CodeGen: Allow small copyable blocks to "break" the CFG.

[iteratee]

Summary

When choosing the best successor for a block, ordinarily we would have preferred
a block that preserves the CFG unless there is a strong probability the other
direction. For small blocks that can be duplicated we now skip that requirement
as well, subject to some simple frequency calculations.

[iteratee]

Realized that one of the calculations I did was only valid for D28522. Re-worked the calculation for now, and will rebase and update the calculation there.

[davidxl]

I like the direction (with more precise cost analysis) this is going. Will review the code soon.

[davidxl]

lib/CodeGen/MachineBlockPlacement.cpp

661

In this case, what is needed to to invoke 'hasBetterLayoutPredecessor' on PDom block. Dependinng the result, we will know that without tailDup, the layout order is Succ-> PDom or Succ->D->PDom. This will make the cost computation more precise.

[davidxl]

lib/CodeGen/MachineBlockPlacement.cpp

419

Suggest new name : isProfitableToTailDup

619

Dom -> PDom

626

Why not just check if there exists a SuccSucc that post dominates Succ directly?

645

PU + PV == P

Also Assuming U > V, the layout order (with tail dup) on should be

BB --> Succ --> D

so the overall cost is:

Q + P V + Q ( which is smaller than Q + QV + PU + PV)

646

We can not assume BB and Succ are in a triangular shape subcfg here -- given where this method is called. Besides, if Succ is not tail-duped, the layout decision may even reject Succ as the layout successor, so the cost is no longer P + V, but 2*Q + V instead (with U > V).

In other words, isProfitable check can not be done inside 'hasBetterLayoutPredecessor', but hoisted to the caller of it when 'hasBetterLayoutPrecessor' returns, at which point we will know the layout decision if taildup does not kick in.

[iteratee]

Updated the cost calculation to not rely on the lattice layout.
This resulted in fewer duplications in tests, so those tests changes have been rolled into D28522

[iteratee]

I made the calculations in terms of frequency instead of probability.

I adjusted the cost calculation when there is a post dominator based on whether it will be laid out after Succ or not.

Let me know if there are any cost calculations that you think are wrong.

[iteratee]

Actually upload the diff with what I said was in the last one:
Use frequency instead of probability

Use slight lookahead for more precise probability calculations.

[iteratee]

Let me know what you think. There is a small cleanup that could go in as a separate patch: I switched to a SmallDenseSet because we don't need the orderedness of the SmallVectorSet.

lib/CodeGen/MachineBlockPlacement.cpp

645

I thought that too. But without the lattice patch, after duplication, we won't put D after Succ because it now has an unplaced predecessor. The lattice patch fixes the behavior and the calculation.

646

I think I have the calculation right for when Succ would not be the layout successor, but you're right to point out that we should also do the calculation even when Succ is the chosen successor.

646

We now only call this function to check if we should use Succ despite it having been rejected. So we know that Succ is not the layout successor.

[iteratee]

Tidied comments and spacing.

[davidxl]

lib/CodeGen/MachineBlockPlacement.cpp

268

There is a reason SmallSetVector is used here -- to make sure the iteration order is deterministic.

638

I assume this is loop back edge source block. You need a test case to cover it.

649

Why break here?

654

nit: -->SuccBestPred

662

Computing BestSuccPred here is unnecessary. See below for more comments.

671

Qin is not necessarily BestSuccPred.

Profitability check is called only after hasBetterLayoutPredecessor is returned and it returns true. There are two scenarios it returns true

1. Qin or Qout is larger than P, or
2. P is larger than Qout, but not the branch is not biased enough such that the layout algorithm still decides to keep the top-order.

Either way, the baseline layout to compare (with taildup) is that BB->Succ is the branch taken edge, and BB->C is the fall through edge. Qin should just be Prob(BB->C)

687

PDom is always a successor of Succ according to the way it is computed.

693

The base cost is as wrote, the DupCost however depends on whether P > Q or not.

If P > Q, the fallthrough path is BB->Succ->D
so the cost (normalized with freq(bb) ==1) is

2*Q+ P*V

If P < Q, the fall through path is BB->C'->D
the cost is

2*P + Q*V

784

Add more description about what blocks to ignore.

[iteratee]

I'll be glad to add some more comments to explain, but I think the calculations are correct. I've commented individually.

lib/CodeGen/MachineBlockPlacement.cpp

268

BlockFilterSet is never iterated. I checked.

646

I think I have the calculation right for when Succ would not be the layout successor, but you're right to point out that we should also do the calculation even when Succ is the chosen successor.

649

Because if PDom is not null, that's all that we look at for the probability calculation.

671

When we place Succ, we remove 2 fallthrough edges BB->C and C'->Succ.

Freq(C'->Succ) may be larger than Freq(BB->C).
I am using Qin to represent Freq(C'->Succ) and Qout for Freq(BB->C). I could just use different letters if that were more clear.

Qout is Freq(BB->C). I don't think Qin should be as well.

687

Thanks.

693

This function is called in a loop looking for the highest probability successor. If Q > P, this function will be ignored and we will lay out Q anyway, so we can ignore the second case.

As to the first case:
Until the 2nd patch lands, the duplication will prevent the BB->Succ->D layout.

Instead you will get BB->Succ ; C'->D
So the cost is as calculated.
D28522 will include an update to this calculation along with an update to the behavior.

784

Well, that's really up to the caller. Do you want me to list why you might want to ignore a block?

[davidxl]

lib/CodeGen/MachineBlockPlacement.cpp

268

See

for (MachineBasicBlock *LoopBB : LoopBlockSet)

fillWorkLists(LoopBB, UpdatedPreds, &LoopBlockSet);

671

differentiate Qin and Qout is fine, but in the code Qin = BestSuccPred which could be Freq(BB->Succ). What I meant is you should directly compute Qin as its definition Freq(C'->Succ)

693

You are right about Q > P case that that scenario will be dropped. It is very subtle, so please add some comment to clarify.

Ok -- for the first case, also add a comment

784

something like : e.g, when called under xxx, we want to ignore yyy. See caller zzz for details. However, see my comment in the function, this parameter seems unnecessary.

910

I think it is equivalent to check Pred == BB. In normal calling context, this is covered by BlockToChain[Pred] == &Chain, but for lookahead case, it is needed to filter BB which is not laid out yet.

[iteratee]

Improved comments based on review.

[davidxl]

Please mark addressed comments as done. Also let me know if it is ready for another round of review (I saw some issues not addressed such as the deterministic iteration of block filter set).

[iteratee]

Missed a comment to rename something.

[iteratee]

In D28583#653869, @davidxl wrote:

Please mark addressed comments as done. Also let me know if it is ready for another round of review (I saw some issues not addressed such as the deterministic iteration of block filter set).

Marked.

I think it's ready, and I put back the deterministic set.

lib/CodeGen/MachineBlockPlacement.cpp

671

Did you still want me to fix something here?

[davidxl]

lib/CodeGen/MachineBlockPlacement.cpp

638

test case for this?

668

Add a short cut here with comments:

// If P is not larger, the best successor selection loop will eventually select C, not Succ (as it is not profitable to do so).
if (P <= Qout)

return false;

671

just add a comment above Qin decl stating that Qin is the largest frequency of Succ's incoming edges which have not been placed.

911

--> ... for lookhead by isProfitableToTailDup when BB has not yet been placed.

[iteratee]

More comments from review, and a new test case.

[davidxl]

This version looks almost fine except for one remaining unaddressed comment.

lib/CodeGen/MachineBlockPlacement.cpp

668

How about this comment? Early return can 1) speed up the computation and 2) make the following code easier to understand.

[iteratee]

lib/CodeGen/MachineBlockPlacement.cpp

638

It's not just a back edge. I added a test case.

668

If we weren't estimating Qout, I'd agree. Instead we'll skip calling this altogether if we know that we won't use the result.

[iteratee]

Sorry. I'd replied to the comment, but Phabricator didn't submit it along with my diff update for some reason.

[iteratee]

Save the blocks with CFG violations that are duplication candidates. Review them in descending order of probability, so we call isProfitableToTailDup the minimum number of times.

[davidxl]

lib/CodeGen/MachineBlockPlacement.cpp

984

Remove the first 'SuccProb > BestProb' check -- it provides only very tiny compile time win depending on the iteration order, but adds more confusion.

1007

no need to set ShouldTailDup in the loop -- it is already initalized outside.

1017

Why not just stable sort it? The vector should be of size 1 for most of the cases. Also why do you need position ?

1027

Should it break instead?

1029

isProfitableToTailDup assumes the baseline layout does not pick Succ. The assumption may not be true here as there are other two possibilities:

1. Succ == BestSucc.BB in the base layout
2. BestSucc.BB == null in the base layout (all BB's successors have conflicts).

In such two cases, isProfitable check should probably be skipped (as it is benefitial)

[iteratee]

Changes from comments:
Just sort the vector instead of make_heap.
If there is a tail duplication opportunity and no other successor, take it.

lib/CodeGen/MachineBlockPlacement.cpp

1017

Will just sort the vector.

Position is because we rely on the successor order being stable and the first successor being a subtle hint. Without the position, we lose track of whether the block in the vector came before or after the block we picked without tail duplication.

1029

Succ won't equal BestSucc.BB because of the continue. These blocks were not chosen by the first loop by construction.

Good catch. I'll add that.

[iteratee]

Per offline discussion, I removed the ordering constraint for blocks that are profitable to tail-duplicate.

This resulted in a lot of test churn, but the source change is relatively small.

[davidxl]

This looks very clean now.

However the amount of churns remind me of one thing. Since the profit computation is based on static branch prediction (without PGO), it is the right thing to do to be a little more conservative in taildup. In other words, instead of making 'isProtifiable' return true when the taildup cost is smaller than baseline cost, add a predefined margin (controlled by a parameter):

if (baseline_cost - taildup_cost > threshold)

return true;

return false;

The threshold also roughly models the side effect of taildup -- increased icache footprint etc due to code size increase.

[iteratee]

Compare frequencies with a small bias against the tail-duplication side to account for increased icache pressure.

Includes a TODO to handle edge frequencies better in general.

[davidxl]

lib/CodeGen/MachineBlockPlacement.cpp

149

perhaps simplify it to tail-dup-penalty ?

605

This basically treats the penality percent parameter as the threshold of normalized improvement: (A-B)/B

if ((A-B)/B > PenaltyPercent/100)

return true;

The problem with this formula is that if B is very hot, it makes (A-B)/B become small, even though the (A-B) is still large.

So I think it is better to compute the normalized improvement as (A-B)/Entry_Freq

basically the improvement relative to the entry frequency. This will help prevent tail dup from happening in very cold paths.

The implementation can makes use of BranchProbablity as well. Suppose we want to implement condition:

if ( (A-B)/Entry_Freq > P/100)
     return true;

do this 3 lines:

BlockFrequency Profit = A - B;
BlockFrequency Threshold = Entry_Freq  * BranchProbability(P, 100);

return Profit > Threshold;

[iteratee]

Use a percentage of the entry frequency as a cutoff.

[davidxl]

lib/CodeGen/MachineBlockPlacement.cpp

154

Is this default value too low? Increase it 5 or 10 perhaps?

610

I suppose this logic here is for rounding errors or overflow? Can you explain why the simple scaling with branch prob (in BranchProbablity.cpp) does not work?

return Gain > EntryFreq*ThresholdProb;

[iteratee]

Simplify the biased comparison.

[iteratee]

lib/CodeGen/MachineBlockPlacement.cpp

154

No, I think we should leave it. Now that it's a flag it's easy to change, and especially comparing with the entry frequency 2% is a big enough margin.

610

I did the math, and found a way to do it simply.

[davidxl]

lgtm

(I only sampled some test case changes which look reasonable)

test/CodeGen/X86/bt.ll

27

This test has not changed in behavior. Better to revert the change.

