Cleanup. Get rid of the old SjLj EH lowering code. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142800 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 584 deletions

diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp
index e5cb1bb..ac88441 100644
--- a/lib/CodeGen/SjLjEHPrepare.cpp
+++ b/lib/CodeGen/SjLjEHPrepare.cpp
@@ -30,17 +30,13 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/IRBuilder.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include <set>
 using namespace llvm;
 
-static cl::opt<bool> DisableOldSjLjEH("disable-old-sjlj-eh", cl::Hidden,
-                                      cl::init(true),
-    cl::desc("Disable the old SjLj EH preparation pass"));
-
 STATISTIC(NumInvokes, "Number of invokes replaced");
-STATISTIC(NumUnwinds, "Number of unwinds replaced");
 STATISTIC(NumSpilled, "Number of registers live across unwind edges");
 
 namespace {
@@ -52,16 +48,12 @@ namespace {
     Constant *BuiltinSetjmpFn;
     Constant *FrameAddrFn;
     Constant *StackAddrFn;
-    Constant *StackRestoreFn;
     Constant *LSDAAddrFn;
     Value *PersonalityFn;
-    Constant *SelectorFn;
-    Constant *ExceptionFn;
     Constant *CallSiteFn;
     Constant *DispatchSetupFn;
     Constant *FuncCtxFn;
     Value *CallSite;
-    DenseMap<InvokeInst*, BasicBlock*> LPadSuccMap;
   public:
     static char ID; // Pass identification, replacement for typeid
     explicit SjLjEHPass(const TargetLowering *tli = NULL)
@@ -79,13 +71,7 @@ namespace {
     Value *setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads);
     void lowerIncomingArguments(Function &F);
     void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst*> Invokes);
-
     void insertCallSiteStore(Instruction *I, int Number, Value *CallSite);
-    void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite,
-                            SwitchInst *CatchSwitch);
-    void splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes);
-    void splitLandingPad(InvokeInst *II);
-    bool insertSjLjEHSupport(Function &F);
   };
 } // end anonymous namespace
 
@@ -121,11 +107,8 @@ bool SjLjEHPass::doInitialization(Module &M) {
                           (Type *)0);
   FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress);
   StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave);
-  StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore);
   BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp);
   LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda);
-  SelectorFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector);
-  ExceptionFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_exception);
   CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite);
   DispatchSetupFn
     = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_dispatch_setup);
@@ -145,572 +128,16 @@ void SjLjEHPass::insertCallSiteStore(Instruction *I, int Number,
   new StoreInst(CallSiteNoC, CallSite, true, I);  // volatile
 }
 
