Index: lib/CodeGen/BranchFolding.h
===================================================================
--- lib/CodeGen/BranchFolding.h
+++ lib/CodeGen/BranchFolding.h
@@ -122,6 +122,7 @@
                                   const MachineBasicBlock *MBB) const;
       raw_ostream &printBlockFreq(raw_ostream &OS,
                                   const BlockFrequency Freq) const;
+      uint64_t getEntryFreq() const;
 
     private:
       const MachineBlockFrequencyInfo &MBFI;
Index: lib/CodeGen/BranchFolding.cpp
===================================================================
--- lib/CodeGen/BranchFolding.cpp
+++ lib/CodeGen/BranchFolding.cpp
@@ -498,6 +498,11 @@
   return MBFI.printBlockFreq(OS, Freq);
 }
 
+uint64_t
+BranchFolder::MBFIWrapper::getEntryFreq() const {
+  return MBFI.getEntryFreq();
+}
+
 /// CountTerminators - Count the number of terminators in the given
 /// block and set I to the position of the first non-terminator, if there
 /// is one, or MBB->end() otherwise.
Index: lib/CodeGen/MachineBlockPlacement.cpp
===================================================================
--- lib/CodeGen/MachineBlockPlacement.cpp
+++ lib/CodeGen/MachineBlockPlacement.cpp
@@ -40,6 +40,7 @@
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachinePostDominators.h"
 #include "llvm/CodeGen/TailDuplicator.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/CommandLine.h"
@@ -49,6 +50,8 @@
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
 #include <algorithm>
+#include <functional>
+#include <utility>
 using namespace llvm;
 
 #define DEBUG_TYPE "block-placement"
@@ -136,13 +139,23 @@
               cl::init(true), cl::Hidden);
 
 // Heuristic for tail duplication.
-static cl::opt<unsigned> TailDuplicatePlacementThreshold(
+static cl::opt<unsigned> TailDupPlacementThreshold(
     "tail-dup-placement-threshold",
     cl::desc("Instruction cutoff for tail duplication during layout. "
              "Tail merging during layout is forced to have a threshold "
              "that won't conflict."), cl::init(2),
     cl::Hidden);
 
+// Heuristic for tail duplication.
+static cl::opt<unsigned> TailDupPlacementPenalty(
+    "tail-dup-placement-penalty",
+    cl::desc("Cost penalty for blocks that can avoid breaking CFG by copying. "
+             "Copying can increase fallthrough, but it also increases icache "
+             "pressure. This parameter controls the penalty to account for that. "
+             "Percent as integer."),
+    cl::init(2),
+    cl::Hidden);
+
 extern cl::opt<unsigned> StaticLikelyProb;
 extern cl::opt<unsigned> ProfileLikelyProb;
 
@@ -266,6 +279,12 @@
   /// \brief A typedef for a block filter set.
   typedef SmallSetVector<MachineBasicBlock *, 16> BlockFilterSet;
 
+  /// Pair struct containing basic block and taildup profitiability
+  struct BlockAndTailDupResult {
+    MachineBasicBlock * BB;
+    bool ShouldTailDup;
+  };
+
   /// \brief work lists of blocks that are ready to be laid out
   SmallVector<MachineBasicBlock *, 16> BlockWorkList;
   SmallVector<MachineBasicBlock *, 16> EHPadWorkList;
@@ -293,9 +312,12 @@
   /// \brief A handle to the target's lowering info.
   const TargetLoweringBase *TLI;
 
-  /// \brief A handle to the post dominator tree.
+  /// \brief A handle to the dominator tree.
   MachineDominatorTree *MDT;
 
+  /// \brief A handle to the post dominator tree.
+  MachinePostDominatorTree *MPDT;
+
   /// \brief Duplicator used to duplicate tails during placement.
   ///
   /// Placement decisions can open up new tail duplication opportunities, but
@@ -368,9 +390,9 @@
                              BlockChain &SuccChain, BranchProbability SuccProb,
                              BranchProbability RealSuccProb, BlockChain &Chain,
                              const BlockFilterSet *BlockFilter);
-  MachineBasicBlock *selectBestSuccessor(MachineBasicBlock *BB,
-                                         BlockChain &Chain,
-                                         const BlockFilterSet *BlockFilter);
+  BlockAndTailDupResult selectBestSuccessor(MachineBasicBlock *BB,
+                                            BlockChain &Chain,
+                                            const BlockFilterSet *BlockFilter);
   MachineBasicBlock *
   selectBestCandidateBlock(BlockChain &Chain,
                            SmallVectorImpl<MachineBasicBlock *> &WorkList);
@@ -403,6 +425,18 @@
   void buildCFGChains();
   void optimizeBranches();
   void alignBlocks();
+  bool shouldTailDuplicate(MachineBasicBlock *BB);
+  /// Check the edge frequencies to see if tail duplication will increase
+  /// fallthroughs.
+  bool isProfitableToTailDup(
+    MachineBasicBlock *BB, MachineBasicBlock *Succ,
+    BranchProbability AdjustedSumProb,
+    BlockChain &Chain, const BlockFilterSet *BlockFilter);
+  /// Returns true if a block can tail duplicate into all unplaced
+  /// predecessors. Filters based on loop.
+  bool canTailDuplicateUnplacedPreds(
+      MachineBasicBlock *BB, MachineBasicBlock *Succ,
+      BlockChain &Chain, const BlockFilterSet *BlockFilter);
 
 public:
   static char ID; // Pass identification, replacement for typeid
@@ -416,6 +450,8 @@
     AU.addRequired<MachineBranchProbabilityInfo>();
     AU.addRequired<MachineBlockFrequencyInfo>();
     AU.addRequired<MachineDominatorTree>();
+    if (TailDupPlacement)
+      AU.addRequired<MachinePostDominatorTree>();
     AU.addRequired<MachineLoopInfo>();
     AU.addRequired<TargetPassConfig>();
     MachineFunctionPass::getAnalysisUsage(AU);
@@ -430,6 +466,7 @@
 INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo)
 INITIALIZE_PASS_DEPENDENCY(MachineBlockFrequencyInfo)
 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
+INITIALIZE_PASS_DEPENDENCY(MachinePostDominatorTree)
 INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
 INITIALIZE_PASS_END(MachineBlockPlacement, "block-placement",
                     "Branch Probability Basic Block Placement", false, false)
@@ -561,6 +598,210 @@
   return SuccProb;
 }
 
