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diff --git a/contrib/llvm/lib/Transforms/Utils/Local.cpp b/contrib/llvm/lib/Transforms/Utils/Local.cpp
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+++ b/contrib/llvm/lib/Transforms/Utils/Local.cpp
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+//===-- Local.cpp - Functions to perform local transformations ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This family of functions perform various local transformations to the
+// program.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Constants.h"
+#include "llvm/GlobalAlias.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Instructions.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/IntrinsicInst.h"
+#include "llvm/Metadata.h"
+#include "llvm/Operator.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Analysis/DebugInfo.h"
+#include "llvm/Analysis/DIBuilder.h"
+#include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/ProfileInfo.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Support/IRBuilder.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/ValueHandle.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+//  Local constant propagation.
+//
+
+/// ConstantFoldTerminator - If a terminator instruction is predicated on a
+/// constant value, convert it into an unconditional branch to the constant
+/// destination.  This is a nontrivial operation because the successors of this
+/// basic block must have their PHI nodes updated.
+/// Also calls RecursivelyDeleteTriviallyDeadInstructions() on any branch/switch
+/// conditions and indirectbr addresses this might make dead if
+/// DeleteDeadConditions is true.
+bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions) {
+  TerminatorInst *T = BB->getTerminator();
+  IRBuilder<> Builder(T);
+
+  // Branch - See if we are conditional jumping on constant
+  if (BranchInst *BI = dyn_cast<BranchInst>(T)) {
+    if (BI->isUnconditional()) return false;  // Can't optimize uncond branch
+    BasicBlock *Dest1 = BI->getSuccessor(0);
+    BasicBlock *Dest2 = BI->getSuccessor(1);
+
+    if (ConstantInt *Cond = dyn_cast<ConstantInt>(BI->getCondition())) {
+      // Are we branching on constant?
+      // YES.  Change to unconditional branch...
+      BasicBlock *Destination = Cond->getZExtValue() ? Dest1 : Dest2;
+      BasicBlock *OldDest     = Cond->getZExtValue() ? Dest2 : Dest1;
+
+      //cerr << "Function: " << T->getParent()->getParent()
+      //     << "\nRemoving branch from " << T->getParent()
+      //     << "\n\nTo: " << OldDest << endl;
+
+      // Let the basic block know that we are letting go of it.  Based on this,
+      // it will adjust it's PHI nodes.
+      OldDest->removePredecessor(BB);
+
+      // Replace the conditional branch with an unconditional one.
+      Builder.CreateBr(Destination);
+      BI->eraseFromParent();
+      return true;
+    }
+    
+    if (Dest2 == Dest1) {       // Conditional branch to same location?
+      // This branch matches something like this:
+      //     br bool %cond, label %Dest, label %Dest
+      // and changes it into:  br label %Dest
+
+      // Let the basic block know that we are letting go of one copy of it.
+      assert(BI->getParent() && "Terminator not inserted in block!");
+      Dest1->removePredecessor(BI->getParent());
+
+      // Replace the conditional branch with an unconditional one.
+      Builder.CreateBr(Dest1);
+      Value *Cond = BI->getCondition();
+      BI->eraseFromParent();
+      if (DeleteDeadConditions)
+        RecursivelyDeleteTriviallyDeadInstructions(Cond);
+      return true;
+    }
+    return false;
+  }
+  
+  if (SwitchInst *SI = dyn_cast<SwitchInst>(T)) {
+    // If we are switching on a constant, we can convert the switch into a
+    // single branch instruction!
+    ConstantInt *CI = dyn_cast<ConstantInt>(SI->getCondition());
+    BasicBlock *TheOnlyDest = SI->getSuccessor(0);  // The default dest
+    BasicBlock *DefaultDest = TheOnlyDest;
+    assert(TheOnlyDest == SI->getDefaultDest() &&
+           "Default destination is not successor #0?");
+
+    // Figure out which case it goes to.
+    for (unsigned i = 1, e = SI->getNumSuccessors(); i != e; ++i) {
+      // Found case matching a constant operand?
+      if (SI->getSuccessorValue(i) == CI) {
+        TheOnlyDest = SI->getSuccessor(i);
+        break;
+      }
+
+      // Check to see if this branch is going to the same place as the default
+      // dest.  If so, eliminate it as an explicit compare.
+      if (SI->getSuccessor(i) == DefaultDest) {
+        // Remove this entry.
+        DefaultDest->removePredecessor(SI->getParent());
+        SI->removeCase(i);
+        --i; --e;  // Don't skip an entry...
+        continue;
+      }
+
+      // Otherwise, check to see if the switch only branches to one destination.