-/// splitLandingPad - Split a landing pad. This takes considerable care because
-/// of PHIs and other nasties. The problem is that the jump table needs to jump
-/// to the landing pad block. However, the landing pad block can be jumped to
-/// only by an invoke instruction. So we clone the landingpad instruction into
-/// its own basic block, have the invoke jump to there. The landingpad
-/// instruction's basic block's successor is now the target for the jump table.
-///
-/// But because of PHI nodes, we need to create another basic block for the jump
-/// table to jump to. This is definitely a hack, because the values for the PHI
-/// nodes may not be defined on the edge from the jump table. But that's okay,
-/// because the jump table is simply a construct to mimic what is happening in
-/// the CFG. So the values are mysteriously there, even though there is no value
-/// for the PHI from the jump table's edge (hence calling this a hack).
-void SjLjEHPass::splitLandingPad(InvokeInst *II) {
-  SmallVector<BasicBlock*, 2> NewBBs;
-  SplitLandingPadPredecessors(II->getUnwindDest(), II->getParent(),
-                              ".1", ".2", this, NewBBs);
-
-  // Create an empty block so that the jump table has something to jump to
-  // which doesn't have any PHI nodes.
-  BasicBlock *LPad = NewBBs[0];
-  BasicBlock *Succ = *succ_begin(LPad);
-  BasicBlock *JumpTo = BasicBlock::Create(II->getContext(), "jt.land",
-                                          LPad->getParent(), Succ);
-  LPad->getTerminator()->eraseFromParent();
-  BranchInst::Create(JumpTo, LPad);
-  BranchInst::Create(Succ, JumpTo);
-  LPadSuccMap[II] = JumpTo;
-
-  for (BasicBlock::iterator I = Succ->begin(); isa<PHINode>(I); ++I) {
-    PHINode *PN = cast<PHINode>(I);
-    Value *Val = PN->removeIncomingValue(LPad, false);
-    PN->addIncoming(Val, JumpTo);
-  }
-}
-
-/// markInvokeCallSite - Insert code to mark the call_site for this invoke
-void SjLjEHPass::markInvokeCallSite(InvokeInst *II, int InvokeNo,
-                                    Value *CallSite,
-                                    SwitchInst *CatchSwitch) {
-  ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()),
-                                              InvokeNo);
-  // The runtime comes back to the dispatcher with the call_site - 1 in
-  // the context. Odd, but there it is.
-  ConstantInt *SwitchValC = ConstantInt::get(Type::getInt32Ty(II->getContext()),
-                                             InvokeNo - 1);
-
-  // If the unwind edge has phi nodes, split the edge.
-  if (isa<PHINode>(II->getUnwindDest()->begin())) {
-    // FIXME: New EH - This if-condition will be always true in the new scheme.
-    if (II->getUnwindDest()->isLandingPad())
-      splitLandingPad(II);
-    else
-      SplitCriticalEdge(II, 1, this);
-
-    // If there are any phi nodes left, they must have a single predecessor.
-    while (PHINode *PN = dyn_cast<PHINode>(II->getUnwindDest()->begin())) {
-      PN->replaceAllUsesWith(PN->getIncomingValue(0));
-      PN->eraseFromParent();
-    }
-  }
-
-  // Insert the store of the call site value
-  insertCallSiteStore(II, InvokeNo, CallSite);
-
-  // Record the call site value for the back end so it stays associated with
-  // the invoke.
-  CallInst::Create(CallSiteFn, CallSiteNoC, "", II);
-
-  // Add a switch case to our unwind block.
-  if (BasicBlock *SuccBB = LPadSuccMap[II]) {
-    CatchSwitch->addCase(SwitchValC, SuccBB);
-  } else {
-    CatchSwitch->addCase(SwitchValC, II->getUnwindDest());
-  }
-
-  // We still want this to look like an invoke so we emit the LSDA properly,
-  // so we don't transform the invoke into a call here.
-}
-
 /// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until
 /// we reach blocks we've already seen.
-static void MarkBlocksLiveIn(BasicBlock *BB, std::set<BasicBlock*> &LiveBBs) {
-  if (!LiveBBs.insert(BB).second) return; // already been here.
+static void MarkBlocksLiveIn(BasicBlock *BB,
+                             SmallPtrSet<BasicBlock*, 64> &LiveBBs) {
+  if (!LiveBBs.insert(BB)) return; // already been here.
 
   for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
     MarkBlocksLiveIn(*PI, LiveBBs);
 }
 