[iteratee]

test/CodeGen/X86/bt.ll

27

I'll do a complete check for any tests that fall into this category and revert them.

lib/CodeGen/MachineBlockPlacement.cpp

 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
 #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
 #include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #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"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
static cl::opt<unsigned> TailDuplicatePlacementThreshold(
     "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);
 
 extern cl::opt<unsigned> StaticLikelyProb;
 extern cl::opt<unsigned> ProfileLikelyProb;
 
 namespace {
 class BlockChain;
 /// \brief Type for our function-wide basic block -> block chain mapping.
 typedef DenseMap<MachineBasicBlock *, BlockChain *> BlockToChainMapType;
 }
 
 namespace {
 /// \brief A chain of blocks which will be laid out contiguously.
 ///
 /// This is the datastructure representing a chain of consecutive blocks that
 /// are profitable to layout together in order to maximize fallthrough
 /// probabilities and code locality. We also can use a block chain to represent
 /// a sequence of basic blocks which have some external (correctness)
#endif // NDEBUG
   /// and then once for the function as a whole.
   unsigned UnscheduledPredecessors;
 };
 }
 
 namespace {
 class MachineBlockPlacement : public MachineFunctionPass {
   /// \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;
 
   /// \brief Machine Function
   MachineFunction *F;
 
   /// \brief A handle to the branch probability pass.
class MachineBlockPlacement : public MachineFunctionPass {
   MachineBasicBlock *PreferredLoopExit;
 
   /// \brief A handle to the target's instruction info.
   const TargetInstrInfo *TII;
 
   /// \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
   /// since tail duplication affects placement decisions of later blocks, it
   /// must be done inline.
   TailDuplicator TailDup;
 
   /// \brief A set of blocks that are unavoidably execute, i.e. they dominate
bool maybeTailDuplicateBlock(MachineBasicBlock *BB, MachineBasicBlock *LPred,
                                BlockFilterSet *BlockFilter,
                                MachineFunction::iterator &PrevUnplacedBlockIt,
                                bool &DuplicatedToPred);
   bool
   hasBetterLayoutPredecessor(MachineBasicBlock *BB, MachineBasicBlock *Succ,
                              BlockChain &SuccChain, BranchProbability SuccProb,
                              BranchProbability RealSuccProb, BlockChain &Chain,
                              const BlockFilterSet *BlockFilter);
-  MachineBasicBlock *selectBestSuccessor(MachineBasicBlock *BB,
+  BlockAndTailDupResult selectBestSuccessor(MachineBasicBlock *BB,
                                             BlockChain &Chain,
                                             const BlockFilterSet *BlockFilter);
   MachineBasicBlock *
   selectBestCandidateBlock(BlockChain &Chain,
                            SmallVectorImpl<MachineBasicBlock *> &WorkList);
   MachineBasicBlock *
   getFirstUnplacedBlock(const BlockChain &PlacedChain,
                         MachineFunction::iterator &PrevUnplacedBlockIt,
                         const BlockFilterSet *BlockFilter);
 
#endif
   void rotateLoop(BlockChain &LoopChain, MachineBasicBlock *ExitingBB,
                   const BlockFilterSet &LoopBlockSet);
   void rotateLoopWithProfile(BlockChain &LoopChain, MachineLoop &L,
                              const BlockFilterSet &LoopBlockSet);
   void collectMustExecuteBBs();
   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);
+  /// 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
   MachineBlockPlacement() : MachineFunctionPass(ID) {
     initializeMachineBlockPlacementPass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnMachineFunction(MachineFunction &F) override;
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.addRequired<MachineBranchProbabilityInfo>();
     AU.addRequired<MachineBlockFrequencyInfo>();
     AU.addRequired<MachineDominatorTree>();
+    if (TailDupPlacement)
+      AU.addRequired<MachinePostDominatorTree>();
     AU.addRequired<MachineLoopInfo>();
     AU.addRequired<TargetPassConfig>();
     MachineFunctionPass::getAnalysisUsage(AU);
   }
 };
 }
 
 char MachineBlockPlacement::ID = 0;
 char &llvm::MachineBlockPlacementID = MachineBlockPlacement::ID;
 INITIALIZE_PASS_BEGIN(MachineBlockPlacement, "block-placement",
                       "Branch Probability Basic Block Placement", false, false)
 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)
 
 #ifndef NDEBUG
 /// \brief Helper to print the name of a MBB.
 ///
 /// Only used by debug logging.
getAdjustedProbability(BranchProbability OrigProb,
   if (SuccProbN >= SuccProbD)
     SuccProb = BranchProbability::getOne();
   else
     SuccProb = BranchProbability(SuccProbN, SuccProbD);
 
   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);
+}
+
+/// Check the edge frequencies to see if tail duplication will increase
+/// fallthroughs.
+/// \p SuccNoTailDup True if Succ would be chosen w/o considering duplication.
+bool MachineBlockPlacement::isProfitableToTailDup(
+    MachineBasicBlock *BB, MachineBasicBlock *Succ, bool SuccNoTailDup) {
+  // 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
+  //    |          |
+  //   P|          |P
+  //    =   C      =   C
+  //    |  /Q      |  /Q
+  //    | /        | /
+  //    Succ       Succ
+  //    / \        | \  V
+  //  U/   =V      |U \
+  //  /     \      =   D
+  //  D      E     |  /
+  //               | /
+  //               |/
+  //               PDom
+  // In the second case, Placing Succ while duplicating it into C prevents the
+  // fallthrough of Succ into either D or Dom, because they now have C as an
+  // unplaced predecessor
+  MachineBasicBlock *PDom = nullptr;
+  auto BestSuccSucc = BranchProbability::getZero();
+  for (MachineBasicBlock *SuccSucc : Succ->successors()) {
+    auto Prob = MBPI->getEdgeProbability(Succ, SuccSucc);
+    if (Prob > BestSuccSucc)
+      BestSuccSucc = Prob;
+    if (PDom == nullptr)
+      if (MPDT->dominates(SuccSucc, Succ))
+        PDom = SuccSucc;
+  }
+  // If it doesn't have a post-dominating successor, here is the calculation:
+  //    BB        BB
+  //    |         |  \
+  //   P|         |   =
+  //    =   C     |    C
+  //    |  /Q     |     |
+  //    | /       |     |
+  //    Succ      Succ /|
+  //    / \       |  \/ |
+  //  U/   =V     =  /= =
+  //  /     \     | /  \|
+  //  D      E    D     E
+  //  Cost in the first case is: P + V
+  //  Cost in the second case is: Q + QV + PU + PV
+  if (Dom == nullptr || !Succ->isSuccessor(Dom)) {
+    BranchProbability P = (MBPI->getEdgeProbability(BB, Succ));
+    BranchProbability Q = P.getCompl();
+    BranchProbability U = BestSuccSucc;
+    BranchProbability V = U.getCompl();
+    BranchProbability QV = Q * V;
+    uint64_t BaseCost = static_cast<uint64_t>(P.getNumerator()) +
+        static_cast<uint64_t>(V.getNumerator());
+    uint64_t DupCost = static_cast<uint64_t>(Q.getNumerator()) +
+        static_cast<uint64_t>(QV.getNumerator()) +
+        static_cast<uint64_t>(P.getNumerator());
+    return (BaseCost > DupCost);
+  }
+  BranchProbability U = MBPI->getEdgeProbability(Succ, Dom);
+  BranchProbability Q = MBPI->getEdgeProbability(BB, Succ).getCompl();
+  // If there is a post-dominating successor, here is the calculation:
+  // BB         BB
+  // | \  Q     |  \  Q
+  // |P \       |   =
+  // =   C      |P   C (+Succ)
+  // |  /       |     |
+  // | /        |     |
+  // Succ       Succ /|
+  // | \  V     |  \/ |
+  // |U \       |U /\ |
+  // =   D      = =  =|
+  // |  /       |/    D
+  // | /        |    /
+  // |/         |   /
+  // Dom        Dom
+  // Branches have been marked with (=)
+  // 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 Q + P*U + P*V + Q*U == Q + P * Q*U. Subtracting P means we need to
+  // compare U vs Q + Q*U.
+  return (U > (Q + Q*U));
+}
+
+
+/// 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. In
+/// addition we keep a set of blocks that have been tail-duplicated into and
+/// allow those blocks to be unplaced as well. This allows the creation of a
+/// second (larger) spine and a short fallthrough spine.
+/// We also identify blocks with the CFG that would have been produced by
+/// tail-duplication and lay them out in the same manner.
+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
 /// are also successors of \p BB (forming triangular shape CFG).
 /// If none of such predecessors are small, it returns true.
 /// The caller can choose to select \p Succ as the layout successors
 /// so that \p Succ's predecessors (optional branches) can be
 /// outlined.
static BranchProbability getLayoutSuccessorProbThreshold(
   if (!BB->getParent()->getFunction()->getEntryCount())
     return BranchProbability(StaticLikelyProb, 100);
   if (BB->succ_size() == 2) {
     const MachineBasicBlock *Succ1 = *BB->succ_begin();
     const MachineBasicBlock *Succ2 = *(BB->succ_begin() + 1);
     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)
        */
       return BranchProbability(2 * ProfileLikelyProb, 150);
     }
   }
   return BranchProbability(ProfileLikelyProb, 100);
 }
 
 /// Checks to see if the layout candidate block \p Succ has a better layout
 /// predecessor than \c BB. If yes, returns true.
 bool MachineBlockPlacement::hasBetterLayoutPredecessor(
     MachineBasicBlock *BB, MachineBasicBlock *Succ, BlockChain &SuccChain,
     BranchProbability SuccProb, BranchProbability RealSuccProb,
     BlockChain &Chain, const BlockFilterSet *BlockFilter) {
 
   // There isn't a better layout when there are no unscheduled predecessors.
   if (SuccChain.UnscheduledPredecessors == 0)
     return false;
 
   // There are two basic scenarios here:
   // -------------------------------------
   // Case 1: triangular shape CFG (if-then):
   //     BB
   //     | \
   //     |  \
bool MachineBlockPlacement::hasBetterLayoutPredecessor(
   // important predecessor.
   BlockFrequency CandidateEdgeFreq = MBFI->getBlockFreq(BB) * RealSuccProb;
   bool BadCFGConflict = false;
 
   for (MachineBasicBlock *Pred : Succ->predecessors()) {
     if (Pred == Succ || BlockToChain[Pred] == &SuccChain ||
         (BlockFilter && !BlockFilter->count(Pred)) ||
         BlockToChain[Pred] == &Chain)
       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.
     // BB  Pred
     //  \ /
     //  Succ
     // We select edge BB->Succ if

 /// \brief Select the best successor for a block.
 ///
 /// This looks across all successors of a particular block and attempts to
 /// select the "best" one to be the layout successor. It only considers direct
 /// successors which also pass the block filter. It will attempt to avoid
 /// 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.
+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;
   auto AdjustedSumProb =
       collectViableSuccessors(BB, Chain, BlockFilter, Successors);
 
   DEBUG(dbgs() << "Selecting best successor for: " << getBlockName(BB) << "\n");
   for (MachineBasicBlock *Succ : Successors) {
+    bool ShouldTailDup = false;
     auto RealSuccProb = MBPI->getEdgeProbability(BB, Succ);
     BranchProbability SuccProb =
         getAdjustedProbability(RealSuccProb, AdjustedSumProb);
 
     // This heuristic is off by default.
     if (shouldPredBlockBeOutlined(BB, Succ, Chain, BlockFilter, SuccProb,
                                   HotProb))
       return Succ;
 
     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
+            && canTailDuplicateUnplacedPreds(BB, Succ, Chain, BlockFilter)
+            && isProfitableToTailDup(BB, Succ, false)))
         continue;
+      ShouldTailDup = true;
+    }
+
+    if (!ShouldTailDup)
+      ShouldTailDup = isProfitableToTailDup(BB, Succ, true);
 
     DEBUG(
         dbgs() << "    Candidate: " << getBlockName(Succ) << ", probability: "
                << SuccProb
                << (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;
+    BestSucc.ShouldTailDup = ShouldTailDup;
     BestProb = SuccProb;
   }
   if (BestSucc)
     DEBUG(dbgs() << "    Selected: " << getBlockName(BestSucc) << "\n");
 
   return BestSucc;
 }
 
 /// \brief Select the best block from a worklist.
 ///
 /// This looks through the provided worklist as a list of candidate basic
 /// blocks and select the most profitable one to place. The definition of
 /// profitable only really makes sense in the context of a loop. This returns
 /// the most frequently visited block in the worklist, which in the case of
 /// a loop, is the one most desirable to be physically close to the rest of the
 /// loop body in order to improve i-cache behavior.
 ///
 /// \returns The best block found, or null if none are viable.
 MachineBasicBlock *MachineBlockPlacement::selectBestCandidateBlock(
     BlockChain &Chain, SmallVectorImpl<MachineBasicBlock *> &WorkList) {
   // Once we need to walk the worklist looking for a candidate, cleanup the
   // worklist of already placed entries.
   // FIXME: If this shows up on profiles, it could be folded (at the cost of
   // some code complexity) into the loop below.
   WorkList.erase(remove_if(WorkList,
                            [&](MachineBasicBlock *BB) {
                              return BlockToChain.lookup(BB) == &Chain;
                            }),
                  WorkList.end());
 
void MachineBlockPlacement::buildChain(
   for (;;) {
     assert(BB && "null block found at end of chain in loop.");
     assert(BlockToChain[BB] == &Chain && "BlockToChainMap mis-match in loop.");
     assert(*std::prev(Chain.end()) == BB && "BB Not found at end of chain.");
 
 
     // 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 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
     // this point. This won't be a fallthrough, but it will increase locality.
     if (!BestSucc)
       BestSucc = selectBestCandidateBlock(Chain, BlockWorkList);
     if (!BestSucc)
       BestSucc = selectBestCandidateBlock(Chain, EHPadWorkList);
 
     if (!BestSucc) {
       BestSucc = getFirstUnplacedBlock(Chain, PrevUnplacedBlockIt, BlockFilter);
       if (!BestSucc)
         break;
 
       DEBUG(dbgs() << "Unnatural loop CFG detected, forcibly merging the "
                       "layout successor until the CFG reduces\n");
     }
 
     // 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.
       if (repeatedlyTailDuplicateBlock(BestSucc, BB, LoopHeaderBB, Chain,
                                        BlockFilter, PrevUnplacedBlockIt))
         continue;
     }
 
bool MachineBlockPlacement::maybeTailDuplicateBlock(
     MachineBasicBlock *BB, MachineBasicBlock *LPred,
     const BlockChain &Chain, BlockFilterSet *BlockFilter,
     MachineFunction::iterator &PrevUnplacedBlockIt,
     bool &DuplicatedToLPred) {
 
   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.
   bool Removed = false;
   auto RemovalCallback =
       [&](MachineBasicBlock *RemBB) {
         // Signal to outer function
         Removed = true;
auto RemovalCallback =
 
