split call handling out to InstCombineCalls.cpp

llvm-svn: 92707

3 files changed, 1133 insertions, 1110 deletions

diff --git a/llvm/lib/Transforms/InstCombine/CMakeLists.txt b/llvm/lib/Transforms/InstCombine/CMakeLists.txt
index 1e6594207f0..142b4622d95 100644
--- a/llvm/lib/Transforms/InstCombine/CMakeLists.txt
+++ b/llvm/lib/Transforms/InstCombine/CMakeLists.txt
@@ -1,6 +1,7 @@
 add_llvm_library(LLVMInstCombine
   InstructionCombining.cpp
   InstCombineAddSub.cpp
+  InstCombineCalls.cpp
   InstCombineCasts.cpp
   InstCombineCompares.cpp
   InstCombineLoadStoreAlloca.cpp
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
new file mode 100644
index 00000000000..da5465988a8
--- /dev/null
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -0,0 +1,1130 @@
+//===- InstCombineCalls.cpp -----------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the visitCall and visitInvoke functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "InstCombine.h"
+#include "llvm/IntrinsicInst.h"
+#include "llvm/Support/CallSite.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
+using namespace llvm;
+
+/// getPromotedType - Return the specified type promoted as it would be to pass
+/// though a va_arg area.
+static const Type *getPromotedType(const Type *Ty) {
+  if (const IntegerType* ITy = dyn_cast<IntegerType>(Ty)) {
+    if (ITy->getBitWidth() < 32)
+      return Type::getInt32Ty(Ty->getContext());
+  }
+  return Ty;
+}
+
+/// 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);
+    }
+    break;
+  }
+  }
+
+  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()) {
+      if (GV->getAlignment() >= PrefAlign)
+        Align = GV->getAlignment();
+      else {
+        GV->setAlignment(PrefAlign);
+        Align = PrefAlign;
+      }
+    }
+  } else if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
+    // If there is a requested alignment and if this is an alloca, round up.
+    if (AI->getAlignment() >= PrefAlign)
+      Align = AI->getAlignment();
+    else {
+      AI->setAlignment(PrefAlign);
+      Align = PrefAlign;
+    }
+  }
+
+  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 InstCombiner::GetOrEnforceKnownAlignment(Value *V,
+                                                  unsigned PrefAlign) {
+  unsigned BitWidth = TD ? TD->getTypeSizeInBits(V->getType()) :
+                      sizeof(PrefAlign) * CHAR_BIT;
+  APInt Mask = APInt::getAllOnesValue(BitWidth);
+  APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
+  ComputeMaskedBits(V, Mask, KnownZero, KnownOne);
+  unsigned TrailZ = KnownZero.countTrailingOnes();
+  unsigned Align = 1u << std::min(BitWidth - 1, TrailZ);
+
+  if (PrefAlign > Align)
+    Align = EnforceKnownAlignment(V, Align, PrefAlign);
+  
+    // We don't need to make any adjustment.
+  return Align;
+}
+
+Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
+  unsigned DstAlign = GetOrEnforceKnownAlignment(MI->getOperand(1));
+  unsigned SrcAlign = GetOrEnforceKnownAlignment(MI->getOperand(2));
+  unsigned MinAlign = std::min(DstAlign, SrcAlign);
+  unsigned CopyAlign = MI->getAlignment();
+
+  if (CopyAlign < MinAlign) {
+    MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), 
+                                             MinAlign, false));
+    return MI;
+  }
+  
+  // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with
+  // load/store.
+  ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getOperand(3));
+  if (MemOpLength == 0) return 0;
+  
+  // Source and destination pointer types are always "i8*" for intrinsic.  See
+  // if the size is something we can handle with a single primitive load/store.
+  // A single load+store correctly handles overlapping memory in the memmove
+  // case.
+  unsigned Size = MemOpLength->getZExtValue();
+  if (Size == 0) return MI;  // Delete this mem transfer.
+  
+  if (Size > 8 || (Size&(Size-1)))
+    return 0;  // If not 1/2/4/8 bytes, exit.
+  
+  // Use an integer load+store unless we can find something better.
+  Type *NewPtrTy =
+            PointerType::getUnqual(IntegerType::get(MI->getContext(), Size<<3));
+  
+  // Memcpy forces the use of i8* for the source and destination.  That means
+  // that if you're using memcpy to move one double around, you'll get a cast
+  // from double* to i8*.  We'd much rather use a double load+store rather than
+  // an i64 load+store, here because this improves the odds that the source or
+  // dest address will be promotable.  See if we can find a better type than the
+  // integer datatype.
+  Value *StrippedDest = MI->getOperand(1)->stripPointerCasts();
+  if (StrippedDest != MI->getOperand(1)) {
+    const Type *SrcETy = cast<PointerType>(StrippedDest->getType())
+                                    ->getElementType();
+    if (TD && SrcETy->isSized() && TD->getTypeStoreSize(SrcETy) == Size) {
+      // The SrcETy might be something like {{{double}}} or [1 x double].  Rip
+      // down through these levels if so.
+      while (!SrcETy->isSingleValueType()) {
+        if (const StructType *STy = dyn_cast<StructType>(SrcETy)) {
+          if (STy->getNumElements() == 1)
+            SrcETy = STy->getElementType(0);
+          else
+            break;
+        } else if (const ArrayType *ATy = dyn_cast<ArrayType>(SrcETy)) {
+          if (ATy->getNumElements() == 1)
+            SrcETy = ATy->getElementType();
+          else
+            break;
+        } else
+          break;
+      }
+      
+      if (SrcETy->isSingleValueType())
+        NewPtrTy = PointerType::getUnqual(SrcETy);
+    }
+  }
+  
+  
+  // If the memcpy/memmove provides better alignment info than we can
+  // infer, use it.
+  SrcAlign = std::max(SrcAlign, CopyAlign);
+  DstAlign = std::max(DstAlign, CopyAlign);
+  
+  Value *Src = Builder->CreateBitCast(MI->getOperand(2), NewPtrTy);
+  Value *Dest = Builder->CreateBitCast(MI->getOperand(1), NewPtrTy);
+  Instruction *L = new LoadInst(Src, "tmp", false, SrcAlign);
+  InsertNewInstBefore(L, *MI);
+  InsertNewInstBefore(new StoreInst(L, Dest, false, DstAlign), *MI);
+
+  // Set the size of the copy to 0, it will be deleted on the next iteration.
+  MI->setOperand(3, Constant::getNullValue(MemOpLength->getType()));
+  return MI;
+}
+
+Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
+  unsigned Alignment = GetOrEnforceKnownAlignment(MI->getDest());
+  if (MI->getAlignment() < Alignment) {
+    MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
+                                             Alignment, false));
+    return MI;
+  }
+  
+  // Extract the length and alignment and fill if they are constant.
+  ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength());
+  ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
+  if (!LenC || !FillC || FillC->getType() != Type::getInt8Ty(MI->getContext()))
+    return 0;
+  uint64_t Len = LenC->getZExtValue();
+  Alignment = MI->getAlignment();
+  
+  // If the length is zero, this is a no-op
+  if (Len == 0) return MI; // memset(d,c,0,a) -> noop
+  
+  // memset(s,c,n) -> store s, c (for n=1,2,4,8)
+  if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) {
+    const Type *ITy = IntegerType::get(MI->getContext(), Len*8);  // n=1 -> i8.
+    
+    Value *Dest = MI->getDest();
+    Dest = Builder->CreateBitCast(Dest, PointerType::getUnqual(ITy));
+
+    // Alignment 0 is identity for alignment 1 for memset, but not store.
+    if (Alignment == 0) Alignment = 1;
+    
+    // Extract the fill value and store.
+    uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL;
+    InsertNewInstBefore(new StoreInst(ConstantInt::get(ITy, Fill),
+                                      Dest, false, Alignment), *MI);
+    
+    // Set the size of the copy to 0, it will be deleted on the next iteration.
+    MI->setLength(Constant::getNullValue(LenC->getType()));
+    return MI;
+  }
+
+  return 0;
+}
+
+
+/// visitCallInst - CallInst simplification.  This mostly only handles folding 
+/// of intrinsic instructions.  For normal calls, it allows visitCallSite to do
+/// the heavy lifting.
+///
+Instruction *InstCombiner::visitCallInst(CallInst &CI) {
+  if (isFreeCall(&CI))
+    return visitFree(CI);
+
+  // If the caller function is nounwind, mark the call as nounwind, even if the
+  // callee isn't.
+  if (CI.getParent()->getParent()->doesNotThrow() &&
+      !CI.doesNotThrow()) {
+    CI.setDoesNotThrow();
+    return &CI;
+  }
+  
+  IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI);
+  if (!II) return visitCallSite(&CI);
+  
+  // Intrinsics cannot occur in an invoke, so handle them here instead of in
+  // visitCallSite.
+  if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) {
+    bool Changed = false;
+
+    // memmove/cpy/set of zero bytes is a noop.
+    if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) {
+      if (NumBytes->isNullValue()) return EraseInstFromFunction(CI);
+
+      if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes))
+        if (CI->getZExtValue() == 1) {
+          // Replace the instruction with just byte operations.  We would
+          // transform other cases to loads/stores, but we don't know if
+          // alignment is sufficient.
+        }
+    }
+
+    // If we have a memmove and the source operation is a constant global,
+    // then the source and dest pointers can't alias, so we can change this
+    // into a call to memcpy.
+    if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) {
+      if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource()))
+        if (GVSrc->isConstant()) {
+          Module *M = CI.getParent()->getParent()->getParent();
+          Intrinsic::ID MemCpyID = Intrinsic::memcpy;
+          const Type *Tys[1];
+          Tys[0] = CI.getOperand(3)->getType();
+          CI.setOperand(0, 
+                        Intrinsic::getDeclaration(M, MemCpyID, Tys, 1));
+          Changed = true;
+        }
+    }
+
+    if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
+      // memmove(x,x,size) -> noop.
+      if (MTI->getSource() == MTI->getDest())
+        return EraseInstFromFunction(CI);
+    }
+
+    // If we can determine a pointer alignment that is bigger than currently
+    // set, update the alignment.
+    if (isa<MemTransferInst>(MI)) {
+      if (Instruction *I = SimplifyMemTransfer(MI))
+        return I;
+    } else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) {
+      if (Instruction *I = SimplifyMemSet(MSI))
+        return I;
+    }
+          
+    if (Changed) return II;
+  }
+  
+  switch (II->getIntrinsicID()) {
+  default: break;
+  case Intrinsic::bswap:
+    // bswap(bswap(x)) -> x
+    if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(II->getOperand(1)))
+      if (Operand->getIntrinsicID() == Intrinsic::bswap)
+        return ReplaceInstUsesWith(CI, Operand->getOperand(1));
+      
+    // bswap(trunc(bswap(x))) -> trunc(lshr(x, c))
+    if (TruncInst *TI = dyn_cast<TruncInst>(II->getOperand(1))) {
+      if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(TI->getOperand(0)))
+        if (Operand->getIntrinsicID() == Intrinsic::bswap) {
+          unsigned C = Operand->getType()->getPrimitiveSizeInBits() -
+                       TI->getType()->getPrimitiveSizeInBits();
+          Value *CV = ConstantInt::get(Operand->getType(), C);
+          Value *V = Builder->CreateLShr(Operand->getOperand(1), CV);
+          return new TruncInst(V, TI->getType());
+        }
+    }
+      
+    break;
+  case Intrinsic::powi:
+    if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getOperand(2))) {
+      // powi(x, 0) -> 1.0
+      if (Power->isZero())
+        return ReplaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0));
+      // powi(x, 1) -> x
+      if (Power->isOne())
+        return ReplaceInstUsesWith(CI, II->getOperand(1));
+      // powi(x, -1) -> 1/x
+      if (Power->isAllOnesValue())
+        return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0),
+                                          II->getOperand(1));
+    }
+    break;
+  case Intrinsic::cttz: {
+    // If all bits below the first known one are known zero,
+    // this value is constant.