+      // We do this by reseting "TheOnlyDest" to null when we find two non-equal
+      // destinations.
+      if (SI->getSuccessor(i) != TheOnlyDest) TheOnlyDest = 0;
+    }
+
+    if (CI && !TheOnlyDest) {
+      // Branching on a constant, but not any of the cases, go to the default
+      // successor.
+      TheOnlyDest = SI->getDefaultDest();
+    }
+
+    // If we found a single destination that we can fold the switch into, do so
+    // now.
+    if (TheOnlyDest) {
+      // Insert the new branch.
+      Builder.CreateBr(TheOnlyDest);
+      BasicBlock *BB = SI->getParent();
+
+      // Remove entries from PHI nodes which we no longer branch to...
+      for (unsigned i = 0, e = SI->getNumSuccessors(); i != e; ++i) {
+        // Found case matching a constant operand?
+        BasicBlock *Succ = SI->getSuccessor(i);
+        if (Succ == TheOnlyDest)
+          TheOnlyDest = 0;  // Don't modify the first branch to TheOnlyDest
+        else
+          Succ->removePredecessor(BB);
+      }
+
+      // Delete the old switch.
+      Value *Cond = SI->getCondition();
+      SI->eraseFromParent();
+      if (DeleteDeadConditions)
+        RecursivelyDeleteTriviallyDeadInstructions(Cond);
+      return true;
+    }
+    
+    if (SI->getNumSuccessors() == 2) {
+      // Otherwise, we can fold this switch into a conditional branch
+      // instruction if it has only one non-default destination.
+      Value *Cond = Builder.CreateICmpEQ(SI->getCondition(),
+                                         SI->getSuccessorValue(1), "cond");
+
+      // Insert the new branch.
+      Builder.CreateCondBr(Cond, SI->getSuccessor(1), SI->getSuccessor(0));
+
+      // Delete the old switch.
+      SI->eraseFromParent();
+      return true;
+    }
+    return false;
+  }
+
+  if (IndirectBrInst *IBI = dyn_cast<IndirectBrInst>(T)) {
+    // indirectbr blockaddress(@F, @BB) -> br label @BB
+    if (BlockAddress *BA =
+          dyn_cast<BlockAddress>(IBI->getAddress()->stripPointerCasts())) {
+      BasicBlock *TheOnlyDest = BA->getBasicBlock();
+      // Insert the new branch.
+      Builder.CreateBr(TheOnlyDest);
+      
+      for (unsigned i = 0, e = IBI->getNumDestinations(); i != e; ++i) {
+        if (IBI->getDestination(i) == TheOnlyDest)
+          TheOnlyDest = 0;
+        else
+          IBI->getDestination(i)->removePredecessor(IBI->getParent());
+      }
+      Value *Address = IBI->getAddress();
+      IBI->eraseFromParent();
+      if (DeleteDeadConditions)
+        RecursivelyDeleteTriviallyDeadInstructions(Address);
+      
+      // If we didn't find our destination in the IBI successor list, then we
+      // have undefined behavior.  Replace the unconditional branch with an
+      // 'unreachable' instruction.
+      if (TheOnlyDest) {
+        BB->getTerminator()->eraseFromParent();
+        new UnreachableInst(BB->getContext(), BB);
+      }
+      
+      return true;
+    }
+  }
+  
+  return false;
+}
+
+
+//===----------------------------------------------------------------------===//
+//  Local dead code elimination.
+//
+
+/// isInstructionTriviallyDead - Return true if the result produced by the
+/// instruction is not used, and the instruction has no side effects.
+///
+bool llvm::isInstructionTriviallyDead(Instruction *I) {
+  if (!I->use_empty() || isa<TerminatorInst>(I)) return false;
+
+  // We don't want debug info removed by anything this general, unless
+  // debug info is empty.
+  if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
+    if (DDI->getAddress()) 
+      return false;
+    return true;
+  } 
+  if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
+    if (DVI->getValue())
+      return false;
+    return true;
+  }
+
+  if (!I->mayHaveSideEffects()) return true;
+
+  // Special case intrinsics that "may have side effects" but can be deleted
+  // when dead.
+  if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
+    // Safe to delete llvm.stacksave if dead.
+    if (II->getIntrinsicID() == Intrinsic::stacksave)
+      return true;
+  return false;
+}
+
+/// RecursivelyDeleteTriviallyDeadInstructions - If the specified value is a
+/// trivially dead instruction, delete it.  If that makes any of its operands
+/// trivially dead, delete them too, recursively.  Return true if any
+/// instructions were deleted.
