Esempio n. 1
0
bool SIDebuggerInsertNops::runOnMachineFunction(MachineFunction &MF) {
  // Skip this pass if "amdgpu-debugger-insert-nops" attribute was not
  // specified.
  const AMDGPUSubtarget &ST = MF.getSubtarget<AMDGPUSubtarget>();
  if (!ST.debuggerInsertNops())
    return false;

  // Skip machine functions without debug info.
  if (!MF.getMMI().hasDebugInfo())
    return false;

  // Target instruction info.
  const SIInstrInfo *TII =
    static_cast<const SIInstrInfo*>(MF.getSubtarget().getInstrInfo());

  // Set containing line numbers that have nop inserted.
  DenseSet<unsigned> NopInserted;

  for (auto &MBB : MF) {
    for (auto MI = MBB.begin(); MI != MBB.end(); ++MI) {
      // Skip DBG_VALUE instructions and instructions without location.
      if (MI->isDebugValue() || !MI->getDebugLoc())
        continue;

      // Insert nop instruction if line number does not have nop inserted.
      auto DL = MI->getDebugLoc();
      if (NopInserted.find(DL.getLine()) == NopInserted.end()) {
        BuildMI(MBB, *MI, DL, TII->get(AMDGPU::S_NOP))
          .addImm(0);
        NopInserted.insert(DL.getLine());
      }
    }
  }

  return true;
}
Esempio n. 2
0
/// \brief Figure out if the loop is worth full unrolling.
///
/// Complete loop unrolling can make some loads constant, and we need to know
/// if that would expose any further optimization opportunities.  This routine
/// estimates this optimization.  It computes cost of unrolled loop
/// (UnrolledCost) and dynamic cost of the original loop (RolledDynamicCost). By
/// dynamic cost we mean that we won't count costs of blocks that are known not
/// to be executed (i.e. if we have a branch in the loop and we know that at the
/// given iteration its condition would be resolved to true, we won't add up the
/// cost of the 'false'-block).
/// \returns Optional value, holding the RolledDynamicCost and UnrolledCost. If
/// the analysis failed (no benefits expected from the unrolling, or the loop is
/// too big to analyze), the returned value is None.
static Optional<EstimatedUnrollCost>
analyzeLoopUnrollCost(const Loop *L, unsigned TripCount, DominatorTree &DT,
                      ScalarEvolution &SE, const TargetTransformInfo &TTI,
                      int MaxUnrolledLoopSize) {
  // We want to be able to scale offsets by the trip count and add more offsets
  // to them without checking for overflows, and we already don't want to
  // analyze *massive* trip counts, so we force the max to be reasonably small.
  assert(UnrollMaxIterationsCountToAnalyze < (INT_MAX / 2) &&
         "The unroll iterations max is too large!");

  // Only analyze inner loops. We can't properly estimate cost of nested loops
  // and we won't visit inner loops again anyway.
  if (!L->empty())
    return None;

  // Don't simulate loops with a big or unknown tripcount
  if (!UnrollMaxIterationsCountToAnalyze || !TripCount ||
      TripCount > UnrollMaxIterationsCountToAnalyze)
    return None;

  SmallSetVector<BasicBlock *, 16> BBWorklist;
  SmallSetVector<std::pair<BasicBlock *, BasicBlock *>, 4> ExitWorklist;
  DenseMap<Value *, Constant *> SimplifiedValues;
  SmallVector<std::pair<Value *, Constant *>, 4> SimplifiedInputValues;

  // The estimated cost of the unrolled form of the loop. We try to estimate
  // this by simplifying as much as we can while computing the estimate.
  int UnrolledCost = 0;

  // We also track the estimated dynamic (that is, actually executed) cost in
  // the rolled form. This helps identify cases when the savings from unrolling
  // aren't just exposing dead control flows, but actual reduced dynamic
  // instructions due to the simplifications which we expect to occur after
  // unrolling.
  int RolledDynamicCost = 0;