+    const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
+    uint32_t BitWidth = IT->getBitWidth();
+    APInt KnownZero(BitWidth, 0);
+    APInt KnownOne(BitWidth, 0);
+    ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth),
+                      KnownZero, KnownOne);
+    unsigned TrailingZeros = KnownOne.countTrailingZeros();
+    APInt Mask(APInt::getLowBitsSet(BitWidth, TrailingZeros));
+    if ((Mask & KnownZero) == Mask)
+      return ReplaceInstUsesWith(CI, ConstantInt::get(IT,
+                                 APInt(BitWidth, TrailingZeros)));
+    
+    }
+    break;
+  case Intrinsic::ctlz: {
+    // If all bits above the first known one are known zero,
+    // this value is constant.
+    const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
+    uint32_t BitWidth = IT->getBitWidth();
+    APInt KnownZero(BitWidth, 0);
+    APInt KnownOne(BitWidth, 0);
+    ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth),
+                      KnownZero, KnownOne);
+    unsigned LeadingZeros = KnownOne.countLeadingZeros();
+    APInt Mask(APInt::getHighBitsSet(BitWidth, LeadingZeros));
+    if ((Mask & KnownZero) == Mask)
+      return ReplaceInstUsesWith(CI, ConstantInt::get(IT,
+                                 APInt(BitWidth, LeadingZeros)));
+    
+    }
+    break;
+  case Intrinsic::uadd_with_overflow: {
+    Value *LHS = II->getOperand(1), *RHS = II->getOperand(2);
+    const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
+    uint32_t BitWidth = IT->getBitWidth();
+    APInt Mask = APInt::getSignBit(BitWidth);
+    APInt LHSKnownZero(BitWidth, 0);
+    APInt LHSKnownOne(BitWidth, 0);
+    ComputeMaskedBits(LHS, Mask, LHSKnownZero, LHSKnownOne);
+    bool LHSKnownNegative = LHSKnownOne[BitWidth - 1];
+    bool LHSKnownPositive = LHSKnownZero[BitWidth - 1];
+
+    if (LHSKnownNegative || LHSKnownPositive) {
+      APInt RHSKnownZero(BitWidth, 0);
+      APInt RHSKnownOne(BitWidth, 0);
+      ComputeMaskedBits(RHS, Mask, RHSKnownZero, RHSKnownOne);
+      bool RHSKnownNegative = RHSKnownOne[BitWidth - 1];
+      bool RHSKnownPositive = RHSKnownZero[BitWidth - 1];
+      if (LHSKnownNegative && RHSKnownNegative) {
+        // The sign bit is set in both cases: this MUST overflow.
+        // Create a simple add instruction, and insert it into the struct.
+        Instruction *Add = BinaryOperator::CreateAdd(LHS, RHS, "", &CI);
+        Worklist.Add(Add);
+        Constant *V[] = {
+          UndefValue::get(LHS->getType()),ConstantInt::getTrue(II->getContext())
+        };
+        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
+        return InsertValueInst::Create(Struct, Add, 0);
+      }
+      
+      if (LHSKnownPositive && RHSKnownPositive) {
+        // The sign bit is clear in both cases: this CANNOT overflow.
+        // Create a simple add instruction, and insert it into the struct.
+        Instruction *Add = BinaryOperator::CreateNUWAdd(LHS, RHS, "", &CI);
+        Worklist.Add(Add);
+        Constant *V[] = {
+          UndefValue::get(LHS->getType()),
+          ConstantInt::getFalse(II->getContext())
+        };
+        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
+        return InsertValueInst::Create(Struct, Add, 0);
+      }
+    }
+  }
+  // FALL THROUGH uadd into sadd
+  case Intrinsic::sadd_with_overflow:
+    // Canonicalize constants into the RHS.
+    if (isa<Constant>(II->getOperand(1)) &&
+        !isa<Constant>(II->getOperand(2))) {
+      Value *LHS = II->getOperand(1);
+      II->setOperand(1, II->getOperand(2));
+      II->setOperand(2, LHS);
+      return II;
+    }
+
+    // X + undef -> undef
+    if (isa<UndefValue>(II->getOperand(2)))
+      return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
+      
+    if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) {
+      // X + 0 -> {X, false}
+      if (RHS->isZero()) {
+        Constant *V[] = {
+          UndefValue::get(II->getOperand(0)->getType()),
+          ConstantInt::getFalse(II->getContext())
+        };
+        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
+        return InsertValueInst::Create(Struct, II->getOperand(1), 0);
+      }
+    }
+    break;
+  case Intrinsic::usub_with_overflow:
+  case Intrinsic::ssub_with_overflow:
+    // undef - X -> undef
+    // X - undef -> undef
+    if (isa<UndefValue>(II->getOperand(1)) ||
+        isa<UndefValue>(II->getOperand(2)))
+      return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
+      
+    if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) {
+      // X - 0 -> {X, false}
+      if (RHS->isZero()) {
+        Constant *V[] = {
+          UndefValue::get(II->getOperand(1)->getType()),
+          ConstantInt::getFalse(II->getContext())
+        };
+        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
+        return InsertValueInst::Create(Struct, II->getOperand(1), 0);
+      }
+    }
+    break;
+  case Intrinsic::umul_with_overflow:
+  case Intrinsic::smul_with_overflow:
+    // Canonicalize constants into the RHS.
+    if (isa<Constant>(II->getOperand(1)) &&
+        !isa<Constant>(II->getOperand(2))) {
+      Value *LHS = II->getOperand(1);
+      II->setOperand(1, II->getOperand(2));
+      II->setOperand(2, LHS);
+      return II;
+    }
+
+    // X * undef -> undef
+    if (isa<UndefValue>(II->getOperand(2)))
+      return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
+      
+    if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getOperand(2))) {
+      // X*0 -> {0, false}
+      if (RHSI->isZero())
+        return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType()));
+      
+      // X * 1 -> {X, false}
+      if (RHSI->equalsInt(1)) {
+        Constant *V[] = {
+          UndefValue::get(II->getOperand(1)->getType()),
+          ConstantInt::getFalse(II->getContext())
+        };
+        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
+        return InsertValueInst::Create(Struct, II->getOperand(1), 0);
+      }
+    }
+    break;
+  case Intrinsic::ppc_altivec_lvx:
+  case Intrinsic::ppc_altivec_lvxl:
+  case Intrinsic::x86_sse_loadu_ps:
+  case Intrinsic::x86_sse2_loadu_pd:
+  case Intrinsic::x86_sse2_loadu_dq:
+    // Turn PPC lvx     -> load if the pointer is known aligned.
+    // Turn X86 loadups -> load if the pointer is known aligned.
+    if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) {
+      Value *Ptr = Builder->CreateBitCast(II->getOperand(1),
+                                         PointerType::getUnqual(II->getType()));
+      return new LoadInst(Ptr);
+    }
+    break;
+  case Intrinsic::ppc_altivec_stvx:
+  case Intrinsic::ppc_altivec_stvxl:
+    // Turn stvx -> store if the pointer is known aligned.
+    if (GetOrEnforceKnownAlignment(II->getOperand(2), 16) >= 16) {
+      const Type *OpPtrTy = 
+        PointerType::getUnqual(II->getOperand(1)->getType());
+      Value *Ptr = Builder->CreateBitCast(II->getOperand(2), OpPtrTy);
+      return new StoreInst(II->getOperand(1), Ptr);
+    }
+    break;
+  case Intrinsic::x86_sse_storeu_ps:
+  case Intrinsic::x86_sse2_storeu_pd:
+  case Intrinsic::x86_sse2_storeu_dq:
+    // Turn X86 storeu -> store if the pointer is known aligned.
+    if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) {
+      const Type *OpPtrTy = 
+        PointerType::getUnqual(II->getOperand(2)->getType());
+      Value *Ptr = Builder->CreateBitCast(II->getOperand(1), OpPtrTy);
+      return new StoreInst(II->getOperand(2), Ptr);
+    }
+    break;
+    
+  case Intrinsic::x86_sse_cvttss2si: {
+    // These intrinsics only demands the 0th element of its input vector.  If
+    // we can simplify the input based on that, do so now.
+    unsigned VWidth =
+      cast<VectorType>(II->getOperand(1)->getType())->getNumElements();
+    APInt DemandedElts(VWidth, 1);
+    APInt UndefElts(VWidth, 0);
+    if (Value *V = SimplifyDemandedVectorElts(II->getOperand(1), DemandedElts,
+                                              UndefElts)) {
+      II->setOperand(1, V);
+      return II;
+    }
+    break;
+  }
+    
+  case Intrinsic::ppc_altivec_vperm:
+    // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
+    if (ConstantVector *Mask = dyn_cast<ConstantVector>(II->getOperand(3))) {
+      assert(Mask->getNumOperands() == 16 && "Bad type for intrinsic!");
+      
+      // Check that all of the elements are integer constants or undefs.
+      bool AllEltsOk = true;
+      for (unsigned i = 0; i != 16; ++i) {
+        if (!isa<ConstantInt>(Mask->getOperand(i)) && 
+            !isa<UndefValue>(Mask->getOperand(i))) {
+          AllEltsOk = false;
+          break;
+        }
+      }
+      
+      if (AllEltsOk) {
+        // Cast the input vectors to byte vectors.
+        Value *Op0 = Builder->CreateBitCast(II->getOperand(1), Mask->getType());
+        Value *Op1 = Builder->CreateBitCast(II->getOperand(2), Mask->getType());
+        Value *Result = UndefValue::get(Op0->getType());
+        
+        // Only extract each element once.
+        Value *ExtractedElts[32];
+        memset(ExtractedElts, 0, sizeof(ExtractedElts));
+        
+        for (unsigned i = 0; i != 16; ++i) {
+          if (isa<UndefValue>(Mask->getOperand(i)))
+            continue;
+          unsigned Idx=cast<ConstantInt>(Mask->getOperand(i))->getZExtValue();
+          Idx &= 31;  // Match the hardware behavior.
+          
+          if (ExtractedElts[Idx] == 0) {
+            ExtractedElts[Idx] = 
+              Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1, 
+                  ConstantInt::get(Type::getInt32Ty(II->getContext()),
+                                   Idx&15, false), "tmp");
+          }
+        
+          // Insert this value into the result vector.