+/// Check if a block should be tail duplicated.
+/// \p BB Block to check.
+bool MachineBlockPlacement::shouldTailDuplicate(MachineBasicBlock *BB) {
+  // Blocks with single successors don't create additional fallthrough
+  // opportunities. Don't duplicate them. TODO: When conditional exits are
+  // analyzable, allow them to be duplicated.
+  bool IsSimple = TailDup.isSimpleBB(BB);
+
+  if (BB->succ_size() == 1)
+    return false;
+  return TailDup.shouldTailDuplicate(IsSimple, *BB);
+}
+
+/// Compare 2 BlockFrequency's with a small penalty for \p A.
+/// In order to be conservative, we apply a X% penalty to account for
+/// increased icache pressure and static heuristics. For small frequencies
+/// we use only the numerators to improve accuracy. For simplicity, we assume the
+/// penalty is less than 100%
+/// TODO(iteratee): Use 64-bit fixed point edge frequencies everywhere.
+static bool greaterWithBias(BlockFrequency A, BlockFrequency B,
+                            uint64_t EntryFreq) {
+  if (B > A)
+    return false;
+  BlockFrequency Gain = A - B;
+  if (Gain.getFrequency() < (uint64_t) 1 << 32) {
+    if (EntryFreq < (uint64_t) 1 << 40) {
+      return (Gain.getFrequency() * 100 > EntryFreq * TailDupPlacementPenalty);
+    }
+    return false;
+  } else {
+    BranchProbability ThresholdProb(TailDupPlacementPenalty, 100);
+    return (Gain / ThresholdProb).getFrequency() > EntryFreq;
+  }
+}
+
+/// Check the edge frequencies to see if tail duplication will increase
+/// fallthroughs. It only makes sense to call this function when
+/// \p Succ would not be chosen otherwise. Tail duplication of \p Succ is
+/// always locally profitable if we would have picked \p Succ without
+/// considering duplication.
+bool MachineBlockPlacement::isProfitableToTailDup(
+    MachineBasicBlock *BB, MachineBasicBlock *Succ,
+    BranchProbability QProb,
+    BlockChain &Chain, const BlockFilterSet *BlockFilter) {
+  // We need to do a probability calculation to make sure this is profitable.
+  // First: does succ have a successor that post-dominates? This affects the
+  // calculation. The 2 relevant cases are:
+  //    BB         BB
+  //    | \Qout    | \Qout
+  //   P|  C       |P C
+  //    =   C'     =   C'
+  //    |  /Qin    |  /Qin
+  //    | /        | /
+  //    Succ       Succ
+  //    / \        | \  V
+  //  U/   =V      |U \
+  //  /     \      =   D
+  //  D      E     |  /
+  //               | /
+  //               |/
+  //               PDom
+  //  '=' : Branch taken for that CFG edge
+  // In the second case, Placing Succ while duplicating it into C prevents the
+  // fallthrough of Succ into either D or PDom, because they now have C as an
+  // unplaced predecessor
+
+  // Start by figuring out which case we fall into
+  MachineBasicBlock *PDom = nullptr;
+  SmallVector<MachineBasicBlock *, 4> SuccSuccs;
+  // Only scan the relevant successors
+  auto AdjustedSuccSumProb =
+      collectViableSuccessors(Succ, Chain, BlockFilter, SuccSuccs);
+  BranchProbability PProb = MBPI->getEdgeProbability(BB, Succ);
+  auto BBFreq = MBFI->getBlockFreq(BB);
+  auto SuccFreq = MBFI->getBlockFreq(Succ);
+  BlockFrequency P = BBFreq * PProb;
+  BlockFrequency Qout = BBFreq * QProb;
+  uint64_t EntryFreq = MBFI->getEntryFreq();
+  // If there are no more successors, it is profitable to copy, as it strictly
+  // increases fallthrough.
+  if (SuccSuccs.size() == 0)
+    return greaterWithBias(P, Qout, EntryFreq);
+
+  auto BestSuccSucc = BranchProbability::getZero();
+  // Find the PDom or the best Succ if no PDom exists.
+  for (MachineBasicBlock *SuccSucc : SuccSuccs) {
+    auto Prob = MBPI->getEdgeProbability(Succ, SuccSucc);
+    if (Prob > BestSuccSucc)
+      BestSuccSucc = Prob;
+    if (PDom == nullptr)
+      if (MPDT->dominates(SuccSucc, Succ)) {
+        PDom = SuccSucc;
+        break;
+      }
+  }
+  // For the comparisons, we need to know Succ's best incoming edge that isn't
+  // from BB.
+  auto SuccBestPred = BlockFrequency(0);
+  for (MachineBasicBlock *SuccPred : Succ->predecessors()) {
+    if (SuccPred == Succ || SuccPred == BB
+        || BlockToChain[SuccPred] == &Chain
+        || (BlockFilter && !BlockFilter->count(SuccPred)))
+      continue;
+    auto Freq = MBFI->getBlockFreq(SuccPred)
+        * MBPI->getEdgeProbability(SuccPred, Succ);
+    if (Freq > SuccBestPred)
+      SuccBestPred = Freq;
+  }
+  // Qin is Succ's best unplaced incoming edge that isn't BB
+  BlockFrequency Qin = SuccBestPred;
+  // If it doesn't have a post-dominating successor, here is the calculation:
+  //    BB        BB
+  //    | \Qout   |  \
+  //   P|  C      |   =
+  //    =   C'    |    C
+  //    |  /Qin   |     |
+  //    | /       |     C' (+Succ)
+  //    Succ      Succ /|
+  //    / \       |  \/ |
+  //  U/   =V     =  /= =
+  //  /     \     | /  \|
+  //  D      E    D     E
+  //  '=' : Branch taken for that CFG edge
+  //  Cost in the first case is: P + V
+  //  For this calculation, we always assume P > Qout. If Qout > P
+  //  The result of this function will be ignored at the caller.
+  //  Cost in the second case is: Qout + Qin * V + P * U + P * V
+  //  TODO(iteratee): If we lay out D after Succ, the P * U term
+  //  goes away. This logic is coming in D28522.
+
+  if (PDom == nullptr || !Succ->isSuccessor(PDom)) {
+    BranchProbability UProb = BestSuccSucc;
+    BranchProbability VProb = AdjustedSuccSumProb - UProb;
+    BlockFrequency V = SuccFreq * VProb;
+    BlockFrequency QinV = Qin * VProb;
+    BlockFrequency BaseCost = P + V;
+    BlockFrequency DupCost = Qout + QinV + P * AdjustedSuccSumProb;
+    return greaterWithBias(BaseCost, DupCost, EntryFreq);
+  }
+  BranchProbability UProb = MBPI->getEdgeProbability(Succ, PDom);
+  BranchProbability VProb = AdjustedSuccSumProb - UProb;
+  BlockFrequency U = SuccFreq * UProb;
+  BlockFrequency V = SuccFreq * VProb;
+  // If there is a post-dominating successor, here is the calculation:
+  // BB         BB                 BB          BB
+  // | \Qout    |  \               | \Qout     |  \
+  // |P C       |   =              |P C        |   =
+  // =   C'     |P   C             =   C'      |P   C
+  // |  /Qin    |     |            |  /Qin     |     |
+  // | /        |     C' (+Succ)   | /         |     C' (+Succ)
+  // Succ       Succ /|            Succ        Succ /|
+  // | \  V     |  \/ |            | \  V      |  \/ |
+  // |U \       |U /\ |            |U =        |U /\ |
+  // =   D      = =  =|            |   D       | =  =|
+  // |  /       |/    D            |  /        |/    D
+  // | /        |    /             | =         |    /
+  // |/         |   /              |/          |   =
+  // Dom        Dom                Dom         Dom
+  //  '=' : Branch taken for that CFG edge
+  // The cost for taken branches in the first case is P + U
+  // The cost in the second case (assuming independence), given the layout:
+  // BB, Succ, (C+Succ), D, Dom
+  // is Qout + P * V + Qin * U
+  // compare P + U vs Qout + P * V + Qin * U.
+  //
+  // The 3rd and 4th cases cover when Dom would be chosen to follow Succ.
+  //
+  // For the 3rd case, the cost is P + 2 * V
+  // For the 4th case, the cost is Qout + Qin * U + P * V + V
+  // We choose 4 over 3 when (P + V) > Qout + Qin * U + P * V
+  if (UProb > AdjustedSuccSumProb / 2
+      && !hasBetterLayoutPredecessor(Succ, PDom, *BlockToChain[PDom],
+                                     UProb, UProb, Chain, BlockFilter)) {
+    // Cases 3 & 4
+    return greaterWithBias((P + V), (Qout + Qin * UProb + P * VProb),
+                           EntryFreq);
+  }
+  // Cases 1 & 2
+  return greaterWithBias(
+      (P + U), (Qout + Qin * UProb + P * AdjustedSuccSumProb), EntryFreq);
+}
+
+
+/// When the option TailDupPlacement is on, this method checks if the
+/// fallthrough candidate block \p Succ (of block \p BB) can be tail-duplicated
+/// into all of its unplaced, unfiltered predecessors, that are not BB.
+bool MachineBlockPlacement::canTailDuplicateUnplacedPreds(
+    MachineBasicBlock *BB, MachineBasicBlock *Succ, BlockChain &Chain,
+    const BlockFilterSet *BlockFilter) {
+  if (!shouldTailDuplicate(Succ))
+    return false;
+
+  for (MachineBasicBlock *Pred : Succ->predecessors()) {
+    // Make sure all unplaced and unfiltered predecessors can be
+    // tail-duplicated into.
+    if (Pred == BB || (BlockFilter && !BlockFilter->count(Pred))
+        || BlockToChain[Pred] == &Chain)
+      continue;
+    if (!TailDup.canTailDuplicate(Succ, Pred))
+      return false;
+  }
+  return true;
+}
+
 /// When the option OutlineOptionalBranches is on, this method
 /// checks if the fallthrough candidate block \p Succ (of block
 /// \p BB) also has other unscheduled predecessor blocks which
@@ -609,11 +850,11 @@
     if (Succ1->isSuccessor(Succ2) || Succ2->isSuccessor(Succ1)) {
       /* See case 1 below for the cost analysis. For BB->Succ to
        * be taken with smaller cost, the following needs to hold:
-       *   Prob(BB->Succ) > 2* Prob(BB->Pred)
-       *   So the threshold T
-       *   T = 2 * (1-Prob(BB->Pred). Since T + Prob(BB->Pred) == 1,
-       * We have  T + T/2 = 1, i.e. T = 2/3. Also adding user specified
-       * branch bias, we have
+       *   Prob(BB->Succ) > 2 * Prob(BB->Pred)
+       *   So the threshold T in the calculation below
+       *   (1-T) * Prob(BB->Succ) > T * Prob(BB->Pred)
+       *   So T / (1 - T) = 2, Yielding T = 2/3
+       * Also adding user specified branch bias, we have
        *   T = (2/3)*(ProfileLikelyProb/50)
        *     = (2*ProfileLikelyProb)/150)
        */
@@ -625,6 +866,12 @@
 
 /// Checks to see if the layout candidate block \p Succ has a better layout
 /// predecessor than \c BB. If yes, returns true.
+/// \p SuccProb: The probability adjusted for only remaining blocks.
+///   Only used for logging
+/// \p RealSuccProb: The un-adjusted probability.
+/// \p Chain: The chain that BB belongs to and Succ is being considered for.
+/// \p BlockFilter: if non-null, the set of blocks that make up the loop being
+///    considered
 bool MachineBlockPlacement::hasBetterLayoutPredecessor(
     MachineBasicBlock *BB, MachineBasicBlock *Succ, BlockChain &SuccChain,
     BranchProbability SuccProb, BranchProbability RealSuccProb,
@@ -756,13 +1003,15 @@
   for (MachineBasicBlock *Pred : Succ->predecessors()) {
     if (Pred == Succ || BlockToChain[Pred] == &SuccChain ||
         (BlockFilter && !BlockFilter->count(Pred)) ||
-        BlockToChain[Pred] == &Chain)
+        BlockToChain[Pred] == &Chain ||
+        // This check is redundant except for look ahead. This function is
+        // called for lookahead by isProfitableToTailDup when BB hasn't been
+        // placed yet.
+        (Pred == BB))
       continue;
     // Do backward checking.
     // For all cases above, we need a backward checking to filter out edges that
-    // are not 'strongly' biased. With profile data available, the check is
-    // mostly redundant for case 2 (when threshold prob is set at 50%) unless S
-    // has more than two successors.
+    // are not 'strongly' biased.
     // BB  Pred
     //  \ /
     //  Succ
@@ -798,14 +1047,15 @@
 /// breaking CFG structure, but cave and break such structures in the case of
 /// very hot successor edges.
 ///
-/// \returns The best successor block found, or null if none are viable.
-MachineBasicBlock *
+/// \returns The best successor block found, or null if none are viable, along
+/// with a boolean indicating if tail duplication is necessary.
+MachineBlockPlacement::BlockAndTailDupResult
 MachineBlockPlacement::selectBestSuccessor(MachineBasicBlock *BB,
                                            BlockChain &Chain,
                                            const BlockFilterSet *BlockFilter) {
   const BranchProbability HotProb(StaticLikelyProb, 100);
 
-  MachineBasicBlock *BestSucc = nullptr;
+  BlockAndTailDupResult BestSucc = { nullptr, false };
   auto BestProb = BranchProbability::getZero();
 
   SmallVector<MachineBasicBlock *, 4> Successors;
@@ -813,6 +1063,12 @@
       collectViableSuccessors(BB, Chain, BlockFilter, Successors);
 
   DEBUG(dbgs() << "Selecting best successor for: " << getBlockName(BB) << "\n");
+
+  // For blocks with CFG violations, we may be able to lay them out anyway with
+  // tail-duplication. We keep this vector so we can perform the probability
+  // calculations the minimum number of times.
+  SmallVector<std::tuple<BranchProbability, MachineBasicBlock *>, 4>
+      DupCandidates;
   for (MachineBasicBlock *Succ : Successors) {
     auto RealSuccProb = MBPI->getEdgeProbability(BB, Succ);
     BranchProbability SuccProb =
@@ -820,15 +1076,21 @@
 
     // This heuristic is off by default.
     if (shouldPredBlockBeOutlined(BB, Succ, Chain, BlockFilter, SuccProb,
-                                  HotProb))
-      return Succ;
+                                  HotProb)) {
+      BestSucc.BB = Succ;
+      return BestSucc;
+    }
 
     BlockChain &SuccChain = *BlockToChain[Succ];
     // Skip the edge \c BB->Succ if block \c Succ has a better layout
     // predecessor that yields lower global cost.
     if (hasBetterLayoutPredecessor(BB, Succ, SuccChain, SuccProb, RealSuccProb,
-                                   Chain, BlockFilter))
+                                   Chain, BlockFilter)) {
+      // If tail duplication would make Succ profitable, place it.
+      if (TailDupPlacement && shouldTailDuplicate(Succ))
+        DupCandidates.push_back(std::make_tuple(SuccProb, Succ));
       continue;
+    }
 