+bool llvm::RecursivelyDeleteTriviallyDeadInstructions(Value *V) {
+  Instruction *I = dyn_cast<Instruction>(V);
+  if (!I || !I->use_empty() || !isInstructionTriviallyDead(I))
+    return false;
+  
+  SmallVector<Instruction*, 16> DeadInsts;
+  DeadInsts.push_back(I);
+  
+  do {
+    I = DeadInsts.pop_back_val();
+
+    // Null out all of the instruction's operands to see if any operand becomes
+    // dead as we go.
+    for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
+      Value *OpV = I->getOperand(i);
+      I->setOperand(i, 0);
+      
+      if (!OpV->use_empty()) continue;
+    
+      // If the operand is an instruction that became dead as we nulled out the
+      // operand, and if it is 'trivially' dead, delete it in a future loop
+      // iteration.
+      if (Instruction *OpI = dyn_cast<Instruction>(OpV))
+        if (isInstructionTriviallyDead(OpI))
+          DeadInsts.push_back(OpI);
+    }
+    
+    I->eraseFromParent();
+  } while (!DeadInsts.empty());
+
+  return true;
+}
+
+/// areAllUsesEqual - Check whether the uses of a value are all the same.
+/// This is similar to Instruction::hasOneUse() except this will also return
+/// true when there are no uses or multiple uses that all refer to the same
+/// value.
+static bool areAllUsesEqual(Instruction *I) {
+  Value::use_iterator UI = I->use_begin();
+  Value::use_iterator UE = I->use_end();
+  if (UI == UE)
+    return true;
+
+  User *TheUse = *UI;
+  for (++UI; UI != UE; ++UI) {
+    if (*UI != TheUse)
+      return false;
+  }
+  return true;
+}
+
+/// RecursivelyDeleteDeadPHINode - If the specified value is an effectively
+/// dead PHI node, due to being a def-use chain of single-use nodes that
+/// either forms a cycle or is terminated by a trivially dead instruction,
+/// delete it.  If that makes any of its operands trivially dead, delete them
+/// too, recursively.  Return true if a change was made.
+bool llvm::RecursivelyDeleteDeadPHINode(PHINode *PN) {
+  SmallPtrSet<Instruction*, 4> Visited;
+  for (Instruction *I = PN; areAllUsesEqual(I) && !I->mayHaveSideEffects();
+       I = cast<Instruction>(*I->use_begin())) {
+    if (I->use_empty())
+      return RecursivelyDeleteTriviallyDeadInstructions(I);
+
+    // If we find an instruction more than once, we're on a cycle that
+    // won't prove fruitful.
+    if (!Visited.insert(I)) {
+      // Break the cycle and delete the instruction and its operands.
+      I->replaceAllUsesWith(UndefValue::get(I->getType()));
+      (void)RecursivelyDeleteTriviallyDeadInstructions(I);
+      return true;
+    }
+  }
+  return false;
+}
+
+/// SimplifyInstructionsInBlock - Scan the specified basic block and try to
+/// simplify any instructions in it and recursively delete dead instructions.
+///
+/// This returns true if it changed the code, note that it can delete
+/// instructions in other blocks as well in this block.
+bool llvm::SimplifyInstructionsInBlock(BasicBlock *BB, const TargetData *TD) {
+  bool MadeChange = false;
+  for (BasicBlock::iterator BI = BB->begin(), E = BB->end(); BI != E; ) {
+    Instruction *Inst = BI++;
+    
+    if (Value *V = SimplifyInstruction(Inst, TD)) {
+      WeakVH BIHandle(BI);
+      ReplaceAndSimplifyAllUses(Inst, V, TD);
+      MadeChange = true;
+      if (BIHandle != BI)
+        BI = BB->begin();
+      continue;
+    }
+
+    if (Inst->isTerminator())
+      break;
+
+    WeakVH BIHandle(BI);
+    MadeChange |= RecursivelyDeleteTriviallyDeadInstructions(Inst);
+    if (BIHandle != BI)
+      BI = BB->begin();
+  }
+  return MadeChange;
+}
+
+//===----------------------------------------------------------------------===//
+//  Control Flow Graph Restructuring.
+//
+
+
+/// RemovePredecessorAndSimplify - Like BasicBlock::removePredecessor, this
+/// method is called when we're about to delete Pred as a predecessor of BB.  If
+/// BB contains any PHI nodes, this drops the entries in the PHI nodes for Pred.
+///
+/// Unlike the removePredecessor method, this attempts to simplify uses of PHI
+/// nodes that collapse into identity values.  For example, if we have:
+///   x = phi(1, 0, 0, 0)
+///   y = and x, z
+///
+/// .. and delete the predecessor corresponding to the '1', this will attempt to
+/// recursively fold the and to 0.
