Remove LLVM 8.0.1 files.

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diff --git a/gnu/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp b/gnu/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp
deleted file mode 100644
index 108f2879a07..00000000000
--- a/gnu/llvm/lib/Target/WebAssembly/WebAssemblyFixIrreducibleControlFlow.cpp
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@@ -1,429 +0,0 @@
-//=- WebAssemblyFixIrreducibleControlFlow.cpp - Fix irreducible control flow -//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-///
-/// \file
-/// This file implements a pass that transforms irreducible control flow into
-/// reducible control flow. Irreducible control flow means multiple-entry
-/// loops; they appear as CFG cycles that are not recorded in MachineLoopInfo
-/// due to being unnatural.
-///
-/// Note that LLVM has a generic pass that lowers irreducible control flow, but
-/// it linearizes control flow, turning diamonds into two triangles, which is
-/// both unnecessary and undesirable for WebAssembly.
-///
-/// The big picture: Ignoring natural loops (seeing them monolithically), we
-/// find all the blocks which can return to themselves ("loopers"). Loopers
-/// reachable from the non-loopers are loop entries: if there are 2 or more,
-/// then we have irreducible control flow. We fix that as follows: a new block
-/// is created that can dispatch to each of the loop entries, based on the
-/// value of a label "helper" variable, and we replace direct branches to the
-/// entries with assignments to the label variable and a branch to the dispatch
-/// block. Then the dispatch block is the single entry in a new natural loop.
-///
-/// This is similar to what the Relooper [1] does, both identify looping code
-/// that requires multiple entries, and resolve it in a similar way. In
-/// Relooper terminology, we implement a Multiple shape in a Loop shape. Note
-/// also that like the Relooper, we implement a "minimal" intervention: we only
-/// use the "label" helper for the blocks we absolutely must and no others. We
-/// also prioritize code size and do not perform node splitting (i.e. we don't
-/// duplicate code in order to resolve irreducibility).
-///
-/// The difference between this code and the Relooper is that the Relooper also
-/// generates ifs and loops and works in a recursive manner, knowing at each
-/// point what the entries are, and recursively breaks down the problem. Here
-/// we just want to resolve irreducible control flow, and we also want to use
-/// as much LLVM infrastructure as possible. So we use the MachineLoopInfo to
-/// identify natural loops, etc., and we start with the whole CFG and must
-/// identify both the looping code and its entries.
-///
-/// [1] Alon Zakai. 2011. Emscripten: an LLVM-to-JavaScript compiler. In
-/// Proceedings of the ACM international conference companion on Object oriented
-/// programming systems languages and applications companion (SPLASH '11). ACM,
-/// New York, NY, USA, 301-312. DOI=10.1145/2048147.2048224
-/// http://doi.acm.org/10.1145/2048147.2048224
-///
-//===----------------------------------------------------------------------===//
-
-#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
-#include "WebAssembly.h"
-#include "WebAssemblyMachineFunctionInfo.h"
-#include "WebAssemblySubtarget.h"
-#include "llvm/ADT/PriorityQueue.h"
-#include "llvm/ADT/SCCIterator.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/CodeGen/MachineDominators.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "wasm-fix-irreducible-control-flow"
-
-namespace {
-
-class LoopFixer {
-public:
-  LoopFixer(MachineFunction &MF, MachineLoopInfo &MLI, MachineLoop *Loop)
-      : MF(MF), MLI(MLI), Loop(Loop) {}
-
-  // Run the fixer on the given inputs. Returns whether changes were made.
-  bool run();
-
-private:
-  MachineFunction &MF;
-  MachineLoopInfo &MLI;
-  MachineLoop *Loop;
-
-  MachineBasicBlock *Header;
-  SmallPtrSet<MachineBasicBlock *, 4> LoopBlocks;
-
-  using BlockSet = SmallPtrSet<MachineBasicBlock *, 4>;
-  DenseMap<MachineBasicBlock *, BlockSet> Reachable;
-
-  // The worklist contains pairs of recent additions, (a, b), where we just
-  // added a link a => b.
-  using BlockPair = std::pair<MachineBasicBlock *, MachineBasicBlock *>;
-  SmallVector<BlockPair, 4> WorkList;
-
-  // Get a canonical block to represent a block or a loop: the block, or if in
-  // an inner loop, the loop header, of it in an outer loop scope, we can
-  // ignore it. We need to call this on all blocks we work on.
