAddress>(UnderlyingObject),
-           "Undefined behavior: Write to text section", &I);
-  }
-  if (Flags & MemRef::Read) {
-    Assert(!isa<Function>(UnderlyingObject), "Unusual: Load from function body",
-           &I);
-    Assert(!isa<BlockAddress>(UnderlyingObject),
-           "Undefined behavior: Load from block address", &I);
-  }
-  if (Flags & MemRef::Callee) {
-    Assert(!isa<BlockAddress>(UnderlyingObject),
-           "Undefined behavior: Call to block address", &I);
-  }
-  if (Flags & MemRef::Branchee) {
-    Assert(!isa<Constant>(UnderlyingObject) ||
-               isa<BlockAddress>(UnderlyingObject),
-           "Undefined behavior: Branch to non-blockaddress", &I);
-  }
-
-  // Check for buffer overflows and misalignment.
-  // Only handles memory references that read/write something simple like an
-  // alloca instruction or a global variable.
-  int64_t Offset = 0;
-  if (Value *Base = GetPointerBaseWithConstantOffset(Ptr, Offset, *DL)) {
-    // OK, so the access is to a constant offset from Ptr.  Check that Ptr is
-    // something we can handle and if so extract the size of this base object
-    // along with its alignment.
-    uint64_t BaseSize = MemoryLocation::UnknownSize;
-    unsigned BaseAlign = 0;
-
-    if (AllocaInst *AI = dyn_cast<AllocaInst>(Base)) {
-      Type *ATy = AI->getAllocatedType();
-      if (!AI->isArrayAllocation() && ATy->isSized())
-        BaseSize = DL->getTypeAllocSize(ATy);
-      BaseAlign = AI->getAlignment();
-      if (BaseAlign == 0 && ATy->isSized())
-        BaseAlign = DL->getABITypeAlignment(ATy);
-    } else if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Base)) {
-      // If the global may be defined differently in another compilation unit
-      // then don't warn about funky memory accesses.
-      if (GV->hasDefinitiveInitializer()) {
-        Type *GTy = GV->getValueType();
-        if (GTy->isSized())
-          BaseSize = DL->getTypeAllocSize(GTy);
-        BaseAlign = GV->getAlignment();
-        if (BaseAlign == 0 && GTy->isSized())
-          BaseAlign = DL->getABITypeAlignment(GTy);
-      }
-    }
-
-    // Accesses from before the start or after the end of the object are not
-    // defined.
-    Assert(Size == MemoryLocation::UnknownSize ||
-               BaseSize == MemoryLocation::UnknownSize ||
-               (Offset >= 0 && Offset + Size <= BaseSize),
-           "Undefined behavior: Buffer overflow", &I);
-
-    // Accesses that say that the memory is more aligned than it is are not
-    // defined.
-    if (Align == 0 && Ty && Ty->isSized())
-      Align = DL->getABITypeAlignment(Ty);
-    Assert(!BaseAlign || Align <= MinAlign(BaseAlign, Offset),
-           "Undefined behavior: Memory reference address is misaligned", &I);
-  }
-}
-
-void Lint::visitLoadInst(LoadInst &I) {
-  visitMemoryReference(I, I.getPointerOperand(),
-                       DL->getTypeStoreSize(I.getType()), I.getAlignment(),
-                       I.getType(), MemRef::Read);
-}
-
-void Lint::visitStoreInst(StoreInst &I) {
-  visitMemoryReference(I, I.getPointerOperand(),
-                       DL->getTypeStoreSize(I.getOperand(0)->getType()),
-                       I.getAlignment(),
-                       I.getOperand(0)->getType(), MemRef::Write);
-}
-
-void Lint::visitXor(BinaryOperator &I) {
-  Assert(!isa<UndefValue>(I.getOperand(0)) || !isa<UndefValue>(I.getOperand(1)),
-         "Undefined result: xor(undef, undef)", &I);
-}
-
-void Lint::visitSub(BinaryOperator &I) {
-  Assert(!isa<UndefValue>(I.getOperand(0)) || !isa<UndefValue>(I.getOperand(1)),
-         "Undefined result: sub(undef, undef)", &I);
-}
-
-void Lint::visitLShr(BinaryOperator &I) {
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(findValue(I.getOperand(1),
-                                                        /*OffsetOk=*/false)))
-    Assert(CI->getValue().ult(cast<IntegerType>(I.getType())->getBitWidth()),
-           "Undefined result: Shift count out of range", &I);
-}
-
-void Lint::visitAShr(BinaryOperator &I) {
-  if (ConstantInt *CI =
-          dyn_cast<ConstantInt>(findValue(I.getOperand(1), /*OffsetOk=*/false)))
-    Assert(CI->getValue().ult(cast<IntegerType>(I.getType())->getBitWidth()),
-           "Undefined result: Shift count out of range", &I);
-}
-
-void Lint::visitShl(BinaryOperator &I) {
-  if (ConstantInt *CI =
-          dyn_cast<ConstantInt>(findValue(I.getOperand(1), /*OffsetOk=*/false)))
-    Assert(CI->getValue().ult(cast<IntegerType>(I.getType())->getBitWidth()),
-           "Undefined result: Shift count out of range", &I);
-}
-
-static bool isZero(Value *V, const DataLayout &DL, DominatorTree *DT,
-                   AssumptionCache *AC) {
-  // Assume undef could be zero.