  // We track the simplification of each instruction in each iteration. We use
  // this to recursively merge costs into the unrolled cost on-demand so that
  // we don't count the cost of any dead code. This is essentially a map from
  // <instruction, int> to <bool, bool>, but stored as a densely packed struct.
  DenseSet<UnrolledInstState, UnrolledInstStateKeyInfo> InstCostMap;

  // A small worklist used to accumulate cost of instructions from each
  // observable and reached root in the loop.
  SmallVector<Instruction *, 16> CostWorklist;

  // PHI-used worklist used between iterations while accumulating cost.
  SmallVector<Instruction *, 4> PHIUsedList;

  // Helper function to accumulate cost for instructions in the loop.
  auto AddCostRecursively = [&](Instruction &RootI, int Iteration) {
    assert(Iteration >= 0 && "Cannot have a negative iteration!");
    assert(CostWorklist.empty() && "Must start with an empty cost list");
    assert(PHIUsedList.empty() && "Must start with an empty phi used list");
    CostWorklist.push_back(&RootI);
    for (;; --Iteration) {
      do {
        Instruction *I = CostWorklist.pop_back_val();

        // InstCostMap only uses I and Iteration as a key, the other two values
        // don't matter here.
        auto CostIter = InstCostMap.find({I, Iteration, 0, 0});
        if (CostIter == InstCostMap.end())
          // If an input to a PHI node comes from a dead path through the loop
          // we may have no cost data for it here. What that actually means is
          // that it is free.
          continue;
        auto &Cost = *CostIter;
        if (Cost.IsCounted)
          // Already counted this instruction.
          continue;

        // Mark that we are counting the cost of this instruction now.
        Cost.IsCounted = true;

        // If this is a PHI node in the loop header, just add it to the PHI set.
        if (auto *PhiI = dyn_cast<PHINode>(I))
          if (PhiI->getParent() == L->getHeader()) {
            assert(Cost.IsFree && "Loop PHIs shouldn't be evaluated as they "
                                  "inherently simplify during unrolling.");
            if (Iteration == 0)
              continue;

            // Push the incoming value from the backedge into the PHI used list
            // if it is an in-loop instruction. We'll use this to populate the
            // cost worklist for the next iteration (as we count backwards).
            if (auto *OpI = dyn_cast<Instruction>(
                    PhiI->getIncomingValueForBlock(L->getLoopLatch())))
              if (L->contains(OpI))
                PHIUsedList.push_back(OpI);
            continue;
          }

        // First accumulate the cost of this instruction.
        if (!Cost.IsFree) {
          UnrolledCost += TTI.getUserCost(I);
          DEBUG(dbgs() << "Adding cost of instruction (iteration " << Iteration
                       << "): ");
          DEBUG(I->dump());
        }

        // We must count the cost of every operand which is not free,
        // recursively. If we reach a loop PHI node, simply add it to the set
        // to be considered on the next iteration (backwards!).
        for (Value *Op : I->operands()) {
          // Check whether this operand is free due to being a constant or
          // outside the loop.
          auto *OpI = dyn_cast<Instruction>(Op);
          if (!OpI || !L->contains(OpI))
            continue;

          // Otherwise accumulate its cost.
          CostWorklist.push_back(OpI);
        }
      } while (!CostWorklist.empty());

      if (PHIUsedList.empty())
        // We've exhausted the search.
        break;

      assert(Iteration > 0 &&
             "Cannot track PHI-used values past the first iteration!");
      CostWorklist.append(PHIUsedList.begin(), PHIUsedList.end());
      PHIUsedList.clear();
    }
  };

  // Ensure that we don't violate the loop structure invariants relied on by
  // this analysis.
  assert(L->isLoopSimplifyForm() && "Must put loop into normal form first.");
  assert(L->isLCSSAForm(DT) &&
         "Must have loops in LCSSA form to track live-out values.");

  DEBUG(dbgs() << "Starting LoopUnroll profitability analysis...\n");

  // Simulate execution of each iteration of the loop counting instructions,
  // which would be simplified.
  // Since the same load will take different values on different iterations,
  // we literally have to go through all loop's iterations.
  for (unsigned Iteration = 0; Iteration < TripCount; ++Iteration) {
    DEBUG(dbgs() << " Analyzing iteration " << Iteration << "\n");