         DEBUG(dbgs() << "TailDuplicator deleted block: "
               << getBlockName(RemBB) << "\n");
       };
   auto RemovalCallbackRef =
       llvm::function_ref<void(MachineBasicBlock*)>(RemovalCallback);
 
   SmallVector<MachineBasicBlock *, 8> DuplicatedPreds;
+  bool IsSimple = TailDup.isSimpleBB(BB);
   TailDup.tailDuplicateAndUpdate(IsSimple, BB, LPred,
                                  &DuplicatedPreds, &RemovalCallbackRef);
 
   // Update UnscheduledPredecessors to reflect tail-duplication.
   DuplicatedToLPred = false;
   for (MachineBasicBlock *Pred : DuplicatedPreds) {
     // We're only looking for unscheduled predecessors that match the filter.
     BlockChain* PredChain = BlockToChain[Pred];
bool MachineBlockPlacement::runOnMachineFunction(MachineFunction &MF) {
   F = &MF;
   MBPI = &getAnalysis<MachineBranchProbabilityInfo>();
   MBFI = llvm::make_unique<BranchFolder::MBFIWrapper>(
       getAnalysis<MachineBlockFrequencyInfo>());
   MLI = &getAnalysis<MachineLoopInfo>();
   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) {
+    MPDT = &getAnalysis<MachinePostDominatorTree>();
     unsigned TailDupSize = TailDuplicatePlacementThreshold;
     if (MF.getFunction()->optForSize())
       TailDupSize = 1;
     TailDup.initMF(MF, MBPI, /* LayoutMode */ true, TailDupSize);
   }
 
   assert(BlockToChain.empty());
 
if (MF.size() > 3 && EnableTailMerge) {
 
     if (BF.OptimizeFunction(MF, TII, MF.getSubtarget().getRegisterInfo(),
                             getAnalysisIfAvailable<MachineModuleInfo>(), MLI,
                             /*AfterBlockPlacement=*/true)) {
       // Redo the layout if tail merging creates/removes/moves blocks.
       BlockToChain.clear();
       // Must redo the dominator tree if blocks were changed.
       MDT->runOnMachineFunction(MF);
+      if (MPDT)
+        MPDT->runOnMachineFunction(MF);
       ChainAllocator.DestroyAll();
       buildCFGChains();
     }
   }
 
   optimizeBranches();
   alignBlocks();
 

test/CodeGen/AArch64/addsub.ll

 ; CHECK: b.gt [[RET]]
   %newval4 = add i32 %val, 3
   store i32 %newval4, i32* @var_i32
   %cmp_pos_sgt = icmp sgt i32 %val2, 321
   br i1 %cmp_pos_sgt, label %ret, label %test5
 
 test5:
 ; CHECK: cmn {{w[0-9]+}}, #444
-; CHECK: b.gt [[RET]]
+; CHECK: b.le [[TEST6:.?LBB[0-9]+_[0-9]+]]
   %newval5 = add i32 %val, 4
   store i32 %newval5, i32* @var_i32
   %cmp_neg_uge = icmp sgt i32 %val2, -444
   br i1 %cmp_neg_uge, label %ret, label %test6
 
+; CHECK: {{^}}[[RET]]:
+; CHECK: ret
+; CHECK: {{^}}[[TEST6]]:
+; CHECK: ret
+
 test6:
   %newval6 = add i32 %val, 5
   store i32 %newval6, i32* @var_i32
   ret void
 
 ret:
   ret void
 }
 ; TODO: adds/subs

test/CodeGen/AArch64/arm64-atomic.ll

 ; RUN: llc < %s -mtriple=arm64-eabi -asm-verbose=false -verify-machineinstrs -mcpu=cyclone | FileCheck %s
 
 define i32 @val_compare_and_swap(i32* %p, i32 %cmp, i32 %new) #0 {
 ; CHECK-LABEL: val_compare_and_swap:
 ; 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: cmp    [[RESULT]], w1
 ; 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
 }
 
 define i32 @val_compare_and_swap_from_load(i32* %p, i32 %cmp, i32* %pnew) #0 {
 ; CHECK-LABEL: val_compare_and_swap_from_load:
 ; CHECK-NEXT: ldr    [[NEW:w[0-9]+]], [x2]
 ; CHECK-NEXT: [[TRYBB:.?LBB[0-9_]+]]:
 ; CHECK-NEXT: ldaxr  [[RESULT:w[0-9]+]], [x0]
 ; CHECK-NEXT: cmp    [[RESULT]], w1
 ; 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
   ret i32 %val
 }
 
 define i32 @val_compare_and_swap_rel(i32* %p, i32 %cmp, i32 %new) #0 {
 ; 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
 }
 
 define i64 @val_compare_and_swap_64(i64* %p, i64 %cmp, i64 %new) #0 {
 ; CHECK-LABEL: val_compare_and_swap_64:
 ; CHECK-NEXT: mov    x[[ADDR:[0-9]+]], x0
 ; CHECK-NEXT: [[TRYBB:.?LBB[0-9_]+]]:
 ; CHECK-NEXT: ldxr   [[RESULT:x[0-9]+]], [x[[ADDR]]]
 ; CHECK-NEXT: cmp    [[RESULT]], x1
 ; 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
 }
 
 define i32 @fetch_and_nand(i32* %p) #0 {
 ; CHECK-LABEL: fetch_and_nand:
 ; CHECK: [[TRYBB:.?LBB[0-9_]+]]:

test/CodeGen/AArch64/arm64-ccmp.ll

 
 ; Speculatively execute division by zero.
 ; The sdiv/udiv instructions do not trap when the divisor is zero, so they are
 ; safe to speculate.
 ; CHECK-LABEL: speculate_division:
 ; CHECK: cmp w0, #1
 ; CHECK: sdiv [[DIVRES:w[0-9]+]], w1, w0
 ; CHECK: ccmp [[DIVRES]], #16, #0, ge
-; CHECK: b.gt [[BLOCK:LBB[0-9_]+]]
-; CHECK: bl _foo
-; CHECK: [[BLOCK]]:
+; CHECK: b.le [[BLOCK:LBB[0-9_]+]]
 ; CHECK: orr w0, wzr, #0x7
+; CHECK: [[BLOCK]]:
+; CHECK: bl _foo
 define i32 @speculate_division(i32 %a, i32 %b) nounwind ssp {
 entry:
   %cmp = icmp sgt i32 %a, 0
   br i1 %cmp, label %land.lhs.true, label %if.end
 
 land.lhs.true:
   %div = sdiv i32 %b, %a
   %cmp1 = icmp slt i32 %div, 17
   br i1 %cmp1, label %if.then, label %if.end
 
 if.then:
   %call = tail call i32 @foo() nounwind
   br label %if.end
 
 if.end:
   ret i32 7
 }
 
 ; Floating point compare.
 ; CHECK: single_fcmp
 ; CHECK: cmp
 ; CHECK-NOT: b.
 ; CHECK: fccmp {{.*}}, #8, ge
-; CHECK: b.lt
+; CHECK: b.ge
 define i32 @single_fcmp(i32 %a, float %b) nounwind ssp {
 entry:
   %cmp = icmp sgt i32 %a, 0
   br i1 %cmp, label %land.lhs.true, label %if.end
 
 land.lhs.true:
   %conv = sitofp i32 %a to float
   %div = fdiv float %b, %conv

test/CodeGen/AArch64/arm64-shrink-wrapping.ll

 ; CHECK: [[LOOP_LABEL:LBB[0-9_]+]]: ; %for.body
 ; CHECK: ldr [[VA_ADDR:x[0-9]+]], [sp, #8]
 ; CHECK-NEXT: add [[NEXT_VA_ADDR:x[0-9]+]], [[VA_ADDR]], #8
 ; CHECK-NEXT: str [[NEXT_VA_ADDR]], [sp, #8]
 ; CHECK-NEXT: ldr [[VA_VAL:w[0-9]+]], {{\[}}[[VA_ADDR]]]
 ; 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
   %tobool = icmp eq i32 %cond, 0
   br i1 %tobool, label %if.else, label %if.then
 
 if.then:                                          ; preds = %entry
   %ap1 = bitcast i8** %ap to i8*

test/CodeGen/AArch64/compare-branch.ll

test3:
   %tst3 = icmp eq i64 %val3, 0
   br i1 %tst3, label %end, label %test4, !prof !1
 ; CHECK: cbz {{x[0-9]+}}, .LBB
 
 test4:
   %val4 = load volatile i64, i64* @var64
   %tst4 = icmp ne i64 %val4, 0
   br i1 %tst4, label %end, label %test5, !prof !1
-; CHECK: cbnz {{x[0-9]+}}, .LBB
+; CHECK: cbz {{x[0-9]+}}, .LBB
 
 test5:
   store volatile i64 %val4, i64* @var64
   ret void
 
 end:
   ret void
 }
 
 
 !1 = !{!"branch_weights", i32 1, i32 1}

test/CodeGen/AArch64/logical_shifted_reg.ll

 ; CHECK: b.lt .L
   %shifted_op = shl i64 %val2, 63
   %shifted_and = and i64 %val1, %shifted_op
   %tst2 = icmp slt i64 %shifted_and, 0
   br i1 %tst2, label %ret, label %test3, !prof !1
 
 test3:
 ; CHECK: tst {{x[0-9]+}}, {{x[0-9]+}}, asr #12
-; CHECK: b.gt .L
+; CHECK: b.le .L
   %asr_op = ashr i64 %val2, 12
   %asr_and = and i64 %asr_op, %val1
   %tst3 = icmp sgt i64 %asr_and, 0
   br i1 %tst3, label %ret, label %other_exit, !prof !1
 
 other_exit:
   store volatile i64 %val1, i64* @var1_64
   ret void
 ret:
   ret void
 }
 
 !1 = !{!"branch_weights", i32 1, i32 1}

test/CodeGen/AArch64/tbz-tbnz.ll

 ; RUN: llc < %s -O1 -mtriple=aarch64-eabi | FileCheck %s
 
 declare void @t()
 
 define void @test1(i32 %a) {
 ; CHECK-LABEL: @test1
 entry:
   %sub = add nsw i32 %a, -12
   %cmp = icmp slt i32 %sub, 0
   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()
   br label %if.end
 
 if.end:
   ret void
 }
 
 define void @test2(i64 %a) {
 ; CHECK-LABEL: @test2
 entry:
   %sub = add nsw i64 %a, -12
   %cmp = icmp slt i64 %sub, 0
   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()
   br label %if.end
 
 if.end:
   ret void
 }

 define void @test7(i32 %a) {
 ; CHECK-LABEL: @test7
 entry:
   %sub = sub nsw i32 %a, 12
   %cmp = icmp slt i32 %sub, 0
   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()
   br label %if.end
 
 if.end:
   ret void
 }

 }
 
 define void @test9(i64 %val1) {
 ; CHECK-LABEL: @test9
   %tst = icmp slt i64 %val1, 0
   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()
   br label %if.end
 
 if.end:
   ret void
 }
 
 define void @test10(i64 %val1) {
 ; CHECK-LABEL: @test10
   %tst = icmp slt i64 %val1, 0
   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()
   br label %if.end
 
 if.end:
   ret void
 }
 
 define void @test11(i64 %val1, i64* %ptr) {
 ; CHECK-LABEL: @test11
 
 ; 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
   br i1 %tst, label %if.then, label %if.end
 
 if.then:
   call void @t()
   br label %if.end
 
 if.end:
   ret void
 }
 
 define void @test12(i64 %val1) {
 ; CHECK-LABEL: @test12
   %tst = icmp slt i64 %val1, 0
   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()
   br label %if.end
 
 if.end:
   ret void
 }
 
 define void @test13(i64 %val1, i64 %val2) {
 ; CHECK-LABEL: @test13
   %or = or i64 %val1, %val2
   %tst = icmp slt i64 %or, 0
   br i1 %tst, label %if.then, label %if.end
 
 ; CHECK: orr [[CMP:x[0-9]+]], x0, x1
 ; CHECK-NOT: cmp
-; CHECK: tbz [[CMP]], #63
+; CHECK: tbnz [[CMP]], #63
 
 if.then:
   call void @t()
   br label %if.end
 
 if.end:
   ret void
 }
 
 define void @test14(i1 %cond) {
 ; CHECK-LABEL: @test14
   br i1 %cond, label %if.end, label %if.then
 
 ; CHECK-NOT: and
-; CHECK: tbnz w0, #0
+; CHECK: tbz w0, #0
 
 if.then:
   call void @t()
   br label %if.end
 
 if.end:
   ret void
 }

test/CodeGen/AMDGPU/branch-relaxation.ll

 ; GCN-NEXT: ;;#ASMSTART
 ; GCN-NEXT: v_nop_e64
 ; GCN-NEXT: v_nop_e64
 ; GCN-NEXT: v_nop_e64
 ; GCN-NEXT: v_nop_e64
 ; 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:
   %tmp = tail call i32 @llvm.amdgcn.workitem.id.x() #0
   %cmp0 = icmp slt i32 %cond0, 0
   br i1 %cmp0, label %bb2, label %bb1
 
 bb1:
   %val = load volatile i32, i32 addrspace(2)* undef
   %cmp1 = icmp eq i32 %val, 3
   br i1 %cmp1, label %bb3, label %bb2
 
 bb2:
   call void asm sideeffect
    "v_nop_e64
     v_nop_e64
     v_nop_e64
     v_nop_e64", ""() #0
   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
 }
 
 ; Requires expanding of required skip branch.
 