-/// splitLiveRangesAcrossInvokes - Each value that is live across an unwind edge
-/// we spill into a stack location, guaranteeing that there is nothing live
-/// across the unwind edge.  This process also splits all critical edges
-/// coming out of invoke's.
-/// FIXME: Move this function to a common utility file (Local.cpp?) so
-/// both SjLj and LowerInvoke can use it.
-void SjLjEHPass::
-splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes) {
-  // First step, split all critical edges from invoke instructions.
-  for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
-    InvokeInst *II = Invokes[i];
-    SplitCriticalEdge(II, 0, this);
-
-    // FIXME: New EH - This if-condition will be always true in the new scheme.
-    if (II->getUnwindDest()->isLandingPad())
-      splitLandingPad(II);
-    else
-      SplitCriticalEdge(II, 1, this);
-
-    assert(!isa<PHINode>(II->getNormalDest()) &&
-           !isa<PHINode>(II->getUnwindDest()) &&
-           "Critical edge splitting left single entry phi nodes?");
-  }
-
-  Function *F = Invokes.back()->getParent()->getParent();
-
-  // To avoid having to handle incoming arguments specially, we lower each arg
-  // to a copy instruction in the entry block.  This ensures that the argument
-  // value itself cannot be live across the entry block.
-  BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin();
-  while (isa<AllocaInst>(AfterAllocaInsertPt) &&
-        isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize()))
-    ++AfterAllocaInsertPt;
-  for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
-       AI != E; ++AI) {
-    Type *Ty = AI->getType();
-    // Aggregate types can't be cast, but are legal argument types, so we have
-    // to handle them differently. We use an extract/insert pair as a
-    // lightweight method to achieve the same goal.
-    if (isa<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) {
-      Instruction *EI = ExtractValueInst::Create(AI, 0, "",AfterAllocaInsertPt);
-      Instruction *NI = InsertValueInst::Create(AI, EI, 0);
-      NI->insertAfter(EI);
-      AI->replaceAllUsesWith(NI);
-      // Set the operand of the instructions back to the AllocaInst.
-      EI->setOperand(0, AI);
-      NI->setOperand(0, AI);
-    } else {
-      // This is always a no-op cast because we're casting AI to AI->getType()
-      // so src and destination types are identical. BitCast is the only
-      // possibility.
-      CastInst *NC = new BitCastInst(
-        AI, AI->getType(), AI->getName()+".tmp", AfterAllocaInsertPt);
-      AI->replaceAllUsesWith(NC);
-      // Set the operand of the cast instruction back to the AllocaInst.
-      // Normally it's forbidden to replace a CastInst's operand because it
-      // could cause the opcode to reflect an illegal conversion. However,
-      // we're replacing it here with the same value it was constructed with.
-      // We do this because the above replaceAllUsesWith() clobbered the
-      // operand, but we want this one to remain.
-      NC->setOperand(0, AI);
-    }
-  }
-
-  // Finally, scan the code looking for instructions with bad live ranges.
-  for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
-    for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++II) {
-      // Ignore obvious cases we don't have to handle.  In particular, most
-      // instructions either have no uses or only have a single use inside the
-      // current block.  Ignore them quickly.
-      Instruction *Inst = II;
-      if (Inst->use_empty()) continue;
-      if (Inst->hasOneUse() &&
-          cast<Instruction>(Inst->use_back())->getParent() == BB &&
-          !isa<PHINode>(Inst->use_back())) continue;
-
-      // If this is an alloca in the entry block, it's not a real register
-      // value.
-      if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst))
-        if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin())
-          continue;
-
-      // Avoid iterator invalidation by copying users to a temporary vector.
-      SmallVector<Instruction*,16> Users;
-      for (Value::use_iterator UI = Inst->use_begin(), E = Inst->use_end();
-           UI != E; ++UI) {
-        Instruction *User = cast<Instruction>(*UI);
-        if (User->getParent() != BB || isa<PHINode>(User))
-          Users.push_back(User);
-      }
-
-      // Find all of the blocks that this value is live in.
-      std::set<BasicBlock*> LiveBBs;
-      LiveBBs.insert(Inst->getParent());
-      while (!Users.empty()) {
-        Instruction *U = Users.back();
-        Users.pop_back();
-
-        if (!isa<PHINode>(U)) {
-          MarkBlocksLiveIn(U->getParent(), LiveBBs);
-        } else {
-          // Uses for a PHI node occur in their predecessor block.
-          PHINode *PN = cast<PHINode>(U);
-          for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
-            if (PN->getIncomingValue(i) == Inst)
-              MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs);
-        }
-      }
-
-      // Now that we know all of the blocks that this thing is live in, see if
-      // it includes any of the unwind locations.
-      bool NeedsSpill = false;
-      for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
-        BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
-        if (UnwindBlock != BB && LiveBBs.count(UnwindBlock))
-          NeedsSpill = true;