     DEBUG(
         dbgs() << "    Candidate: " << getBlockName(Succ) << ", probability: "
@@ -836,17 +1098,52 @@
                << (SuccChain.UnscheduledPredecessors != 0 ? " (CFG break)" : "")
                << "\n");
 
-    if (BestSucc && BestProb >= SuccProb) {
+    if (BestSucc.BB && BestProb >= SuccProb) {
       DEBUG(dbgs() << "    Not the best candidate, continuing\n");
       continue;
     }
 
     DEBUG(dbgs() << "    Setting it as best candidate\n");
-    BestSucc = Succ;
+    BestSucc.BB = Succ;
     BestProb = SuccProb;
   }
-  if (BestSucc)
-    DEBUG(dbgs() << "    Selected: " << getBlockName(BestSucc) << "\n");
+  // Handle the tail duplication candidates in order of decreasing probability.
+  // Stop at the first one that is profitable. Also stop if they are less
+  // profitable than BestSucc. Position is important because we preserve it and
+  // prefer first best match. Here we aren't comparing in order, so we capture
+  // the position instead.
+  if (DupCandidates.size() != 0) {
+    auto cmp =
+        [](const std::tuple<BranchProbability, MachineBasicBlock *> &a,
+           const std::tuple<BranchProbability, MachineBasicBlock *> &b) {
+          return std::get<0>(a) > std::get<0>(b);
+        };
+    std::stable_sort(DupCandidates.begin(), DupCandidates.end(), cmp);
+  }
+  for(auto &Tup : DupCandidates) {
+    BranchProbability DupProb;
+    MachineBasicBlock *Succ;
+    std::tie(DupProb, Succ) = Tup;
+    if (DupProb < BestProb)
+      break;
+    if (canTailDuplicateUnplacedPreds(BB, Succ, Chain, BlockFilter)
+        // If tail duplication gives us fallthrough when we otherwise wouldn't
+        // have it, that is a strict gain.
+        && (BestSucc.BB == nullptr
+            || isProfitableToTailDup(BB, Succ, BestProb, Chain,
+                                     BlockFilter))) {
+      DEBUG(
+          dbgs() << "    Candidate: " << getBlockName(Succ) << ", probability: "
+                 << DupProb
+                 << " (Tail Duplicate)\n");
+      BestSucc.BB = Succ;
+      BestSucc.ShouldTailDup = true;
+      break;
+    }
+  }
+
+  if (BestSucc.BB)
+    DEBUG(dbgs() << "    Selected: " << getBlockName(BestSucc.BB) << "\n");
 
   return BestSucc;
 }
@@ -995,7 +1292,11 @@
 
     // Look for the best viable successor if there is one to place immediately
     // after this block.
-    MachineBasicBlock *BestSucc = selectBestSuccessor(BB, Chain, BlockFilter);
+    auto Result = selectBestSuccessor(BB, Chain, BlockFilter);
+    MachineBasicBlock* BestSucc = Result.BB;
+    bool ShouldTailDup = Result.ShouldTailDup;
+    if (TailDupPlacement)
+      ShouldTailDup |= (BestSucc && shouldTailDuplicate(BestSucc));
 
     // If an immediate successor isn't available, look for the best viable
     // block among those we've identified as not violating the loop's CFG at
@@ -1016,7 +1317,7 @@
 
     // Placement may have changed tail duplication opportunities.
     // Check for that now.
-    if (TailDupPlacement && BestSucc) {
+    if (TailDupPlacement && BestSucc && ShouldTailDup) {
       // If the chosen successor was duplicated into all its predecessors,
       // don't bother laying it out, just go round the loop again with BB as
       // the chain end.
@@ -1908,13 +2209,8 @@
   DuplicatedToLPred = false;
   DEBUG(dbgs() << "Redoing tail duplication for Succ#"
         << BB->getNumber() << "\n");
-  bool IsSimple = TailDup.isSimpleBB(BB);
-  // Blocks with single successors don't create additional fallthrough
-  // opportunities. Don't duplicate them. TODO: When conditional exits are
-  // analyzable, allow them to be duplicated.
-  if (!IsSimple && BB->succ_size() == 1)
-    return false;
-  if (!TailDup.shouldTailDuplicate(IsSimple, *BB))
+
+  if (!shouldTailDuplicate(BB))
     return false;
   // This has to be a callback because none of it can be done after
   // BB is deleted.
@@ -1967,6 +2263,7 @@
       llvm::function_ref<void(MachineBasicBlock*)>(RemovalCallback);
 
   SmallVector<MachineBasicBlock *, 8> DuplicatedPreds;
+  bool IsSimple = TailDup.isSimpleBB(BB);
   TailDup.tailDuplicateAndUpdate(IsSimple, BB, LPred,
                                  &DuplicatedPreds, &RemovalCallbackRef);
 
@@ -2007,13 +2304,15 @@
   TII = MF.getSubtarget().getInstrInfo();
   TLI = MF.getSubtarget().getTargetLowering();
   MDT = &getAnalysis<MachineDominatorTree>();
+  MPDT = nullptr;
 
   // Initialize PreferredLoopExit to nullptr here since it may never be set if
   // there are no MachineLoops.
   PreferredLoopExit = nullptr;
 
   if (TailDupPlacement) {
-    unsigned TailDupSize = TailDuplicatePlacementThreshold;
+    MPDT = &getAnalysis<MachinePostDominatorTree>();
+    unsigned TailDupSize = TailDupPlacementThreshold;
     if (MF.getFunction()->optForSize())
       TailDupSize = 1;
     TailDup.initMF(MF, MBPI, /* LayoutMode */ true, TailDupSize);
@@ -2032,7 +2331,7 @@
                          BranchFoldPlacement;
   // No tail merging opportunities if the block number is less than four.
   if (MF.size() > 3 && EnableTailMerge) {
-    unsigned TailMergeSize = TailDuplicatePlacementThreshold + 1;
+    unsigned TailMergeSize = TailDupPlacementThreshold + 1;
     BranchFolder BF(/*EnableTailMerge=*/true, /*CommonHoist=*/false, *MBFI,
                     *MBPI, TailMergeSize);
 