+          Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx],
+                         ConstantInt::get(Type::getInt32Ty(II->getContext()),
+                                          i, false), "tmp");
+        }
+        return CastInst::Create(Instruction::BitCast, Result, CI.getType());
+      }
+    }
+    break;
+
+  case Intrinsic::stackrestore: {
+    // If the save is right next to the restore, remove the restore.  This can
+    // happen when variable allocas are DCE'd.
+    if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getOperand(1))) {
+      if (SS->getIntrinsicID() == Intrinsic::stacksave) {
+        BasicBlock::iterator BI = SS;
+        if (&*++BI == II)
+          return EraseInstFromFunction(CI);
+      }
+    }
+    
+    // Scan down this block to see if there is another stack restore in the
+    // same block without an intervening call/alloca.
+    BasicBlock::iterator BI = II;
+    TerminatorInst *TI = II->getParent()->getTerminator();
+    bool CannotRemove = false;
+    for (++BI; &*BI != TI; ++BI) {
+      if (isa<AllocaInst>(BI) || isMalloc(BI)) {
+        CannotRemove = true;
+        break;
+      }
+      if (CallInst *BCI = dyn_cast<CallInst>(BI)) {
+        if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) {
+          // If there is a stackrestore below this one, remove this one.
+          if (II->getIntrinsicID() == Intrinsic::stackrestore)
+            return EraseInstFromFunction(CI);
+          // Otherwise, ignore the intrinsic.
+        } else {
+          // If we found a non-intrinsic call, we can't remove the stack
+          // restore.
+          CannotRemove = true;
+          break;
+        }
+      }
+    }
+    
+    // If the stack restore is in a return/unwind block and if there are no
+    // allocas or calls between the restore and the return, nuke the restore.
+    if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI)))
+      return EraseInstFromFunction(CI);
+    break;
+  }
+  }
+
+  return visitCallSite(II);
+}
+
+// InvokeInst simplification
+//
+Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) {
+  return visitCallSite(&II);
+}
+
+/// isSafeToEliminateVarargsCast - If this cast does not affect the value 
+/// passed through the varargs area, we can eliminate the use of the cast.
+static bool isSafeToEliminateVarargsCast(const CallSite CS,
+                                         const CastInst * const CI,
+                                         const TargetData * const TD,
+                                         const int ix) {
+  if (!CI->isLosslessCast())
+    return false;
+
+  // The size of ByVal arguments is derived from the type, so we
+  // can't change to a type with a different size.  If the size were
+  // passed explicitly we could avoid this check.
+  if (!CS.paramHasAttr(ix, Attribute::ByVal))
+    return true;
+
+  const Type* SrcTy = 
+            cast<PointerType>(CI->getOperand(0)->getType())->getElementType();
+  const Type* DstTy = cast<PointerType>(CI->getType())->getElementType();
+  if (!SrcTy->isSized() || !DstTy->isSized())
+    return false;
+  if (!TD || TD->getTypeAllocSize(SrcTy) != TD->getTypeAllocSize(DstTy))
+    return false;
+  return true;
+}
+
+// visitCallSite - Improvements for call and invoke instructions.
+//
+Instruction *InstCombiner::visitCallSite(CallSite CS) {
+  bool Changed = false;
+
+  // If the callee is a constexpr cast of a function, attempt to move the cast
+  // to the arguments of the call/invoke.
+  if (transformConstExprCastCall(CS)) return 0;
+
+  Value *Callee = CS.getCalledValue();
+
+  if (Function *CalleeF = dyn_cast<Function>(Callee))
+    if (CalleeF->getCallingConv() != CS.getCallingConv()) {
+      Instruction *OldCall = CS.getInstruction();
+      // If the call and callee calling conventions don't match, this call must
+      // be unreachable, as the call is undefined.
+      new StoreInst(ConstantInt::getTrue(Callee->getContext()),
+                UndefValue::get(Type::getInt1PtrTy(Callee->getContext())), 
+                                  OldCall);
+      // If OldCall dues not return void then replaceAllUsesWith undef.
+      // This allows ValueHandlers and custom metadata to adjust itself.
+      if (!OldCall->getType()->isVoidTy())
+        OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType()));
+      if (isa<CallInst>(OldCall))   // Not worth removing an invoke here.
+        return EraseInstFromFunction(*OldCall);
+      return 0;
+    }
+
+  if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
+    // This instruction is not reachable, just remove it.  We insert a store to
+    // undef so that we know that this code is not reachable, despite the fact
+    // that we can't modify the CFG here.
+    new StoreInst(ConstantInt::getTrue(Callee->getContext()),
+               UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
+                  CS.getInstruction());
+
+    // If CS dues not return void then replaceAllUsesWith undef.
+    // This allows ValueHandlers and custom metadata to adjust itself.
+    if (!CS.getInstruction()->getType()->isVoidTy())
+      CS.getInstruction()->
+        replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType()));
+
+    if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
+      // Don't break the CFG, insert a dummy cond branch.
+      BranchInst::Create(II->getNormalDest(), II->getUnwindDest(),
+                         ConstantInt::getTrue(Callee->getContext()), II);
+    }
+    return EraseInstFromFunction(*CS.getInstruction());
+  }
+
+  if (BitCastInst *BC = dyn_cast<BitCastInst>(Callee))
+    if (IntrinsicInst *In = dyn_cast<IntrinsicInst>(BC->getOperand(0)))
+      if (In->getIntrinsicID() == Intrinsic::init_trampoline)
+        return transformCallThroughTrampoline(CS);
+
+  const PointerType *PTy = cast<PointerType>(Callee->getType());
+  const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
+  if (FTy->isVarArg()) {
+    int ix = FTy->getNumParams() + (isa<InvokeInst>(Callee) ? 3 : 1);
+    // See if we can optimize any arguments passed through the varargs area of
+    // the call.
+    for (CallSite::arg_iterator I = CS.arg_begin()+FTy->getNumParams(),
+           E = CS.arg_end(); I != E; ++I, ++ix) {
+      CastInst *CI = dyn_cast<CastInst>(*I);
+      if (CI && isSafeToEliminateVarargsCast(CS, CI, TD, ix)) {
+        *I = CI->getOperand(0);
+        Changed = true;
+      }
+    }
+  }
+
+  if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) {
+    // Inline asm calls cannot throw - mark them 'nounwind'.
+    CS.setDoesNotThrow();
+    Changed = true;
+  }
+
+  return Changed ? CS.getInstruction() : 0;
+}
+
+// transformConstExprCastCall - If the callee is a constexpr cast of a function,
+// attempt to move the cast to the arguments of the call/invoke.
+//
+bool InstCombiner::transformConstExprCastCall(CallSite CS) {
+  if (!isa<ConstantExpr>(CS.getCalledValue())) return false;
+  ConstantExpr *CE = cast<ConstantExpr>(CS.getCalledValue());
+  if (CE->getOpcode() != Instruction::BitCast || 
+      !isa<Function>(CE->getOperand(0)))
+    return false;
+  Function *Callee = cast<Function>(CE->getOperand(0));
+  Instruction *Caller = CS.getInstruction();
+  const AttrListPtr &CallerPAL = CS.getAttributes();
+
+  // Okay, this is a cast from a function to a different type.  Unless doing so
+  // would cause a type conversion of one of our arguments, change this call to
+  // be a direct call with arguments casted to the appropriate types.
+  //
+  const FunctionType *FT = Callee->getFunctionType();
+  const Type *OldRetTy = Caller->getType();
+  const Type *NewRetTy = FT->getReturnType();
+
+  if (isa<StructType>(NewRetTy))
+    return false; // TODO: Handle multiple return values.
+
+  // Check to see if we are changing the return type...
+  if (OldRetTy != NewRetTy) {
+    if (Callee->isDeclaration() &&
+        // Conversion is ok if changing from one pointer type to another or from
+        // a pointer to an integer of the same size.
+        !((isa<PointerType>(OldRetTy) || !TD ||
+           OldRetTy == TD->getIntPtrType(Caller->getContext())) &&
+          (isa<PointerType>(NewRetTy) || !TD ||
+           NewRetTy == TD->getIntPtrType(Caller->getContext()))))
+      return false;   // Cannot transform this return value.
+
+    if (!Caller->use_empty() &&
+        // void -> non-void is handled specially
+        !NewRetTy->isVoidTy() && !CastInst::isCastable(NewRetTy, OldRetTy))
+      return false;   // Cannot transform this return value.
+
+    if (!CallerPAL.isEmpty() && !Caller->use_empty()) {
+      Attributes RAttrs = CallerPAL.getRetAttributes();
+      if (RAttrs & Attribute::typeIncompatible(NewRetTy))
+        return false;   // Attribute not compatible with transformed value.
+    }
+
+    // If the callsite is an invoke instruction, and the return value is used by
+    // a PHI node in a successor, we cannot change the return type of the call
+    // because there is no place to put the cast instruction (without breaking
+    // the critical edge).  Bail out in this case.
+    if (!Caller->use_empty())
+      if (InvokeInst *II = dyn_cast<InvokeInst>(Caller))
+        for (Value::use_iterator UI = II->use_begin(), E = II->use_end();
+             UI != E; ++UI)
+          if (PHINode *PN = dyn_cast<PHINode>(*UI))
+            if (PN->getParent() == II->getNormalDest() ||
+                PN->getParent() == II->getUnwindDest())
+              return false;
+  }
+
+  unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin());
+  unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
+
+  CallSite::arg_iterator AI = CS.arg_begin();
+  for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) {
+    const Type *ParamTy = FT->getParamType(i);
+    const Type *ActTy = (*AI)->getType();
+
+    if (!CastInst::isCastable(ActTy, ParamTy))
+      return false;   // Cannot transform this parameter value.
+
+    if (CallerPAL.getParamAttributes(i + 1) 
+        & Attribute::typeIncompatible(ParamTy))
+      return false;   // Attribute not compatible with transformed value.
+
+    // Converting from one pointer type to another or between a pointer and an
+    // integer of the same size is safe even if we do not have a body.
+    bool isConvertible = ActTy == ParamTy ||
+      (TD && ((isa<PointerType>(ParamTy) ||
+      ParamTy == TD->getIntPtrType(Caller->getContext())) &&
+              (isa<PointerType>(ActTy) ||
+              ActTy == TD->getIntPtrType(Caller->getContext()))));
+    if (Callee->isDeclaration() && !isConvertible) return false;
+  }
+
+  if (FT->getNumParams() < NumActualArgs && !FT->isVarArg() &&
+      Callee->isDeclaration())
+    return false;   // Do not delete arguments unless we have a function body.
+
+  if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
+      !CallerPAL.isEmpty())
+    // In this case we have more arguments than the new function type, but we
+    // won't be dropping them.  Check that these extra arguments have attributes
+    // that are compatible with being a vararg call argument.