 ; GCN-LABEL: {{^}}uniform_inside_divergent:
 ; GCN: v_cmp_gt_u32_e32 vcc, 16, v{{[0-9]+}}
 ; GCN-NEXT: s_and_saveexec_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], vcc

 ; GCN: s_cbranch_scc1 [[ENDIF]]
 
 ; GCN-NEXT: ; BB#2: ; %if_uniform
 ; GCN: buffer_store_dword
 ; GCN: s_waitcnt vmcnt(0)
 
 ; 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:
   %tid = call i32 @llvm.amdgcn.workitem.id.x()
   %d_cmp = icmp ult i32 %tid, 16
   br i1 %d_cmp, label %if, label %endif
 
 if:
   store i32 0, i32 addrspace(1)* %out
   %u_cmp = icmp eq i32 %cond, 0
   br i1 %u_cmp, label %if_uniform, label %endif
 
 if_uniform:
   store i32 1, i32 addrspace(1)* %out
   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
 }
 
 ; si_mask_branch
 ; s_cbranch_execz
 ; s_branch
 
 ; GCN-LABEL: {{^}}analyze_mask_branch:

test/CodeGen/AMDGPU/si-annotate-cf-noloop.ll

bb5:                                              ; preds = %bb3, %bb1
   unreachable
 }
 
 
 ; OPT-LABEL: @annotate_ret_noloop(
 ; OPT-NOT: call i1 @llvm.amdgcn.loop
 
 ; GCN-LABEL: {{^}}annotate_ret_noloop:
-; GCN: s_cbranch_scc1
+; GCN: s_cbranch_scc0 [[BODY:BB[0-9]+_[0-9]+]]
+; GCN: s_endpgm
+
+; GCN: {{^}}[[BODY]]:
 ; GCN: s_endpgm
 ; GCN: .Lfunc_end1
 define void @annotate_ret_noloop(<4 x float> addrspace(1)* noalias nocapture readonly %arg) #0 {
 bb:
   %tmp = tail call i32 @llvm.amdgcn.workitem.id.x()
   br label %bb1
 
 bb1:                                              ; preds = %bb

test/CodeGen/AMDGPU/uniform-cfg.ll

ENDIF:                                            ; preds = %IF, %main_body
   ret void
 }
 
 ; GCN-LABEL: {{^}}icmp_users_different_blocks:
 ; GCN: s_load_dword [[COND:s[0-9]+]]
 ; 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
   %cmp0 = icmp sgt i32 %cond0, 0
   %cmp1 = icmp sgt i32 %cond1, 0
   br i1 %cmp0, label %bb2, label %bb9
 
 bb2:                                              ; preds = %bb

 }
 
 ; Test uniform and divergent.
 
 ; GCN-LABEL: {{^}}uniform_inside_divergent:
 ; 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) {
 entry:
   %tid = call i32 @llvm.amdgcn.workitem.id.x() #0
   %d_cmp = icmp ult i32 %tid, 16
   br i1 %d_cmp, label %if, label %endif
 
 if:
   store i32 0, i32 addrspace(1)* %out
   %u_cmp = icmp eq i32 %cond, 0
   br i1 %u_cmp, label %if_uniform, label %endif
 
 if_uniform:
   store i32 1, i32 addrspace(1)* %out
   br label %endif
 
 endif:
   ret void
 }
 
 ; 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
   br i1 %u_cmp, label %if, label %endif
 
 if:
   store i32 0, i32 addrspace(1)* %out
   %tid = call i32 @llvm.amdgcn.workitem.id.x() #0

 ; GCN-LABEL: {{^}}divergent_if_uniform_if:
 ; GCN: v_cmp_eq_u32_e32 vcc, 0, v0
 ; GCN: s_and_saveexec_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], vcc
 ; GCN: s_xor_b64 [[MASK:s\[[0-9]+:[0-9]+\]]], exec, [[MASK]]
 ; GCN: v_mov_b32_e32 [[ONE:v[0-9]+]], 1
 ; 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
   %d_cmp = icmp eq i32 %tid, 0
   br i1 %d_cmp, label %if, label %endif
 
 if:
   store i32 1, i32 addrspace(1)* %out

 ; The condition of the branches in the two blocks are
 ; uniform. MachineCSE replaces the 2nd condition with the inverse of
 ; the first, leaving an scc use in a different block than it was
 ; defed.
 
 ; GCN-LABEL: {{^}}cse_uniform_condition_different_blocks:
 ; GCN: s_load_dword [[COND:s[0-9]+]]
 ; GCN: s_cmp_lt_i32 [[COND]], 1
-; GCN: s_cbranch_scc1 BB[[FNNUM:[0-9]+]]_3
+; GCN: s_cbranch_scc1 [[FN:BB[0-9_]+]]
 
 ; GCN: BB#1:
 ; GCN-NOT: cmp
 ; GCN: buffer_load_dword
 ; GCN: buffer_store_dword
-; GCN: s_cbranch_scc1 BB[[FNNUM]]_3
+; GCN: s_cbranch_scc0 [[BB7:BB[0-9_]+]]
 
-; GCN: BB[[FNNUM]]_3:
+; GCN: [[FN]]:
 ; GCN: s_endpgm
+
+; GCN: [[BB7]]:
+; GCN: s_endpgm
+
 define void @cse_uniform_condition_different_blocks(i32 %cond, i32 addrspace(1)* %out) {
 bb:
   %tmp = tail call i32 @llvm.amdgcn.workitem.id.x() #0
   %tmp1 = icmp sgt i32 %cond, 0
   br i1 %tmp1, label %bb2, label %bb9
 
 bb2:                                              ; preds = %bb
   %tmp3 = load volatile i32, i32 addrspace(1)* undef

test/CodeGen/ARM/arm-and-tst-peephole.ll

 ; V8-LABEL: %tailrecurse.switch
 ; V8: cmp
 ; V8-NEXT: beq
 ; V8-NEXT: %tailrecurse.switch
 ; V8: cmp
 ; 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
     i32 2, label %sw.bb8
   ], !prof !1
 
 sw.bb:                                            ; preds = %tailrecurse.switch, %tailrecurse
   %shl = shl i32 %acc.tr, 1

test/CodeGen/ARM/atomic-op.ll

 ; CHECK-NOT:     dmb ish
 ; CHECK: [[LOOP_BB:\.?LBB[0-9]+_1]]:
 ; CHECK:     ldrex   [[OLDVAL:r[0-9]+]], [r[[ADDR:[0-9]+]]]
 ; CHECK:     cmp     [[OLDVAL]], r1
 ; CHECK:     bne     [[FAIL_BB:\.?LBB[0-9]+_[0-9]+]]
 ; 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
 
   ret i32 %oldval
 }
 
 define i32 @load_load_add_acquire(i32* %mem1, i32* %mem2) nounwind {
 ; CHECK-LABEL: load_load_add_acquire

test/CodeGen/ARM/atomic-ops-v8.ll

 ; CHECK-THUMB-DAG: mov r[[WANTED:[0-9]+]], r0
 
 ; CHECK: .LBB{{[0-9]+}}_1:
 ; CHECK: ldaexb r[[OLD:[0-9]+]], [r[[ADDR]]]
   ; r0 below is a reasonable guess but could change: it certainly comes into the
   ;  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
 }
 
 define i16 @test_atomic_cmpxchg_i16(i16 zeroext %wanted, i16 zeroext %new) nounwind {
 ; CHECK-LABEL: test_atomic_cmpxchg_i16:
    %pair = cmpxchg i16* @var16, i16 %wanted, i16 %new seq_cst seq_cst
    %old = extractvalue { i16, i1 } %pair, 0
 ; CHECK-NOT: dmb
 ; CHECK-NOT: mcr
 ; CHECK-DAG: movw r[[ADDR:[0-9]+]], :lower16:var16
 ; CHECK-DAG: movt r[[ADDR]], :upper16:var16
 ; CHECK-THUMB-DAG: mov r[[WANTED:[0-9]+]], r0
 
 ; CHECK: .LBB{{[0-9]+}}_1:
 ; CHECK: ldaexh r[[OLD:[0-9]+]], [r[[ADDR]]]
   ; r0 below is a reasonable guess but could change: it certainly comes into the
   ;  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
 }
 
 define void @test_atomic_cmpxchg_i32(i32 %wanted, i32 %new) nounwind {
 ; CHECK-LABEL: test_atomic_cmpxchg_i32:
    %pair = cmpxchg i32* @var32, i32 %wanted, i32 %new release monotonic
    %old = extractvalue { i32, i1 } %pair, 0
    store i32 %old, i32* @var32
 ; CHECK-NOT: dmb
 ; CHECK-NOT: mcr
 ; CHECK: movw r[[ADDR:[0-9]+]], :lower16:var32
 ; CHECK: movt r[[ADDR]], :upper16:var32
 
 ; CHECK: .LBB{{[0-9]+}}_1:
 ; CHECK: ldrex r[[OLD:[0-9]+]], [r[[ADDR]]]
   ; 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
 }
 
 define void @test_atomic_cmpxchg_i64(i64 %wanted, i64 %new) nounwind {
 ; CHECK-LABEL: test_atomic_cmpxchg_i64:
    %pair = cmpxchg i64* @var64, i64 %wanted, i64 %new monotonic monotonic
    %old = extractvalue { i64, i1 } %pair, 0
 ; CHECK-NOT: dmb
 ; CHECK-NOT: mcr
 ; CHECK: movw r[[ADDR:[0-9]+]], :lower16:var64
 ; CHECK: movt r[[ADDR]], :upper16:var64
 
 ; CHECK: .LBB{{[0-9]+}}_1:
 ; CHECK: ldrexd [[OLD1:r[0-9]+|lr]], [[OLD2:r[0-9]+|lr]], [r[[ADDR]]]
   ; r0, r1 below is a reasonable guess but could change: it certainly comes into the
   ; function there.
 ; CHECK-LE-DAG: eor{{(\.w)?}} [[MISMATCH_LO:r[0-9]+|lr]], [[OLD1]], r0
 ; CHECK-LE-DAG: eor{{(\.w)?}} [[MISMATCH_HI:r[0-9]+|lr]], [[OLD2]], r1
 ; CHECK-ARM-LE: orrs{{(\.w)?}} {{r[0-9]+}}, [[MISMATCH_LO]], [[MISMATCH_HI]]
 ; CHECK-THUMB-LE: orrs{{(\.w)?}} {{(r[0-9]+, )?}}[[MISMATCH_HI]], [[MISMATCH_LO]]
 ; CHECK-BE-DAG: eor{{(\.w)?}} [[MISMATCH_HI:r[0-9]+|lr]], [[OLD2]], r1
 ; 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
 
 ; CHECK-ARM: strd [[OLD1]], [[OLD2]], [r[[ADDR]]]
    store i64 %old, i64* @var64
    ret void
 }
 

test/CodeGen/ARM/cmpxchg-weak.ll

 ; RUN: llc < %s -mtriple=armv7-apple-ios -verify-machineinstrs | FileCheck %s
 
 define void @test_cmpxchg_weak(i32 *%addr, i32 %desired, i32 %new) {
 ; CHECK-LABEL: test_cmpxchg_weak:
 
   %pair = cmpxchg weak i32* %addr, i32 %desired, i32 %new seq_cst monotonic
   %oldval = extractvalue { i32, i1 } %pair, 0
 ; CHECK-NEXT: BB#0:
 ; CHECK-NEXT:     ldrex   [[LOADED:r[0-9]+]], [r0]
 ; CHECK-NEXT:     cmp     [[LOADED]], r1
 ; CHECK-NEXT:     bne     [[LDFAILBB:LBB[0-9]+_[0-9]+]]
 ; CHECK-NEXT: BB#1:
 ; 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
 
   store i32 %oldval, i32* %addr
   ret void
 }
 
 

test/CodeGen/ARM/machine-cse-cmp.ll

 declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) nounwind
 
 ; rdar://12462006
 define i8* @f3(i8* %base, i32* nocapture %offset, i32 %size) nounwind {
 entry:
 ; CHECK-LABEL: f3:
 ; CHECK-NOT: sub
 ; CHECK: cmp
-; CHECK: blt
+; CHECK: bge
 %0 = load i32, i32* %offset, align 4
 %cmp = icmp slt i32 %0, %size
 %s = sub nsw i32 %0, %size
 %size2 = sub nsw i32 %size, 0
 br i1 %cmp, label %return, label %if.end
 
 if.end:
 ; We are checking cse between %sub here and %s in entry block.

test/CodeGen/Mips/brconeq.ll

 ; RUN: llc  -march=mipsel -mattr=mips16 -relocation-model=pic -O3 < %s | FileCheck %s -check-prefix=16
 
 @i = global i32 5, align 4
 @j = global i32 10, align 4
 @result = global i32 0, align 4
 
 define void @test() nounwind {
 entry:
   %0 = load i32, i32* @i, align 4
   %1 = load i32, i32* @j, align 4
-  %cmp = icmp eq i32 %0, %1
+  %cmp = icmp ne i32 %0, %1
 ; 16: cmp ${{[0-9]+}}, ${{[0-9]+}}
 ; 16: bteqz $[[LABEL:[0-9A-Ba-b_]+]]
 ; 16: $[[LABEL]]:
-  br i1 %cmp, label %if.end, label %if.then
+  br i1 %cmp, label %if.then, label %if.end
 
 if.then:                                          ; preds = %entry
   store i32 1, i32* @result, align 4
   br label %if.end
 
 if.end:                                           ; preds = %entry, %if.then
   ret void
 }

test/CodeGen/Mips/brconeqk.ll

 ; RUN: llc  -march=mipsel -mattr=mips16 -relocation-model=pic -O3 < %s | FileCheck %s -check-prefix=16
 