@@ -2043,6 +2342,8 @@
       BlockToChain.clear();
       // Must redo the dominator tree if blocks were changed.
       MDT->runOnMachineFunction(MF);
+      if (MPDT)
+        MPDT->runOnMachineFunction(MF);
       ChainAllocator.DestroyAll();
       buildCFGChains();
     }
Index: test/CodeGen/AArch64/arm64-atomic.ll
===================================================================
--- test/CodeGen/AArch64/arm64-atomic.ll
+++ test/CodeGen/AArch64/arm64-atomic.ll
@@ -9,10 +9,10 @@
 ; CHECK-NEXT: b.ne   [[FAILBB:.?LBB[0-9_]+]]
 ; CHECK-NEXT: stxr   [[SCRATCH_REG:w[0-9]+]], w2, [x[[ADDR]]]
 ; CHECK-NEXT: cbnz   [[SCRATCH_REG]], [[TRYBB]]
-; CHECK-NEXT: b      [[EXITBB:.?LBB[0-9_]+]]
+; CHECK-NEXT: ret
 ; CHECK-NEXT: [[FAILBB]]:
 ; CHECK-NEXT: clrex
-; CHECK-NEXT: [[EXITBB]]:
+; CHECK-NEXT: ret
   %pair = cmpxchg i32* %p, i32 %cmp, i32 %new acquire acquire
   %val = extractvalue { i32, i1 } %pair, 0
   ret i32 %val
@@ -27,10 +27,12 @@
 ; CHECK-NEXT: b.ne   [[FAILBB:.?LBB[0-9_]+]]
 ; CHECK-NEXT: stxr   [[SCRATCH_REG:w[0-9]+]], [[NEW]], [x0]
 ; CHECK-NEXT: cbnz   [[SCRATCH_REG]], [[TRYBB]]
-; CHECK-NEXT: b      [[EXITBB:.?LBB[0-9_]+]]
+; CHECK-NEXT: mov    x0, x[[ADDR]]
+; CHECK-NEXT: ret
 ; CHECK-NEXT: [[FAILBB]]:
 ; CHECK-NEXT: clrex
-; CHECK-NEXT: [[EXITBB]]:
+; CHECK-NEXT: mov    x0, x[[ADDR]]
+; CHECK-NEXT: ret
   %new = load i32, i32* %pnew
   %pair = cmpxchg i32* %p, i32 %cmp, i32 %new acquire acquire
   %val = extractvalue { i32, i1 } %pair, 0
@@ -41,15 +43,15 @@
 ; CHECK-LABEL: val_compare_and_swap_rel:
 ; CHECK-NEXT: mov    x[[ADDR:[0-9]+]], x0
 ; CHECK-NEXT: [[TRYBB:.?LBB[0-9_]+]]:
-; CHECK-NEXT: ldaxr  [[RESULT:w[0-9]+]], [x[[ADDR]]
+; CHECK-NEXT: ldaxr  [[RESULT:w[0-9]+]], [x[[ADDR]]]
 ; CHECK-NEXT: cmp    [[RESULT]], w1
 ; CHECK-NEXT: b.ne   [[FAILBB:.?LBB[0-9_]+]]
-; CHECK-NEXT: stlxr  [[SCRATCH_REG:w[0-9]+]], w2, [x[[ADDR]]
+; CHECK-NEXT: stlxr  [[SCRATCH_REG:w[0-9]+]], w2, [x[[ADDR]]]
 ; CHECK-NEXT: cbnz   [[SCRATCH_REG]], [[TRYBB]]
-; CHECK-NEXT: b      [[EXITBB:.?LBB[0-9_]+]]
+; CHECK-NEXT: ret
 ; CHECK-NEXT: [[FAILBB]]:
 ; CHECK-NEXT: clrex
-; CHECK-NEXT: [[EXITBB]]:
+; CHECK-NEXT: ret
   %pair = cmpxchg i32* %p, i32 %cmp, i32 %new acq_rel monotonic
   %val = extractvalue { i32, i1 } %pair, 0
   ret i32 %val
@@ -64,10 +66,10 @@
 ; CHECK-NEXT: b.ne   [[FAILBB:.?LBB[0-9_]+]]
 ; CHECK-NEXT: stxr   [[SCRATCH_REG:w[0-9]+]], x2, [x[[ADDR]]]
 ; CHECK-NEXT: cbnz   [[SCRATCH_REG]], [[TRYBB]]
-; CHECK-NEXT: b      [[EXITBB:.?LBB[0-9_]+]]
+; CHECK-NEXT: ret
 ; CHECK-NEXT: [[FAILBB]]:
 ; CHECK-NEXT: clrex
-; CHECK-NEXT: [[EXITBB]]:
+; CHECK-NEXT: ret
   %pair = cmpxchg i64* %p, i64 %cmp, i64 %new monotonic monotonic
   %val = extractvalue { i64, i1 } %pair, 0
   ret i64 %val
Index: test/CodeGen/AArch64/arm64-shrink-wrapping.ll
===================================================================
--- test/CodeGen/AArch64/arm64-shrink-wrapping.ll
+++ test/CodeGen/AArch64/arm64-shrink-wrapping.ll
@@ -346,19 +346,15 @@
 ; CHECK-NEXT: sub w1, w1, #1
 ; CHECK-NEXT: add [[SUM]], [[SUM]], [[VA_VAL]]
 ; CHECK-NEXT: cbnz w1, [[LOOP_LABEL]]
-; DISABLE-NEXT: b [[IFEND_LABEL]]
-;
-; DISABLE: [[ELSE_LABEL]]: ; %if.else
-; DISABLE: lsl w0, w1, #1
-;
-; CHECK: [[IFEND_LABEL]]:
+; CHECK-NEXT: [[IFEND_LABEL]]:
 ; Epilogue code.
 ; CHECK: add sp, sp, #16
 ; CHECK-NEXT: ret
 ;
-; ENABLE: [[ELSE_LABEL]]: ; %if.else
-; ENABLE-NEXT: lsl w0, w1, #1
-; ENABLE_NEXT: ret
+; CHECK: [[ELSE_LABEL]]: ; %if.else
+; CHECK-NEXT: lsl w0, w1, #1
+; DISABLE-NEXT: add sp, sp, #16
+; CHECK-NEXT: ret
 define i32 @variadicFunc(i32 %cond, i32 %count, ...) #0 {
 entry:
   %ap = alloca i8*, align 8
Index: test/CodeGen/AArch64/tail-dup-repeat-worklist.ll
===================================================================
--- test/CodeGen/AArch64/tail-dup-repeat-worklist.ll
+++ /dev/null
@@ -1,69 +0,0 @@
-; RUN: llc -O3 -o - -verify-machineinstrs %s | FileCheck %s
-target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
-target triple = "aarch64-unknown-linux-gnu"
-
-%struct.s1 = type { %struct.s3*, %struct.s1* }
-%struct.s2 = type opaque
-%struct.s3 = type { i32 }
-
-; Function Attrs: nounwind
-define internal fastcc i32 @repeated_dup_worklist(%struct.s1** %pp1, %struct.s2* %p2, i32 %state, i1 %i1_1, i32 %i32_1) unnamed_addr #0 {
-entry:
-  br label %while.cond.outer
-
-; The loop gets laid out:
-; %while.cond.outer
-; %(null)
-; %(null)
-; %dup2
-; and then %dup1 gets chosen as the next block.
-; when dup2 is duplicated into dup1, %worklist could erroneously be placed on
-; the worklist, because all of its current predecessors are now scheduled.
-; However, after dup2 is tail-duplicated, %worklist can't be on the worklist
-; because it now has unscheduled predecessors.q
-; CHECK-LABEL: repeated_dup_worklist
-; CHECK: // %entry
-; CHECK: // %while.cond.outer
-; first %(null) block
-; CHECK: // in Loop:
-; CHECK: ldr
-; CHECK-NEXT: tbnz
-; second %(null) block
-; CHECK: // in Loop:
-; CHECK: // %dup2
-; CHECK: // %worklist
-; CHECK: // %if.then96.i
-while.cond.outer:                                 ; preds = %dup1, %entry
-  %progress.0.ph = phi i32 [ 0, %entry ], [ %progress.1, %dup1 ]
-  %inc77 = add nsw i32 %progress.0.ph, 1
-  %cmp = icmp slt i32 %progress.0.ph, %i32_1
-  br i1 %cmp, label %dup2, label %dup1
-
-dup2:                       ; preds = %if.then96.i, %worklist, %while.cond.outer
-  %progress.1.ph = phi i32 [ 0, %while.cond.outer ], [ %progress.1, %if.then96.i ], [ %progress.1, %worklist ]
-  %.pr = load %struct.s1*, %struct.s1** %pp1, align 8
-  br label %dup1
-
-dup1:                                       ; preds = %dup2, %while.cond.outer
-  %0 = phi %struct.s1* [ %.pr, %dup2 ], [ undef, %while.cond.outer ]
-  %progress.1 = phi i32 [ %progress.1.ph, %dup2 ], [ %inc77, %while.cond.outer ]
-  br i1 %i1_1, label %while.cond.outer, label %worklist
-
-worklist:                                       ; preds = %dup1
-  %snode94 = getelementptr inbounds %struct.s1, %struct.s1* %0, i64 0, i32 0
-  %1 = load %struct.s3*, %struct.s3** %snode94, align 8
-  %2 = getelementptr inbounds %struct.s3, %struct.s3* %1, i32 0, i32 0
-  %3 = load i32, i32* %2, align 4
-  %tobool95.i = icmp eq i32 %3, 0
-  br i1 %tobool95.i, label %if.then96.i, label %dup2
-
-if.then96.i:                                      ; preds = %worklist
-  call fastcc void @free_s3(%struct.s2* %p2, %struct.s3* %1) #1
-  br label %dup2
-}
-
-; Function Attrs: nounwind
-declare fastcc void @free_s3(%struct.s2*, %struct.s3*) unnamed_addr #0
-
-attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="cortex-a57" "target-features"="+crc,+crypto,+neon" "unsafe-fp-math"="false" "use-soft-float"="false" }
-attributes #1 = { nounwind }
Index: test/CodeGen/AArch64/tbz-tbnz.ll
===================================================================
--- test/CodeGen/AArch64/tbz-tbnz.ll
+++ test/CodeGen/AArch64/tbz-tbnz.ll
@@ -10,7 +10,7 @@
   br i1 %cmp, label %if.then, label %if.end
 
 ; CHECK: sub [[CMP:w[0-9]+]], w0, #12
-; CHECK: tbz [[CMP]], #31
+; CHECK: tbnz [[CMP]], #31
 
 if.then:
   call void @t()
@@ -28,7 +28,7 @@
   br i1 %cmp, label %if.then, label %if.end
 
 ; CHECK: sub [[CMP:x[0-9]+]], x0, #12
-; CHECK: tbz [[CMP]], #63
+; CHECK: tbnz [[CMP]], #63
 
 if.then:
   call void @t()
@@ -118,7 +118,7 @@
   br i1 %cmp, label %if.then, label %if.end
 
 ; CHECK: sub [[CMP:w[0-9]+]], w0, #12
-; CHECK: tbz [[CMP]], #31
+; CHECK: tbnz [[CMP]], #31
 
 if.then:
   call void @t()
@@ -178,7 +178,7 @@
   br i1 %tst, label %if.then, label %if.end
 
 ; CHECK-NOT: cmp
-; CHECK: tbz x0, #63
+; CHECK: tbnz x0, #63
 
 if.then:
   call void @t()
@@ -194,7 +194,7 @@
   br i1 %tst, label %if.then, label %if.end
 
 ; CHECK-NOT: cmp
-; CHECK: tbz x0, #63
+; CHECK: tbnz x0, #63
 
 if.then:
   call void @t()
@@ -209,7 +209,7 @@
 
 ; CHECK: ldr [[CMP:x[0-9]+]], [x1]
 ; CHECK-NOT: cmp
-; CHECK: tbz [[CMP]], #63
+; CHECK: tbnz [[CMP]], #63
 
   %val = load i64, i64* %ptr
   %tst = icmp slt i64 %val, 0
@@ -229,7 +229,7 @@
   br i1 %tst, label %if.then, label %if.end
 
 ; CHECK-NOT: cmp
-; CHECK: tbz x0, #63
+; CHECK: tbnz x0, #63
 
 if.then:
   call void @t()
@@ -247,7 +247,7 @@
 
 ; CHECK: orr [[CMP:x[0-9]+]], x0, x1
 ; CHECK-NOT: cmp
-; CHECK: tbz [[CMP]], #63
+; CHECK: tbnz [[CMP]], #63
 
 if.then:
   call void @t()
Index: test/CodeGen/AMDGPU/branch-relaxation.ll
===================================================================
--- test/CodeGen/AMDGPU/branch-relaxation.ll
+++ test/CodeGen/AMDGPU/branch-relaxation.ll
@@ -335,6 +335,12 @@
 ; GCN-NEXT: ;;#ASMEND
 
 ; GCN-NEXT: [[BB3]]: ; %bb3
+; GCN-NEXT: ;;#ASMSTART
+; GCN-NEXT: v_nop_e64
+; GCN-NEXT: ;;#ASMEND
+; GCN-NEXT: ;;#ASMSTART
+; GCN-NEXT: v_nop_e64
+; GCN-NEXT: ;;#ASMEND
 ; GCN-NEXT: s_endpgm
 define void @expand_requires_expand(i32 %cond0) #0 {
 bb0:
@@ -356,6 +362,12 @@
   br label %bb3
 
 bb3:
+; These NOPs prevent tail-duplication-based outlining
+; from firing, which defeats the need to expand the branches and this test.
+  call void asm sideeffect
+   "v_nop_e64", ""() #0
+  call void asm sideeffect
+   "v_nop_e64", ""() #0
   ret void
 }
 
@@ -385,6 +397,7 @@
 
 ; GCN-NEXT: [[ENDIF]]: ; %endif
 ; GCN-NEXT: s_or_b64 exec, exec, [[MASK]]
+; GCN-NEXT: s_sleep 5
 ; GCN-NEXT: s_endpgm
 define void @uniform_inside_divergent(i32 addrspace(1)* %out, i32 %cond) #0 {
 entry:
@@ -402,6 +415,9 @@
   br label %endif
 
 endif:
+  ; layout can remove the split branch if it can copy the return block.
+  ; This call makes the return block long enough that it doesn't get copied.
+  call void @llvm.amdgcn.s.sleep(i32 5);
   ret void
 }
 