-      }
-
-      // If we decided we need a spill, do it.
-      // FIXME: Spilling this way is overkill, as it forces all uses of
-      // the value to be reloaded from the stack slot, even those that aren't
-      // in the unwind blocks. We should be more selective.
-      if (NeedsSpill) {
-        ++NumSpilled;
-        DemoteRegToStack(*Inst, true);
-      }
-    }
-}
-
-/// CreateLandingPadLoad - Load the exception handling values and insert them
-/// into a structure.
-static Instruction *CreateLandingPadLoad(Function &F, Value *ExnAddr,
-                                         Value *SelAddr,
-                                         BasicBlock::iterator InsertPt) {
-  Value *Exn = new LoadInst(ExnAddr, "exn", false,
-                            InsertPt);
-  Type *Ty = Type::getInt8PtrTy(F.getContext());
-  Exn = CastInst::Create(Instruction::IntToPtr, Exn, Ty, "", InsertPt);
-  Value *Sel = new LoadInst(SelAddr, "sel", false, InsertPt);
-
-  Ty = StructType::get(Exn->getType(), Sel->getType(), NULL);
-  InsertValueInst *LPadVal = InsertValueInst::Create(llvm::UndefValue::get(Ty),
-                                                     Exn, 0,
-                                                     "lpad.val", InsertPt);
-  return InsertValueInst::Create(LPadVal, Sel, 1, "lpad.val", InsertPt);
-}
-
-/// ReplaceLandingPadVal - Replace the landingpad instruction's value with a
-/// load from the stored values (via CreateLandingPadLoad). This looks through
-/// PHI nodes, and removes them if they are dead.
-static void ReplaceLandingPadVal(Function &F, Instruction *Inst, Value *ExnAddr,
-                                 Value *SelAddr) {
-  if (Inst->use_empty()) return;
-
-  while (!Inst->use_empty()) {
-    Instruction *I = cast<Instruction>(Inst->use_back());
-
-    if (PHINode *PN = dyn_cast<PHINode>(I)) {
-      ReplaceLandingPadVal(F, PN, ExnAddr, SelAddr);
-      if (PN->use_empty()) PN->eraseFromParent();
-      continue;
-    }
-
-    I->replaceUsesOfWith(Inst, CreateLandingPadLoad(F, ExnAddr, SelAddr, I));
-  }
-}
-
-bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
-  SmallVector<ReturnInst*,16> Returns;
-  SmallVector<UnwindInst*,16> Unwinds;
-  SmallVector<InvokeInst*,16> Invokes;
-
-  // Look through the terminators of the basic blocks to find invokes, returns
-  // and unwinds.
-  for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
-    if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
-      // Remember all return instructions in case we insert an invoke into this
-      // function.
-      Returns.push_back(RI);
-    } else if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
-      Invokes.push_back(II);
-    } else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
-      Unwinds.push_back(UI);
-    }
-  }
-
-  NumInvokes += Invokes.size();
-  NumUnwinds += Unwinds.size();
-
-  // If we don't have any invokes, there's nothing to do.
-  if (Invokes.empty()) return false;
-
-  // Find the eh.selector.*, eh.exception and alloca calls.
-  //
-  // Remember any allocas() that aren't in the entry block, as the
-  // jmpbuf saved SP will need to be updated for them.
-  //
-  // We'll use the first eh.selector to determine the right personality
-  // function to use. For SJLJ, we always use the same personality for the
-  // whole function, not on a per-selector basis.
-  // FIXME: That's a bit ugly. Better way?
-  SmallVector<CallInst*,16> EH_Selectors;
-  SmallVector<CallInst*,16> EH_Exceptions;
-  SmallVector<Instruction*,16> JmpbufUpdatePoints;
-
-  for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
-    // Note: Skip the entry block since there's nothing there that interests
-    // us. eh.selector and eh.exception shouldn't ever be there, and we
-    // want to disregard any allocas that are there.
-    // 
-    // FIXME: This is awkward. The new EH scheme won't need to skip the entry
-    //        block.
-    if (BB == F.begin()) {
-      if (InvokeInst *II = dyn_cast<InvokeInst>(F.begin()->getTerminator())) {
-        // FIXME: This will be always non-NULL in the new EH.
-        if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
-          if (!PersonalityFn) PersonalityFn = LPI->getPersonalityFn();
-      }
-
-      continue;
-    }
-
-    for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
-      if (CallInst *CI = dyn_cast<CallInst>(I)) {
-        if (CI->getCalledFunction() == SelectorFn) {
-          if (!PersonalityFn) PersonalityFn = CI->getArgOperand(1);
-          EH_Selectors.push_back(CI);
-        } else if (CI->getCalledFunction() == ExceptionFn) {
-          EH_Exceptions.push_back(CI);
-        } else if (CI->getCalledFunction() == StackRestoreFn) {
-          JmpbufUpdatePoints.push_back(CI);
-        }
-      } else if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
-        JmpbufUpdatePoints.push_back(AI);
-      } else if (InvokeInst *II = dyn_cast<InvokeInst>(I)) {
-        // FIXME: This will be always non-NULL in the new EH.
-        if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
-          if (!PersonalityFn) PersonalityFn = LPI->getPersonalityFn();
-      }
-    }
-  }
-
-  // If we don't have any eh.selector calls, we can't determine the personality
-  // function. Without a personality function, we can't process exceptions.
-  if (!PersonalityFn) return false;
-