+void llvm::RemovePredecessorAndSimplify(BasicBlock *BB, BasicBlock *Pred,
+                                        TargetData *TD) {
+  // This only adjusts blocks with PHI nodes.
+  if (!isa<PHINode>(BB->begin()))
+    return;
+  
+  // Remove the entries for Pred from the PHI nodes in BB, but do not simplify
+  // them down.  This will leave us with single entry phi nodes and other phis
+  // that can be removed.
+  BB->removePredecessor(Pred, true);
+  
+  WeakVH PhiIt = &BB->front();
+  while (PHINode *PN = dyn_cast<PHINode>(PhiIt)) {
+    PhiIt = &*++BasicBlock::iterator(cast<Instruction>(PhiIt));
+
+    Value *PNV = SimplifyInstruction(PN, TD);
+    if (PNV == 0) continue;
+
+    // If we're able to simplify the phi to a single value, substitute the new
+    // value into all of its uses.
+    assert(PNV != PN && "SimplifyInstruction broken!");
+    
+    Value *OldPhiIt = PhiIt;
+    ReplaceAndSimplifyAllUses(PN, PNV, TD);
+    
+    // If recursive simplification ended up deleting the next PHI node we would
+    // iterate to, then our iterator is invalid, restart scanning from the top
+    // of the block.
+    if (PhiIt != OldPhiIt) PhiIt = &BB->front();
+  }
+}
+
+
+/// MergeBasicBlockIntoOnlyPred - DestBB is a block with one predecessor and its
+/// predecessor is known to have one successor (DestBB!).  Eliminate the edge
+/// between them, moving the instructions in the predecessor into DestBB and
+/// deleting the predecessor block.
+///
+void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) {
+  // If BB has single-entry PHI nodes, fold them.
+  while (PHINode *PN = dyn_cast<PHINode>(DestBB->begin())) {
+    Value *NewVal = PN->getIncomingValue(0);
+    // Replace self referencing PHI with undef, it must be dead.
+    if (NewVal == PN) NewVal = UndefValue::get(PN->getType());
+    PN->replaceAllUsesWith(NewVal);
+    PN->eraseFromParent();
+  }
+  
+  BasicBlock *PredBB = DestBB->getSinglePredecessor();
+  assert(PredBB && "Block doesn't have a single predecessor!");
+  
+  // Splice all the instructions from PredBB to DestBB.
+  PredBB->getTerminator()->eraseFromParent();
+  DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList());
+
+  // Zap anything that took the address of DestBB.  Not doing this will give the
+  // address an invalid value.
+  if (DestBB->hasAddressTaken()) {
+    BlockAddress *BA = BlockAddress::get(DestBB);
+    Constant *Replacement =
+      ConstantInt::get(llvm::Type::getInt32Ty(BA->getContext()), 1);
+    BA->replaceAllUsesWith(ConstantExpr::getIntToPtr(Replacement,
+                                                     BA->getType()));
+    BA->destroyConstant();
+  }
+  
+  // Anything that branched to PredBB now branches to DestBB.
+  PredBB->replaceAllUsesWith(DestBB);
+  
+  if (P) {
+    DominatorTree *DT = P->getAnalysisIfAvailable<DominatorTree>();
+    if (DT) {
+      BasicBlock *PredBBIDom = DT->getNode(PredBB)->getIDom()->getBlock();
+      DT->changeImmediateDominator(DestBB, PredBBIDom);
+      DT->eraseNode(PredBB);
+    }
+    ProfileInfo *PI = P->getAnalysisIfAvailable<ProfileInfo>();
+    if (PI) {
+      PI->replaceAllUses(PredBB, DestBB);
+      PI->removeEdge(ProfileInfo::getEdge(PredBB, DestBB));
+    }
+  }
+  // Nuke BB.
+  PredBB->eraseFromParent();
+}
+
+/// CanPropagatePredecessorsForPHIs - Return true if we can fold BB, an
+/// almost-empty BB ending in an unconditional branch to Succ, into succ.
+///
+/// Assumption: Succ is the single successor for BB.