Index: test/CodeGen/AMDGPU/uniform-cfg.ll
===================================================================
--- test/CodeGen/AMDGPU/uniform-cfg.ll
+++ test/CodeGen/AMDGPU/uniform-cfg.ll
@@ -252,10 +252,12 @@
 ; GCN: s_cmp_lt_i32 [[COND]], 1
 ; GCN: s_cbranch_scc1 [[EXIT:[A-Za-z0-9_]+]]
 ; GCN: v_cmp_gt_i32_e64 vcc, [[COND]], 0{{$}}
-; GCN: s_cbranch_vccnz [[EXIT]]
-; GCN: buffer_store
+; GCN: s_cbranch_vccz [[BODY:[A-Za-z0-9_]+]]
 ; GCN: {{^}}[[EXIT]]:
 ; GCN: s_endpgm
+; GCN: {{^}}[[BODY]]:
+; GCN: buffer_store
+; GCN: s_endpgm
 define void @icmp_users_different_blocks(i32 %cond0, i32 %cond1, i32 addrspace(1)* %out) {
 bb:
   %tmp = tail call i32 @llvm.amdgcn.workitem.id.x() #0
@@ -302,9 +304,10 @@
 ; GCN: v_cmp_gt_u32_e32 vcc, 16, v{{[0-9]+}}
 ; GCN: s_and_saveexec_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], vcc
 ; GCN: s_xor_b64  [[MASK1:s\[[0-9]+:[0-9]+\]]], exec, [[MASK]]
-; GCN: s_cbranch_execz [[ENDIF_LABEL:[0-9_A-Za-z]+]]
 ; GCN: s_cmp_lg_u32 {{s[0-9]+}}, 0
-; GCN: s_cbranch_scc1 [[ENDIF_LABEL]]
+; GCN: s_cbranch_scc0 [[IF_UNIFORM_LABEL:[A-Z0-9_a-z]+]]
+; GCN: s_endpgm
+; GCN: {{^}}[[IF_UNIFORM_LABEL]]:
 ; GCN: v_mov_b32_e32 [[ONE:v[0-9]+]], 1
 ; GCN: buffer_store_dword [[ONE]]
 define void @uniform_inside_divergent(i32 addrspace(1)* %out, i32 %cond) {
@@ -328,14 +331,13 @@
 
 ; GCN-LABEL: {{^}}divergent_inside_uniform:
 ; GCN: s_cmp_lg_u32 s{{[0-9]+}}, 0
-; GCN: s_cbranch_scc1 [[ENDIF_LABEL:[0-9_A-Za-z]+]]
+; GCN: s_cbranch_scc0 [[IF_LABEL:[0-9_A-Za-z]+]]
+; GCN: [[IF_LABEL]]:
 ; GCN: v_cmp_gt_u32_e32 vcc, 16, v{{[0-9]+}}
 ; GCN: s_and_saveexec_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], vcc
 ; GCN: s_xor_b64  [[MASK1:s\[[0-9]+:[0-9]+\]]], exec, [[MASK]]
 ; GCN: v_mov_b32_e32 [[ONE:v[0-9]+]], 1
 ; GCN: buffer_store_dword [[ONE]]
-; GCN: [[ENDIF_LABEL]]:
-; GCN: s_endpgm
 define void @divergent_inside_uniform(i32 addrspace(1)* %out, i32 %cond) {
 entry:
   %u_cmp = icmp eq i32 %cond, 0
@@ -363,11 +365,11 @@
 ; GCN: buffer_store_dword [[ONE]]
 ; GCN: s_or_b64 exec, exec, [[MASK]]
 ; GCN: s_cmp_lg_u32 s{{[0-9]+}}, 0
-; GCN: s_cbranch_scc1 [[EXIT:[A-Z0-9_]+]]
+; GCN: s_cbranch_scc0 [[IF_UNIFORM:[A-Z0-9_]+]]
+; GCN: s_endpgm
+; GCN: [[IF_UNIFORM]]:
 ; GCN: v_mov_b32_e32 [[TWO:v[0-9]+]], 2
 ; GCN: buffer_store_dword [[TWO]]
-; GCN: [[EXIT]]:
-; GCN: s_endpgm
 define void @divergent_if_uniform_if(i32 addrspace(1)* %out, i32 %cond) {
 entry:
   %tid = call i32 @llvm.amdgcn.workitem.id.x() #0
Index: test/CodeGen/ARM/arm-and-tst-peephole.ll
===================================================================
--- test/CodeGen/ARM/arm-and-tst-peephole.ll
+++ test/CodeGen/ARM/arm-and-tst-peephole.ll
@@ -49,9 +49,9 @@
 ; V8-NEXT: beq
 ; V8-NEXT: %tailrecurse.switch
 ; V8: cmp
-; V8-NEXT: bne
-; V8-NEXT: b	
-; The trailing space in the last line checks that the branch is unconditional
+; V8-NEXT: beq
+; V8-NEXT: %sw.epilog
+; V8-NEXT: bx lr
   switch i32 %and, label %sw.epilog [
     i32 1, label %sw.bb
     i32 3, label %sw.bb6
Index: test/CodeGen/ARM/atomic-op.ll
===================================================================
--- test/CodeGen/ARM/atomic-op.ll
+++ test/CodeGen/ARM/atomic-op.ll
@@ -320,10 +320,10 @@
 ; CHECK:     strex   [[SUCCESS:r[0-9]+]], r2, [r[[ADDR]]]
 ; CHECK:     cmp     [[SUCCESS]], #0
 ; CHECK:     bne     [[LOOP_BB]]
-; CHECK:     b       [[END_BB:\.?LBB[0-9]+_[0-9]+]]
+; CHECK:     dmb     ish
+; CHECK:     bx      lr
 ; CHECK: [[FAIL_BB]]:
 ; CHECK-NEXT: clrex
-; CHECK-NEXT: [[END_BB]]:
 ; CHECK:     dmb     ish
 ; CHECK:     bx      lr
 
Index: test/CodeGen/ARM/atomic-ops-v8.ll
===================================================================
--- test/CodeGen/ARM/atomic-ops-v8.ll
+++ test/CodeGen/ARM/atomic-ops-v8.ll
@@ -1045,20 +1045,21 @@
   ;  function there.
 ; CHECK-ARM-NEXT:   cmp r[[OLD]], r0
 ; CHECK-THUMB-NEXT: cmp r[[OLD]], r[[WANTED]]
-; CHECK-NEXT: bne .LBB{{[0-9]+}}_3
+; CHECK-NEXT: bne .LBB{{[0-9]+}}_4
 ; CHECK-NEXT: BB#2:
   ; As above, r1 is a reasonable guess.
 ; CHECK: strexb [[STATUS:r[0-9]+]], r1, [r[[ADDR]]]
 ; CHECK-NEXT: cmp [[STATUS]], #0
 ; CHECK-NEXT: bne .LBB{{[0-9]+}}_1
-; CHECK-NEXT: b .LBB{{[0-9]+}}_4
-; CHECK-NEXT: .LBB{{[0-9]+}}_3:
-; CHECK-NEXT: clrex
+; CHECK-ARM: mov r0, r[[OLD]]
+; CHECK: bx lr
 ; CHECK-NEXT: .LBB{{[0-9]+}}_4:
+; CHECK-NEXT: clrex
 ; CHECK-NOT: dmb
 ; CHECK-NOT: mcr
 
 ; CHECK-ARM: mov r0, r[[OLD]]
+; CHECK-ARM-NEXT: bx lr
    ret i8 %old
 }
 
@@ -1078,20 +1079,21 @@
   ;  function there.
 ; CHECK-ARM-NEXT:   cmp r[[OLD]], r0
 ; CHECK-THUMB-NEXT: cmp r[[OLD]], r[[WANTED]]
-; CHECK-NEXT: bne .LBB{{[0-9]+}}_3
+; CHECK-NEXT: bne .LBB{{[0-9]+}}_4
 ; CHECK-NEXT: BB#2:
   ; As above, r1 is a reasonable guess.
 ; CHECK: stlexh [[STATUS:r[0-9]+]], r1, [r[[ADDR]]]
 ; CHECK-NEXT: cmp [[STATUS]], #0
 ; CHECK-NEXT: bne .LBB{{[0-9]+}}_1
-; CHECK-NEXT: b .LBB{{[0-9]+}}_4
-; CHECK-NEXT: .LBB{{[0-9]+}}_3:
-; CHECK-NEXT: clrex
+; CHECK-ARM: mov r0, r[[OLD]]
+; CHECK: bx lr
 ; CHECK-NEXT: .LBB{{[0-9]+}}_4:
+; CHECK-NEXT: clrex
 ; CHECK-NOT: dmb
 ; CHECK-NOT: mcr
 
 ; CHECK-ARM: mov r0, r[[OLD]]
+; CHECK-ARM-NEXT: bx lr
    ret i16 %old
 }
 
@@ -1110,20 +1112,21 @@
   ; r0 below is a reasonable guess but could change: it certainly comes into the
   ;  function there.
 ; CHECK-NEXT: cmp r[[OLD]], r0
-; CHECK-NEXT: bne .LBB{{[0-9]+}}_3
+; CHECK-NEXT: bne .LBB{{[0-9]+}}_4
 ; CHECK-NEXT: BB#2:
   ; As above, r1 is a reasonable guess.
 ; CHECK: stlex [[STATUS:r[0-9]+]], r1, [r[[ADDR]]]
 ; CHECK-NEXT: cmp [[STATUS]], #0
 ; CHECK-NEXT: bne .LBB{{[0-9]+}}_1
-; CHECK-NEXT: b .LBB{{[0-9]+}}_4
-; CHECK-NEXT: .LBB{{[0-9]+}}_3:
-; CHECK-NEXT: clrex
+; CHECK: str{{(.w)?}} r[[OLD]],
+; CHECK-NEXT: bx lr
 ; CHECK-NEXT: .LBB{{[0-9]+}}_4:
+; CHECK-NEXT: clrex
 ; CHECK-NOT: dmb
 ; CHECK-NOT: mcr
 
 ; CHECK: str{{(.w)?}} r[[OLD]],
+; CHECK-ARM-NEXT: bx lr
    ret void
 }
 
@@ -1148,16 +1151,16 @@
 ; CHECK-BE-DAG: eor{{(\.w)?}} [[MISMATCH_LO:r[0-9]+|lr]], [[OLD1]], r0
 ; CHECK-ARM-BE: orrs{{(\.w)?}} {{r[0-9]+}}, [[MISMATCH_HI]], [[MISMATCH_LO]]
 ; CHECK-THUMB-BE: orrs{{(\.w)?}} {{(r[0-9]+, )?}}[[MISMATCH_LO]], [[MISMATCH_HI]]
-; CHECK-NEXT: bne .LBB{{[0-9]+}}_3
+; CHECK-NEXT: bne .LBB{{[0-9]+}}_4
 ; CHECK-NEXT: BB#2:
   ; As above, r2, r3 is a reasonable guess.
 ; CHECK: strexd [[STATUS:r[0-9]+]], r2, r3, [r[[ADDR]]]
 ; CHECK-NEXT: cmp [[STATUS]], #0
 ; CHECK-NEXT: bne .LBB{{[0-9]+}}_1
-; CHECK-NEXT: b .LBB{{[0-9]+}}_4
-; CHECK-NEXT: .LBB{{[0-9]+}}_3:
-; CHECK-NEXT: clrex
+; CHECK: strd [[OLD1]], [[OLD2]], [r[[ADDR]]]
+; CHECK-NEXT: pop
 ; CHECK-NEXT: .LBB{{[0-9]+}}_4:
+; CHECK-NEXT: clrex
 ; CHECK-NOT: dmb
 ; CHECK-NOT: mcr
 