-  // We have invokes, so we need to add register/unregister calls to get this
-  // function onto the global unwind stack.
-  //
-  // First thing we need to do is scan the whole function for values that are
-  // live across unwind edges.  Each value that is live across an unwind edge we
-  // spill into a stack location, guaranteeing that there is nothing live across
-  // the unwind edge.  This process also splits all critical edges coming out of
-  // invoke's.
-  splitLiveRangesAcrossInvokes(Invokes);
-
-
-  SmallVector<LandingPadInst*, 16> LandingPads;
-  for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
-    if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator()))
-      // FIXME: This will be always non-NULL in the new EH.
-      if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
-        LandingPads.push_back(LPI);
-  }
-
-
-  BasicBlock *EntryBB = F.begin();
-  // Create an alloca for the incoming jump buffer ptr and the new jump buffer
-  // that needs to be restored on all exits from the function.  This is an
-  // alloca because the value needs to be added to the global context list.
-  unsigned Align = 4; // FIXME: Should be a TLI check?
-  AllocaInst *FunctionContext =
-    new AllocaInst(FunctionContextTy, 0, Align,
-                   "fcn_context", F.begin()->begin());
-
-  Value *Idxs[2];
-  Type *Int32Ty = Type::getInt32Ty(F.getContext());
-  Value *Zero = ConstantInt::get(Int32Ty, 0);
-  // We need to also keep around a reference to the call_site field
-  Idxs[0] = Zero;
-  Idxs[1] = ConstantInt::get(Int32Ty, 1);
-  CallSite = GetElementPtrInst::Create(FunctionContext, Idxs, "call_site",
-                                       EntryBB->getTerminator());
-
-  // The exception selector comes back in context->data[1]
-  Idxs[1] = ConstantInt::get(Int32Ty, 2);
-  Value *FCData = GetElementPtrInst::Create(FunctionContext, Idxs, "fc_data",
-                                            EntryBB->getTerminator());
-  Idxs[1] = ConstantInt::get(Int32Ty, 1);
-  Value *SelectorAddr = GetElementPtrInst::Create(FCData, Idxs,
-                                                  "exc_selector_gep",
-                                                  EntryBB->getTerminator());
-  // The exception value comes back in context->data[0]
-  Idxs[1] = Zero;
-  Value *ExceptionAddr = GetElementPtrInst::Create(FCData, Idxs,
-                                                   "exception_gep",
-                                                   EntryBB->getTerminator());
-
-  // The result of the eh.selector call will be replaced with a a reference to
-  // the selector value returned in the function context. We leave the selector
-  // itself so the EH analysis later can use it.
-  for (int i = 0, e = EH_Selectors.size(); i < e; ++i) {
-    CallInst *I = EH_Selectors[i];
-    Value *SelectorVal = new LoadInst(SelectorAddr, "select_val", true, I);
-    I->replaceAllUsesWith(SelectorVal);
-  }
-
-  // eh.exception calls are replaced with references to the proper location in
-  // the context. Unlike eh.selector, the eh.exception calls are removed
-  // entirely.
-  for (int i = 0, e = EH_Exceptions.size(); i < e; ++i) {
-    CallInst *I = EH_Exceptions[i];
-    // Possible for there to be duplicates, so check to make sure the
-    // instruction hasn't already been removed.
-    if (!I->getParent()) continue;
-    Value *Val = new LoadInst(ExceptionAddr, "exception", true, I);
-    Type *Ty = Type::getInt8PtrTy(F.getContext());
-    Val = CastInst::Create(Instruction::IntToPtr, Val, Ty, "", I);
-
-    I->replaceAllUsesWith(Val);
-    I->eraseFromParent();
-  }
-
-  for (unsigned i = 0, e = LandingPads.size(); i != e; ++i)
-    ReplaceLandingPadVal(F, LandingPads[i], ExceptionAddr, SelectorAddr);
-
-  // The entry block changes to have the eh.sjlj.setjmp, with a conditional
-  // branch to a dispatch block for non-zero returns. If we return normally,
-  // we're not handling an exception and just register the function context and
-  // continue.
-
-  // Create the dispatch block.  The dispatch block is basically a big switch
-  // statement that goes to all of the invoke landing pads.
-  BasicBlock *DispatchBlock =
-    BasicBlock::Create(F.getContext(), "eh.sjlj.setjmp.catch", &F);
-
-  // Insert a load of the callsite in the dispatch block, and a switch on its
-  // value. By default, we issue a trap statement.
-  BasicBlock *TrapBlock =
-    BasicBlock::Create(F.getContext(), "trapbb", &F);
-  CallInst::Create(Intrinsic::getDeclaration(F.getParent(), Intrinsic::trap),
-                   "", TrapBlock);
-  new UnreachableInst(F.getContext(), TrapBlock);
-
-  Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true,
-                                     DispatchBlock);
-  SwitchInst *DispatchSwitch =
-    SwitchInst::Create(DispatchLoad, TrapBlock, Invokes.size(),
-                       DispatchBlock);
-  // Split the entry block to insert the conditional branch for the setjmp.
-  BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(),
-                                                   "eh.sjlj.setjmp.cont");
-
-  // Populate the Function Context
-  //   1. LSDA address
-  //   2. Personality function address
-  //   3. jmpbuf (save SP, FP and call eh.sjlj.setjmp)
-
-  // LSDA address
-  Idxs[0] = Zero;
-  Idxs[1] = ConstantInt::get(Int32Ty, 4);
-  Value *LSDAFieldPtr =
-    GetElementPtrInst::Create(FunctionContext, Idxs, "lsda_gep",