+///
+static bool CanPropagatePredecessorsForPHIs(BasicBlock *BB, BasicBlock *Succ) {
+  assert(*succ_begin(BB) == Succ && "Succ is not successor of BB!");
+
+  DEBUG(dbgs() << "Looking to fold " << BB->getName() << " into " 
+        << Succ->getName() << "\n");
+  // Shortcut, if there is only a single predecessor it must be BB and merging
+  // is always safe
+  if (Succ->getSinglePredecessor()) return true;
+
+  // Make a list of the predecessors of BB
+  typedef SmallPtrSet<BasicBlock*, 16> BlockSet;
+  BlockSet BBPreds(pred_begin(BB), pred_end(BB));
+
+  // Use that list to make another list of common predecessors of BB and Succ
+  BlockSet CommonPreds;
+  for (pred_iterator PI = pred_begin(Succ), PE = pred_end(Succ);
+       PI != PE; ++PI) {
+    BasicBlock *P = *PI;
+    if (BBPreds.count(P))
+      CommonPreds.insert(P);
+  }
+
+  // Shortcut, if there are no common predecessors, merging is always safe
+  if (CommonPreds.empty())
+    return true;
+  
+  // Look at all the phi nodes in Succ, to see if they present a conflict when
+  // merging these blocks
+  for (BasicBlock::iterator I = Succ->begin(); isa<PHINode>(I); ++I) {
+    PHINode *PN = cast<PHINode>(I);
+
+    // If the incoming value from BB is again a PHINode in
+    // BB which has the same incoming value for *PI as PN does, we can
+    // merge the phi nodes and then the blocks can still be merged
+    PHINode *BBPN = dyn_cast<PHINode>(PN->getIncomingValueForBlock(BB));
+    if (BBPN && BBPN->getParent() == BB) {
+      for (BlockSet::iterator PI = CommonPreds.begin(), PE = CommonPreds.end();
+            PI != PE; PI++) {
+        if (BBPN->getIncomingValueForBlock(*PI) 
+              != PN->getIncomingValueForBlock(*PI)) {
+          DEBUG(dbgs() << "Can't fold, phi node " << PN->getName() << " in " 
+                << Succ->getName() << " is conflicting with " 
+                << BBPN->getName() << " with regard to common predecessor "
+                << (*PI)->getName() << "\n");
+          return false;
+        }
+      }
+    } else {
+      Value* Val = PN->getIncomingValueForBlock(BB);
+      for (BlockSet::iterator PI = CommonPreds.begin(), PE = CommonPreds.end();
+            PI != PE; PI++) {
+        // See if the incoming value for the common predecessor is equal to the
+        // one for BB, in which case this phi node will not prevent the merging
+        // of the block.
+        if (Val != PN->getIncomingValueForBlock(*PI)) {
+          DEBUG(dbgs() << "Can't fold, phi node " << PN->getName() << " in " 
+                << Succ->getName() << " is conflicting with regard to common "
+                << "predecessor " << (*PI)->getName() << "\n");
+          return false;
+        }
+      }
+    }
+  }
+
+  return true;
+}
+
+/// TryToSimplifyUncondBranchFromEmptyBlock - BB is known to contain an
+/// unconditional branch, and contains no instructions other than PHI nodes,
+/// potential debug intrinsics and the branch.  If possible, eliminate BB by
+/// rewriting all the predecessors to branch to the successor block and return
+/// true.  If we can't transform, return false.
+bool llvm::TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB) {
+  assert(BB != &BB->getParent()->getEntryBlock() &&
+         "TryToSimplifyUncondBranchFromEmptyBlock called on entry block!");
+
+  // We can't eliminate infinite loops.
+  BasicBlock *Succ = cast<BranchInst>(BB->getTerminator())->getSuccessor(0);
+  if (BB == Succ) return false;
+  
+  // Check to see if merging these blocks would cause conflicts for any of the
+  // phi nodes in BB or Succ. If not, we can safely merge.
+  if (!CanPropagatePredecessorsForPHIs(BB, Succ)) return false;
+
+  // Check for cases where Succ has multiple predecessors and a PHI node in BB
+  // has uses which will not disappear when the PHI nodes are merged.  It is
+  // possible to handle such cases, but difficult: it requires checking whether
+  // BB dominates Succ, which is non-trivial to calculate in the case where
+  // Succ has multiple predecessors.  Also, it requires checking whether
+  // constructing the necessary self-referential PHI node doesn't intoduce any
+  // conflicts; this isn't too difficult, but the previous code for doing this
+  // was incorrect.
+  //
+  // Note that if this check finds a live use, BB dominates Succ, so BB is
+  // something like a loop pre-header (or rarely, a part of an irreducible CFG);
+  // folding the branch isn't profitable in that case anyway.