 @i = global i32 5, align 4
 @result = global i32 0, align 4
 
 define void @test() nounwind {
 entry:
   %0 = load i32, i32* @i, align 4
-  %cmp = icmp eq i32 %0, 10
-  br i1 %cmp, label %if.end, label %if.then
+  %cmp = icmp ne i32 %0, 10
+  br i1 %cmp, label %if.then, label %if.end
 ; 16: cmpi  ${{[0-9]+}}, {{[0-9]+}}
 ; 16: bteqz $[[LABEL:[0-9A-Ba-b_]+]]
 ; 16: $[[LABEL]]:
 if.then:                                          ; preds = %entry
   store i32 1, i32* @result, align 4
   br label %if.end
 
 if.end:                                           ; preds = %entry, %if.then
   ret void
 }
 
 

test/CodeGen/Mips/brcongt.ll

 ; RUN: llc  -march=mipsel -mattr=mips16 -relocation-model=pic -O3 < %s | FileCheck %s -check-prefix=16
 
 @i = global i32 5, align 4
 @j = global i32 10, align 4
 @k = global i32 5, align 4
 @result = global i32 0, align 4
 
 define void @test() nounwind {
 entry:
   %0 = load i32, i32* @i, align 4
   %1 = load i32, i32* @j, align 4
-  %cmp = icmp sgt i32 %0, %1
-  br i1 %cmp, label %if.end, label %if.then
+  %cmp = icmp sle i32 %0, %1
+  br i1 %cmp, label %if.then, label %if.end
 ; 16: slt ${{[0-9]+}}, ${{[0-9]+}}
 ; 16: btnez $[[LABEL:[0-9A-Ba-b_]+]]
 ; 16: $[[LABEL]]:
 if.then:                                          ; preds = %entry
   store i32 1, i32* @result, align 4
   br label %if.end
 
 if.end:                                           ; preds = %entry, %if.then
   ret void
 }
 
 

test/CodeGen/Mips/brconlt.ll

 ; RUN: llc  -march=mipsel -mattr=mips16 -relocation-model=pic -O3 < %s | FileCheck %s -check-prefix=16
 ; RUN: llc  -march=mips -mattr=micromips -mcpu=mips32r6 -relocation-model=pic -O3 < %s | FileCheck %s -check-prefix=MM32R6
 
 @i = global i32 5, align 4
 @j = global i32 10, align 4
 @k = global i32 5, align 4
 @result = global i32 0, align 4
 
 define void @test() nounwind {
 entry:
   %0 = load i32, i32* @j, align 4
   %1 = load i32, i32* @i, align 4
-  %cmp = icmp slt i32 %0, %1
-  br i1 %cmp, label %if.end, label %if.then
+  %cmp = icmp sge i32 %0, %1
+  br i1 %cmp, label %if.then, label %if.end
 
 ; 16:     slt   ${{[0-9]+}}, ${{[0-9]+}}
 ; MM32R6: slt   ${{[0-9]+}}, ${{[0-9]+}}
 ; 16:     btnez $[[LABEL:[0-9A-Ba-b_]+]]
 ; 16:     $[[LABEL]]:
 
 if.then:                                          ; preds = %entry
   store i32 1, i32* @result, align 4
   br label %if.end
 
 if.end:                                           ; preds = %entry, %if.then
   ret void
 }
 
 

test/CodeGen/Mips/brconnez.ll

 ; RUN: llc  -march=mipsel -mattr=mips16 -relocation-model=pic -O3 < %s | FileCheck %s -check-prefix=16
 
 @j = global i32 0, align 4
 @result = global i32 0, align 4
 
 define void @test() nounwind {
 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]+}})
 ; 16: $[[LABEL]]:
 
 if.then:                                          ; preds = %entry
   store i32 1, i32* @result, align 4
   br label %if.end
 
 if.end:                                           ; preds = %if.then, %entry
   ret void
 }
 
-
+!1 = !{!"branch_weights", i32 2, i32 1}

test/CodeGen/Mips/llvm-ir/ashr.ll

; ALL-LABEL: ashr_i64:
   ; M2:         bnez      $[[T1]], $[[BB0:BB[0-9_]+]]
   ; M2:         move      $3, $[[T0]]
   ; M2:         srlv      $[[T2:[0-9]+]], $5, $7
   ; M2:         not       $[[T3:[0-9]+]], $7
   ; M2:         sll       $[[T4:[0-9]+]], $4, 1
   ; M2:         sllv      $[[T5:[0-9]+]], $[[T4]], $[[T3]]
   ; M2:         or        $3, $[[T3]], $[[T2]]
   ; M2:         $[[BB0]]:
-  ; M2:         beqz      $[[T1]], $[[BB1:BB[0-9_]+]]
+  ; M2:         bnez      $[[T1]], $[[BB1:BB[0-9_]+]]
   ; M2:         nop
-  ; M2:         sra       $2, $4, 31
-  ; M2:         $[[BB1]]:
   ; M2:         jr        $ra
   ; M2:         nop
+  ; M2:         $[[BB1]]:
+  ; M2:         jr        $ra
+  ; M2:         sra       $2, $4, 31
 
   ; 32R1-R5:    srlv      $[[T0:[0-9]+]], $5, $7
   ; 32R1-R5:    not       $[[T1:[0-9]+]], $7
   ; 32R1-R5:    sll       $[[T2:[0-9]+]], $4, 1
   ; 32R1-R5:    sllv      $[[T3:[0-9]+]], $[[T2]], $[[T1]]
   ; 32R1-R5:    or        $3, $[[T3]], $[[T0]]
   ; 32R1-R5:    srav      $[[T4:[0-9]+]], $4, $7
   ; 32R1-R5:    andi      $[[T5:[0-9]+]], $7, 32
; ALL-LABEL: ashr_i128:
   ; M3:             bnez      $[[T3:[0-9]+]], [[BB0:.LBB[0-9_]+]]
   ; M3:             move      $3, $[[T1]]
   ; M3:             dsrlv     $[[T4:[0-9]+]], $5, $7
   ; M3:             dsll      $[[T5:[0-9]+]], $4, 1
   ; M3:             not       $[[T6:[0-9]+]], $[[T0]]
   ; M3:             dsllv     $[[T7:[0-9]+]], $[[T5]], $[[T6]]
   ; M3:             or        $3, $[[T7]], $[[T4]]
   ; M3:             [[BB0]]:
-  ; M3:             beqz      $[[T3]], [[BB1:.LBB[0-9_]+]]
+  ; M3:             bnez      $[[T3]], [[BB1:.LBB[0-9_]+]]
   ; M3:             nop
-  ; M3:             dsra      $2, $4, 63
-  ; M3:             [[BB1]]:
   ; M3:             jr        $ra
   ; M3:             nop
+  ; M3:             [[BB1]]:
+  ; M3:             jr        $ra
+  ; M3:             dsra      $2, $4, 63
 
   ; GP64-NOT-R6:    dsrlv     $[[T0:[0-9]+]], $5, $7
   ; GP64-NOT-R6:    dsll      $[[T1:[0-9]+]], $4, 1
   ; GP64-NOT-R6:    sll       $[[T2:[0-9]+]], $7, 0
   ; GP64-NOT-R6:    not       $[[T3:[0-9]+]], $[[T2]]
   ; GP64-NOT-R6:    dsllv     $[[T4:[0-9]+]], $[[T1]], $[[T3]]
   ; GP64-NOT-R6:    or        $3, $[[T4]], $[[T0]]
   ; GP64-NOT-R6:    dsrav     $2, $4, $7

test/CodeGen/Mips/micromips-compact-branches.ll

 ; RUN: llc %s -march=mipsel -mattr=micromips -filetype=asm -O3 \
 ; RUN: -disable-mips-delay-filler -relocation-model=pic -o - | FileCheck %s
 
 define void @main() nounwind uwtable {
 entry:
   %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
   br label %if.end
 
 if.end:
   ret void
 }
 
 ; CHECK: bnezc
+!1 = !{!"branch_weights", i32 2, i32 1}

test/CodeGen/PowerPC/misched-inorder-latency.ll

 ; CHECK: addi
 ; CHECK: bne
 ; CHECK: %true
 define i32 @testload(i32 *%ptr, i32 %sumin) {
 entry:
   %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
   %val = load i32, i32* %ptr2
   %val2 = add i32 %val1, %val
   br label %end
 end:
   %valmerge = phi i32 [ %val1, %entry], [ %val2, %true ]

 true:
   %val2 = add i32 %val1, 1
   br label %end
 end:
   %valmerge = phi i32 [ %val1, %entry], [ %val2, %true ]
   ret i32 %valmerge
 }
 declare void @llvm.prefetch(i8*, i32, i32, i32) nounwind
+
+!1 = !{!"branch_weights", i32 2, i32 1}

test/CodeGen/PowerPC/tail-dup-break-cfg.ll

+; 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()
+
+!1 = !{!"branch_weights", i32 5, i32 3}

test/CodeGen/PowerPC/tail-dup-layout.ll

 ; optional3
 ; optional4
 ; Tail duplication puts test n+1 at the end of optional n
 ; so optional1 includes a copy of test2 at the end, and branches
 ; to test3 (at the top) or falls through to optional 2.
 ; 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: 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: rlwinm. {{[0-9]+}}, [[TAGREG]], 0, 29, 29
 ;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]]
 
-define void @f(i32 %tag) {
+define void @straight_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 %optional1
 optional1:
   call void @a()
optional4:
   call void @d()
   call void @d()
   call void @d()
   br label %exit
 exit:
   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}

test/CodeGen/SPARC/sjlj.ll

 ; CHECK:  or %i1, %lo(.LBB1_2), %i1
 ; CHECK:  st %i1, [%i0+4]
 ; CHECK:  st %sp, [%i0+8]
 ; CHECK:  bn   .LBB1_2
 ; CHECK:  st %i7, [%i0+12]
 ; 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
 
 declare i8* @llvm.stacksave() #3
 
 declare i32 @llvm.eh.sjlj.setjmp(i8*) #3
 
 attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
 attributes #1 = { noreturn nounwind }
 attributes #2 = { nounwind readnone }
 attributes #3 = { nounwind }
 

test/CodeGen/SystemZ/asm-18.ll

 ; Test selects involving high registers.
 define void @f13(i32 %x, i32 %y) {
 ; CHECK-LABEL: f13:
 ; CHECK: llihl [[REG:%r[0-5]]], 0
 ; CHECK: cije %r2, 0
 ; CHECK: iihf [[REG]], 2102030405
 ; CHECK: blah [[REG]]
 ; CHECK: br %r14
-  %cmp = icmp eq i32 %x, 0
+  %cmp = icmp ne i32 %x, 0
   %val = select i1 %cmp, i32 0, i32 2102030405
   call void asm sideeffect "blah $0", "h"(i32 %val)
   ret void
 }
 
 ; Test selects involving low registers.
 define void @f14(i32 %x, i32 %y) {
 ; CHECK-LABEL: f14:
 ; CHECK: lhi [[REG:%r[0-5]]], 0
 ; CHECK: cije %r2, 0
 ; CHECK: iilf [[REG]], 2102030405
 ; CHECK: blah [[REG]]
 ; CHECK: br %r14
-  %cmp = icmp eq i32 %x, 0
+  %cmp = icmp ne i32 %x, 0
   %val = select i1 %cmp, i32 0, i32 2102030405
   call void asm sideeffect "blah $0", "r"(i32 %val)
   ret void
 }
 
 ; Test immediate insertion involving high registers.
 define void @f15() {
 ; CHECK-LABEL: f15:

test/CodeGen/SystemZ/cond-store-01.ll

; CHECK: br %r14
   store i8 %res, i8 *%ptr
   ret void
 }
 
 ; Check that volatile loads are not matched.
 define void @f18(i8 *%ptr, i8 %alt, i32 %limit) {
 ; CHECK-LABEL: f18:
 ; CHECK: lb {{%r[0-5]}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: stc {{%r[0-5]}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: lr {{%r[0-5]}}, {{%r[0-5]}}
 ; CHECK: stc {{%r[0-5]}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load volatile i8 , i8 *%ptr
   %res = select i1 %cond, i8 %orig, i8 %alt
   store i8 %res, i8 *%ptr
   ret void
 }

 ; Check that atomic loads are not matched.  The transformation is OK for
 ; the "unordered" case tested here, but since we don't try to handle atomic
 ; operations at all in this context, it seems better to assert that than
 ; to restrict the test to a stronger ordering.
 define void @f20(i8 *%ptr, i8 %alt, i32 %limit) {
 ; FIXME: should use a normal load instead of CS.
 ; CHECK-LABEL: f20:
 ; CHECK: lb {{%r[0-9]+}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: stc {{%r[0-9]+}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: lr {{%r[0-5]}}, {{%r[0-5]}}
 ; CHECK: stc {{%r[0-9]+}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load atomic i8 , i8 *%ptr unordered, align 1
   %res = select i1 %cond, i8 %orig, i8 %alt
   store i8 %res, i8 *%ptr
   ret void
 }

test/CodeGen/SystemZ/cond-store-02.ll

; CHECK: br %r14
   store i16 %res, i16 *%ptr
   ret void
 }
 
 ; Check that volatile loads are not matched.
 define void @f18(i16 *%ptr, i16 %alt, i32 %limit) {
 ; CHECK-LABEL: f18:
 ; CHECK: lh {{%r[0-5]}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: sth {{%r[0-5]}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: lr {{%r[0-5]}}, {{%r[0-5]}}
 ; CHECK: sth {{%r[0-5]}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load volatile i16 , i16 *%ptr
   %res = select i1 %cond, i16 %orig, i16 %alt
   store i16 %res, i16 *%ptr
   ret void
 }