Index: test/CodeGen/ARM/cmpxchg-weak.ll
===================================================================
--- test/CodeGen/ARM/cmpxchg-weak.ll
+++ test/CodeGen/ARM/cmpxchg-weak.ll
@@ -13,14 +13,16 @@
 ; CHECK-NEXT:     dmb ish
 ; CHECK-NEXT:     strex   [[SUCCESS:r[0-9]+]], r2, [r0]
 ; CHECK-NEXT:     cmp     [[SUCCESS]], #0
-; CHECK-NEXT:     bne     [[FAILBB:LBB[0-9]+_[0-9]+]]
+; CHECK-NEXT:     beq     [[SUCCESSBB:LBB[0-9]+_[0-9]+]]
 ; CHECK-NEXT: BB#2:
-; CHECK-NEXT:     dmb     ish
 ; CHECK-NEXT:     str     r3, [r0]
 ; CHECK-NEXT:     bx      lr
 ; CHECK-NEXT: [[LDFAILBB]]:
 ; CHECK-NEXT:     clrex
-; CHECK-NEXT: [[FAILBB]]:
+; CHECK-NEXT:     str     r3, [r0]
+; CHECK-NEXT:     bx      lr
+; CHECK-NEXT: [[SUCCESSBB]]:
+; CHECK-NEXT:     dmb     ish
 ; CHECK-NEXT:     str     r3, [r0]
 ; CHECK-NEXT:     bx      lr
 
Index: test/CodeGen/Mips/brconnez.ll
===================================================================
--- test/CodeGen/Mips/brconnez.ll
+++ test/CodeGen/Mips/brconnez.ll
@@ -7,7 +7,7 @@
 entry:
   %0 = load i32, i32* @j, align 4
   %cmp = icmp eq i32 %0, 0
-  br i1 %cmp, label %if.then, label %if.end
+  br i1 %cmp, label %if.then, label %if.end, !prof !1
 
 ; 16:	bnez	${{[0-9]+}}, $[[LABEL:[0-9A-Ba-b_]+]]
 ; 16:   lw ${{[0-9]+}}, %got(result)(${{[0-9]+}})
@@ -21,4 +21,4 @@
   ret void
 }
 
-
+!1 = !{!"branch_weights", i32 2, i32 1}
Index: test/CodeGen/Mips/micromips-compact-branches.ll
===================================================================
--- test/CodeGen/Mips/micromips-compact-branches.ll
+++ test/CodeGen/Mips/micromips-compact-branches.ll
@@ -6,7 +6,7 @@
   %x = alloca i32, align 4
   %0 = load i32, i32* %x, align 4
   %cmp = icmp eq i32 %0, 0
-  br i1 %cmp, label %if.then, label %if.end
+  br i1 %cmp, label %if.then, label %if.end, !prof !1
 
 if.then:
   store i32 10, i32* %x, align 4
@@ -17,3 +17,4 @@
 }
 
 ; CHECK: bnezc
+!1 = !{!"branch_weights", i32 2, i32 1}
Index: test/CodeGen/PowerPC/misched-inorder-latency.ll
===================================================================
--- test/CodeGen/PowerPC/misched-inorder-latency.ll
+++ test/CodeGen/PowerPC/misched-inorder-latency.ll
@@ -17,7 +17,7 @@
   %sum1 = add i32 %sumin, 1
   %val1 = load i32, i32* %ptr
   %p = icmp eq i32 %sumin, 0
-  br i1 %p, label %true, label %end
+  br i1 %p, label %true, label %end, !prof !1
 true:
   %sum2 = add i32 %sum1, 1
   %ptr2 = getelementptr i32, i32* %ptr, i32 1
@@ -53,3 +53,5 @@
   ret i32 %valmerge
 }
 declare void @llvm.prefetch(i8*, i32, i32, i32) nounwind
+
+!1 = !{!"branch_weights", i32 2, i32 1}
Index: test/CodeGen/PowerPC/tail-dup-break-cfg.ll
===================================================================
--- /dev/null
+++ test/CodeGen/PowerPC/tail-dup-break-cfg.ll
@@ -0,0 +1,140 @@
+; RUN: llc -O2 -o - %s | FileCheck %s
+target datalayout = "e-m:e-i64:64-n32:64"
+target triple = "powerpc64le-grtev4-linux-gnu"
+
+; Intended layout:
+; The code for tail-duplication during layout will produce the layout:
+; test1
+; test2
+; body1 (with copy of test2)
+; body2
+; exit
+
+;CHECK-LABEL: tail_dup_break_cfg:
+;CHECK: mr [[TAGREG:[0-9]+]], 3
+;CHECK: andi. {{[0-9]+}}, [[TAGREG]], 1
+;CHECK-NEXT: bc 12, 1, [[BODY1LABEL:[._0-9A-Za-z]+]]
+;CHECK-NEXT: # %test2
+;CHECK-NEXT: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 30, 30
+;CHECK-NEXT: beq 0, [[EXITLABEL:[._0-9A-Za-z]+]]
+;CHECK-NEXT: b [[BODY2LABEL:[._0-9A-Za-z]+]]
+;CHECK-NEXT: [[BODY1LABEL]]
+;CHECK: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 30, 30
+;CHECK-NEXT: beq 0, [[EXITLABEL]]
+;CHECK-NEXT: [[BODY2LABEL]]
+;CHECK: [[EXITLABEL:[._0-9A-Za-z]+]]: # %exit
+;CHECK: blr
+define void @tail_dup_break_cfg(i32 %tag) {
+entry:
+  br label %test1
+test1:
+  %tagbit1 = and i32 %tag, 1
+  %tagbit1eq0 = icmp eq i32 %tagbit1, 0
+  br i1 %tagbit1eq0, label %test2, label %body1, !prof !1 ; %test2 more likely
+body1:
+  call void @a()
+  call void @a()
+  call void @a()
+  call void @a()
+  br label %test2
+test2:
+  %tagbit2 = and i32 %tag, 2
+  %tagbit2eq0 = icmp eq i32 %tagbit2, 0
+  br i1 %tagbit2eq0, label %exit, label %body2, !prof !1 ; %exit more likely
+body2:
+  call void @b()
+  call void @b()
+  call void @b()
+  call void @b()
+  br label %exit
+exit:
+  ret void
+}
+
+; The branch weights here hint that we shouldn't tail duplicate in this case.
+;CHECK-LABEL: tail_dup_dont_break_cfg:
+;CHECK: mr [[TAGREG:[0-9]+]], 3
+;CHECK: andi. {{[0-9]+}}, [[TAGREG]], 1
+;CHECK-NEXT: bc 4, 1, [[TEST2LABEL:[._0-9A-Za-z]+]]
+;CHECK-NEXT: # %body1
+;CHECK: [[TEST2LABEL]]: # %test2
+;CHECK-NEXT: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 30, 30
+;CHECK-NEXT: beq 0, [[EXITLABEL:[._0-9A-Za-z]+]]
+;CHECK-NEXT: # %body2
+;CHECK: [[EXITLABEL:[._0-9A-Za-z]+]]: # %exit
+;CHECK: blr
+define void @tail_dup_dont_break_cfg(i32 %tag) {
+entry:
+  br label %test1
+test1:
+  %tagbit1 = and i32 %tag, 1
+  %tagbit1eq0 = icmp eq i32 %tagbit1, 0
+  br i1 %tagbit1eq0, label %test2, label %body1, !prof !1 ; %test2 more likely
+body1:
+  call void @a()
+  call void @a()
+  call void @a()
+  call void @a()
+  br label %test2
+test2:
+  %tagbit2 = and i32 %tag, 2
+  %tagbit2eq0 = icmp ne i32 %tagbit2, 0
+  br i1 %tagbit2eq0, label %body2, label %exit, !prof !1 ; %body2 more likely
+body2:
+  call void @b()
+  call void @b()
+  call void @b()
+  call void @b()
+  br label %exit
+exit:
+  ret void
+}
+declare void @a()
+declare void @b()
+declare void @c()
+declare void @d()
+
+; This function arranges for the successors of %succ to have already been laid
+; out. When we consider whether to lay out succ after bb and to tail-duplicate
+; it, v and ret have already been placed, so we tail-duplicate as it removes a
+; branch and strictly increases fallthrough
+; CHECK-LABEL: tail_dup_no_succ
+; CHECK: # %entry
+; CHECK: # %v
+; CHECK: # %ret
+; CHECK: # %bb
+; CHECK: # %succ
+; CHECK: # %c
+; CHECK: bl c
+; CHECK: rlwinm. {{[0-9]+}}, {{[0-9]+}}, 0, 29, 29
+; CHECK: beq
+; CHECK: b
+define void @tail_dup_no_succ(i32 %tag) {
+entry:
+  %tagbit1 = and i32 %tag, 1
+  %tagbit1eq0 = icmp eq i32 %tagbit1, 0
+  br i1 %tagbit1eq0, label %v, label %bb, !prof !2 ; %v very much more likely
+bb:
+  %tagbit2 = and i32 %tag, 2
+  %tagbit2eq0 = icmp eq i32 %tagbit2, 0
+  br i1 %tagbit2eq0, label %succ, label %c, !prof !3 ; %succ more likely
+c:
+  call void @c()
+  call void @c()
+  br label %succ
+succ:
+  %tagbit3 = and i32 %tag, 4
+  %tagbit3eq0 = icmp eq i32 %tagbit3, 0
+  br i1 %tagbit3eq0, label %ret, label %v, !prof !1 ; %u more likely
+v:
+  call void @d()
+  call void @d()
+  br label %ret
+ret:
+  ret void
+}
+
+
+!1 = !{!"branch_weights", i32 5, i32 3}
+!2 = !{!"branch_weights", i32 95, i32 5}
+!3 = !{!"branch_weights", i32 7, i32 3}
Index: test/CodeGen/PowerPC/tail-dup-layout.ll
===================================================================
--- test/CodeGen/PowerPC/tail-dup-layout.ll
+++ test/CodeGen/PowerPC/tail-dup-layout.ll
@@ -19,35 +19,35 @@
 ; The CHECK statements check for the whole string of tests and exit block,
 ; and then check that the correct test has been duplicated into the end of
 ; the optional blocks and that the optional blocks are in the correct order.
-;CHECK-LABEL: f:
+;CHECK-LABEL: straight_test:
 ; test1 may have been merged with entry
 ;CHECK: mr [[TAGREG:[0-9]+]], 3
 ;CHECK: andi. {{[0-9]+}}, [[TAGREG]], 1
-;CHECK-NEXT: bc 12, 1, [[OPT1LABEL:[._0-9A-Za-z]+]]
-;CHECK-NEXT: [[TEST2LABEL:[._0-9A-Za-z]+]]: # %test2
+;CHECK-NEXT: bc 12, 1, .[[OPT1LABEL:[_0-9A-Za-z]+]]
+;CHECK-NEXT: # %test2
 ;CHECK-NEXT: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 30, 30
-;CHECK-NEXT: bne 0, [[OPT2LABEL:[._0-9A-Za-z]+]]
-;CHECK-NEXT: [[TEST3LABEL:[._0-9A-Za-z]+]]: # %test3
+;CHECK-NEXT: bne 0, .[[OPT2LABEL:[_0-9A-Za-z]+]]
+;CHECK-NEXT: .[[TEST3LABEL:[_0-9A-Za-z]+]]: # %test3
 ;CHECK-NEXT: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 29, 29
-;CHECK-NEXT: bne 0, .[[OPT3LABEL:[._0-9A-Za-z]+]]
-;CHECK-NEXT: [[TEST4LABEL:[._0-9A-Za-z]+]]: # %test4
+;CHECK-NEXT: bne 0, .[[OPT3LABEL:[_0-9A-Za-z]+]]
+;CHECK-NEXT: .[[TEST4LABEL:[_0-9A-Za-z]+]]: # %test4
 ;CHECK-NEXT: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 28, 28
-;CHECK-NEXT: bne 0, .[[OPT4LABEL:[._0-9A-Za-z]+]]
-;CHECK-NEXT: [[EXITLABEL:[._0-9A-Za-z]+]]: # %exit
+;CHECK-NEXT: bne 0, .[[OPT4LABEL:[_0-9A-Za-z]+]]
+;CHECK-NEXT: .[[EXITLABEL:[_0-9A-Za-z]+]]: # %exit
 ;CHECK: blr
-;CHECK-NEXT: [[OPT1LABEL]]
+;CHECK-NEXT: .[[OPT1LABEL]]
 ;CHECK: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 30, 30
-;CHECK-NEXT: beq 0, [[TEST3LABEL]]
-;CHECK-NEXT: [[OPT2LABEL]]
+;CHECK-NEXT: beq 0, .[[TEST3LABEL]]
+;CHECK-NEXT: .[[OPT2LABEL]]
 ;CHECK: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 29, 29
-;CHECK-NEXT: beq 0, [[TEST4LABEL]]
-;CHECK-NEXT: [[OPT3LABEL]]
+;CHECK-NEXT: beq 0, .[[TEST4LABEL]]
+;CHECK-NEXT: .[[OPT3LABEL]]
 ;CHECK: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 28, 28
-;CHECK-NEXT: beq 0, [[EXITLABEL]]
-;CHECK-NEXT: [[OPT4LABEL]]
-;CHECK: b [[EXITLABEL]]
+;CHECK-NEXT: beq 0, .[[EXITLABEL]]
+;CHECK-NEXT: .[[OPT4LABEL]]
+;CHECK: b .[[EXITLABEL]]
 