    // Prepare for the iteration by collecting any simplified entry or backedge
    // inputs.
    for (Instruction &I : *L->getHeader()) {
      auto *PHI = dyn_cast<PHINode>(&I);
      if (!PHI)
        break;

      // The loop header PHI nodes must have exactly two input: one from the
      // loop preheader and one from the loop latch.
      assert(
          PHI->getNumIncomingValues() == 2 &&
          "Must have an incoming value only for the preheader and the latch.");

      Value *V = PHI->getIncomingValueForBlock(
          Iteration == 0 ? L->getLoopPreheader() : L->getLoopLatch());
      Constant *C = dyn_cast<Constant>(V);
      if (Iteration != 0 && !C)
        C = SimplifiedValues.lookup(V);
      if (C)
        SimplifiedInputValues.push_back({PHI, C});
    }

    // Now clear and re-populate the map for the next iteration.
    SimplifiedValues.clear();
    while (!SimplifiedInputValues.empty())
      SimplifiedValues.insert(SimplifiedInputValues.pop_back_val());

    UnrolledInstAnalyzer Analyzer(Iteration, SimplifiedValues, SE, L);

    BBWorklist.clear();
    BBWorklist.insert(L->getHeader());
    // Note that we *must not* cache the size, this loop grows the worklist.
    for (unsigned Idx = 0; Idx != BBWorklist.size(); ++Idx) {
      BasicBlock *BB = BBWorklist[Idx];

      // Visit all instructions in the given basic block and try to simplify
      // it.  We don't change the actual IR, just count optimization
      // opportunities.
      for (Instruction &I : *BB) {
        // Track this instruction's expected baseline cost when executing the
        // rolled loop form.
        RolledDynamicCost += TTI.getUserCost(&I);

        // Visit the instruction to analyze its loop cost after unrolling,
        // and if the visitor returns true, mark the instruction as free after
        // unrolling and continue.
        bool IsFree = Analyzer.visit(I);
        bool Inserted = InstCostMap.insert({&I, (int)Iteration,
                                           (unsigned)IsFree,
                                           /*IsCounted*/ false}).second;
        (void)Inserted;
        assert(Inserted && "Cannot have a state for an unvisited instruction!");

        if (IsFree)
          continue;

        // If the instruction might have a side-effect recursively account for
        // the cost of it and all the instructions leading up to it.
        if (I.mayHaveSideEffects())
          AddCostRecursively(I, Iteration);

        // Can't properly model a cost of a call.
        // FIXME: With a proper cost model we should be able to do it.
        if(isa<CallInst>(&I))
          return None;

        // If unrolled body turns out to be too big, bail out.
        if (UnrolledCost > MaxUnrolledLoopSize) {
          DEBUG(dbgs() << "  Exceeded threshold.. exiting.\n"
                       << "  UnrolledCost: " << UnrolledCost
                       << ", MaxUnrolledLoopSize: " << MaxUnrolledLoopSize
                       << "\n");
          return None;
        }
      }

      TerminatorInst *TI = BB->getTerminator();

      // Add in the live successors by first checking whether we have terminator
      // that may be simplified based on the values simplified by this call.
      BasicBlock *KnownSucc = nullptr;
      if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
        if (BI->isConditional()) {
          if (Constant *SimpleCond =
                  SimplifiedValues.lookup(BI->getCondition())) {
            // Just take the first successor if condition is undef
            if (isa<UndefValue>(SimpleCond))
              KnownSucc = BI->getSuccessor(0);
            else if (ConstantInt *SimpleCondVal =
                         dyn_cast<ConstantInt>(SimpleCond))
              KnownSucc = BI->getSuccessor(SimpleCondVal->isZero() ? 1 : 0);
          }
        }
      } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
        if (Constant *SimpleCond =
                SimplifiedValues.lookup(SI->getCondition())) {
          // Just take the first successor if condition is undef
          if (isa<UndefValue>(SimpleCond))
            KnownSucc = SI->getSuccessor(0);
          else if (ConstantInt *SimpleCondVal =
                       dyn_cast<ConstantInt>(SimpleCond))
            KnownSucc = SI->findCaseValue(SimpleCondVal).getCaseSuccessor();
        }
      }
      if (KnownSucc) {
        if (L->contains(KnownSucc))
          BBWorklist.insert(KnownSucc);
        else
          ExitWorklist.insert({BB, KnownSucc});
        continue;
      }