 ; Check that atomic loads are not matched.  The transformation is OK for
 ; the "unordered" case tested here, but since we don't try to handle atomic
 ; operations at all in this context, it seems better to assert that than
 ; to restrict the test to a stronger ordering.
 define void @f20(i16 *%ptr, i16 %alt, i32 %limit) {
 ; FIXME: should use a normal load instead of CS.
 ; CHECK-LABEL: f20:
 ; CHECK: lh {{%r[0-9]+}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: sth {{%r[0-9]+}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: lr {{%r[0-9]+}}, {{%r[0-9]+}}
 ; CHECK: sth {{%r[0-9]+}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load atomic i16 , i16 *%ptr unordered, align 2
   %res = select i1 %cond, i16 %orig, i16 %alt
   store i16 %res, i16 *%ptr
   ret void
 }

test/CodeGen/SystemZ/cond-store-03.ll

; CHECK: br %r14
   store i32 %res, i32 *%ptr
   ret void
 }
 
 ; Check that volatile loads are not matched.
 define void @f14(i32 *%ptr, i32 %alt, i32 %limit) {
 ; CHECK-LABEL: f14:
 ; CHECK: l {{%r[0-5]}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: st {{%r[0-5]}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: lr {{%r[0-5]}}, {{%r[0-5]}}
 ; CHECK: st {{%r[0-5]}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load volatile i32 , i32 *%ptr
   %res = select i1 %cond, i32 %orig, i32 %alt
   store i32 %res, i32 *%ptr
   ret void
 }

 ; Check that atomic loads are not matched.  The transformation is OK for
 ; the "unordered" case tested here, but since we don't try to handle atomic
 ; operations at all in this context, it seems better to assert that than
 ; to restrict the test to a stronger ordering.
 define void @f16(i32 *%ptr, i32 %alt, i32 %limit) {
 ; FIXME: should use a normal load instead of CS.
 ; CHECK-LABEL: f16:
 ; CHECK: l {{%r[0-5]}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: st {{%r[0-5]}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: lr {{%r[0-5]}}, {{%r[0-5]}}
 ; CHECK: st {{%r[0-5]}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load atomic i32 , i32 *%ptr unordered, align 4
   %res = select i1 %cond, i32 %orig, i32 %alt
   store i32 %res, i32 *%ptr
   ret void
 }

test/CodeGen/SystemZ/cond-store-04.ll

; CHECK: br %r14
   store i64 %res, i64 *%ptr
   ret void
 }
 
 ; Check that volatile loads are not matched.
 define void @f8(i64 *%ptr, i64 %alt, i32 %limit) {
 ; CHECK-LABEL: f8:
 ; CHECK: lg {{%r[0-5]}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: stg {{%r[0-5]}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: lgr {{%r[0-5]}}, {{%r[0-5]}}
 ; CHECK: stg {{%r[0-5]}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load volatile i64 , i64 *%ptr
   %res = select i1 %cond, i64 %orig, i64 %alt
   store i64 %res, i64 *%ptr
   ret void
 }

 ; Check that atomic loads are not matched.  The transformation is OK for
 ; the "unordered" case tested here, but since we don't try to handle atomic
 ; operations at all in this context, it seems better to assert that than
 ; to restrict the test to a stronger ordering.
 define void @f10(i64 *%ptr, i64 %alt, i32 %limit) {
 ; FIXME: should use a normal load instead of CSG.
 ; CHECK-LABEL: f10:
 ; CHECK: lg {{%r[0-5]}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: stg {{%r[0-5]}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: lgr {{%r[0-5]}}, {{%r[0-5]}}
 ; CHECK: stg {{%r[0-5]}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load atomic i64 , i64 *%ptr unordered, align 8
   %res = select i1 %cond, i64 %orig, i64 %alt
   store i64 %res, i64 *%ptr
   ret void
 }

test/CodeGen/SystemZ/cond-store-05.ll

; CHECK: br %r14
   store float %res, float *%ptr
   ret void
 }
 
 ; Check that volatile loads are not matched.
 define void @f10(float *%ptr, float %alt, i32 %limit) {
 ; CHECK-LABEL: f10:
 ; CHECK: le {{%f[0-5]}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: ste {{%f[0-5]}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: ler {{%f[0-5]}}, {{%f[0-5]}}
 ; CHECK: ste {{%f[0-5]}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load volatile float , float *%ptr
   %res = select i1 %cond, float %orig, float %alt
   store float %res, float *%ptr
   ret void
 }

test/CodeGen/SystemZ/cond-store-06.ll

; CHECK: br %r14
   store double %res, double *%ptr
   ret void
 }
 
 ; Check that volatile loads are not matched.
 define void @f10(double *%ptr, double %alt, i32 %limit) {
 ; CHECK-LABEL: f10:
 ; CHECK: ld {{%f[0-5]}}, 0(%r2)
-; CHECK: {{jl|jnl}} [[LABEL:[^ ]*]]
+; CHECK: {{jhe|jnhe}} [[LABEL:[^ ]*]]
+; CHECK: std {{%f[0-5]}}, 0(%r2)
+; CHECK: br %r14
 ; CHECK: [[LABEL]]:
+; CHECK: ldr {{%f[0-5]}}, {{%f[0-5]}}
 ; CHECK: std {{%f[0-5]}}, 0(%r2)
 ; CHECK: br %r14
   %cond = icmp ult i32 %limit, 420
   %orig = load volatile double , double *%ptr
   %res = select i1 %cond, double %orig, double %alt
   store double %res, double *%ptr
   ret void
 }

test/CodeGen/SystemZ/int-cmp-37.ll

 define i32 @f1(i32 %src1) {
 ; CHECK-LABEL: f1:
 ; CHECK: clhrl %r2, g
 ; CHECK-NEXT: jl
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src2 = zext i16 %val to i32
-  %cond = icmp ult i32 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp uge i32 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i32 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i32 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i32 %tmp, 1
   ret i32 %res
 }
 
 ; Check signed comparison.
 define i32 @f2(i32 %src1) {
 ; CHECK-LABEL: f2:
 ; CHECK-NOT: clhrl
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src2 = zext i16 %val to i32
-  %cond = icmp slt i32 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp sge i32 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i32 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i32 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i32 %tmp, 1
   ret i32 %res
 }
 
 ; Check equality.
 define i32 @f3(i32 %src1) {
 ; CHECK-LABEL: f3:
 ; CHECK: clhrl %r2, g
 ; CHECK-NEXT: je
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src2 = zext i16 %val to i32
-  %cond = icmp eq i32 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp ne i32 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i32 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i32 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i32 %tmp, 1
   ret i32 %res
 }
 
 ; Check inequality.
 define i32 @f4(i32 %src1) {
 ; CHECK-LABEL: f4:
 ; CHECK: clhrl %r2, g
 ; CHECK-NEXT: jlh
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src2 = zext i16 %val to i32
-  %cond = icmp ne i32 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp eq i32 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i32 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i32 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i32 %tmp, 1
   ret i32 %res
 }
 
 ; Repeat f1 with an unaligned address.
 define i32 @f5(i32 %src1) {
 ; CHECK-LABEL: f5:
 ; CHECK: lgrl [[REG:%r[0-5]]], h@GOT
 ; CHECK: llh [[VAL:%r[0-5]]], 0([[REG]])
 ; CHECK: clrjl %r2, [[VAL]],
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@h, align 1
   %src2 = zext i16 %val to i32
-  %cond = icmp ult i32 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp uge i32 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i32 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i32 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i32 %tmp, 1
   ret i32 %res
 }
 
 ; Check the comparison can be reversed if that allows CLHRL to be used.
 define i32 @f6(i32 %src2) {
 ; CHECK-LABEL: f6:
 ; CHECK: clhrl %r2, g
 ; CHECK-NEXT: jh {{\.L.*}}
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src1 = zext i16 %val to i32
-  %cond = icmp ult i32 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp uge i32 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i32 %src2, %src2
   br label %exit
 exit:
   %tmp = phi i32 [ %src2, %entry ], [ %mul, %mulb ]
   %res = add i32 %tmp, 1
   ret i32 %res
 }

test/CodeGen/SystemZ/int-cmp-40.ll

 define i64 @f1(i64 %src1) {
 ; CHECK-LABEL: f1:
 ; CHECK: clghrl %r2, g
 ; CHECK-NEXT: jl
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src2 = zext i16 %val to i64
-  %cond = icmp ult i64 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp uge i64 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i64 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i64 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i64 %tmp, 1
   ret i64 %res
 }

 define i64 @f3(i64 %src1) {
 ; CHECK-LABEL: f3:
 ; CHECK: clghrl %r2, g
 ; CHECK-NEXT: je
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src2 = zext i16 %val to i64
-  %cond = icmp eq i64 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp ne i64 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i64 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i64 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i64 %tmp, 1
   ret i64 %res
 }
 
 ; Check inequality.
 define i64 @f4(i64 %src1) {
 ; CHECK-LABEL: f4:
 ; CHECK: clghrl %r2, g
 ; CHECK-NEXT: jlh
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src2 = zext i16 %val to i64
-  %cond = icmp ne i64 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp eq i64 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i64 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i64 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i64 %tmp, 1
   ret i64 %res
 }
 
 ; Repeat f1 with an unaligned address.
 define i64 @f5(i64 %src1) {
 ; CHECK-LABEL: f5:
 ; CHECK: lgrl [[REG:%r[0-5]]], h@GOT
 ; CHECK: llgh [[VAL:%r[0-5]]], 0([[REG]])
 ; CHECK: clgrjl %r2, [[VAL]],
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@h, align 1
   %src2 = zext i16 %val to i64
-  %cond = icmp ult i64 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp uge i64 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i64 %src1, %src1
   br label %exit
 exit:
   %tmp = phi i64 [ %src1, %entry ], [ %mul, %mulb ]
   %res = add i64 %tmp, 1
   ret i64 %res
 }
 
 ; Check the comparison can be reversed if that allows CLGHRL to be used.
 define i64 @f6(i64 %src2) {
 ; CHECK-LABEL: f6:
 ; CHECK: clghrl %r2, g
 ; CHECK-NEXT: jh {{\.L.*}}
 ; CHECK: br %r14
 entry:
   %val = load i16 , i16 *@g
   %src1 = zext i16 %val to i64
-  %cond = icmp ult i64 %src1, %src2
-  br i1 %cond, label %exit, label %mulb
+  %cond = icmp uge i64 %src1, %src2
+  br i1 %cond, label %mulb, label %exit
 mulb:
   %mul = mul i64 %src2, %src2
   br label %exit
 exit:
   %tmp = phi i64 [ %src2, %entry ], [ %mul, %mulb ]
   %res = add i64 %tmp, 1
   ret i64 %res
 }

test/CodeGen/SystemZ/int-cmp-44.ll

 ; CHECK-NEXT: brasl %r14, foo@PLT
 ; CHECK-NEXT: cijlh [[REG]], 0, .L{{.*}}
 ; CHECK: br %r14
 entry:
   %val = load i32 , i32 *%ptr
   %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
   br label %exit
 
 exit:
   ret void
 }

 
 store:
   store i64 %res, i64 *%dest
   br label %exit
 
 exit:
   ret i64 %res
 }
+
+!1 = !{!"branch_weights", i32 2, i32 1}

test/CodeGen/SystemZ/int-cmp-48.ll

 exit:
   ret void
 }
 
 ; Check a simple select-based use of TM.
 define double @f3(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f3:
 ; CHECK: tm 0(%r2), 1
-; CHECK: je {{\.L.*}}
+; CHECK: jne {{\.L.*}}
 ; CHECK: br %r14
   %byte = load i8 , i8 *%src
   %and = and i8 %byte, 1
   %cmp = icmp eq i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
; CHECK: br %r14
   store i8 0, i8 *%src
   ret double %res
 }
 