+    for (unsigned i = CallerPAL.getNumSlots(); i; --i) {
+      if (CallerPAL.getSlot(i - 1).Index <= FT->getNumParams())
+        break;
+      Attributes PAttrs = CallerPAL.getSlot(i - 1).Attrs;
+      if (PAttrs & Attribute::VarArgsIncompatible)
+        return false;
+    }
+
+  // Okay, we decided that this is a safe thing to do: go ahead and start
+  // inserting cast instructions as necessary...
+  std::vector<Value*> Args;
+  Args.reserve(NumActualArgs);
+  SmallVector<AttributeWithIndex, 8> attrVec;
+  attrVec.reserve(NumCommonArgs);
+
+  // Get any return attributes.
+  Attributes RAttrs = CallerPAL.getRetAttributes();
+
+  // If the return value is not being used, the type may not be compatible
+  // with the existing attributes.  Wipe out any problematic attributes.
+  RAttrs &= ~Attribute::typeIncompatible(NewRetTy);
+
+  // Add the new return attributes.
+  if (RAttrs)
+    attrVec.push_back(AttributeWithIndex::get(0, RAttrs));
+
+  AI = CS.arg_begin();
+  for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) {
+    const Type *ParamTy = FT->getParamType(i);
+    if ((*AI)->getType() == ParamTy) {
+      Args.push_back(*AI);
+    } else {
+      Instruction::CastOps opcode = CastInst::getCastOpcode(*AI,
+          false, ParamTy, false);
+      Args.push_back(Builder->CreateCast(opcode, *AI, ParamTy, "tmp"));
+    }
+
+    // Add any parameter attributes.
+    if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1))
+      attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs));
+  }
+
+  // If the function takes more arguments than the call was taking, add them
+  // now.
+  for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i)
+    Args.push_back(Constant::getNullValue(FT->getParamType(i)));
+
+  // If we are removing arguments to the function, emit an obnoxious warning.
+  if (FT->getNumParams() < NumActualArgs) {
+    if (!FT->isVarArg()) {
+      errs() << "WARNING: While resolving call to function '"
+             << Callee->getName() << "' arguments were dropped!\n";
+    } else {
+      // Add all of the arguments in their promoted form to the arg list.
+      for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) {
+        const Type *PTy = getPromotedType((*AI)->getType());
+        if (PTy != (*AI)->getType()) {
+          // Must promote to pass through va_arg area!
+          Instruction::CastOps opcode =
+            CastInst::getCastOpcode(*AI, false, PTy, false);
+          Args.push_back(Builder->CreateCast(opcode, *AI, PTy, "tmp"));
+        } else {
+          Args.push_back(*AI);
+        }
+
+        // Add any parameter attributes.
+        if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1))
+          attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs));
+      }
+    }
+  }
+
+  if (Attributes FnAttrs =  CallerPAL.getFnAttributes())
+    attrVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
+
+  if (NewRetTy->isVoidTy())
+    Caller->setName("");   // Void type should not have a name.
+
+  const AttrListPtr &NewCallerPAL = AttrListPtr::get(attrVec.begin(),
+                                                     attrVec.end());
+
+  Instruction *NC;
+  if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
+    NC = InvokeInst::Create(Callee, II->getNormalDest(), II->getUnwindDest(),
+                            Args.begin(), Args.end(),
+                            Caller->getName(), Caller);
+    cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv());
+    cast<InvokeInst>(NC)->setAttributes(NewCallerPAL);
+  } else {
+    NC = CallInst::Create(Callee, Args.begin(), Args.end(),
+                          Caller->getName(), Caller);
+    CallInst *CI = cast<CallInst>(Caller);
+    if (CI->isTailCall())
+      cast<CallInst>(NC)->setTailCall();
+    cast<CallInst>(NC)->setCallingConv(CI->getCallingConv());
+    cast<CallInst>(NC)->setAttributes(NewCallerPAL);
+  }
+
+  // Insert a cast of the return type as necessary.
+  Value *NV = NC;
+  if (OldRetTy != NV->getType() && !Caller->use_empty()) {
+    if (!NV->getType()->isVoidTy()) {
+      Instruction::CastOps opcode = CastInst::getCastOpcode(NC, false, 
+                                                            OldRetTy, false);
+      NV = NC = CastInst::Create(opcode, NC, OldRetTy, "tmp");
+
+      // If this is an invoke instruction, we should insert it after the first
+      // non-phi, instruction in the normal successor block.
+      if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
+        BasicBlock::iterator I = II->getNormalDest()->getFirstNonPHI();
+        InsertNewInstBefore(NC, *I);
+      } else {
+        // Otherwise, it's a call, just insert cast right after the call instr
+        InsertNewInstBefore(NC, *Caller);
+      }
+      Worklist.AddUsersToWorkList(*Caller);
+    } else {
+      NV = UndefValue::get(Caller->getType());
+    }
+  }
+
+
+  if (!Caller->use_empty())
+    Caller->replaceAllUsesWith(NV);
+  
+  EraseInstFromFunction(*Caller);
+  return true;
+}
+
+// transformCallThroughTrampoline - Turn a call to a function created by the
+// init_trampoline intrinsic into a direct call to the underlying function.
+//
+Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) {
+  Value *Callee = CS.getCalledValue();
+  const PointerType *PTy = cast<PointerType>(Callee->getType());
+  const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
+  const AttrListPtr &Attrs = CS.getAttributes();
+
+  // If the call already has the 'nest' attribute somewhere then give up -
+  // otherwise 'nest' would occur twice after splicing in the chain.
+  if (Attrs.hasAttrSomewhere(Attribute::Nest))
+    return 0;
+
+  IntrinsicInst *Tramp =
+    cast<IntrinsicInst>(cast<BitCastInst>(Callee)->getOperand(0));
+
+  Function *NestF = cast<Function>(Tramp->getOperand(2)->stripPointerCasts());
+  const PointerType *NestFPTy = cast<PointerType>(NestF->getType());
+  const FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType());
+
+  const AttrListPtr &NestAttrs = NestF->getAttributes();
+  if (!NestAttrs.isEmpty()) {
+    unsigned NestIdx = 1;
+    const Type *NestTy = 0;
+    Attributes NestAttr = Attribute::None;
+
+    // Look for a parameter marked with the 'nest' attribute.
+    for (FunctionType::param_iterator I = NestFTy->param_begin(),
+         E = NestFTy->param_end(); I != E; ++NestIdx, ++I)
+      if (NestAttrs.paramHasAttr(NestIdx, Attribute::Nest)) {
+        // Record the parameter type and any other attributes.
+        NestTy = *I;
+        NestAttr = NestAttrs.getParamAttributes(NestIdx);
+        break;
+      }
+
+    if (NestTy) {
+      Instruction *Caller = CS.getInstruction();
+      std::vector<Value*> NewArgs;
+      NewArgs.reserve(unsigned(CS.arg_end()-CS.arg_begin())+1);
+
+      SmallVector<AttributeWithIndex, 8> NewAttrs;
+      NewAttrs.reserve(Attrs.getNumSlots() + 1);
+
+      // Insert the nest argument into the call argument list, which may
+      // mean appending it.  Likewise for attributes.
+
+      // Add any result attributes.
+      if (Attributes Attr = Attrs.getRetAttributes())
+        NewAttrs.push_back(AttributeWithIndex::get(0, Attr));
+
+      {
+        unsigned Idx = 1;
+        CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
+        do {
+          if (Idx == NestIdx) {
+            // Add the chain argument and attributes.
+            Value *NestVal = Tramp->getOperand(3);
+            if (NestVal->getType() != NestTy)
+              NestVal = new BitCastInst(NestVal, NestTy, "nest", Caller);
+            NewArgs.push_back(NestVal);
+            NewAttrs.push_back(AttributeWithIndex::get(NestIdx, NestAttr));
+          }
+
+          if (I == E)
+            break;
+
+          // Add the original argument and attributes.
+          NewArgs.push_back(*I);
+          if (Attributes Attr = Attrs.getParamAttributes(Idx))
+            NewAttrs.push_back
+              (AttributeWithIndex::get(Idx + (Idx >= NestIdx), Attr));
+
+          ++Idx, ++I;
+        } while (1);
+      }
+
+      // Add any function attributes.
+      if (Attributes Attr = Attrs.getFnAttributes())
+        NewAttrs.push_back(AttributeWithIndex::get(~0, Attr));
+
+      // The trampoline may have been bitcast to a bogus type (FTy).
+      // Handle this by synthesizing a new function type, equal to FTy
+      // with the chain parameter inserted.
+
+      std::vector<const Type*> NewTypes;
+      NewTypes.reserve(FTy->getNumParams()+1);
+
+      // Insert the chain's type into the list of parameter types, which may
+      // mean appending it.
+      {
+        unsigned Idx = 1;
+        FunctionType::param_iterator I = FTy->param_begin(),
+          E = FTy->param_end();
+
+        do {
+          if (Idx == NestIdx)
+            // Add the chain's type.
+            NewTypes.push_back(NestTy);
+
+          if (I == E)
+            break;
+
+          // Add the original type.
+          NewTypes.push_back(*I);
+
+          ++Idx, ++I;
+        } while (1);
+      }
+
+      // Replace the trampoline call with a direct call.  Let the generic
+      // code sort out any function type mismatches.
+      FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes, 
+                                                FTy->isVarArg());
+      Constant *NewCallee =
+        NestF->getType() == PointerType::getUnqual(NewFTy) ?
+        NestF : ConstantExpr::getBitCast(NestF, 
+                                         PointerType::getUnqual(NewFTy));
+      const AttrListPtr &NewPAL = AttrListPtr::get(NewAttrs.begin(),
+                                                   NewAttrs.end());
+
+      Instruction *NewCaller;
+      if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
+        NewCaller = InvokeInst::Create(NewCallee,
+                                       II->getNormalDest(), II->getUnwindDest(),
+                                       NewArgs.begin(), NewArgs.end(),
+                                       Caller->getName(), Caller);
+        cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv());
+        cast<InvokeInst>(NewCaller)->setAttributes(NewPAL);
+      } else {
+        NewCaller = CallInst::Create(NewCallee, NewArgs.begin(), NewArgs.end(),
+                                     Caller->getName(), Caller);
+        if (cast<CallInst>(Caller)->isTailCall())
+          cast<CallInst>(NewCaller)->setTailCall();
+        cast<CallInst>(NewCaller)->
+          setCallingConv(cast<CallInst>(Caller)->getCallingConv());
+        cast<CallInst>(NewCaller)->setAttributes(NewPAL);
+      }
+      if (!Caller->getType()->isVoidTy())
+        Caller->replaceAllUsesWith(NewCaller);
+      Caller->eraseFromParent();
+      Worklist.Remove(Caller);
+      return 0;
+    }
+  }
+
+  // Replace the trampoline call with a direct call.  Since there is no 'nest'
+  // parameter, there is no need to adjust the argument list.  Let the generic
+  // code sort out any function type mismatches.