-  MachineBasicBlock *canonicalize(MachineBasicBlock *MBB) {
-    MachineLoop *InnerLoop = MLI.getLoopFor(MBB);
-    if (InnerLoop == Loop) {
-      return MBB;
-    } else {
-      // This is either in an outer or an inner loop, and not in ours.
-      if (!LoopBlocks.count(MBB)) {
-        // It's in outer code, ignore it.
-        return nullptr;
-      }
-      assert(InnerLoop);
-      // It's in an inner loop, canonicalize it to the header of that loop.
-      return InnerLoop->getHeader();
-    }
-  }
-
-  // For a successor we can additionally ignore it if it's a branch back to a
-  // natural loop top, as when we are in the scope of a loop, we just care
-  // about internal irreducibility, and can ignore the loop we are in. We need
-  // to call this on all blocks in a context where they are a successor.
-  MachineBasicBlock *canonicalizeSuccessor(MachineBasicBlock *MBB) {
-    if (Loop && MBB == Loop->getHeader()) {
-      // Ignore branches going to the loop's natural header.
-      return nullptr;
-    }
-    return canonicalize(MBB);
-  }
-
-  // Potentially insert a new reachable edge, and if so, note it as further
-  // work.
-  void maybeInsert(MachineBasicBlock *MBB, MachineBasicBlock *Succ) {
-    assert(MBB == canonicalize(MBB));
-    assert(Succ);
-    // Succ may not be interesting as a sucessor.
-    Succ = canonicalizeSuccessor(Succ);
-    if (!Succ)
-      return;
-    if (Reachable[MBB].insert(Succ).second) {
-      // For there to be further work, it means that we have
-      //   X => MBB => Succ
-      // for some other X, and in that case X => Succ would be a new edge for
-      // us to discover later. However, if we don't care about MBB as a
-      // successor, then we don't care about that anyhow.
-      if (canonicalizeSuccessor(MBB)) {
-        WorkList.emplace_back(MBB, Succ);
-      }
-    }
-  }
-};
-
-bool LoopFixer::run() {
-  Header = Loop ? Loop->getHeader() : &*MF.begin();
-
-  // Identify all the blocks in this loop scope.
-  if (Loop) {
-    for (auto *MBB : Loop->getBlocks()) {
-      LoopBlocks.insert(MBB);
-    }
-  } else {
-    for (auto &MBB : MF) {
-      LoopBlocks.insert(&MBB);
-    }
-  }
-
-  // Compute which (canonicalized) blocks each block can reach.
-
-  // Add all the initial work.
-  for (auto *MBB : LoopBlocks) {
-    MachineLoop *InnerLoop = MLI.getLoopFor(MBB);
-
-    if (InnerLoop == Loop) {
-      for (auto *Succ : MBB->successors()) {
-        maybeInsert(MBB, Succ);
-      }
-    } else {
-      // It can't be in an outer loop - we loop on LoopBlocks - and so it must
-      // be an inner loop.
-      assert(InnerLoop);
-      // Check if we are the canonical block for this loop.
-      if (canonicalize(MBB) != MBB) {
-        continue;
-      }
-      // The successors are those of the loop.
-      SmallVector<MachineBasicBlock *, 2> ExitBlocks;
-      InnerLoop->getExitBlocks(ExitBlocks);
-      for (auto *Succ : ExitBlocks) {
-        maybeInsert(MBB, Succ);
-      }
-    }
-  }
-
-  // Do work until we are all done.
-  while (!WorkList.empty()) {
-    MachineBasicBlock *MBB;
-    MachineBasicBlock *Succ;
-    std::tie(MBB, Succ) = WorkList.pop_back_val();
-    // The worklist item is an edge we just added, so it must have valid blocks
-    // (and not something canonicalized to nullptr).
-    assert(MBB);
-    assert(Succ);
-    // The successor in that pair must also be a valid successor.
-    assert(MBB == canonicalizeSuccessor(MBB));
-    // We recently added MBB => Succ, and that means we may have enabled
-    // Pred => MBB => Succ. Check all the predecessors. Note that our loop here
-    // is correct for both a block and a block representing a loop, as the loop
-    // is natural and so the predecessors are all predecessors of the loop
-    // header, which is the block we have here.
-    for (auto *Pred : MBB->predecessors()) {
-      // Canonicalize, make sure it's relevant, and check it's not the same
-      // block (an update to the block itself doesn't help compute that same
-      // block).