-                              EntryBB->getTerminator());
-  Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr",
-                                 EntryBB->getTerminator());
-  new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator());
-
-  Idxs[1] = ConstantInt::get(Int32Ty, 3);
-  Value *PersonalityFieldPtr =
-    GetElementPtrInst::Create(FunctionContext, Idxs, "lsda_gep",
-                              EntryBB->getTerminator());
-  new StoreInst(PersonalityFn, PersonalityFieldPtr, true,
-                EntryBB->getTerminator());
-
-  // Save the frame pointer.
-  Idxs[1] = ConstantInt::get(Int32Ty, 5);
-  Value *JBufPtr
-    = GetElementPtrInst::Create(FunctionContext, Idxs, "jbuf_gep",
-                                EntryBB->getTerminator());
-  Idxs[1] = ConstantInt::get(Int32Ty, 0);
-  Value *FramePtr =
-    GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_fp_gep",
-                              EntryBB->getTerminator());
-
-  Value *Val = CallInst::Create(FrameAddrFn,
-                                ConstantInt::get(Int32Ty, 0),
-                                "fp",
-                                EntryBB->getTerminator());
-  new StoreInst(Val, FramePtr, true, EntryBB->getTerminator());
-
-  // Save the stack pointer.
-  Idxs[1] = ConstantInt::get(Int32Ty, 2);
-  Value *StackPtr =
-    GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_sp_gep",
-                              EntryBB->getTerminator());
-
-  Val = CallInst::Create(StackAddrFn, "sp", EntryBB->getTerminator());
-  new StoreInst(Val, StackPtr, true, EntryBB->getTerminator());
-
-  // Call the setjmp instrinsic. It fills in the rest of the jmpbuf.
-  Value *SetjmpArg =
-    CastInst::Create(Instruction::BitCast, JBufPtr,
-                     Type::getInt8PtrTy(F.getContext()), "",
-                     EntryBB->getTerminator());
-  Value *DispatchVal = CallInst::Create(BuiltinSetjmpFn, SetjmpArg,
-                                        "",
-                                        EntryBB->getTerminator());
-
-  // Add a call to dispatch_setup after the setjmp call. This is expanded to any
-  // target-specific setup that needs to be done.
-  CallInst::Create(DispatchSetupFn, DispatchVal, "", EntryBB->getTerminator());
-
-  // check the return value of the setjmp. non-zero goes to dispatcher.
-  Value *IsNormal = new ICmpInst(EntryBB->getTerminator(),
-                                 ICmpInst::ICMP_EQ, DispatchVal, Zero,
-                                 "notunwind");
-  // Nuke the uncond branch.
-  EntryBB->getTerminator()->eraseFromParent();
-
-  // Put in a new condbranch in its place.
-  BranchInst::Create(ContBlock, DispatchBlock, IsNormal, EntryBB);
-
-  // Register the function context and make sure it's known to not throw
-  CallInst *Register =
-    CallInst::Create(RegisterFn, FunctionContext, "",
-                     ContBlock->getTerminator());
-  Register->setDoesNotThrow();
-
-  // At this point, we are all set up, update the invoke instructions to mark
-  // their call_site values, and fill in the dispatch switch accordingly.
-  for (unsigned i = 0, e = Invokes.size(); i != e; ++i)
-    markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch);
-
-  // Mark call instructions that aren't nounwind as no-action (call_site ==
-  // -1). Skip the entry block, as prior to then, no function context has been
-  // created for this function and any unexpected exceptions thrown will go
-  // directly to the caller's context, which is what we want anyway, so no need
-  // to do anything here.
-  for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) {
-    for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I)
-      if (CallInst *CI = dyn_cast<CallInst>(I)) {
-        // Ignore calls to the EH builtins (eh.selector, eh.exception)
-        Constant *Callee = CI->getCalledFunction();
-        if (Callee != SelectorFn && Callee != ExceptionFn
-            && !CI->doesNotThrow())
-          insertCallSiteStore(CI, -1, CallSite);
-      } else if (ResumeInst *RI = dyn_cast<ResumeInst>(I)) {
-        insertCallSiteStore(RI, -1, CallSite);
-      }
-  }
-
-  // Replace all unwinds with a branch to the unwind handler.
-  // ??? Should this ever happen with sjlj exceptions?
-  for (unsigned i = 0, e = Unwinds.size(); i != e; ++i) {
-    BranchInst::Create(TrapBlock, Unwinds[i]);
-    Unwinds[i]->eraseFromParent();
-  }
-
-  // Following any allocas not in the entry block, update the saved SP in the
-  // jmpbuf to the new value.
-  for (unsigned i = 0, e = JmpbufUpdatePoints.size(); i != e; ++i) {
-    Instruction *AI = JmpbufUpdatePoints[i];
-    Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp");
-    StackAddr->insertAfter(AI);
-    Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true);
-    StoreStackAddr->insertAfter(StackAddr);
-  }
-
-  // Finally, for any returns from this function, if this function contains an
-  // invoke, add a call to unregister the function context.
-  for (unsigned i = 0, e = Returns.size(); i != e; ++i)
-    CallInst::Create(UnregisterFn, FunctionContext, "", Returns[i]);
-
-  return true;
-}
-
 /// setupFunctionContext - Allocate the function context on the stack and fill
 /// it with all of the data that we know at this point.
 Value *SjLjEHPass::
@@ -871,7 +298,7 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
       }
 