+  Constant *NewCallee =
+    NestF->getType() == PTy ? NestF : 
+                              ConstantExpr::getBitCast(NestF, PTy);
+  CS.setCalledFunction(NewCallee);
+  return CS.getInstruction();
+}
+
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 81640f36a8e..b3cf01342bd 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -47,7 +47,6 @@
 #include "llvm/Target/TargetData.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Support/CallSite.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/GetElementPtrTypeIterator.h"
@@ -77,16 +76,6 @@ void InstCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
 }
 
 
-// getPromotedType - Return the specified type promoted as it would be to pass
-// though a va_arg area.
-static const Type *getPromotedType(const Type *Ty) {
-  if (const IntegerType* ITy = dyn_cast<IntegerType>(Ty)) {
-    if (ITy->getBitWidth() < 32)
-      return Type::getInt32Ty(Ty->getContext());
-  }
-  return Ty;
-}
-
 /// ShouldChangeType - Return true if it is desirable to convert a computation
 /// from 'From' to 'To'.  We don't want to convert from a legal to an illegal
 /// type for example, or from a smaller to a larger illegal type.
@@ -117,6 +106,8 @@ bool InstCombiner::ShouldChangeType(const Type *From, const Type *To) const {
 /// getBitCastOperand - If the specified operand is a CastInst, a constant
 /// expression bitcast, or a GetElementPtrInst with all zero indices, return the
 /// operand value, otherwise return null.
+
+// FIXME: Value::stripPointerCasts
 static Value *getBitCastOperand(Value *V) {
   if (Operator *O = dyn_cast<Operator>(V)) {
     if (O->getOpcode() == Instruction::BitCast)
@@ -2837,1105 +2828,6 @@ const Type *InstCombiner::FindElementAtOffset(const Type *Ty, int64_t Offset,
 }
 
 
-/// 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);
-    }
-    break;
-  }
-  }
-
-  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()) {
-      if (GV->getAlignment() >= PrefAlign)
-        Align = GV->getAlignment();
-      else {
-        GV->setAlignment(PrefAlign);
-        Align = PrefAlign;
-      }
-    }
-  } else if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
-    // If there is a requested alignment and if this is an alloca, round up.
-    if (AI->getAlignment() >= PrefAlign)
-      Align = AI->getAlignment();
-    else {
-      AI->setAlignment(PrefAlign);
-      Align = PrefAlign;
-    }
-  }
-
-  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 InstCombiner::GetOrEnforceKnownAlignment(Value *V,
-                                                  unsigned PrefAlign) {
-  unsigned BitWidth = TD ? TD->getTypeSizeInBits(V->getType()) :
-                      sizeof(PrefAlign) * CHAR_BIT;
-  APInt Mask = APInt::getAllOnesValue(BitWidth);
-  APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
-  ComputeMaskedBits(V, Mask, KnownZero, KnownOne);
-  unsigned TrailZ = KnownZero.countTrailingOnes();
-  unsigned Align = 1u << std::min(BitWidth - 1, TrailZ);
-
-  if (PrefAlign > Align)
-    Align = EnforceKnownAlignment(V, Align, PrefAlign);
-  
-    // We don't need to make any adjustment.
-  return Align;
-}
-
-Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
-  unsigned DstAlign = GetOrEnforceKnownAlignment(MI->getOperand(1));
-  unsigned SrcAlign = GetOrEnforceKnownAlignment(MI->getOperand(2));
-  unsigned MinAlign = std::min(DstAlign, SrcAlign);
-  unsigned CopyAlign = MI->getAlignment();
-
-  if (CopyAlign < MinAlign) {
-    MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), 
-                                             MinAlign, false));
-    return MI;
-  }
-  
-  // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with
-  // load/store.
-  ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getOperand(3));
-  if (MemOpLength == 0) return 0;
-  
-  // Source and destination pointer types are always "i8*" for intrinsic.  See
-  // if the size is something we can handle with a single primitive load/store.
-  // A single load+store correctly handles overlapping memory in the memmove
-  // case.
-  unsigned Size = MemOpLength->getZExtValue();
-  if (Size == 0) return MI;  // Delete this mem transfer.
-  
-  if (Size > 8 || (Size&(Size-1)))
-    return 0;  // If not 1/2/4/8 bytes, exit.
-  
-  // Use an integer load+store unless we can find something better.
-  Type *NewPtrTy =
-            PointerType::getUnqual(IntegerType::get(MI->getContext(), Size<<3));
-  
-  // Memcpy forces the use of i8* for the source and destination.  That means
-  // that if you're using memcpy to move one double around, you'll get a cast
-  // from double* to i8*.  We'd much rather use a double load+store rather than
-  // an i64 load+store, here because this improves the odds that the source or
-  // dest address will be promotable.  See if we can find a better type than the
-  // integer datatype.
-  if (Value *Op = getBitCastOperand(MI->getOperand(1))) {
-    const Type *SrcETy = cast<PointerType>(Op->getType())->getElementType();
-    if (TD && SrcETy->isSized() && TD->getTypeStoreSize(SrcETy) == Size) {
-      // The SrcETy might be something like {{{double}}} or [1 x double].  Rip
-      // down through these levels if so.
-      while (!SrcETy->isSingleValueType()) {
-        if (const StructType *STy = dyn_cast<StructType>(SrcETy)) {
-          if (STy->getNumElements() == 1)
-            SrcETy = STy->getElementType(0);
-          else
-            break;
-        } else if (const ArrayType *ATy = dyn_cast<ArrayType>(SrcETy)) {
-          if (ATy->getNumElements() == 1)
-            SrcETy = ATy->getElementType();
-          else
-            break;
-        } else
-          break;
-      }
-      
-      if (SrcETy->isSingleValueType())
-        NewPtrTy = PointerType::getUnqual(SrcETy);
-    }
-  }
-  
-  
-  // If the memcpy/memmove provides better alignment info than we can
-  // infer, use it.
-  SrcAlign = std::max(SrcAlign, CopyAlign);
-  DstAlign = std::max(DstAlign, CopyAlign);
-  
-  Value *Src = Builder->CreateBitCast(MI->getOperand(2), NewPtrTy);
-  Value *Dest = Builder->CreateBitCast(MI->getOperand(1), NewPtrTy);
-  Instruction *L = new LoadInst(Src, "tmp", false, SrcAlign);
-  InsertNewInstBefore(L, *MI);
-  InsertNewInstBefore(new StoreInst(L, Dest, false, DstAlign), *MI);
-
-  // Set the size of the copy to 0, it will be deleted on the next iteration.
-  MI->setOperand(3, Constant::getNullValue(MemOpLength->getType()));
-  return MI;
-}
-
-Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
-  unsigned Alignment = GetOrEnforceKnownAlignment(MI->getDest());
-  if (MI->getAlignment() < Alignment) {
-    MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
-                                             Alignment, false));
-    return MI;
-  }
-  
-  // Extract the length and alignment and fill if they are constant.
-  ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength());
-  ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
-  if (!LenC || !FillC || FillC->getType() != Type::getInt8Ty(MI->getContext()))
-    return 0;
-  uint64_t Len = LenC->getZExtValue();
-  Alignment = MI->getAlignment();
-  
-  // If the length is zero, this is a no-op
-  if (Len == 0) return MI; // memset(d,c,0,a) -> noop
-  
-  // memset(s,c,n) -> store s, c (for n=1,2,4,8)
-  if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) {
-    const Type *ITy = IntegerType::get(MI->getContext(), Len*8);  // n=1 -> i8.
-    
-    Value *Dest = MI->getDest();
-    Dest = Builder->CreateBitCast(Dest, PointerType::getUnqual(ITy));
-
-    // Alignment 0 is identity for alignment 1 for memset, but not store.
-    if (Alignment == 0) Alignment = 1;
-    
-    // Extract the fill value and store.
-    uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL;
-    InsertNewInstBefore(new StoreInst(ConstantInt::get(ITy, Fill),
-                                      Dest, false, Alignment), *MI);
-    
-    // Set the size of the copy to 0, it will be deleted on the next iteration.
-    MI->setLength(Constant::getNullValue(LenC->getType()));
-    return MI;
-  }
-
-  return 0;
-}
-
-
-/// visitCallInst - CallInst simplification.  This mostly only handles folding 
-/// of intrinsic instructions.  For normal calls, it allows visitCallSite to do
-/// the heavy lifting.
-///
-Instruction *InstCombiner::visitCallInst(CallInst &CI) {
-  if (isFreeCall(&CI))
-    return visitFree(CI);
-
-  // If the caller function is nounwind, mark the call as nounwind, even if the
-  // callee isn't.
-  if (CI.getParent()->getParent()->doesNotThrow() &&
-      !CI.doesNotThrow()) {
-    CI.setDoesNotThrow();
-    return &CI;
-  }
-  
-  IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI);
-  if (!II) return visitCallSite(&CI);
-  
-  // Intrinsics cannot occur in an invoke, so handle them here instead of in
-  // visitCallSite.
-  if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) {
-    bool Changed = false;
-
-    // memmove/cpy/set of zero bytes is a noop.
-    if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) {
-      if (NumBytes->isNullValue()) return EraseInstFromFunction(CI);
-
-      if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes))
-        if (CI->getZExtValue() == 1) {
-          // Replace the instruction with just byte operations.  We would
-          // transform other cases to loads/stores, but we don't know if
-          // alignment is sufficient.
-        }
-    }
-
-    // If we have a memmove and the source operation is a constant global,
-    // then the source and dest pointers can't alias, so we can change this
-    // into a call to memcpy.
-    if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) {
-      if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource()))
-        if (GVSrc->isConstant()) {
-          Module *M = CI.getParent()->getParent()->getParent();
-          Intrinsic::ID MemCpyID = Intrinsic::memcpy;
-          const Type *Tys[1];
-          Tys[0] = CI.getOperand(3)->getType();
-          CI.setOperand(0, 
-                        Intrinsic::getDeclaration(M, MemCpyID, Tys, 1));
-          Changed = true;
-        }
-    }
-
-    if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
-      // memmove(x,x,size) -> noop.
-      if (MTI->getSource() == MTI->getDest())
-        return EraseInstFromFunction(CI);
-    }
-
-    // If we can determine a pointer alignment that is bigger than currently
-    // set, update the alignment.
-    if (isa<MemTransferInst>(MI)) {
-      if (Instruction *I = SimplifyMemTransfer(MI))
-        return I;
-    } else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) {
-      if (Instruction *I = SimplifyMemSet(MSI))
-        return I;
-    }
-          
-    if (Changed) return II;
-  }
-  
-  switch (II->getIntrinsicID()) {
-  default: break;
-  case Intrinsic::bswap:
-    // bswap(bswap(x)) -> x
-    if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(II->getOperand(1)))
-      if (Operand->getIntrinsicID() == Intrinsic::bswap)
-        return ReplaceInstUsesWith(CI, Operand->getOperand(1));
-      
-    // bswap(trunc(bswap(x))) -> trunc(lshr(x, c))
-    if (TruncInst *TI = dyn_cast<TruncInst>(II->getOperand(1))) {
-      if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(TI->getOperand(0)))
-        if (Operand->getIntrinsicID() == Intrinsic::bswap) {
-          unsigned C = Operand->getType()->getPrimitiveSizeInBits() -
-                       TI->getType()->getPrimitiveSizeInBits();
-          Value *CV = ConstantInt::get(Operand->getType(), C);
-          Value *V = Builder->CreateLShr(Operand->getOperand(1), CV);
-          return new TruncInst(V, TI->getType());
-        }
-    }
-      
-    break;
-  case Intrinsic::powi:
-    if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getOperand(2))) {
-      // powi(x, 0) -> 1.0
-      if (Power->isZero())
-        return ReplaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0));
-      // powi(x, 1) -> x
-      if (Power->isOne())
-        return ReplaceInstUsesWith(CI, II->getOperand(1));
-      // powi(x, -1) -> 1/x
-      if (Power->isAllOnesValue())
-        return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0),
-                                          II->getOperand(1));
-    }
-    break;
-  case Intrinsic::cttz: {
-    // If all bits below the first known one are known zero,
-    // this value is constant.