-  if (isa<UndefValue>(V))
-    return true;
-
-  VectorType *VecTy = dyn_cast<VectorType>(V->getType());
-  if (!VecTy) {
-    KnownBits Known = computeKnownBits(V, DL, 0, AC, dyn_cast<Instruction>(V), DT);
-    return Known.isZero();
-  }
-
-  // Per-component check doesn't work with zeroinitializer
-  Constant *C = dyn_cast<Constant>(V);
-  if (!C)
-    return false;
-
-  if (C->isZeroValue())
-    return true;
-
-  // For a vector, KnownZero will only be true if all values are zero, so check
-  // this per component
-  for (unsigned I = 0, N = VecTy->getNumElements(); I != N; ++I) {
-    Constant *Elem = C->getAggregateElement(I);
-    if (isa<UndefValue>(Elem))
-      return true;
-
-    KnownBits Known = computeKnownBits(Elem, DL);
-    if (Known.isZero())
-      return true;
-  }
-
-  return false;
-}
-
-void Lint::visitSDiv(BinaryOperator &I) {
-  Assert(!isZero(I.getOperand(1), I.getModule()->getDataLayout(), DT, AC),
-         "Undefined behavior: Division by zero", &I);
-}
-
-void Lint::visitUDiv(BinaryOperator &I) {
-  Assert(!isZero(I.getOperand(1), I.getModule()->getDataLayout(), DT, AC),
-         "Undefined behavior: Division by zero", &I);
-}
-
-void Lint::visitSRem(BinaryOperator &I) {
-  Assert(!isZero(I.getOperand(1), I.getModule()->getDataLayout(), DT, AC),
-         "Undefined behavior: Division by zero", &I);
-}
-
-void Lint::visitURem(BinaryOperator &I) {
-  Assert(!isZero(I.getOperand(1), I.getModule()->getDataLayout(), DT, AC),
-         "Undefined behavior: Division by zero", &I);
-}
-
-void Lint::visitAllocaInst(AllocaInst &I) {
-  if (isa<ConstantInt>(I.getArraySize()))
-    // This isn't undefined behavior, it's just an obvious pessimization.
-    Assert(&I.getParent()->getParent()->getEntryBlock() == I.getParent(),
-           "Pessimization: Static alloca outside of entry block", &I);
-
-  // TODO: Check for an unusual size (MSB set?)
-}
-
-void Lint::visitVAArgInst(VAArgInst &I) {
-  visitMemoryReference(I, I.getOperand(0), MemoryLocation::UnknownSize, 0,
-                       nullptr, MemRef::Read | MemRef::Write);
-}
-
-void Lint::visitIndirectBrInst(IndirectBrInst &I) {
-  visitMemoryReference(I, I.getAddress(), MemoryLocation::UnknownSize, 0,
-                       nullptr, MemRef::Branchee);
-
-  Assert(I.getNumDestinations() != 0,
-         "Undefined behavior: indirectbr with no destinations", &I);
-}
-
-void Lint::visitExtractElementInst(ExtractElementInst &I) {
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(findValue(I.getIndexOperand(),
-                                                        /*OffsetOk=*/false)))
-    Assert(CI->getValue().ult(I.getVectorOperandType()->getNumElements()),
-           "Undefined result: extractelement index out of range", &I);
-}
-
-void Lint::visitInsertElementInst(InsertElementInst &I) {
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(findValue(I.getOperand(2),
-                                                        /*OffsetOk=*/false)))
-    Assert(CI->getValue().ult(I.getType()->getNumElements()),
-           "Undefined result: insertelement index out of range", &I);
-}
-
-void Lint::visitUnreachableInst(UnreachableInst &I) {
-  // This isn't undefined behavior, it's merely suspicious.
-  Assert(&I == &I.getParent()->front() ||
-             std::prev(I.getIterator())->mayHaveSideEffects(),
-         "Unusual: unreachable immediately preceded by instruction without "
-         "side effects",
-         &I);
-}
-
-/// findValue - Look through bitcasts and simple memory reference patterns
-/// to identify an equivalent, but more informative, value.  If OffsetOk
-/// is true, look through getelementptrs with non-zero offsets too.