      // Add BB's successors to the worklist.
      for (BasicBlock *Succ : successors(BB))
        if (L->contains(Succ))
          BBWorklist.insert(Succ);
        else
          ExitWorklist.insert({BB, Succ});
      AddCostRecursively(*TI, Iteration);
    }

    // If we found no optimization opportunities on the first iteration, we
    // won't find them on later ones too.
    if (UnrolledCost == RolledDynamicCost) {
      DEBUG(dbgs() << "  No opportunities found.. exiting.\n"
                   << "  UnrolledCost: " << UnrolledCost << "\n");
      return None;
    }
  }

  while (!ExitWorklist.empty()) {
    BasicBlock *ExitingBB, *ExitBB;
    std::tie(ExitingBB, ExitBB) = ExitWorklist.pop_back_val();

    for (Instruction &I : *ExitBB) {
      auto *PN = dyn_cast<PHINode>(&I);
      if (!PN)
        break;

      Value *Op = PN->getIncomingValueForBlock(ExitingBB);
      if (auto *OpI = dyn_cast<Instruction>(Op))
        if (L->contains(OpI))
          AddCostRecursively(*OpI, TripCount - 1);
    }
  }

  DEBUG(dbgs() << "Analysis finished:\n"
               << "UnrolledCost: " << UnrolledCost << ", "
               << "RolledDynamicCost: " << RolledDynamicCost << "\n");
  return {{UnrolledCost, RolledDynamicCost}};
}
Esempio n. 3
0
MCFunction
MCFunction::createFunctionFromMC(StringRef Name, const MCDisassembler *DisAsm,
                                 const MemoryObject &Region, uint64_t Start,
                                 uint64_t End, const MCInstrAnalysis *Ana,
                                 raw_ostream &DebugOut,
                                 SmallVectorImpl<uint64_t> &Calls) {
  std::vector<MCDecodedInst> Instructions;
  std::set<uint64_t> Splits;
  Splits.insert(Start);
  uint64_t Size;

  MCFunction f(Name);

  {
  DenseSet<uint64_t> VisitedInsts;
  SmallVector<uint64_t, 16> WorkList;
  WorkList.push_back(Start);
  // Disassemble code and gather basic block split points.
  while (!WorkList.empty()) {
    uint64_t Index = WorkList.pop_back_val();
    if (VisitedInsts.find(Index) != VisitedInsts.end())
      continue; // Already visited this location.

    for (;Index < End; Index += Size) {
      VisitedInsts.insert(Index);

      MCInst Inst;
      if (DisAsm->getInstruction(Inst, Size, Region, Index, DebugOut, nulls())){
        Instructions.push_back(MCDecodedInst(Index, Size, Inst));
        if (Ana->isBranch(Inst)) {
          uint64_t targ = Ana->evaluateBranch(Inst, Index, Size);
          if (targ != -1ULL && targ == Index+Size)
            continue; // Skip nop jumps.

          // If we could determine the branch target, make a note to start a
          // new basic block there and add the target to the worklist.
          if (targ != -1ULL) {
            Splits.insert(targ);
            WorkList.push_back(targ);
            WorkList.push_back(Index+Size);
          }
          Splits.insert(Index+Size);
          break;
        } else if (Ana->isReturn(Inst)) {
          // Return instruction. This basic block ends here.
          Splits.insert(Index+Size);
          break;
        } else if (Ana->isCall(Inst)) {
          uint64_t targ = Ana->evaluateBranch(Inst, Index, Size);
          // Add the call to the call list if the destination is known.
          if (targ != -1ULL && targ != Index+Size)
            Calls.push_back(targ);
        }
      } else {
        errs().write_hex(Index) << ": warning: invalid instruction encoding\n";
        if (Size == 0)
          Size = 1; // skip illegible bytes
      }
    }
  }
  }