-define void @f(i32 %tag) {
+define void @straight_test(i32 %tag) {
 entry:
   br label %test1
 test1:
@@ -94,7 +94,57 @@
   ret void
 }
 
+; The block then2 is not unavoidable, but since it can be tail-duplicated, it
+; should be placed as a fallthrough from test2 and copied.
+; CHECK-LABEL: avoidable_test:
+; CHECK: # %entry
+; CHECK: andi.
+; CHECK: # %test2
+; Make sure then2 falls through from test2
+; CHECK-NOT: # %{{[-_a-zA-Z0-9]+}}
+; CHECK: # %then2
+; CHECK: rlwinm. {{[0-9]+}}, {{[0-9]+}}, 0, 29, 29
+; CHECK-NOT: # %{{[-_a-zA-Z0-9]+}}
+; CHECK: # %end2
+; CHECK: # %else1
+; CHECK: bl a
+; CHECK: bl a
+; Make sure then2 was copied into else1
+; CHECK: rlwinm. {{[0-9]+}}, {{[0-9]+}}, 0, 29, 29
+; CHECK: # %else2
+; CHECK: bl c
+define void @avoidable_test(i32 %tag) {
+entry:
+  br label %test1
+test1:
+  %tagbit1 = and i32 %tag, 1
+  %tagbit1eq0 = icmp eq i32 %tagbit1, 0
+  br i1 %tagbit1eq0, label %test2, label %else1, !prof !1 ; %test2 more likely
+else1:
+  call void @a()
+  call void @a()
+  br label %then2
+test2:
+  %tagbit2 = and i32 %tag, 2
+  %tagbit2eq0 = icmp eq i32 %tagbit2, 0
+  br i1 %tagbit2eq0, label %then2, label %else2, !prof !1 ; %then2 more likely
+then2:
+  %tagbit3 = and i32 %tag, 4
+  %tagbit3eq0 = icmp eq i32 %tagbit3, 0
+  br i1 %tagbit3eq0, label %end2, label %end1, !prof !1 ; %end2 more likely
+else2:
+  call void @c()
+  br label %end2
+end2:
+  ret void
+end1:
+  call void @d()
+  ret void
+}
+
 declare void @a()
 declare void @b()
 declare void @c()
 declare void @d()
+
+!1 = !{!"branch_weights", i32 2, i32 1}
Index: test/CodeGen/SPARC/sjlj.ll
===================================================================
--- test/CodeGen/SPARC/sjlj.ll
+++ test/CodeGen/SPARC/sjlj.ll
@@ -66,14 +66,15 @@
 ; CHECK:  ba   .LBB1_1
 ; CHECK:  nop
 ; CHECK:.LBB1_1:                                ! %entry
-; CHECK:  ba   .LBB1_3
 ; CHECK:  mov  %g0, %i0
+; CHECK:  cmp %i0, 0
+; CHECK:  bne  .LBB1_4
+; CHECK:  ba   .LBB1_5
 ; CHECK:.LBB1_2:                                ! Block address taken
 ; CHECK:  mov  1, %i0
-; CHECK:.LBB1_3:                                ! %entry
-; CHECK:  cmp %i0, 0
 ; CHECK:  be   .LBB1_5
-; CHECK:  nop
+; CHECK:.LBB1_4:
+; CHECK:  ba   .LBB1_6
 }
 declare i8* @llvm.frameaddress(i32) #2
 
Index: test/CodeGen/SystemZ/int-cmp-44.ll
===================================================================
--- test/CodeGen/SystemZ/int-cmp-44.ll
+++ test/CodeGen/SystemZ/int-cmp-44.ll
@@ -473,8 +473,8 @@
   %xor = xor i32 %val, 1
   %add = add i32 %xor, 1000000
   call void @foo()
-  %cmp = icmp ne i32 %add, 0
-  br i1 %cmp, label %exit, label %store
+  %cmp = icmp eq i32 %add, 0
+  br i1 %cmp, label %store, label %exit, !prof !1
 
 store:
   store i32 %add, i32 *%ptr
@@ -888,3 +888,5 @@
 exit:
   ret i64 %res
 }
+
+!1 = !{!"branch_weights", i32 2, i32 1}
Index: test/CodeGen/Thumb/thumb-shrink-wrapping.ll
===================================================================
--- test/CodeGen/Thumb/thumb-shrink-wrapping.ll
+++ test/CodeGen/Thumb/thumb-shrink-wrapping.ll
@@ -1,11 +1,12 @@
-; RUN: llc %s -o - -enable-shrink-wrap=true -ifcvt-fn-start=1 -ifcvt-fn-stop=0 -mtriple=thumb-macho \
+; RUN: llc %s -o - -enable-shrink-wrap=true -ifcvt-fn-start=1 -ifcvt-fn-stop=0 -tail-dup-placement=0 -mtriple=thumb-macho \
 ; RUN:      | FileCheck %s --check-prefix=CHECK --check-prefix=ENABLE --check-prefix=ENABLE-V4T
-; RUN: llc %s -o - -enable-shrink-wrap=true -ifcvt-fn-start=1 -ifcvt-fn-stop=0 -mtriple=thumbv5-macho \
+; RUN: llc %s -o - -enable-shrink-wrap=true -ifcvt-fn-start=1 -ifcvt-fn-stop=0 -tail-dup-placement=0 -mtriple=thumbv5-macho \
 ; RUN:      | FileCheck %s --check-prefix=CHECK --check-prefix=ENABLE --check-prefix=ENABLE-V5T
-; RUN: llc %s -o - -enable-shrink-wrap=false -ifcvt-fn-start=1 -ifcvt-fn-stop=0 -mtriple=thumb-macho \
+; RUN: llc %s -o - -enable-shrink-wrap=false -ifcvt-fn-start=1 -ifcvt-fn-stop=0 -tail-dup-placement=0 -mtriple=thumb-macho \
 ; RUN:      | FileCheck %s --check-prefix=CHECK --check-prefix=DISABLE --check-prefix=DISABLE-V4T
-; RUN: llc %s -o - -enable-shrink-wrap=false -ifcvt-fn-start=1 -ifcvt-fn-stop=0 -mtriple=thumbv5-macho \
+; RUN: llc %s -o - -enable-shrink-wrap=false -ifcvt-fn-start=1 -ifcvt-fn-stop=0 -tail-dup-placement=0 -mtriple=thumbv5-macho \
 ; RUN:      | FileCheck %s --check-prefix=CHECK --check-prefix=DISABLE --check-prefix=DISABLE-V5T
+
 ;
 ; Note: Lots of tests use inline asm instead of regular calls.
 ; This allows to have a better control on what the allocation will do.
@@ -15,6 +16,8 @@
 ; edges.
 ; Also disable the late if-converter as it makes harder to reason on
 ; the diffs.
+; Disable tail-duplication during placement, as v4t vs v5t get different
+; results due to branches not being analyzable under v5
 
 ; Initial motivating example: Simple diamond with a call just on one side.
 ; CHECK-LABEL: foo:
Index: test/CodeGen/Thumb2/cbnz.ll
===================================================================
--- test/CodeGen/Thumb2/cbnz.ll
+++ test/CodeGen/Thumb2/cbnz.ll
@@ -26,7 +26,7 @@
   call void @x()
   call void @x()
   call void @x()
-  ; CHECK: cbnz
+  ; CHECK: cbz
   %q = icmp eq i32 %y, 0
   br i1 %q, label %t2, label %f
 