-///
-/// Most analysis passes don't require this logic, because instcombine
-/// will simplify most of these kinds of things away. But it's a goal of
-/// this Lint pass to be useful even on non-optimized IR.
-Value *Lint::findValue(Value *V, bool OffsetOk) const {
-  SmallPtrSet<Value *, 4> Visited;
-  return findValueImpl(V, OffsetOk, Visited);
-}
-
-/// findValueImpl - Implementation helper for findValue.
-Value *Lint::findValueImpl(Value *V, bool OffsetOk,
-                           SmallPtrSetImpl<Value *> &Visited) const {
-  // Detect self-referential values.
-  if (!Visited.insert(V).second)
-    return UndefValue::get(V->getType());
-
-  // TODO: Look through sext or zext cast, when the result is known to
-  // be interpreted as signed or unsigned, respectively.
-  // TODO: Look through eliminable cast pairs.
-  // TODO: Look through calls with unique return values.
-  // TODO: Look through vector insert/extract/shuffle.
-  V = OffsetOk ? GetUnderlyingObject(V, *DL) : V->stripPointerCasts();
-  if (LoadInst *L = dyn_cast<LoadInst>(V)) {
-    BasicBlock::iterator BBI = L->getIterator();
-    BasicBlock *BB = L->getParent();
-    SmallPtrSet<BasicBlock *, 4> VisitedBlocks;
-    for (;;) {
-      if (!VisitedBlocks.insert(BB).second)
-        break;
-      if (Value *U =
-          FindAvailableLoadedValue(L, BB, BBI, DefMaxInstsToScan, AA))
-        return findValueImpl(U, OffsetOk, Visited);
-      if (BBI != BB->begin()) break;
-      BB = BB->getUniquePredecessor();
-      if (!BB) break;
-      BBI = BB->end();
-    }
-  } else if (PHINode *PN = dyn_cast<PHINode>(V)) {
-    if (Value *W = PN->hasConstantValue())
-      if (W != V)
-        return findValueImpl(W, OffsetOk, Visited);
-  } else if (CastInst *CI = dyn_cast<CastInst>(V)) {
-    if (CI->isNoopCast(*DL))
-      return findValueImpl(CI->getOperand(0), OffsetOk, Visited);
-  } else if (ExtractValueInst *Ex = dyn_cast<ExtractValueInst>(V)) {
-    if (Value *W = FindInsertedValue(Ex->getAggregateOperand(),
-                                     Ex->getIndices()))
-      if (W != V)
-        return findValueImpl(W, OffsetOk, Visited);
-  } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
-    // Same as above, but for ConstantExpr instead of Instruction.
-    if (Instruction::isCast(CE->getOpcode())) {
-      if (CastInst::isNoopCast(Instruction::CastOps(CE->getOpcode()),
-                               CE->getOperand(0)->getType(), CE->getType(),
-                               *DL))
-        return findValueImpl(CE->getOperand(0), OffsetOk, Visited);
-    } else if (CE->getOpcode() == Instruction::ExtractValue) {
-      ArrayRef<unsigned> Indices = CE->getIndices();
-      if (Value *W = FindInsertedValue(CE->getOperand(0), Indices))
-        if (W != V)
-          return findValueImpl(W, OffsetOk, Visited);
-    }
-  }
-
-  // As a last resort, try SimplifyInstruction or constant folding.
-  if (Instruction *Inst = dyn_cast<Instruction>(V)) {
-    if (Value *W = SimplifyInstruction(Inst, {*DL, TLI, DT, AC}))
-      return findValueImpl(W, OffsetOk, Visited);
-  } else if (auto *C = dyn_cast<Constant>(V)) {
-    if (Value *W = ConstantFoldConstant(C, *DL, TLI))
-      if (W && W != V)
-        return findValueImpl(W, OffsetOk, Visited);
-  }
-
-  return V;
-}
-
-//===----------------------------------------------------------------------===//
-//  Implement the public interfaces to this file...
-//===----------------------------------------------------------------------===//
-
-FunctionPass *llvm::createLintPass() {
-  return new Lint();
-}
-
-/// lintFunction - Check a function for errors, printing messages on stderr.
-///
-void llvm::lintFunction(const Function &f) {
-  Function &F = const_cast<Function&>(f);
-  assert(!F.isDeclaration() && "Cannot lint external functions");
-
-  legacy::FunctionPassManager FPM(F.getParent());
-  Lint *V = new Lint();
-  FPM.add(V);
-  FPM.run(F);
-}
-
-/// lintModule - Check a module for errors, printing messages on stderr.
-///
-void llvm::lintModule(const Module &M) {
-  legacy::PassManager PM;
-  Lint *V = new Lint();
-  PM.add(V);
-  PM.run(const_cast<Module&>(M));
-}