+  if (!Succ->getSinglePredecessor()) {
+    BasicBlock::iterator BBI = BB->begin();
+    while (isa<PHINode>(*BBI)) {
+      for (Value::use_iterator UI = BBI->use_begin(), E = BBI->use_end();
+           UI != E; ++UI) {
+        if (PHINode* PN = dyn_cast<PHINode>(*UI)) {
+          if (PN->getIncomingBlock(UI) != BB)
+            return false;
+        } else {
+          return false;
+        }
+      }
+      ++BBI;
+    }
+  }
+
+  DEBUG(dbgs() << "Killing Trivial BB: \n" << *BB);
+  
+  if (isa<PHINode>(Succ->begin())) {
+    // If there is more than one pred of succ, and there are PHI nodes in
+    // the successor, then we need to add incoming edges for the PHI nodes
+    //
+    const SmallVector<BasicBlock*, 16> BBPreds(pred_begin(BB), pred_end(BB));
+    
+    // Loop over all of the PHI nodes in the successor of BB.
+    for (BasicBlock::iterator I = Succ->begin(); isa<PHINode>(I); ++I) {
+      PHINode *PN = cast<PHINode>(I);
+      Value *OldVal = PN->removeIncomingValue(BB, false);
+      assert(OldVal && "No entry in PHI for Pred BB!");
+      
+      // If this incoming value is one of the PHI nodes in BB, the new entries
+      // in the PHI node are the entries from the old PHI.
+      if (isa<PHINode>(OldVal) && cast<PHINode>(OldVal)->getParent() == BB) {
+        PHINode *OldValPN = cast<PHINode>(OldVal);
+        for (unsigned i = 0, e = OldValPN->getNumIncomingValues(); i != e; ++i)
+          // Note that, since we are merging phi nodes and BB and Succ might
+          // have common predecessors, we could end up with a phi node with
+          // identical incoming branches. This will be cleaned up later (and
+          // will trigger asserts if we try to clean it up now, without also
+          // simplifying the corresponding conditional branch).
+          PN->addIncoming(OldValPN->getIncomingValue(i),
+                          OldValPN->getIncomingBlock(i));
+      } else {
+        // Add an incoming value for each of the new incoming values.
+        for (unsigned i = 0, e = BBPreds.size(); i != e; ++i)
+          PN->addIncoming(OldVal, BBPreds[i]);
+      }
+    }
+  }
+  
+  while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) {
+    if (Succ->getSinglePredecessor()) {
+      // BB is the only predecessor of Succ, so Succ will end up with exactly
+      // the same predecessors BB had.
+      Succ->getInstList().splice(Succ->begin(),
+                                 BB->getInstList(), BB->begin());
+    } else {
+      // We explicitly check for such uses in CanPropagatePredecessorsForPHIs.
+      assert(PN->use_empty() && "There shouldn't be any uses here!");
+      PN->eraseFromParent();
+    }
+  }
+    
+  // Everything that jumped to BB now goes to Succ.
+  BB->replaceAllUsesWith(Succ);
+  if (!Succ->hasName()) Succ->takeName(BB);
+  BB->eraseFromParent();              // Delete the old basic block.
+  return true;
+}
+
+/// EliminateDuplicatePHINodes - Check for and eliminate duplicate PHI
+/// nodes in this block. This doesn't try to be clever about PHI nodes
+/// which differ only in the order of the incoming values, but instcombine
+/// orders them so it usually won't matter.
+///
+bool llvm::EliminateDuplicatePHINodes(BasicBlock *BB) {
+  bool Changed = false;
+
+  // This implementation doesn't currently consider undef operands
+  // specially. Theroetically, two phis which are identical except for
+  // one having an undef where the other doesn't could be collapsed.
+
+  // Map from PHI hash values to PHI nodes. If multiple PHIs have
+  // the same hash value, the element is the first PHI in the
+  // linked list in CollisionMap.
+  DenseMap<uintptr_t, PHINode *> HashMap;
+
+  // Maintain linked lists of PHI nodes with common hash values.
+  DenseMap<PHINode *, PHINode *> CollisionMap;
+
+  // Examine each PHI.
+  for (BasicBlock::iterator I = BB->begin();
+       PHINode *PN = dyn_cast<PHINode>(I++); ) {
+    // Compute a hash value on the operands. Instcombine will likely have sorted
+    // them, which helps expose duplicates, but we have to check all the
+    // operands to be safe in case instcombine hasn't run.
+    uintptr_t Hash = 0;
+    for (User::op_iterator I = PN->op_begin(), E = PN->op_end(); I != E; ++I) {
+      // This hash algorithm is quite weak as hash functions go, but it seems
+      // to do a good enough job for this particular purpose, and is very quick.
+      Hash ^= reinterpret_cast<uintptr_t>(static_cast<Value *>(*I));
+      Hash = (Hash << 7) | (Hash >> (sizeof(uintptr_t) * CHAR_BIT - 7));
+    }
+    // Avoid colliding with the DenseMap sentinels ~0 and ~0-1.
+    Hash >>= 1;
+    // If we've never seen this hash value before, it's a unique PHI.