-      Pred = canonicalize(Pred);
-      if (Pred && Pred != MBB) {
-        maybeInsert(Pred, Succ);
-      }
-    }
-  }
-
-  // It's now trivial to identify the loopers.
-  SmallPtrSet<MachineBasicBlock *, 4> Loopers;
-  for (auto MBB : LoopBlocks) {
-    if (Reachable[MBB].count(MBB)) {
-      Loopers.insert(MBB);
-    }
-  }
-  // The header cannot be a looper. At the toplevel, LLVM does not allow the
-  // entry to be in a loop, and in a natural loop we should ignore the header.
-  assert(Loopers.count(Header) == 0);
-
-  // Find the entries, loopers reachable from non-loopers.
-  SmallPtrSet<MachineBasicBlock *, 4> Entries;
-  SmallVector<MachineBasicBlock *, 4> SortedEntries;
-  for (auto *Looper : Loopers) {
-    for (auto *Pred : Looper->predecessors()) {
-      Pred = canonicalize(Pred);
-      if (Pred && !Loopers.count(Pred)) {
-        Entries.insert(Looper);
-        SortedEntries.push_back(Looper);
-        break;
-      }
-    }
-  }
-
-  // Check if we found irreducible control flow.
-  if (LLVM_LIKELY(Entries.size() <= 1))
-    return false;
-
-  // Sort the entries to ensure a deterministic build.
-  llvm::sort(SortedEntries,
-             [&](const MachineBasicBlock *A, const MachineBasicBlock *B) {
-               auto ANum = A->getNumber();
-               auto BNum = B->getNumber();
-               return ANum < BNum;
-             });
-
-#ifndef NDEBUG
-  for (auto Block : SortedEntries)
-    assert(Block->getNumber() != -1);
-  if (SortedEntries.size() > 1) {
-    for (auto I = SortedEntries.begin(), E = SortedEntries.end() - 1;
-         I != E; ++I) {
-      auto ANum = (*I)->getNumber();
-      auto BNum = (*(std::next(I)))->getNumber();
-      assert(ANum != BNum);
-    }
-  }
-#endif
-
-  // Create a dispatch block which will contain a jump table to the entries.
-  MachineBasicBlock *Dispatch = MF.CreateMachineBasicBlock();
-  MF.insert(MF.end(), Dispatch);
-  MLI.changeLoopFor(Dispatch, Loop);
-
-  // Add the jump table.
-  const auto &TII = *MF.getSubtarget<WebAssemblySubtarget>().getInstrInfo();
-  MachineInstrBuilder MIB = BuildMI(*Dispatch, Dispatch->end(), DebugLoc(),
-                                    TII.get(WebAssembly::BR_TABLE_I32));
-
-  // Add the register which will be used to tell the jump table which block to
-  // jump to.
-  MachineRegisterInfo &MRI = MF.getRegInfo();
-  unsigned Reg = MRI.createVirtualRegister(&WebAssembly::I32RegClass);
-  MIB.addReg(Reg);
-
-  // Compute the indices in the superheader, one for each bad block, and
-  // add them as successors.
-  DenseMap<MachineBasicBlock *, unsigned> Indices;
-  for (auto *MBB : SortedEntries) {
-    auto Pair = Indices.insert(std::make_pair(MBB, 0));
-    if (!Pair.second) {
-      continue;
-    }
-
-    unsigned Index = MIB.getInstr()->getNumExplicitOperands() - 1;
-    Pair.first->second = Index;
-
-    MIB.addMBB(MBB);
-    Dispatch->addSuccessor(MBB);
-  }
-
-  // Rewrite the problematic successors for every block that wants to reach the
-  // bad blocks. For simplicity, we just introduce a new block for every edge
-  // we need to rewrite. (Fancier things are possible.)
-
-  SmallVector<MachineBasicBlock *, 4> AllPreds;
-  for (auto *MBB : SortedEntries) {
-    for (auto *Pred : MBB->predecessors()) {
-      if (Pred != Dispatch) {
-        AllPreds.push_back(Pred);
-      }
-    }
-  }
-
-  for (MachineBasicBlock *MBB : AllPreds) {
-    DenseMap<MachineBasicBlock *, MachineBasicBlock *> Map;
-    for (auto *Succ : MBB->successors()) {
-      if (!Entries.count(Succ)) {
-        continue;
-      }
-
-      // This is a successor we need to rewrite.