  // Make sure the instruction list is sorted.
  std::sort(Instructions.begin(), Instructions.end());

  // Create basic blocks.
  unsigned ii = 0, ie = Instructions.size();
  for (std::set<uint64_t>::iterator spi = Splits.begin(),
       spe = llvm::prior(Splits.end()); spi != spe; ++spi) {
    MCBasicBlock BB;
    uint64_t BlockEnd = *llvm::next(spi);
    // Add instructions to the BB.
    for (; ii != ie; ++ii) {
      if (Instructions[ii].Address < *spi ||
          Instructions[ii].Address >= BlockEnd)
        break;
      BB.addInst(Instructions[ii]);
    }
    f.addBlock(*spi, BB);
  }

  std::sort(f.Blocks.begin(), f.Blocks.end());

  // Calculate successors of each block.
  for (MCFunction::iterator i = f.begin(), e = f.end(); i != e; ++i) {
    MCBasicBlock &BB = const_cast<MCBasicBlock&>(i->second);
    if (BB.getInsts().empty()) continue;
    const MCDecodedInst &Inst = BB.getInsts().back();

    if (Ana->isBranch(Inst.Inst)) {
      uint64_t targ = Ana->evaluateBranch(Inst.Inst, Inst.Address, Inst.Size);
      if (targ == -1ULL) {
        // Indirect branch. Bail and add all blocks of the function as a
        // successor.
        for (MCFunction::iterator i = f.begin(), e = f.end(); i != e; ++i)
          BB.addSucc(i->first);
      } else if (targ != Inst.Address+Inst.Size)
        BB.addSucc(targ);
      // Conditional branches can also fall through to the next block.
      if (Ana->isConditionalBranch(Inst.Inst) && llvm::next(i) != e)
        BB.addSucc(llvm::next(i)->first);
    } else {
      // No branch. Fall through to the next block.
      if (!Ana->isReturn(Inst.Inst) && llvm::next(i) != e)
        BB.addSucc(llvm::next(i)->first);
    }
  }

  return f;
}
/// canonicalizeInputFunction - Functions like swift_retain return an
/// argument as a low-level performance optimization.  This makes it difficult
/// to reason about pointer equality though, so undo it as an initial
/// canonicalization step.  After this step, all swift_retain's have been
/// replaced with swift_retain.
///
/// This also does some trivial peep-hole optimizations as we go.
static bool canonicalizeInputFunction(Function &F, ARCEntryPointBuilder &B,
                                      SwiftRCIdentity *RC) {
  bool Changed = false;
  DenseSet<Value *> NativeRefs;
  DenseMap<Value *, TinyPtrVector<Instruction *>> UnknownRetains;
  DenseMap<Value *, TinyPtrVector<Instruction *>> UnknownReleases;
  for (auto &BB : F) {
    UnknownRetains.clear();
    UnknownReleases.clear();
    NativeRefs.clear();
    for (auto I = BB.begin(); I != BB.end(); ) {
      Instruction &Inst = *I++;