Index: test/CodeGen/Thumb2/ifcvt-compare.ll
===================================================================
--- test/CodeGen/Thumb2/ifcvt-compare.ll
+++ test/CodeGen/Thumb2/ifcvt-compare.ll
@@ -4,7 +4,7 @@
 
 define void @f0(i32 %x) optsize {
   ; CHECK-LABEL: f0:
-  ; CHECK: cbnz
+  ; CHECK: cbz
   %p = icmp eq i32 %x, 0
   br i1 %p, label %t, label %f
 
Index: test/CodeGen/Thumb2/v8_IT_4.ll
===================================================================
--- test/CodeGen/Thumb2/v8_IT_4.ll
+++ test/CodeGen/Thumb2/v8_IT_4.ll
@@ -12,10 +12,11 @@
 
 define weak arm_aapcs_vfpcc i32 @_ZNKSs7compareERKSs(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this, %"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %__str) {
 ; CHECK-LABEL: _ZNKSs7compareERKSs:
-; CHECK:      cbnz	r0,
+; CHECK:      cbz	r0,
+; CHECK-NEXT: %bb1
+; CHECK-NEXT: pop.w
 ; CHECK-NEXT: %bb
 ; CHECK-NEXT: sub{{(.w)?}} r0, r{{[0-9]+}}, r{{[0-9]+}}
-; CHECK-NEXT: %bb1
 ; CHECK-NEXT: pop.w
 entry:
   %0 = tail call arm_aapcs_vfpcc  i32 @_ZNKSs4sizeEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this) ; <i32> [#uses=3]
Index: test/CodeGen/WebAssembly/phi.ll
===================================================================
--- test/CodeGen/WebAssembly/phi.ll
+++ test/CodeGen/WebAssembly/phi.ll
@@ -8,8 +8,9 @@
 ; Basic phi triangle.
 
 ; CHECK-LABEL: test0:
-; CHECK: div_s $[[NUM0:[0-9]+]]=, $0, $pop[[NUM1:[0-9]+]]{{$}}
-; CHECK: return $[[NUM0]]{{$}}
+; CHECK: return $0
+; CHECK: div_s $push[[NUM0:[0-9]+]]=, $0, $pop[[NUM1:[0-9]+]]{{$}}
+; CHECK: return $pop[[NUM0]]{{$}}
 define i32 @test0(i32 %p) {
 entry:
   %t = icmp slt i32 %p, 0
Index: test/CodeGen/X86/avx512-cmp.ll
===================================================================
--- test/CodeGen/X86/avx512-cmp.ll
+++ test/CodeGen/X86/avx512-cmp.ll
@@ -69,13 +69,14 @@
 ; ALL-NEXT:    vxorps %xmm1, %xmm1, %xmm1
 ; ALL-NEXT:    vucomiss %xmm1, %xmm0
 ; ALL-NEXT:    jne LBB3_1
-; ALL-NEXT:    jnp LBB3_2
+; ALL-NEXT:    jp  LBB3_1
+; ALL-NEXT:  ## BB#2: ## %return
+; ALL-NEXT:    retq
 ; ALL-NEXT:  LBB3_1: ## %if.end
 ; ALL-NEXT:    seta %al
 ; ALL-NEXT:    movzbl %al, %eax
 ; ALL-NEXT:    leaq {{.*}}(%rip), %rcx
 ; ALL-NEXT:    vmovss {{.*#+}} xmm0 = mem[0],zero,zero,zero
-; ALL-NEXT:  LBB3_2: ## %return
 ; ALL-NEXT:    retq
 entry:
   %cmp = fcmp oeq float %p, 0.000000e+00
Index: test/CodeGen/X86/bt.ll
===================================================================
--- test/CodeGen/X86/bt.ll
+++ test/CodeGen/X86/bt.ll
@@ -1,4 +1,4 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc < %s -mtriple=x86_64-unknown-unknown | FileCheck %s
 ; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=+avx512f | FileCheck %s
 ; PR3253
@@ -24,7 +24,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB0_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB0_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
@@ -44,12 +49,17 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB1_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB1_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 1, %tmp29
   %tmp4 = icmp eq i32 %tmp3, 0
-  br i1 %tmp4, label %bb, label %UnifiedReturnBlock
+  br i1 %tmp4, label %bb, label %UnifiedReturnBlock, !prof !1
 
 bb:
   call void @foo()
@@ -64,7 +74,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB2_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB2_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = ashr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
@@ -84,12 +99,17 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB3_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB3_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = ashr i32 %x, %n
   %tmp3 = and i32 1, %tmp29
   %tmp4 = icmp eq i32 %tmp3, 0
-  br i1 %tmp4, label %bb, label %UnifiedReturnBlock
+  br i1 %tmp4, label %bb, label %UnifiedReturnBlock, !prof !1
 
 bb:
   call void @foo()
@@ -104,12 +124,17 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB4_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB4_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %tmp29, %x
   %tmp4 = icmp eq i32 %tmp3, 0
-  br i1 %tmp4, label %bb, label %UnifiedReturnBlock
+  br i1 %tmp4, label %bb, label %UnifiedReturnBlock, !prof !1
 
 bb:
   call void @foo()
@@ -124,12 +149,17 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB5_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB5_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %x, %tmp29
   %tmp4 = icmp eq i32 %tmp3, 0
-  br i1 %tmp4, label %bb, label %UnifiedReturnBlock
+  br i1 %tmp4, label %bb, label %UnifiedReturnBlock, !prof !1
 
 bb:
   call void @foo()
@@ -144,7 +174,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB6_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB6_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
@@ -164,7 +199,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB7_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB7_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 1, %tmp29
@@ -184,7 +224,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB8_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB8_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = ashr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
@@ -204,7 +249,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB9_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB9_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = ashr i32 %x, %n
   %tmp3 = and i32 1, %tmp29
@@ -224,7 +274,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB10_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB10_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %tmp29, %x
@@ -244,7 +299,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB11_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB11_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %x, %tmp29
@@ -264,7 +324,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB12_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB12_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
@@ -284,7 +349,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB13_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB13_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 1, %tmp29
@@ -304,7 +374,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB14_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB14_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = ashr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
@@ -324,7 +399,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB15_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB15_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = ashr i32 %x, %n
   %tmp3 = and i32 1, %tmp29
@@ -344,7 +424,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB16_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB16_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %tmp29, %x
@@ -364,7 +449,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB17_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB17_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %x, %tmp29
@@ -384,7 +474,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB18_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB18_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %tmp29, %x
@@ -404,7 +499,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jae .LBB19_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB19_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %x, %tmp29
@@ -424,7 +524,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB20_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB20_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
@@ -444,7 +549,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB21_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB21_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 1, %tmp29
@@ -464,7 +574,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB22_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB22_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = ashr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
@@ -484,7 +599,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB23_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB23_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = ashr i32 %x, %n
   %tmp3 = and i32 1, %tmp29
@@ -504,7 +624,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB24_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB24_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %tmp29, %x
@@ -524,7 +649,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB25_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB25_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %x, %tmp29
@@ -544,7 +674,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB26_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB26_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %tmp29, %x
@@ -564,7 +699,12 @@
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB27_2
-;
+; CHECK-NEXT:  # BB#1: # %bb
+; CHECK-NEXT:    pushq %rax
+; CHECK-NEXT:    callq foo
+; CHECK-NEXT:    popq %rax
+; CHECK-NEXT:  .LBB27_2: # %UnifiedReturnBlock
+; CHECK-NEXT:    retq
 entry:
   %tmp29 = shl i32 1, %n
   %tmp3 = and i32 %x, %tmp29
@@ -588,7 +728,6 @@
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    setb %al
 ; CHECK-NEXT:    retq
-;
   %neg = xor i32 %flags, -1
   %shl = shl i32 1, %flag
   %and = and i32 %shl, %neg
@@ -598,8 +737,10 @@
 
 define zeroext i1 @extend(i32 %bit, i64 %bits) {
 ; CHECK-LABEL: extend:
-; CHECK:       # BB#0:
-; CHECK-NEXT:  btl %edi, %esi
+; CHECK:       # BB#0: # %entry
+; CHECK-NEXT:    btl %edi, %esi
+; CHECK-NEXT:    setb %al
+; CHECK-NEXT:    retq
 entry:
   %and = and i32 %bit, 31
   %sh_prom = zext i32 %and to i64
@@ -608,3 +749,5 @@
   %tobool = icmp ne i64 %and1, 0
   ret i1 %tobool
 }
+
+!1 = !{!"branch_weights", i32 2, i32 1}
Index: test/CodeGen/X86/fp-une-cmp.ll
===================================================================
--- test/CodeGen/X86/fp-une-cmp.ll
+++ test/CodeGen/X86/fp-une-cmp.ll
@@ -36,8 +36,8 @@
 
 entry:
   %mul = fmul double %x, %y
-  %cmp = fcmp une double %mul, 0.000000e+00
-  br i1 %cmp, label %bb2, label %bb1
+  %cmp = fcmp oeq double %mul, 0.000000e+00
+  br i1 %cmp, label %bb1, label %bb2
 
 bb1:
   %add = fadd double %mul, -1.000000e+00
Index: test/CodeGen/X86/jump_sign.ll
===================================================================
--- test/CodeGen/X86/jump_sign.ll
+++ test/CodeGen/X86/jump_sign.ll
@@ -6,7 +6,7 @@
 ; CHECK: jns
 	%tmp1 = add i32 %X, 1		; <i32> [#uses=1]
 	%tmp = icmp slt i32 %tmp1, 0		; <i1> [#uses=1]
-	br i1 %tmp, label %cond_true, label %cond_next
+	br i1 %tmp, label %cond_true, label %cond_next, !prof !1
 
 cond_true:		; preds = %entry
 	%tmp2 = tail call i32 (...) @bar( )		; <i32> [#uses=0]
@@ -303,3 +303,5 @@
 if.end:
   ret i32 undef
 }
+
+!1 = !{!"branch_weights", i32 2, i32 1}
Index: test/CodeGen/X86/testb-je-fusion.ll
===================================================================
--- test/CodeGen/X86/testb-je-fusion.ll
+++ test/CodeGen/X86/testb-je-fusion.ll
@@ -9,7 +9,7 @@
 entry:
   %and = and i32 %flags, 512
   %tobool = icmp eq i32 %and, 0
-  br i1 %tobool, label %if.end, label %if.then
+  br i1 %tobool, label %if.end, label %if.then, !prof !1
 
 if.then:
   br label %if.end
@@ -18,3 +18,4 @@
   %hasflag = phi i32 [ 1, %if.then ], [ 0, %entry ]
   ret i32 %hasflag
 }
+!1 = !{!"branch_weights", i32 1, i32 2}