 ; Check an inequality check.
 define double @f5(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f5:
 ; CHECK: tm 0(%r2), 1
-; CHECK: jne {{\.L.*}}
+; CHECK: je {{\.L.*}}
 ; CHECK: br %r14
   %byte = load i8 , i8 *%src
   %and = and i8 %byte, 1
   %cmp = icmp ne i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check that we can also use TM for equality comparisons with the mask.
 define double @f6(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f6:
 ; CHECK: tm 0(%r2), 254
-; CHECK: jo {{\.L.*}}
+; CHECK: jno {{\.L.*}}
 ; CHECK: br %r14
   %byte = load i8 , i8 *%src
   %and = and i8 %byte, 254
   %cmp = icmp eq i8 %and, 254
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check inequality comparisons with the mask.
 define double @f7(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f7:
 ; CHECK: tm 0(%r2), 254
-; CHECK: jno {{\.L.*}}
+; CHECK: jo {{\.L.*}}
 ; CHECK: br %r14
   %byte = load i8 , i8 *%src
   %and = and i8 %byte, 254
   %cmp = icmp ne i8 %and, 254
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check that we do not use the memory TM instruction when CC is being tested
 ; for 2.
 define double @f8(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f8:
 ; CHECK: llc [[REG:%r[0-5]]], 0(%r2)
 ; CHECK: tmll [[REG]], 3
-; CHECK: jh {{\.L.*}}
+; CHECK: jnh {{\.L.*}}
 ; CHECK: br %r14
   %byte = load i8 , i8 *%src
   %and = and i8 %byte, 3
   %cmp = icmp eq i8 %and, 2
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; ...likewise 1.
 define double @f9(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f9:
 ; CHECK: llc [[REG:%r[0-5]]], 0(%r2)
 ; CHECK: tmll [[REG]], 3
-; CHECK: jl {{\.L.*}}
+; CHECK: jnl {{\.L.*}}
 ; CHECK: br %r14
   %byte = load i8 , i8 *%src
   %and = and i8 %byte, 3
   %cmp = icmp eq i8 %and, 1
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check the high end of the TM range.
 define double @f10(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f10:
 ; CHECK: tm 4095(%r2), 1
-; CHECK: je {{\.L.*}}
+; CHECK: jne {{\.L.*}}
 ; CHECK: br %r14
   %ptr = getelementptr i8, i8 *%src, i64 4095
   %byte = load i8 , i8 *%ptr
   %and = and i8 %byte, 1
   %cmp = icmp eq i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check the low end of the positive TMY range.
 define double @f11(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f11:
 ; CHECK: tmy 4096(%r2), 1
-; CHECK: je {{\.L.*}}
+; CHECK: jne {{\.L.*}}
 ; CHECK: br %r14
   %ptr = getelementptr i8, i8 *%src, i64 4096
   %byte = load i8 , i8 *%ptr
   %and = and i8 %byte, 1
   %cmp = icmp eq i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check the high end of the TMY range.
 define double @f12(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f12:
 ; CHECK: tmy 524287(%r2), 1
-; CHECK: je {{\.L.*}}
+; CHECK: jne {{\.L.*}}
 ; CHECK: br %r14
   %ptr = getelementptr i8, i8 *%src, i64 524287
   %byte = load i8 , i8 *%ptr
   %and = and i8 %byte, 1
   %cmp = icmp eq i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check the next byte up, which needs separate address logic.
 define double @f13(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f13:
 ; CHECK: agfi %r2, 524288
 ; CHECK: tm 0(%r2), 1
-; CHECK: je {{\.L.*}}
+; CHECK: jne {{\.L.*}}
 ; CHECK: br %r14
   %ptr = getelementptr i8, i8 *%src, i64 524288
   %byte = load i8 , i8 *%ptr
   %and = and i8 %byte, 1
   %cmp = icmp eq i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check the low end of the TMY range.
 define double @f14(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f14:
 ; CHECK: tmy -524288(%r2), 1
-; CHECK: je {{\.L.*}}
+; CHECK: jne {{\.L.*}}
 ; CHECK: br %r14
   %ptr = getelementptr i8, i8 *%src, i64 -524288
   %byte = load i8 , i8 *%ptr
   %and = and i8 %byte, 1
   %cmp = icmp eq i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check the next byte down, which needs separate address logic.
 define double @f15(i8 *%src, double %a, double %b) {
 ; CHECK-LABEL: f15:
 ; CHECK: agfi %r2, -524289
 ; CHECK: tm 0(%r2), 1
-; CHECK: je {{\.L.*}}
+; CHECK: jne {{\.L.*}}
 ; CHECK: br %r14
   %ptr = getelementptr i8, i8 *%src, i64 -524289
   %byte = load i8 , i8 *%ptr
   %and = and i8 %byte, 1
   %cmp = icmp eq i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }
 
 ; Check that TM(Y) does not allow an index
 define double @f16(i8 *%src, i64 %index, double %a, double %b) {
 ; CHECK-LABEL: f16:
 ; CHECK: tm 0({{%r[1-5]}}), 1
-; CHECK: je {{\.L.*}}
+; CHECK: jne {{\.L.*}}
 ; CHECK: br %r14
   %ptr = getelementptr i8, i8 *%src, i64 %index
   %byte = load i8 , i8 *%ptr
   %and = and i8 %byte, 1
   %cmp = icmp eq i8 %and, 0
   %res = select i1 %cmp, double %b, double %a
   ret double %res
 }

test/CodeGen/SystemZ/tdc-06.ll

 ; CHECK: cdbr %f0, %f0
 ; CHECK: jo [[RET]]
   %testnan = fcmp uno double %x, 0.000000e+00
   br i1 %testnan, label %ret, label %nonzeroord, !prof !1
 
 nonzeroord:
 ; CHECK: lhi %r2, 2
 ; CHECK: tcdb %f0, 48
-; CHECK: jl [[RET]]
+; CHECK: je [[FINITE:.]]
   %abs = tail call double @llvm.fabs.f64(double %x)
   %testinf = fcmp oeq double %abs, 0x7FF0000000000000
   br i1 %testinf, label %ret, label %finite, !prof !1
 
+ret:
+; CHECK: [[RET]]:
+; CHECK: br %r14
+  %res = phi i32 [ 5, %entry ], [ 1, %nonzero ], [ 2, %nonzeroord ], [ %finres, %finite ]
+  ret i32 %res
+
 finite:
 ; CHECK: lhi %r2, 3
 ; CHECK: tcdb %f0, 831
 ; CHECK: blr %r14
 ; CHECK: lhi %r2, 4
+; CHECK: br %r14
   %testnormal = fcmp uge double %abs, 0x10000000000000
   %finres = select i1 %testnormal, i32 3, i32 4
   br label %ret
 
-ret:
-; CHECK: [[RET]]:
-; CHECK: br %r14
-  %res = phi i32 [ 5, %entry ], [ 1, %nonzero ], [ 2, %nonzeroord ], [ %finres, %finite ]
-  ret i32 %res
 }
 
 !1 = !{!"branch_weights", i32 1, i32 1}

test/CodeGen/Thumb/thumb-shrink-wrapping.ll

-; 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.
 ; Otherwise, we may have spill right in the entry block, defeating
 ; shrink-wrapping. Moreover, some of the inline asm statements (nop)
 ; are here to ensure that the related paths do not end up as critical
 ; 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:
 ;
 ; Compare the arguments and jump to exit.
 ; No prologue needed.
 ; ENABLE: cmp r0, r1
 ; ENABLE-NEXT: bge [[EXIT_LABEL:LBB[0-9_]+]]

test/CodeGen/Thumb2/cbnz.ll

t:
   call void @x()
   call void @x()
   call void @x()
   call void @x()
   call void @x()
   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
 
 t2:
   call void @x()
   call void @x()
   call void @x()
   call void @x()

test/CodeGen/Thumb2/ifcvt-compare.ll

 ; RUN: llc -mtriple=thumbv7-unknown-linux %s -o - | FileCheck %s
 
 declare void @x()
 
 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
 
 t:
   call void @x()
   br label %f
 
 f:

test/CodeGen/Thumb2/v8_IT_4.ll

 ; RUN: llc < %s -mtriple=thumbv8-eabi -float-abi=hard | FileCheck %s
 ; RUN: llc < %s -mtriple=thumbv7-eabi -float-abi=hard -arm-restrict-it | FileCheck %s
 ; RUN: llc < %s -mtriple=thumbv8-eabi -float-abi=hard -regalloc=basic | FileCheck %s
 ; RUN: llc < %s -mtriple=thumbv7-eabi -float-abi=hard -regalloc=basic -arm-restrict-it | FileCheck %s
 
 %"struct.__gnu_cxx::__normal_iterator<char*,std::basic_string<char, std::char_traits<char>, std::allocator<char> > >" = type { i8* }
 %"struct.__gnu_cxx::new_allocator<char>" = type <{ i8 }>
 %"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >" = type { %"struct.__gnu_cxx::__normal_iterator<char*,std::basic_string<char, std::char_traits<char>, std::allocator<char> > >" }
 %"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_Rep" = type { %"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_Rep_base" }
 %"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >::_Rep_base" = type { i32, i32, i32 }
 
 
 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]
   %1 = tail call arm_aapcs_vfpcc  i32 @_ZNKSs4sizeEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %__str) ; <i32> [#uses=3]
   %2 = icmp ult i32 %1, %0                        ; <i1> [#uses=1]
   %3 = select i1 %2, i32 %1, i32 %0               ; <i32> [#uses=1]
   %4 = tail call arm_aapcs_vfpcc  i8* @_ZNKSs7_M_dataEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %this) ; <i8*> [#uses=1]
   %5 = tail call arm_aapcs_vfpcc  i8* @_ZNKSs4dataEv(%"struct.std::basic_string<char,std::char_traits<char>,std::allocator<char> >"* %__str) ; <i8*> [#uses=1]

test/CodeGen/WebAssembly/phi.ll

 ; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -verify-machineinstrs | FileCheck %s
 
 ; Test that phis are lowered.
 
 target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
 target triple = "wasm32-unknown-unknown"
 
 ; 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
   br i1 %t, label %true, label %done
 true:
   %a = sdiv i32 %p, 3
   br label %done
 done:

test/CodeGen/X86/2008-11-29-ULT-Sign.ll

 ; RUN:  llc < %s -mtriple=i686-pc-linux-gnu | grep "jns" | count 1
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
 target triple = "i686-pc-linux-gnu"
 
 define i32 @a(i32 %x) nounwind {
 entry:
-  %cmp = icmp ult i32 %x, -2147483648    ; <i1> [#uses=1]
-  br i1 %cmp, label %if.end, label %if.then
+  %cmp = icmp uge i32 %x, -2147483648    ; <i1> [#uses=1]
+  br i1 %cmp, label %if.then, label %if.end
 
 if.then:    ; preds = %entry
   %call = call i32 (...) @b()   ; <i32> [#uses=0]
   br label %if.end
 
 if.end:   ; preds = %if.then, %entry
   br label %return
 
 return:   ; preds = %if.end
   ret i32 undef
 }
 
 declare i32 @b(...)
 

test/CodeGen/X86/add.ll

 ; X64: subq $-128,
 }
 
 define i1 @test4(i32 %v1, i32 %v2, i32* %X) nounwind {
 entry:
   %t = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %v1, i32 %v2)
   %sum = extractvalue {i32, i1} %t, 0
   %obit = extractvalue {i32, i1} %t, 1
-  br i1 %obit, label %overflow, label %normal
+  %notobit = xor i1 1, %obit
+  br i1 %notobit, label %normal, label %overflow
 
 normal:
   store i32 0, i32* %X
   br label %overflow
 
 overflow:
   ret i1 false
 
 ; X32-LABEL: test4:
 ; X32: addl
 ; X32-NEXT: jo
 
 ; X64-LABEL:        test4:
 ; X64:          addl  %e[[A1:si|dx]], %e[[A0:di|cx]]
 ; X64-NEXT: jo
 }
 
 define i1 @test5(i32 %v1, i32 %v2, i32* %X) nounwind {
 entry:
   %t = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %v1, i32 %v2)
   %sum = extractvalue {i32, i1} %t, 0
   %obit = extractvalue {i32, i1} %t, 1
-  br i1 %obit, label %carry, label %normal
+  %notobit = xor i1 1, %obit
+  br i1 %notobit, label %normal, label %carry
 
 normal:
   store i32 0, i32* %X
   br label %carry
 
 carry:
   ret i1 false
 

test/CodeGen/X86/avx-splat.ll

 ;   shuffle (scalar_to_vector (load (ptr + 4))), undef, <0, 0, 0, 0>
 ;
 define <8 x float> @funcE() nounwind {
 ; CHECK-LABEL: funcE:
 ; CHECK:       ## BB#0: ## %for_exit499
 ; CHECK-NEXT:    xorl %eax, %eax
 ; CHECK-NEXT:    ## implicit-def: %YMM0
 ; CHECK-NEXT:    testb %al, %al
-; CHECK-NEXT:    jne LBB4_2
-; CHECK-NEXT:  ## BB#1: ## %load.i1247
+; CHECK-NEXT:    je LBB4_1
+; CHECK-NEXT:  ## BB#2: ## %__load_and_broadcast_32.exit1249
+; CHECK-NEXT:    retq
+; CHECK-NEXT:  LBB4_1: ## %load.i1247
 ; CHECK-NEXT:    pushq %rbp
 ; CHECK-NEXT:    movq %rsp, %rbp
 ; CHECK-NEXT:    andq $-32, %rsp
 ; CHECK-NEXT:    subq $1312, %rsp ## imm = 0x520
 ; CHECK-NEXT:    vbroadcastss {{[0-9]+}}(%rsp), %ymm0
 ; CHECK-NEXT:    movq %rbp, %rsp
 ; CHECK-NEXT:    popq %rbp
-; CHECK-NEXT:  LBB4_2: ## %__load_and_broadcast_32.exit1249
 ; CHECK-NEXT:    retq
 allocas:
   %udx495 = alloca [18 x [18 x float]], align 32
   br label %for_test505.preheader
 
 for_test505.preheader:                            ; preds = %for_test505.preheader, %allocas
   br i1 undef, label %for_exit499, label %for_test505.preheader
 

test/CodeGen/X86/avx512-cmp.ll

 }
 
 define float @test5(float %p) #0 {
 ; ALL-LABEL: test5:
 ; ALL:       ## BB#0: ## %entry
 ; 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
   br i1 %cmp, label %return, label %if.end
 
 if.end:                                           ; preds = %entry
   %cmp1 = fcmp ogt float %p, 0.000000e+00
   %cond = select i1 %cmp1, float 1.000000e+00, float -1.000000e+00

test/CodeGen/X86/bt.ll

 ;      operand is constant are included).
 ;    - The and can be commuted.
 