      switch (classifyInstruction(Inst)) {
      // These instructions should not reach here based on the pass ordering.
      // i.e. LLVMARCOpt -> LLVMContractOpt.
      case RT_RetainN:
      case RT_UnknownRetainN:
      case RT_BridgeRetainN:
      case RT_ReleaseN:
      case RT_UnknownReleaseN:
      case RT_BridgeReleaseN:
        llvm_unreachable("These are only created by LLVMARCContract !");
      case RT_Unknown:
      case RT_BridgeRelease:
      case RT_AllocObject:
      case RT_FixLifetime:
      case RT_NoMemoryAccessed:
      case RT_RetainUnowned:
      case RT_CheckUnowned:
        break;
      case RT_Retain: {
        CallInst &CI = cast<CallInst>(Inst);
        Value *ArgVal = RC->getSwiftRCIdentityRoot(CI.getArgOperand(0));
        // retain(null) is a no-op.
        if (isa<ConstantPointerNull>(ArgVal)) {
          CI.eraseFromParent();
          Changed = true;
          ++NumNoopDeleted;
          continue;
        }
        // Rewrite unknown retains into swift_retains.
        NativeRefs.insert(ArgVal);
        for (auto &X : UnknownRetains[ArgVal]) {
          B.setInsertPoint(X);
          B.createRetain(ArgVal, cast<CallInst>(X));
          X->eraseFromParent();
          ++NumUnknownRetainReleaseSRed;
          Changed = true;
        }
        UnknownRetains[ArgVal].clear();
        break;
      }
      case RT_UnknownRetain: {
        CallInst &CI = cast<CallInst>(Inst);
        Value *ArgVal = RC->getSwiftRCIdentityRoot(CI.getArgOperand(0));
        // unknownRetain(null) is a no-op.
        if (isa<ConstantPointerNull>(ArgVal)) {
          CI.eraseFromParent();
          Changed = true;
          ++NumNoopDeleted;
          continue;
        }

        // Have not encountered a strong retain/release. keep it in the
        // unknown retain/release list for now. It might get replaced
        // later.
        if (NativeRefs.find(ArgVal) == NativeRefs.end()) {
           UnknownRetains[ArgVal].push_back(&CI);
        } else {
          B.setInsertPoint(&CI);
          B.createRetain(ArgVal, &CI);
          CI.eraseFromParent();
          ++NumUnknownRetainReleaseSRed;
          Changed = true;
        }
        break;
      }
      case RT_Release: {
        CallInst &CI = cast<CallInst>(Inst);
        Value *ArgVal = RC->getSwiftRCIdentityRoot(CI.getArgOperand(0));
        // release(null) is a no-op.
        if (isa<ConstantPointerNull>(ArgVal)) {
          CI.eraseFromParent();
          Changed = true;
          ++NumNoopDeleted;
          continue;
        }
        // Rewrite unknown releases into swift_releases.
        NativeRefs.insert(ArgVal);
        for (auto &X : UnknownReleases[ArgVal]) {
          B.setInsertPoint(X);
          B.createRelease(ArgVal, cast<CallInst>(X));
          X->eraseFromParent();
          ++NumUnknownRetainReleaseSRed;
          Changed = true;
        }
        UnknownReleases[ArgVal].clear();
        break;
      }
      case RT_UnknownRelease: {
        CallInst &CI = cast<CallInst>(Inst);
        Value *ArgVal = RC->getSwiftRCIdentityRoot(CI.getArgOperand(0));
        // unknownRelease(null) is a no-op.
        if (isa<ConstantPointerNull>(ArgVal)) {
          CI.eraseFromParent();
          Changed = true;
          ++NumNoopDeleted;
          continue;
        }

        // Have not encountered a strong retain/release. keep it in the
        // unknown retain/release list for now. It might get replaced
        // later.
        if (NativeRefs.find(ArgVal) == NativeRefs.end()) {
          UnknownReleases[ArgVal].push_back(&CI);
        } else {
          B.setInsertPoint(&CI);
          B.createRelease(ArgVal, &CI);
          CI.eraseFromParent();
          ++NumUnknownRetainReleaseSRed;
          Changed = true;
        }
        break;
      }
      case RT_ObjCRelease: {
        CallInst &CI = cast<CallInst>(Inst);
        Value *ArgVal = RC->getSwiftRCIdentityRoot(CI.getArgOperand(0));
        // objc_release(null) is a noop, zap it.
        if (isa<ConstantPointerNull>(ArgVal)) {
          CI.eraseFromParent();
          Changed = true;
          ++NumNoopDeleted;
          continue;
        }
        break;
      }

      // These retain instructions return their argument so must be processed
      // specially.
      case RT_BridgeRetain:
      case RT_ObjCRetain: {
        // Canonicalize the retain so that nothing uses its result.
        CallInst &CI = cast<CallInst>(Inst);
        // Do not get RC identical value here, could end up with a
        // crash in replaceAllUsesWith as the type maybe different.
        Value *ArgVal = CI.getArgOperand(0);
        if (!CI.use_empty()) {
          CI.replaceAllUsesWith(ArgVal);
          Changed = true;
        }