       // Find all of the blocks that this value is live in.
-      std::set<BasicBlock*> LiveBBs;
+      SmallPtrSet<BasicBlock*, 64> LiveBBs;
       LiveBBs.insert(Inst->getParent());
       while (!Users.empty()) {
         Instruction *U = Users.back();
@@ -895,6 +322,7 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
         BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
         if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) {
           NeedsSpill = true;
+          break;
         }
       }
 
@@ -903,8 +331,8 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
       // the value to be reloaded from the stack slot, even those that aren't
       // in the unwind blocks. We should be more selective.
       if (NeedsSpill) {
-        ++NumSpilled;
         DemoteRegToStack(*Inst, true);
+        ++NumSpilled;
       }
     }
   }
@@ -950,6 +378,8 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
 
   if (Invokes.empty()) return false;
 
+  NumInvokes += Invokes.size();
+
   lowerIncomingArguments(F);
   lowerAcrossUnwindEdges(F, Invokes);
 
@@ -1039,10 +469,6 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
 }
 
 bool SjLjEHPass::runOnFunction(Function &F) {
-  bool Res = false;
-  if (!DisableOldSjLjEH)
-    Res = insertSjLjEHSupport(F);
-  else
-    Res = setupEntryBlockAndCallSites(F);
+  bool Res = setupEntryBlockAndCallSites(F);
   return Res;
 }