 define void @test2(i32 %x, i32 %n) nounwind {
 ; CHECK-LABEL: test2:
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB0_2
 ;
 entry:
   %tmp29 = lshr i32 %x, %n
   %tmp3 = and i32 %tmp29, 1
   %tmp4 = icmp eq i32 %tmp3, 0
   br i1 %tmp4, label %bb, label %UnifiedReturnBlock
 
 bb:
   call void @foo()
   ret void
 
 UnifiedReturnBlock:
   ret void
 }
 
 define void @test2b(i32 %x, i32 %n) nounwind {
 ; CHECK-LABEL: test2b:
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB1_2
 ;
 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()
   ret void
 
 UnifiedReturnBlock:
   ret void
 }

 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB3_2
 ;
 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()
   ret void
 
 UnifiedReturnBlock:
   ret void
 }
 
 define void @test3(i32 %x, i32 %n) nounwind {
 ; CHECK-LABEL: test3:
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB4_2
 ;
 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()
   ret void
 
 UnifiedReturnBlock:
   ret void
 }
 
 define void @test3b(i32 %x, i32 %n) nounwind {
 ; CHECK-LABEL: test3b:
 ; CHECK:       # BB#0: # %entry
 ; CHECK-NEXT:    btl %esi, %edi
 ; CHECK-NEXT:    jb .LBB5_2
 ;
 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()
   ret void
 
 UnifiedReturnBlock:
   ret void
 }

 entry:
   %and = and i32 %bit, 31
   %sh_prom = zext i32 %and to i64
   %shl = shl i64 1, %sh_prom
   %and1 = and i64 %shl, %bits
   %tobool = icmp ne i64 %and1, 0
   ret i1 %tobool
 }
+
+!1 = !{!"branch_weights", i32 2, i32 1}

test/CodeGen/X86/critical-edge-split-2.ll

 
 cond.end.i:                                       ; preds = %entry
   %call1 = phi i16 [ trunc (i32 srem (i32 1, i32 zext (i1 icmp eq (%1* bitcast (i8* getelementptr inbounds (%0, %0* @g_2, i64 0, i32 1, i32 0) to %1*), %1* @g_4) to i32)) to i16), %cond.false.i ], [ 1, %entry ]
   ret i16 %call1
 }
 
 ; CHECK-LABEL: test1:
 ; CHECK: testb %dil, %dil
-; CHECK: jne LBB0_2
+; CHECK: je LBB0_1
+; CHECK: retq
+; CHECK: LBB0_1:
 ; CHECK: divl
-; CHECK: LBB0_2:

test/CodeGen/X86/fp-une-cmp.ll

 ; CHECK-NEXT:    jp .LBB0_2
 ; CHECK-NEXT:  # BB#1: # %bb1
 ; CHECK-NEXT:    addsd {{.*}}(%rip), %xmm0
 ; CHECK-NEXT:  .LBB0_2: # %bb2
 ; CHECK-NEXT:    retq
 
 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
   br label %bb2
 
 bb2:
   %phi = phi double [ %add, %bb1 ], [ %mul, %entry ]
   ret double %phi

test/CodeGen/X86/jump_sign.ll

 ; RUN: llc < %s -march=x86 -mcpu=pentiumpro -verify-machineinstrs | FileCheck %s
 
 define i32 @func_f(i32 %X) {
 entry:
 ; CHECK-LABEL: func_f:
 ; 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]
   br label %cond_next
 
 cond_next:    ; preds = %cond_true, %entry
   %tmp3 = tail call i32 (...) @baz( )    ; <i32> [#uses=0]
   ret i32 undef

 if.then:
   %dec = add nsw i32 %1, -1
   store i32 %dec, i32* @a, align 4
   br label %if.end
 
 if.end:
   ret i32 undef
 }
+
+!1 = !{!"branch_weights", i32 2, i32 1}

test/CodeGen/X86/machine-cse.ll

 
 ; CSE physical register defining instruction across MBB boundary.
 ; rdar://10660865
 define i32 @cross_mbb_phys_cse(i32 %a, i32 %b) nounwind ssp {
 entry:
 ; CHECK-LABEL: cross_mbb_phys_cse:
 ; CHECK: cmpl
 ; CHECK: ja
-  %cmp = icmp ugt i32 %a, %b
-  br i1 %cmp, label %return, label %if.end
+  %cmp = icmp ule i32 %a, %b
+  br i1 %cmp, label %if.end, label %return
 
 if.end:                                           ; preds = %entry
 ; CHECK-NOT: cmpl
 ; CHECK: sbbl
   %cmp1 = icmp ult i32 %a, %b
   %. = sext i1 %cmp1 to i32
   br label %return
 

test/CodeGen/X86/shift-double.ll

 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc < %s -mtriple=i686-unknown | FileCheck %s
 
 ; Shift i64 integers on 32-bit target
 
 define i64 @test1(i64 %X, i8 %C) nounwind {
 ; CHECK-LABEL: test1:
 ; CHECK:       # BB#0:
 ; CHECK-NEXT:    pushl %esi
 ; CHECK-NEXT:    movb {{[0-9]+}}(%esp), %cl
 ; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %esi
 ; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %edx
 ; CHECK-NEXT:    movl %esi, %eax
 ; CHECK-NEXT:    shll %cl, %eax
 ; CHECK-NEXT:    shldl %cl, %esi, %edx
 ; CHECK-NEXT:    testb $32, %cl
-; CHECK-NEXT:    je .LBB0_2
-; CHECK-NEXT:  # BB#1:
+; CHECK-NEXT:    jne .LBB0_1
+; CHECK-NEXT:  # BB#2:
+; CHECK-NEXT:    popl %esi
+; CHECK-NEXT:    retl
+; CHECK-NEXT:  .LBB0_1:
 ; CHECK-NEXT:    movl %eax, %edx
 ; CHECK-NEXT:    xorl %eax, %eax
-; CHECK-NEXT:  .LBB0_2:
 ; CHECK-NEXT:    popl %esi
 ; CHECK-NEXT:    retl
         %shift.upgrd.1 = zext i8 %C to i64              ; <i64> [#uses=1]
         %Y = shl i64 %X, %shift.upgrd.1         ; <i64> [#uses=1]
         ret i64 %Y
 }
 
 define i64 @test2(i64 %X, i8 %C) nounwind {
 ; CHECK-LABEL: test2:
 ; CHECK:       # BB#0:
 ; CHECK-NEXT:    pushl %esi
 ; CHECK-NEXT:    movb {{[0-9]+}}(%esp), %cl
 ; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %esi
 ; CHECK-NEXT:    movl %esi, %edx
 ; CHECK-NEXT:    sarl %cl, %edx
 ; CHECK-NEXT:    shrdl %cl, %esi, %eax
 ; CHECK-NEXT:    testb $32, %cl
-; CHECK-NEXT:    je .LBB1_2
-; CHECK-NEXT:  # BB#1:
+; CHECK-NEXT:    jne .LBB1_1
+; CHECK-NEXT:  # BB#2:
+; CHECK-NEXT:    popl %esi
+; CHECK-NEXT:    retl
+; CHECK-NEXT:  .LBB1_1:
 ; CHECK-NEXT:    sarl $31, %esi
 ; CHECK-NEXT:    movl %edx, %eax
 ; CHECK-NEXT:    movl %esi, %edx
-; CHECK-NEXT:  .LBB1_2:
 ; CHECK-NEXT:    popl %esi
 ; CHECK-NEXT:    retl
         %shift.upgrd.2 = zext i8 %C to i64              ; <i64> [#uses=1]
         %Y = ashr i64 %X, %shift.upgrd.2                ; <i64> [#uses=1]
         ret i64 %Y
 }
 
 define i64 @test3(i64 %X, i8 %C) nounwind {
 ; CHECK-LABEL: test3:
 ; CHECK:       # BB#0:
 ; CHECK-NEXT:    pushl %esi
 ; CHECK-NEXT:    movb {{[0-9]+}}(%esp), %cl
 ; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; CHECK-NEXT:    movl {{[0-9]+}}(%esp), %esi
 ; CHECK-NEXT:    movl %esi, %edx
 ; CHECK-NEXT:    shrl %cl, %edx
 ; CHECK-NEXT:    shrdl %cl, %esi, %eax
 ; CHECK-NEXT:    testb $32, %cl
-; CHECK-NEXT:    je .LBB2_2
-; CHECK-NEXT:  # BB#1:
+; CHECK-NEXT:    jne .LBB2_1
+; CHECK-NEXT:  # BB#2:
+; CHECK-NEXT:    popl %esi
+; CHECK-NEXT:    retl
+; CHECK-NEXT:  .LBB2_1:
 ; CHECK-NEXT:    movl %edx, %eax
 ; CHECK-NEXT:    xorl %edx, %edx
-; CHECK-NEXT:  .LBB2_2:
 ; CHECK-NEXT:    popl %esi
 ; CHECK-NEXT:    retl
         %shift.upgrd.3 = zext i8 %C to i64              ; <i64> [#uses=1]
         %Y = lshr i64 %X, %shift.upgrd.3                ; <i64> [#uses=1]
         ret i64 %Y
 }
 
 ; Combine 2xi32/2xi16 shifts into SHLD

test/CodeGen/X86/sink-hoist.ll

 }
 
 ; Make sure the critical edge is broken so the divsd is sunken below
 ; the conditional branch.
 ; rdar://8454886
 
 ; CHECK-LABEL: split:
 ; CHECK-NEXT: testb $1, %dil
-; CHECK-NEXT: je
+; CHECK-NEXT: jne
+; CHECK:      ret
 ; CHECK:      divsd
 ; CHECK:      movapd
 ; CHECK:      ret
 define double @split(double %x, double %y, i1 %c) nounwind {
   %a = fdiv double %x, 3.2
   %z = select i1 %c, double %a, double %y
   ret double %z
 }

test/CodeGen/X86/sse-scalar-fp-arith.ll

 ; SSE41-NEXT:  .LBB62_1:
 ; SSE41-NEXT:    addss %xmm0, %xmm1
 ; SSE41-NEXT:    blendps {{.*#+}} xmm0 = xmm1[0],xmm0[1,2,3]
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: add_ss_mask:
 ; AVX1:       # BB#0:
 ; AVX1-NEXT:    testb $1, %dil
-; AVX1-NEXT:    je .LBB62_2
-; AVX1-NEXT:  # BB#1:
+; AVX1-NEXT:    jne .LBB62_1
+; AVX1-NEXT:  # BB#2:
+; AVX1-NEXT:    vblendps {{.*#+}} xmm0 = xmm2[0],xmm0[1,2,3]
+; AVX1-NEXT:    retq
+; AVX1-NEXT:  .LBB62_1:
 ; AVX1-NEXT:    vaddss %xmm1, %xmm0, %xmm2
-; AVX1-NEXT:  .LBB62_2:
 ; AVX1-NEXT:    vblendps {{.*#+}} xmm0 = xmm2[0],xmm0[1,2,3]
 ; AVX1-NEXT:    retq
 ;
 ; AVX512-LABEL: add_ss_mask:
 ; AVX512:       # BB#0:
 ; AVX512-NEXT:    andl $1, %edi
 ; AVX512-NEXT:    kmovw %edi, %k1
 ; AVX512-NEXT:    vaddss %xmm1, %xmm0, %xmm2 {%k1}

 ; SSE41-NEXT:  .LBB63_1:
 ; SSE41-NEXT:    addsd %xmm0, %xmm1
 ; SSE41-NEXT:    blendpd {{.*#+}} xmm0 = xmm1[0],xmm0[1]
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: add_sd_mask:
 ; AVX1:       # BB#0:
 ; AVX1-NEXT:    testb $1, %dil
-; AVX1-NEXT:    je .LBB63_2
-; AVX1-NEXT:  # BB#1:
+; AVX1-NEXT:    jne .LBB63_1
+; AVX1-NEXT:  # BB#2:
+; AVX1-NEXT:    vblendpd {{.*#+}} xmm0 = xmm2[0],xmm0[1]
+; AVX1-NEXT:    retq
+; AVX1-NEXT:  .LBB63_1:
 ; AVX1-NEXT:    vaddsd %xmm1, %xmm0, %xmm2
-; AVX1-NEXT:  .LBB63_2:
 ; AVX1-NEXT:    vblendpd {{.*#+}} xmm0 = xmm2[0],xmm0[1]
 ; AVX1-NEXT:    retq
 ;
 ; AVX512-LABEL: add_sd_mask:
 ; AVX512:       # BB#0:
 ; AVX512-NEXT:    andl $1, %edi
 ; AVX512-NEXT:    kmovw %edi, %k1
 ; AVX512-NEXT:    vaddsd %xmm1, %xmm0, %xmm2 {%k1}

test/CodeGen/X86/testb-je-fusion.ll

 ; RUN: llc < %s -march=x86-64 -mcpu=corei7-avx | FileCheck %s
 
 ; testb should be scheduled right before je to enable macro-fusion.
 
 ; CHECK: testb $2, %{{[abcd]}}h
 ; CHECK-NEXT: je
 
 define i32 @check_flag(i32 %flags, ...) nounwind {
 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
 
 if.end:
   %hasflag = phi i32 [ 1, %if.then ], [ 0, %entry ]
   ret i32 %hasflag
 }
+!1 = !{!"branch_weights", i32 1, i32 2}