-      MachineBasicBlock *Split = MF.CreateMachineBasicBlock();
-      MF.insert(MBB->isLayoutSuccessor(Succ) ? MachineFunction::iterator(Succ)
-                                             : MF.end(),
-                Split);
-      MLI.changeLoopFor(Split, Loop);
-
-      // Set the jump table's register of the index of the block we wish to
-      // jump to, and jump to the jump table.
-      BuildMI(*Split, Split->end(), DebugLoc(), TII.get(WebAssembly::CONST_I32),
-              Reg)
-          .addImm(Indices[Succ]);
-      BuildMI(*Split, Split->end(), DebugLoc(), TII.get(WebAssembly::BR))
-          .addMBB(Dispatch);
-      Split->addSuccessor(Dispatch);
-      Map[Succ] = Split;
-    }
-    // Remap the terminator operands and the successor list.
-    for (MachineInstr &Term : MBB->terminators())
-      for (auto &Op : Term.explicit_uses())
-        if (Op.isMBB() && Indices.count(Op.getMBB()))
-          Op.setMBB(Map[Op.getMBB()]);
-    for (auto Rewrite : Map)
-      MBB->replaceSuccessor(Rewrite.first, Rewrite.second);
-  }
-
-  // Create a fake default label, because br_table requires one.
-  MIB.addMBB(MIB.getInstr()
-                 ->getOperand(MIB.getInstr()->getNumExplicitOperands() - 1)
-                 .getMBB());
-
-  return true;
-}
-
-class WebAssemblyFixIrreducibleControlFlow final : public MachineFunctionPass {
-  StringRef getPassName() const override {
-    return "WebAssembly Fix Irreducible Control Flow";
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.setPreservesCFG();
-    AU.addRequired<MachineDominatorTree>();
-    AU.addPreserved<MachineDominatorTree>();
-    AU.addRequired<MachineLoopInfo>();
-    AU.addPreserved<MachineLoopInfo>();
-    MachineFunctionPass::getAnalysisUsage(AU);
-  }
-
-  bool runOnMachineFunction(MachineFunction &MF) override;
-
-  bool runIteration(MachineFunction &MF, MachineLoopInfo &MLI) {
-    // Visit the function body, which is identified as a null loop.
-    if (LoopFixer(MF, MLI, nullptr).run()) {
-      return true;
-    }
-
-    // Visit all the loops.
-    SmallVector<MachineLoop *, 8> Worklist(MLI.begin(), MLI.end());
-    while (!Worklist.empty()) {
-      MachineLoop *Loop = Worklist.pop_back_val();
-      Worklist.append(Loop->begin(), Loop->end());
-      if (LoopFixer(MF, MLI, Loop).run()) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-
-public:
-  static char ID; // Pass identification, replacement for typeid
-  WebAssemblyFixIrreducibleControlFlow() : MachineFunctionPass(ID) {}
-};
-} // end anonymous namespace
-
-char WebAssemblyFixIrreducibleControlFlow::ID = 0;
-INITIALIZE_PASS(WebAssemblyFixIrreducibleControlFlow, DEBUG_TYPE,
-                "Removes irreducible control flow", false, false)
-
-FunctionPass *llvm::createWebAssemblyFixIrreducibleControlFlow() {
-  return new WebAssemblyFixIrreducibleControlFlow();
-}
-
-bool WebAssemblyFixIrreducibleControlFlow::runOnMachineFunction(
-    MachineFunction &MF) {
-  LLVM_DEBUG(dbgs() << "********** Fixing Irreducible Control Flow **********\n"
-                       "********** Function: "
-                    << MF.getName() << '\n');
-
-  bool Changed = false;
-  auto &MLI = getAnalysis<MachineLoopInfo>();
-
-  // When we modify something, bail out and recompute MLI, then start again, as
-  // we create a new natural loop when we resolve irreducible control flow, and
-  // other loops may become nested in it, etc. In practice this is not an issue
-  // because irreducible control flow is rare, only very few cycles are needed
-  // here.
-  while (LLVM_UNLIKELY(runIteration(MF, MLI))) {
-    // We rewrote part of the function; recompute MLI and start again.
-    LLVM_DEBUG(dbgs() << "Recomputing loops.\n");
-    MF.getRegInfo().invalidateLiveness();
-    MF.RenumberBlocks();
-    getAnalysis<MachineDominatorTree>().runOnMachineFunction(MF);
-    MLI.runOnMachineFunction(MF);
-    Changed = true;
-  }
-
-  return Changed;
-}