+    std::pair<DenseMap<uintptr_t, PHINode *>::iterator, bool> Pair =
+      HashMap.insert(std::make_pair(Hash, PN));
+    if (Pair.second) continue;
+    // Otherwise it's either a duplicate or a hash collision.
+    for (PHINode *OtherPN = Pair.first->second; ; ) {
+      if (OtherPN->isIdenticalTo(PN)) {
+        // A duplicate. Replace this PHI with its duplicate.
+        PN->replaceAllUsesWith(OtherPN);
+        PN->eraseFromParent();
+        Changed = true;
+        break;
+      }
+      // A non-duplicate hash collision.
+      DenseMap<PHINode *, PHINode *>::iterator I = CollisionMap.find(OtherPN);
+      if (I == CollisionMap.end()) {
+        // Set this PHI to be the head of the linked list of colliding PHIs.
+        PHINode *Old = Pair.first->second;
+        Pair.first->second = PN;
+        CollisionMap[PN] = Old;
+        break;
+      }
+      // Procede to the next PHI in the list.
+      OtherPN = I->second;
+    }
+  }
+
+  return Changed;
+}
+
+/// enforceKnownAlignment - If the specified pointer points to an object that
+/// we control, modify the object's alignment to PrefAlign. This isn't
+/// often possible though. If alignment is important, a more reliable approach
+/// is to simply align all global variables and allocation instructions to
+/// their preferred alignment from the beginning.
+///
+static unsigned enforceKnownAlignment(Value *V, unsigned Align,
+                                      unsigned PrefAlign) {
+
+  User *U = dyn_cast<User>(V);
+  if (!U) return Align;
+
+  switch (Operator::getOpcode(U)) {
+  default: break;
+  case Instruction::BitCast:
+    return enforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
+  case Instruction::GetElementPtr: {
+    // If all indexes are zero, it is just the alignment of the base pointer.
+    bool AllZeroOperands = true;
+    for (User::op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i)
+      if (!isa<Constant>(*i) ||
+          !cast<Constant>(*i)->isNullValue()) {
+        AllZeroOperands = false;
+        break;
+      }
+
+    if (AllZeroOperands) {
+      // Treat this like a bitcast.
+      return enforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
+    }
+    return Align;
+  }
+  case Instruction::Alloca: {
+    AllocaInst *AI = cast<AllocaInst>(V);
+    // If there is a requested alignment and if this is an alloca, round up.
+    if (AI->getAlignment() >= PrefAlign)
+      return AI->getAlignment();
+    AI->setAlignment(PrefAlign);
+    return PrefAlign;
+  }
+  }
+
+  if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
+    // If there is a large requested alignment and we can, bump up the alignment
+    // of the global.
+    if (GV->isDeclaration()) return Align;
+    
+    if (GV->getAlignment() >= PrefAlign)
+      return GV->getAlignment();
+    // We can only increase the alignment of the global if it has no alignment
+    // specified or if it is not assigned a section.  If it is assigned a
+    // section, the global could be densely packed with other objects in the
+    // section, increasing the alignment could cause padding issues.
+    if (!GV->hasSection() || GV->getAlignment() == 0)
+      GV->setAlignment(PrefAlign);
+    return GV->getAlignment();
+  }
+
+  return Align;
+}
+
+/// getOrEnforceKnownAlignment - If the specified pointer has an alignment that
+/// we can determine, return it, otherwise return 0.  If PrefAlign is specified,
+/// and it is more than the alignment of the ultimate object, see if we can
+/// increase the alignment of the ultimate object, making this check succeed.
+unsigned llvm::getOrEnforceKnownAlignment(Value *V, unsigned PrefAlign,
+                                          const TargetData *TD) {
+  assert(V->getType()->isPointerTy() &&
+         "getOrEnforceKnownAlignment expects a pointer!");
+  unsigned BitWidth = TD ? TD->getPointerSizeInBits() : 64;
+  APInt Mask = APInt::getAllOnesValue(BitWidth);
+  APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
+  ComputeMaskedBits(V, Mask, KnownZero, KnownOne, TD);
+  unsigned TrailZ = KnownZero.countTrailingOnes();
+  
+  // Avoid trouble with rediculously large TrailZ values, such as
+  // those computed from a null pointer.
+  TrailZ = std::min(TrailZ, unsigned(sizeof(unsigned) * CHAR_BIT - 1));
+  
+  unsigned Align = 1u << std::min(BitWidth - 1, TrailZ);
+  
+  // LLVM doesn't support alignments larger than this currently.