        // {objc_retain,swift_unknownRetain}(null) is a noop, delete it.
        if (isa<ConstantPointerNull>(ArgVal)) {
          CI.eraseFromParent();
          Changed = true;
          ++NumNoopDeleted;
          continue;
        }

        break;
      }
      }
    }
  }
  return Changed;
}
Esempio n. 5
0
Error AnalysisStyle::dump() {
  auto Tpi = File.getPDBTpiStream();
  if (!Tpi)
    return Tpi.takeError();

  TypeDatabase TypeDB(Tpi->getNumTypeRecords());
  TypeDatabaseVisitor DBV(TypeDB);
  TypeVisitorCallbackPipeline Pipeline;
  HashLookupVisitor Hasher(*Tpi);
  // Add them to the database
  Pipeline.addCallbackToPipeline(DBV);
  // Store their hash values
  Pipeline.addCallbackToPipeline(Hasher);

  if (auto EC = codeview::visitTypeStream(Tpi->typeArray(), Pipeline))
    return EC;

  auto &Adjusters = Tpi->getHashAdjusters();
  DenseSet<uint32_t> AdjusterSet;
  for (const auto &Adj : Adjusters) {
    assert(AdjusterSet.find(Adj.second) == AdjusterSet.end());
    AdjusterSet.insert(Adj.second);
  }

  uint32_t Count = 0;
  outs() << "Searching for hash collisions\n";
  for (const auto &H : Hasher.Lookup) {
    if (H.second.size() <= 1)
      continue;
    ++Count;
    outs() << formatv("Hash: {0}, Count: {1} records\n", H.first,
                      H.second.size());
    for (const auto &R : H.second) {
      auto Iter = AdjusterSet.find(R.TI.getIndex());
      StringRef Prefix;
      if (Iter != AdjusterSet.end()) {
        Prefix = "[HEAD]";
        AdjusterSet.erase(Iter);
      }
      StringRef LeafName = getLeafTypeName(R.Record.Type);
      uint32_t TI = R.TI.getIndex();
      StringRef TypeName = TypeDB.getTypeName(R.TI);
      outs() << formatv("{0,-6} {1} ({2:x}) {3}\n", Prefix, LeafName, TI,
                        TypeName);
    }
  }

  outs() << "\n";
  outs() << "Dumping hash adjustment chains\n";
  for (const auto &A : Tpi->getHashAdjusters()) {
    TypeIndex TI(A.second);
    StringRef TypeName = TypeDB.getTypeName(TI);
    const CVType &HeadRecord = TypeDB.getTypeRecord(TI);
    assert(HeadRecord.Hash.hasValue());

    auto CollisionsIter = Hasher.Lookup.find(*HeadRecord.Hash);
    if (CollisionsIter == Hasher.Lookup.end())
      continue;

    const auto &Collisions = CollisionsIter->second;
    outs() << TypeName << "\n";
    outs() << formatv("    [HEAD] {0:x} {1} {2}\n", A.second,
                      getLeafTypeName(HeadRecord.Type), TypeName);
    for (const auto &Chain : Collisions) {
      if (Chain.TI == TI)
        continue;
      const CVType &TailRecord = TypeDB.getTypeRecord(Chain.TI);
      outs() << formatv("           {0:x} {1} {2}\n", Chain.TI.getIndex(),
                        getLeafTypeName(TailRecord.Type),
                        TypeDB.getTypeName(Chain.TI));
    }
  }
  outs() << formatv("There are {0} orphaned hash adjusters\n",
                    AdjusterSet.size());
  for (const auto &Adj : AdjusterSet) {
    outs() << formatv("    {0}\n", Adj);
  }

  uint32_t DistinctHashValues = Hasher.Lookup.size();
  outs() << formatv("{0}/{1} hash collisions", Count, DistinctHashValues);
  return Error::success();
}