-    const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
-    uint32_t BitWidth = IT->getBitWidth();
-    APInt KnownZero(BitWidth, 0);
-    APInt KnownOne(BitWidth, 0);
-    ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth),
-                      KnownZero, KnownOne);
-    unsigned TrailingZeros = KnownOne.countTrailingZeros();
-    APInt Mask(APInt::getLowBitsSet(BitWidth, TrailingZeros));
-    if ((Mask & KnownZero) == Mask)
-      return ReplaceInstUsesWith(CI, ConstantInt::get(IT,
-                                 APInt(BitWidth, TrailingZeros)));
-    
-    }
-    break;
-  case Intrinsic::ctlz: {
-    // If all bits above the first known one are known zero,
-    // this value is constant.
-    const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
-    uint32_t BitWidth = IT->getBitWidth();
-    APInt KnownZero(BitWidth, 0);
-    APInt KnownOne(BitWidth, 0);
-    ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth),
-                      KnownZero, KnownOne);
-    unsigned LeadingZeros = KnownOne.countLeadingZeros();
-    APInt Mask(APInt::getHighBitsSet(BitWidth, LeadingZeros));
-    if ((Mask & KnownZero) == Mask)
-      return ReplaceInstUsesWith(CI, ConstantInt::get(IT,
-                                 APInt(BitWidth, LeadingZeros)));
-    
-    }
-    break;
-  case Intrinsic::uadd_with_overflow: {
-    Value *LHS = II->getOperand(1), *RHS = II->getOperand(2);
-    const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType());
-    uint32_t BitWidth = IT->getBitWidth();
-    APInt Mask = APInt::getSignBit(BitWidth);
-    APInt LHSKnownZero(BitWidth, 0);
-    APInt LHSKnownOne(BitWidth, 0);
-    ComputeMaskedBits(LHS, Mask, LHSKnownZero, LHSKnownOne);
-    bool LHSKnownNegative = LHSKnownOne[BitWidth - 1];
-    bool LHSKnownPositive = LHSKnownZero[BitWidth - 1];
-
-    if (LHSKnownNegative || LHSKnownPositive) {
-      APInt RHSKnownZero(BitWidth, 0);
-      APInt RHSKnownOne(BitWidth, 0);
-      ComputeMaskedBits(RHS, Mask, RHSKnownZero, RHSKnownOne);
-      bool RHSKnownNegative = RHSKnownOne[BitWidth - 1];
-      bool RHSKnownPositive = RHSKnownZero[BitWidth - 1];
-      if (LHSKnownNegative && RHSKnownNegative) {
-        // The sign bit is set in both cases: this MUST overflow.
-        // Create a simple add instruction, and insert it into the struct.
-        Instruction *Add = BinaryOperator::CreateAdd(LHS, RHS, "", &CI);
-        Worklist.Add(Add);
-        Constant *V[] = {
-          UndefValue::get(LHS->getType()),ConstantInt::getTrue(II->getContext())
-        };
-        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
-        return InsertValueInst::Create(Struct, Add, 0);
-      }
-      
-      if (LHSKnownPositive && RHSKnownPositive) {
-        // The sign bit is clear in both cases: this CANNOT overflow.
-        // Create a simple add instruction, and insert it into the struct.
-        Instruction *Add = BinaryOperator::CreateNUWAdd(LHS, RHS, "", &CI);
-        Worklist.Add(Add);
-        Constant *V[] = {
-          UndefValue::get(LHS->getType()),
-          ConstantInt::getFalse(II->getContext())
-        };
-        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
-        return InsertValueInst::Create(Struct, Add, 0);
-      }
-    }
-  }
-  // FALL THROUGH uadd into sadd
-  case Intrinsic::sadd_with_overflow:
-    // Canonicalize constants into the RHS.
-    if (isa<Constant>(II->getOperand(1)) &&
-        !isa<Constant>(II->getOperand(2))) {
-      Value *LHS = II->getOperand(1);
-      II->setOperand(1, II->getOperand(2));
-      II->setOperand(2, LHS);
-      return II;
-    }
-
-    // X + undef -> undef
-    if (isa<UndefValue>(II->getOperand(2)))
-      return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
-      
-    if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) {
-      // X + 0 -> {X, false}
-      if (RHS->isZero()) {
-        Constant *V[] = {
-          UndefValue::get(II->getOperand(0)->getType()),
-          ConstantInt::getFalse(II->getContext())
-        };
-        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
-        return InsertValueInst::Create(Struct, II->getOperand(1), 0);
-      }
-    }
-    break;
-  case Intrinsic::usub_with_overflow:
-  case Intrinsic::ssub_with_overflow:
-    // undef - X -> undef
-    // X - undef -> undef
-    if (isa<UndefValue>(II->getOperand(1)) ||
-        isa<UndefValue>(II->getOperand(2)))
-      return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
-      
-    if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) {
-      // X - 0 -> {X, false}
-      if (RHS->isZero()) {
-        Constant *V[] = {
-          UndefValue::get(II->getOperand(1)->getType()),
-          ConstantInt::getFalse(II->getContext())
-        };
-        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
-        return InsertValueInst::Create(Struct, II->getOperand(1), 0);
-      }
-    }
-    break;
-  case Intrinsic::umul_with_overflow:
-  case Intrinsic::smul_with_overflow:
-    // Canonicalize constants into the RHS.
-    if (isa<Constant>(II->getOperand(1)) &&
-        !isa<Constant>(II->getOperand(2))) {
-      Value *LHS = II->getOperand(1);
-      II->setOperand(1, II->getOperand(2));
-      II->setOperand(2, LHS);
-      return II;
-    }
-
-    // X * undef -> undef
-    if (isa<UndefValue>(II->getOperand(2)))
-      return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
-      
-    if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getOperand(2))) {
-      // X*0 -> {0, false}
-      if (RHSI->isZero())
-        return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType()));
-      
-      // X * 1 -> {X, false}
-      if (RHSI->equalsInt(1)) {
-        Constant *V[] = {
-          UndefValue::get(II->getOperand(1)->getType()),
-          ConstantInt::getFalse(II->getContext())
-        };
-        Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false);
-        return InsertValueInst::Create(Struct, II->getOperand(1), 0);
-      }
-    }
-    break;
-  case Intrinsic::ppc_altivec_lvx:
-  case Intrinsic::ppc_altivec_lvxl:
-  case Intrinsic::x86_sse_loadu_ps:
-  case Intrinsic::x86_sse2_loadu_pd:
-  case Intrinsic::x86_sse2_loadu_dq:
-    // Turn PPC lvx     -> load if the pointer is known aligned.
-    // Turn X86 loadups -> load if the pointer is known aligned.
-    if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) {
-      Value *Ptr = Builder->CreateBitCast(II->getOperand(1),
-                                         PointerType::getUnqual(II->getType()));
-      return new LoadInst(Ptr);
-    }
-    break;
-  case Intrinsic::ppc_altivec_stvx:
-  case Intrinsic::ppc_altivec_stvxl:
-    // Turn stvx -> store if the pointer is known aligned.
-    if (GetOrEnforceKnownAlignment(II->getOperand(2), 16) >= 16) {
-      const Type *OpPtrTy = 
-        PointerType::getUnqual(II->getOperand(1)->getType());
-      Value *Ptr = Builder->CreateBitCast(II->getOperand(2), OpPtrTy);
-      return new StoreInst(II->getOperand(1), Ptr);
-    }
-    break;
-  case Intrinsic::x86_sse_storeu_ps:
-  case Intrinsic::x86_sse2_storeu_pd:
-  case Intrinsic::x86_sse2_storeu_dq:
-    // Turn X86 storeu -> store if the pointer is known aligned.
-    if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) {
-      const Type *OpPtrTy = 
-        PointerType::getUnqual(II->getOperand(2)->getType());
-      Value *Ptr = Builder->CreateBitCast(II->getOperand(1), OpPtrTy);
-      return new StoreInst(II->getOperand(2), Ptr);
-    }
-    break;
-    
-  case Intrinsic::x86_sse_cvttss2si: {
-    // These intrinsics only demands the 0th element of its input vector.  If
-    // we can simplify the input based on that, do so now.
-    unsigned VWidth =
-      cast<VectorType>(II->getOperand(1)->getType())->getNumElements();
-    APInt DemandedElts(VWidth, 1);
-    APInt UndefElts(VWidth, 0);
-    if (Value *V = SimplifyDemandedVectorElts(II->getOperand(1), DemandedElts,
-                                              UndefElts)) {
-      II->setOperand(1, V);
-      return II;
-    }
-    break;
-  }
-    
-  case Intrinsic::ppc_altivec_vperm:
-    // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
-    if (ConstantVector *Mask = dyn_cast<ConstantVector>(II->getOperand(3))) {
-      assert(Mask->getNumOperands() == 16 && "Bad type for intrinsic!");
-      
-      // Check that all of the elements are integer constants or undefs.
-      bool AllEltsOk = true;
-      for (unsigned i = 0; i != 16; ++i) {
-        if (!isa<ConstantInt>(Mask->getOperand(i)) && 
-            !isa<UndefValue>(Mask->getOperand(i))) {
-          AllEltsOk = false;
-          break;
-        }
-      }
-      
-      if (AllEltsOk) {
-        // Cast the input vectors to byte vectors.
-        Value *Op0 = Builder->CreateBitCast(II->getOperand(1), Mask->getType());
-        Value *Op1 = Builder->CreateBitCast(II->getOperand(2), Mask->getType());
-        Value *Result = UndefValue::get(Op0->getType());
-        
-        // Only extract each element once.
-        Value *ExtractedElts[32];
-        memset(ExtractedElts, 0, sizeof(ExtractedElts));
-        
-        for (unsigned i = 0; i != 16; ++i) {
-          if (isa<UndefValue>(Mask->getOperand(i)))
-            continue;
-          unsigned Idx=cast<ConstantInt>(Mask->getOperand(i))->getZExtValue();
-          Idx &= 31;  // Match the hardware behavior.
-          
-          if (ExtractedElts[Idx] == 0) {
-            ExtractedElts[Idx] = 
-              Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1, 
-                  ConstantInt::get(Type::getInt32Ty(II->getContext()),
-                                   Idx&15, false), "tmp");
-          }
-        
-          // Insert this value into the result vector.