+  Align = std::min(Align, +Value::MaximumAlignment);
+  
+  if (PrefAlign > Align)
+    Align = enforceKnownAlignment(V, Align, PrefAlign);
+    
+  // We don't need to make any adjustment.
+  return Align;
+}
+
+///===---------------------------------------------------------------------===//
+///  Dbg Intrinsic utilities
+///
+
+/// Inserts a llvm.dbg.value instrinsic before the stores to an alloca'd value
+/// that has an associated llvm.dbg.decl intrinsic.
+bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
+                                           StoreInst *SI, DIBuilder &Builder) {
+  DIVariable DIVar(DDI->getVariable());
+  if (!DIVar.Verify())
+    return false;
+
+  Instruction *DbgVal = NULL;
+  // If an argument is zero extended then use argument directly. The ZExt
+  // may be zapped by an optimization pass in future.
+  Argument *ExtendedArg = NULL;
+  if (ZExtInst *ZExt = dyn_cast<ZExtInst>(SI->getOperand(0)))
+    ExtendedArg = dyn_cast<Argument>(ZExt->getOperand(0));
+  if (SExtInst *SExt = dyn_cast<SExtInst>(SI->getOperand(0)))
+    ExtendedArg = dyn_cast<Argument>(SExt->getOperand(0));
+  if (ExtendedArg)
+    DbgVal = Builder.insertDbgValueIntrinsic(ExtendedArg, 0, DIVar, SI);
+  else
+    DbgVal = Builder.insertDbgValueIntrinsic(SI->getOperand(0), 0, DIVar, SI);
+
+  // Propagate any debug metadata from the store onto the dbg.value.
+  DebugLoc SIDL = SI->getDebugLoc();
+  if (!SIDL.isUnknown())
+    DbgVal->setDebugLoc(SIDL);
+  // Otherwise propagate debug metadata from dbg.declare.
+  else
+    DbgVal->setDebugLoc(DDI->getDebugLoc());
+  return true;
+}
+
+/// Inserts a llvm.dbg.value instrinsic before the stores to an alloca'd value
+/// that has an associated llvm.dbg.decl intrinsic.
+bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
+                                           LoadInst *LI, DIBuilder &Builder) {
+  DIVariable DIVar(DDI->getVariable());
+  if (!DIVar.Verify())
+    return false;
+
+  Instruction *DbgVal = 
+    Builder.insertDbgValueIntrinsic(LI->getOperand(0), 0,
+                                    DIVar, LI);
+  
+  // Propagate any debug metadata from the store onto the dbg.value.
+  DebugLoc LIDL = LI->getDebugLoc();
+  if (!LIDL.isUnknown())
+    DbgVal->setDebugLoc(LIDL);
+  // Otherwise propagate debug metadata from dbg.declare.
+  else
+    DbgVal->setDebugLoc(DDI->getDebugLoc());
+  return true;
+}
+
+/// LowerDbgDeclare - Lowers llvm.dbg.declare intrinsics into appropriate set
+/// of llvm.dbg.value intrinsics.
+bool llvm::LowerDbgDeclare(Function &F) {
+  DIBuilder DIB(*F.getParent());
+  SmallVector<DbgDeclareInst *, 4> Dbgs;
+  for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI)
+    for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE; ++BI) {
+      if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(BI))
+        Dbgs.push_back(DDI);
+    }
+  if (Dbgs.empty())
+    return false;
+
+  for (SmallVector<DbgDeclareInst *, 4>::iterator I = Dbgs.begin(),
+         E = Dbgs.end(); I != E; ++I) {
+    DbgDeclareInst *DDI = *I;
+    if (AllocaInst *AI = dyn_cast_or_null<AllocaInst>(DDI->getAddress())) {
+      bool RemoveDDI = true;
+      for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end();
+           UI != E; ++UI)
+        if (StoreInst *SI = dyn_cast<StoreInst>(*UI))
+          ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
+        else if (LoadInst *LI = dyn_cast<LoadInst>(*UI))
+          ConvertDebugDeclareToDebugValue(DDI, LI, DIB);
+        else
+          RemoveDDI = false;
+      if (RemoveDDI)
+        DDI->eraseFromParent();
+    }
+  }
+  return true;
+}
+
+/// FindAllocaDbgDeclare - Finds the llvm.dbg.declare intrinsic describing the
+/// alloca 'V', if any.
+DbgDeclareInst *llvm::FindAllocaDbgDeclare(Value *V) {
+  if (MDNode *DebugNode = MDNode::getIfExists(V->getContext(), V))
+    for (Value::use_iterator UI = DebugNode->use_begin(),
+         E = DebugNode->use_end(); UI != E; ++UI)
+      if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(*UI))
+        return DDI;
+
+  return 0;
+}