-          Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx],
-                         ConstantInt::get(Type::getInt32Ty(II->getContext()),
-                                          i, false), "tmp");
-        }
-        return CastInst::Create(Instruction::BitCast, Result, CI.getType());
-      }
-    }
-    break;
-
-  case Intrinsic::stackrestore: {
-    // If the save is right next to the restore, remove the restore.  This can
-    // happen when variable allocas are DCE'd.
-    if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getOperand(1))) {
-      if (SS->getIntrinsicID() == Intrinsic::stacksave) {
-        BasicBlock::iterator BI = SS;
-        if (&*++BI == II)
-          return EraseInstFromFunction(CI);
-      }
-    }
-    
-    // Scan down this block to see if there is another stack restore in the
-    // same block without an intervening call/alloca.
-    BasicBlock::iterator BI = II;
-    TerminatorInst *TI = II->getParent()->getTerminator();
-    bool CannotRemove = false;
-    for (++BI; &*BI != TI; ++BI) {
-      if (isa<AllocaInst>(BI) || isMalloc(BI)) {
-        CannotRemove = true;
-        break;
-      }
-      if (CallInst *BCI = dyn_cast<CallInst>(BI)) {
-        if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) {
-          // If there is a stackrestore below this one, remove this one.
-          if (II->getIntrinsicID() == Intrinsic::stackrestore)
-            return EraseInstFromFunction(CI);
-          // Otherwise, ignore the intrinsic.
-        } else {
-          // If we found a non-intrinsic call, we can't remove the stack
-          // restore.
-          CannotRemove = true;
-          break;
-        }
-      }
-    }
-    
-    // If the stack restore is in a return/unwind block and if there are no
-    // allocas or calls between the restore and the return, nuke the restore.
-    if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI)))
-      return EraseInstFromFunction(CI);
-    break;
-  }
-  }
-
-  return visitCallSite(II);
-}
-
-// InvokeInst simplification
-//
-Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) {
-  return visitCallSite(&II);
-}
-
-/// isSafeToEliminateVarargsCast - If this cast does not affect the value 
-/// passed through the varargs area, we can eliminate the use of the cast.
-static bool isSafeToEliminateVarargsCast(const CallSite CS,
-                                         const CastInst * const CI,
-                                         const TargetData * const TD,
-                                         const int ix) {
-  if (!CI->isLosslessCast())
-    return false;
-
-  // The size of ByVal arguments is derived from the type, so we
-  // can't change to a type with a different size.  If the size were
-  // passed explicitly we could avoid this check.
-  if (!CS.paramHasAttr(ix, Attribute::ByVal))
-    return true;
-
-  const Type* SrcTy = 
-            cast<PointerType>(CI->getOperand(0)->getType())->getElementType();
-  const Type* DstTy = cast<PointerType>(CI->getType())->getElementType();
-  if (!SrcTy->isSized() || !DstTy->isSized())
-    return false;
-  if (!TD || TD->getTypeAllocSize(SrcTy) != TD->getTypeAllocSize(DstTy))
-    return false;
-  return true;
-}
-
-// visitCallSite - Improvements for call and invoke instructions.
-//
-Instruction *InstCombiner::visitCallSite(CallSite CS) {
-  bool Changed = false;
-
-  // If the callee is a constexpr cast of a function, attempt to move the cast
-  // to the arguments of the call/invoke.
-  if (transformConstExprCastCall(CS)) return 0;
-
-  Value *Callee = CS.getCalledValue();
-
-  if (Function *CalleeF = dyn_cast<Function>(Callee))
-    if (CalleeF->getCallingConv() != CS.getCallingConv()) {
-      Instruction *OldCall = CS.getInstruction();
-      // If the call and callee calling conventions don't match, this call must
-      // be unreachable, as the call is undefined.
-      new StoreInst(ConstantInt::getTrue(Callee->getContext()),
-                UndefValue::get(Type::getInt1PtrTy(Callee->getContext())), 
-                                  OldCall);
-      // If OldCall dues not return void then replaceAllUsesWith undef.
-      // This allows ValueHandlers and custom metadata to adjust itself.
-      if (!OldCall->getType()->isVoidTy())
-        OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType()));
-      if (isa<CallInst>(OldCall))   // Not worth removing an invoke here.
-        return EraseInstFromFunction(*OldCall);
-      return 0;
-    }
-
-  if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
-    // This instruction is not reachable, just remove it.  We insert a store to
-    // undef so that we know that this code is not reachable, despite the fact
-    // that we can't modify the CFG here.
-    new StoreInst(ConstantInt::getTrue(Callee->getContext()),
-               UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
-                  CS.getInstruction());
-
-    // If CS dues not return void then replaceAllUsesWith undef.
-    // This allows ValueHandlers and custom metadata to adjust itself.
-    if (!CS.getInstruction()->getType()->isVoidTy())
-      CS.getInstruction()->
-        replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType()));
-
-    if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) {
-      // Don't break the CFG, insert a dummy cond branch.
-      BranchInst::Create(II->getNormalDest(), II->getUnwindDest(),
-                         ConstantInt::getTrue(Callee->getContext()), II);
-    }
-    return EraseInstFromFunction(*CS.getInstruction());
-  }
-
-  if (BitCastInst *BC = dyn_cast<BitCastInst>(Callee))
-    if (IntrinsicInst *In = dyn_cast<IntrinsicInst>(BC->getOperand(0)))
-      if (In->getIntrinsicID() == Intrinsic::init_trampoline)
-        return transformCallThroughTrampoline(CS);
-
-  const PointerType *PTy = cast<PointerType>(Callee->getType());
-  const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
-  if (FTy->isVarArg()) {
-    int ix = FTy->getNumParams() + (isa<InvokeInst>(Callee) ? 3 : 1);
-    // See if we can optimize any arguments passed through the varargs area of
-    // the call.
-    for (CallSite::arg_iterator I = CS.arg_begin()+FTy->getNumParams(),
-           E = CS.arg_end(); I != E; ++I, ++ix) {
-      CastInst *CI = dyn_cast<CastInst>(*I);
-      if (CI && isSafeToEliminateVarargsCast(CS, CI, TD, ix)) {
-        *I = CI->getOperand(0);
-        Changed = true;
-      }
-    }
-  }
-
-  if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) {
-    // Inline asm calls cannot throw - mark them 'nounwind'.
-    CS.setDoesNotThrow();
-    Changed = true;
-  }
-
-  return Changed ? CS.getInstruction() : 0;
-}
-
-// transformConstExprCastCall - If the callee is a constexpr cast of a function,
-// attempt to move the cast to the arguments of the call/invoke.
-//
-bool InstCombiner::transformConstExprCastCall(CallSite CS) {
-  if (!isa<ConstantExpr>(CS.getCalledValue())) return false;
-  ConstantExpr *CE = cast<ConstantExpr>(CS.getCalledValue());
-  if (CE->getOpcode() != Instruction::BitCast || 
-      !isa<Function>(CE->getOperand(0)))
-    return false;
-  Function *Callee = cast<Function>(CE->getOperand(0));
-  Instruction *Caller = CS.getInstruction();
-  const AttrListPtr &CallerPAL = CS.getAttributes();
-
-  // Okay, this is a cast from a function to a different type.  Unless doing so
-  // would cause a type conversion of one of our arguments, change this call to
-  // be a direct call with arguments casted to the appropriate types.
-  //
-  const FunctionType *FT = Callee->getFunctionType();
-  const Type *OldRetTy = Caller->getType();
-  const Type *NewRetTy = FT->getReturnType();
-
-  if (isa<StructType>(NewRetTy))
-    return false; // TODO: Handle multiple return values.
-
-  // Check to see if we are changing the return type...
-  if (OldRetTy != NewRetTy) {
-    if (Callee->isDeclaration() &&
-        // Conversion is ok if changing from one pointer type to another or from
-        // a pointer to an integer of the same size.
-        !((isa<PointerType>(OldRetTy) || !TD ||
-           OldRetTy == TD->getIntPtrType(Caller->getContext())) &&
-          (isa<PointerType>(NewRetTy) || !TD ||
-           NewRetTy == TD->getIntPtrType(Caller->getContext()))))
-      return false;   // Cannot transform this return value.
-
-    if (!Caller->use_empty() &&
-        // void -> non-void is handled specially
-        !NewRetTy->isVoidTy() && !CastInst::isCastable(NewRetTy, OldRetTy))
-      return false;   // Cannot transform this return value.
-
-    if (!CallerPAL.isEmpty() && !Caller->use_empty()) {
-      Attributes RAttrs = CallerPAL.getRetAttributes();
-      if (RAttrs & Attribute::typeIncompatible(NewRetTy))
-        return false;   // Attribute not compatible with transformed value.
-    }
-
-    // If the callsite is an invoke instruction, and the return value is used by
-    // a PHI node in a successor, we cannot change the return type of the call
-    // because there is no place to put the cast instruction (without breaking
-    // the critical edge).  Bail out in this case.
-    if (!Caller->use_empty())
-      if (InvokeInst *II = dyn_cast<InvokeInst>(Caller))
-        for (Value::use_iterator UI = II->use_begin(), E = II->use_end();
-             UI != E; ++UI)
-          if (PHINode *PN = dyn_cast<PHINode>(*UI))
-            if (PN->getParent() == II->getNormalDest() ||
-                PN->getParent() == II->getUnwindDest())
-              return false;
-  }
-
-  unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin());
-  unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
-
-  CallSite::arg_iterator AI = CS.arg_begin();
-  for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) {
-    const Type *ParamTy = FT->getParamType(i);
-    const Type *ActTy = (*AI)->getType();
-
-    if (!CastInst::isCastable(ActTy, ParamTy))
-      return false;   // Cannot transform this parameter value.
-
-    if (CallerPAL.getParamAttributes(i + 1) 
-        & Attribute::typeIncompatible(ParamTy))
-      return false;   // Attribute not compatible with transformed value.
-
-    // Converting from one pointer type to another or between a pointer and an
-    // integer of the same size is safe even if we do not have a body.
-    bool isConvertible = ActTy == ParamTy ||
-      (TD && ((isa<PointerType>(ParamTy) ||
-      ParamTy == TD->getIntPtrType(Caller->getContext())) &&
-              (isa<PointerType>(ActTy) ||
-              ActTy == TD->getIntPtrType(Caller->getContext()))));
-    if (Callee->isDeclaration() && !isConvertible) return false;
-  }
-
-  if (FT->getNumParams() < NumActualArgs && !FT->isVarArg() &&
-      Callee->isDeclaration())
-    return false;   // Do not delete arguments unless we have a function body.
-
-  if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
-      !CallerPAL.isEmpty())
-    // In this case we have more arguments than the new function type, but we
-    // won't be dropping them.  Check that these extra arguments have attributes
-    // that are compatible with being a vararg call argument.
-    for (unsigned i = CallerPAL.getNumSlots(); i; --i) {
-      if (CallerPAL.getSlot(i - 1).Index <= FT->getNumParams())
-        break;
-      Attributes PAttrs = CallerPAL.getSlot(i - 1).Attrs;
-      if (PAttrs & Attribute::VarArgsIncompatible)
-        return false;
-    }
-
-  // Okay, we decided that this is a safe thing to do: go ahead and start
-  // inserting cast instructions as necessary...
-  std::vector<Value*> Args;
-  Args.reserve(NumActualArgs);
-  SmallVector<AttributeWithIndex, 8> attrVec;
-  attrVec.reserve(NumCommonArgs);
-
-  // Get any return attributes.
-  Attributes RAttrs = CallerPAL.getRetAttributes();
-
-  // If the return value is not being used, the type may not be compatible
-  // with the existing attributes.  Wipe out any problematic attributes.
-  RAttrs &= ~Attribute::typeIncompatible(NewRetTy);
-
-  // Add the new return attributes.
-  if (RAttrs)
-    attrVec.push_back(AttributeWithIndex::get(0, RAttrs));
-
-  AI = CS.arg_begin();
-  for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) {
-    const Type *ParamTy = FT->getParamType(i);
-    if ((*AI)->getType() == ParamTy) {
-      Args.push_back(*AI);
-    } else {
-      Instruction::CastOps opcode = CastInst::getCastOpcode(*AI,
-          false, ParamTy, false);
-      Args.push_back(Builder->CreateCast(opcode, *AI, ParamTy, "tmp"));
-    }
-
-    // Add any parameter attributes.
-    if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1))
-      attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs));
-  }
-
-  // If the function takes more arguments than the call was taking, add them
-  // now.
-  for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i)
-    Args.push_back(Constant::getNullValue(FT->getParamType(i)));
-
-  // If we are removing arguments to the function, emit an obnoxious warning.
-  if (FT->getNumParams() < NumActualArgs) {
-    if (!FT->isVarArg()) {
-      errs() << "WARNING: While resolving call to function '"
-             << Callee->getName() << "' arguments were dropped!\n";
-    } else {
-      // Add all of the arguments in their promoted form to the arg list.
-      for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) {
-        const Type *PTy = getPromotedType((*AI)->getType());
-        if (PTy != (*AI)->getType()) {
-          // Must promote to pass through va_arg area!
-          Instruction::CastOps opcode =
-            CastInst::getCastOpcode(*AI, false, PTy, false);
-          Args.push_back(Builder->CreateCast(opcode, *AI, PTy, "tmp"));
-        } else {
-          Args.push_back(*AI);
-        }
-
-        // Add any parameter attributes.
-        if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1))
-          attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs));
-      }
-    }
-  }
-
-  if (Attributes FnAttrs =  CallerPAL.getFnAttributes())
-    attrVec.push_back(AttributeWithIndex::get(~0, FnAttrs));
-
-  if (NewRetTy->isVoidTy())
-    Caller->setName("");   // Void type should not have a name.
-
-  const AttrListPtr &NewCallerPAL = AttrListPtr::get(attrVec.begin(),
-                                                     attrVec.end());
-
-  Instruction *NC;
-  if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
-    NC = InvokeInst::Create(Callee, II->getNormalDest(), II->getUnwindDest(),
-                            Args.begin(), Args.end(),
-                            Caller->getName(), Caller);
-    cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv());
-    cast<InvokeInst>(NC)->setAttributes(NewCallerPAL);
-  } else {
-    NC = CallInst::Create(Callee, Args.begin(), Args.end(),
-                          Caller->getName(), Caller);
-    CallInst *CI = cast<CallInst>(Caller);
-    if (CI->isTailCall())
-      cast<CallInst>(NC)->setTailCall();
-    cast<CallInst>(NC)->setCallingConv(CI->getCallingConv());
-    cast<CallInst>(NC)->setAttributes(NewCallerPAL);
-  }
-
-  // Insert a cast of the return type as necessary.
-  Value *NV = NC;
-  if (OldRetTy != NV->getType() && !Caller->use_empty()) {
-    if (!NV->getType()->isVoidTy()) {
-      Instruction::CastOps opcode = CastInst::getCastOpcode(NC, false, 
-                                                            OldRetTy, false);
-      NV = NC = CastInst::Create(opcode, NC, OldRetTy, "tmp");
-
-      // If this is an invoke instruction, we should insert it after the first
-      // non-phi, instruction in the normal successor block.
-      if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
-        BasicBlock::iterator I = II->getNormalDest()->getFirstNonPHI();
-        InsertNewInstBefore(NC, *I);
-      } else {
-        // Otherwise, it's a call, just insert cast right after the call instr
-        InsertNewInstBefore(NC, *Caller);
-      }
-      Worklist.AddUsersToWorkList(*Caller);
-    } else {
-      NV = UndefValue::get(Caller->getType());
-    }
-  }
-
-
-  if (!Caller->use_empty())
-    Caller->replaceAllUsesWith(NV);
-  
-  EraseInstFromFunction(*Caller);
-  return true;
-}
-
-// transformCallThroughTrampoline - Turn a call to a function created by the
-// init_trampoline intrinsic into a direct call to the underlying function.
-//
-Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) {
-  Value *Callee = CS.getCalledValue();
-  const PointerType *PTy = cast<PointerType>(Callee->getType());
-  const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
-  const AttrListPtr &Attrs = CS.getAttributes();
-
-  // If the call already has the 'nest' attribute somewhere then give up -
-  // otherwise 'nest' would occur twice after splicing in the chain.
-  if (Attrs.hasAttrSomewhere(Attribute::Nest))
-    return 0;
-
-  IntrinsicInst *Tramp =
-    cast<IntrinsicInst>(cast<BitCastInst>(Callee)->getOperand(0));
-
-  Function *NestF = cast<Function>(Tramp->getOperand(2)->stripPointerCasts());
-  const PointerType *NestFPTy = cast<PointerType>(NestF->getType());
-  const FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType());
-
-  const AttrListPtr &NestAttrs = NestF->getAttributes();
-  if (!NestAttrs.isEmpty()) {
-    unsigned NestIdx = 1;
-    const Type *NestTy = 0;
-    Attributes NestAttr = Attribute::None;
-
-    // Look for a parameter marked with the 'nest' attribute.
-    for (FunctionType::param_iterator I = NestFTy->param_begin(),
-         E = NestFTy->param_end(); I != E; ++NestIdx, ++I)
-      if (NestAttrs.paramHasAttr(NestIdx, Attribute::Nest)) {
-        // Record the parameter type and any other attributes.
-        NestTy = *I;
-        NestAttr = NestAttrs.getParamAttributes(NestIdx);
-        break;
-      }
-
-    if (NestTy) {
-      Instruction *Caller = CS.getInstruction();
-      std::vector<Value*> NewArgs;
-      NewArgs.reserve(unsigned(CS.arg_end()-CS.arg_begin())+1);
-
-      SmallVector<AttributeWithIndex, 8> NewAttrs;
-      NewAttrs.reserve(Attrs.getNumSlots() + 1);
-
-      // Insert the nest argument into the call argument list, which may
-      // mean appending it.  Likewise for attributes.
-
-      // Add any result attributes.
-      if (Attributes Attr = Attrs.getRetAttributes())
-        NewAttrs.push_back(AttributeWithIndex::get(0, Attr));
-
-      {
-        unsigned Idx = 1;
-        CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
-        do {
-          if (Idx == NestIdx) {
-            // Add the chain argument and attributes.
-            Value *NestVal = Tramp->getOperand(3);
-            if (NestVal->getType() != NestTy)
-              NestVal = new BitCastInst(NestVal, NestTy, "nest", Caller);
-            NewArgs.push_back(NestVal);
-            NewAttrs.push_back(AttributeWithIndex::get(NestIdx, NestAttr));
-          }
-
-          if (I == E)
-            break;
-
-          // Add the original argument and attributes.
-          NewArgs.push_back(*I);
-          if (Attributes Attr = Attrs.getParamAttributes(Idx))
-            NewAttrs.push_back
-              (AttributeWithIndex::get(Idx + (Idx >= NestIdx), Attr));
-
-          ++Idx, ++I;
-        } while (1);
-      }
-
-      // Add any function attributes.
-      if (Attributes Attr = Attrs.getFnAttributes())
-        NewAttrs.push_back(AttributeWithIndex::get(~0, Attr));
-
-      // The trampoline may have been bitcast to a bogus type (FTy).
-      // Handle this by synthesizing a new function type, equal to FTy
-      // with the chain parameter inserted.
-
-      std::vector<const Type*> NewTypes;
-      NewTypes.reserve(FTy->getNumParams()+1);
-
-      // Insert the chain's type into the list of parameter types, which may
-      // mean appending it.
-      {
-        unsigned Idx = 1;
-        FunctionType::param_iterator I = FTy->param_begin(),
-          E = FTy->param_end();
-
-        do {
-          if (Idx == NestIdx)
-            // Add the chain's type.
-            NewTypes.push_back(NestTy);
-
-          if (I == E)
-            break;
-
-          // Add the original type.
-          NewTypes.push_back(*I);
-
-          ++Idx, ++I;
-        } while (1);
-      }
-
-      // Replace the trampoline call with a direct call.  Let the generic
-      // code sort out any function type mismatches.
-      FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes, 
-                                                FTy->isVarArg());
-      Constant *NewCallee =
-        NestF->getType() == PointerType::getUnqual(NewFTy) ?
-        NestF : ConstantExpr::getBitCast(NestF, 
-                                         PointerType::getUnqual(NewFTy));
-      const AttrListPtr &NewPAL = AttrListPtr::get(NewAttrs.begin(),
-                                                   NewAttrs.end());
-
-      Instruction *NewCaller;
-      if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
-        NewCaller = InvokeInst::Create(NewCallee,
-                                       II->getNormalDest(), II->getUnwindDest(),
-                                       NewArgs.begin(), NewArgs.end(),
-                                       Caller->getName(), Caller);
-        cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv());
-        cast<InvokeInst>(NewCaller)->setAttributes(NewPAL);
-      } else {
-        NewCaller = CallInst::Create(NewCallee, NewArgs.begin(), NewArgs.end(),
-                                     Caller->getName(), Caller);
-        if (cast<CallInst>(Caller)->isTailCall())
-          cast<CallInst>(NewCaller)->setTailCall();
-        cast<CallInst>(NewCaller)->
-          setCallingConv(cast<CallInst>(Caller)->getCallingConv());
-        cast<CallInst>(NewCaller)->setAttributes(NewPAL);
-      }
-      if (!Caller->getType()->isVoidTy())
-        Caller->replaceAllUsesWith(NewCaller);
-      Caller->eraseFromParent();
-      Worklist.Remove(Caller);
-      return 0;
-    }
-  }
-
-  // Replace the trampoline call with a direct call.  Since there is no 'nest'
-  // parameter, there is no need to adjust the argument list.  Let the generic
-  // code sort out any function type mismatches.
-  Constant *NewCallee =
-    NestF->getType() == PTy ? NestF : 
-                              ConstantExpr::getBitCast(NestF, PTy);
-  CS.setCalledFunction(NewCallee);
-  return CS.getInstruction();
-}
-
-
 
 Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
   SmallVector<Value*, 8> Ops(GEP.op_begin(), GEP.op_end());