diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
new file mode 100644
index 0000000..e85d150
--- /dev/null
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -0,0 +1,486 @@
+//===-- ConstantFolding.cpp - Analyze constant folding possibilities ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This family of functions determines the possibility of performing constant
+// folding.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/Instructions.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Support/MathExtras.h"
+#include <cerrno>
+#include <cmath>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Constant Folding internal helper functions
+//===----------------------------------------------------------------------===//
+
+/// IsConstantOffsetFromGlobal - If this constant is actually a constant offset
+/// from a global, return the global and the constant.  Because of
+/// constantexprs, this function is recursive.
+static bool IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
+                                       int64_t &Offset, const TargetData &TD) {
+  // Trivial case, constant is the global.
+  if ((GV = dyn_cast<GlobalValue>(C))) {
+    Offset = 0;
+    return true;
+  }
+  
+  // Otherwise, if this isn't a constant expr, bail out.
+  ConstantExpr *CE = dyn_cast<ConstantExpr>(C);
+  if (!CE) return false;
+  
+  // Look through ptr->int and ptr->ptr casts.
+  if (CE->getOpcode() == Instruction::PtrToInt ||
+      CE->getOpcode() == Instruction::BitCast)
+    return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD);
+  
+  // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)    
+  if (CE->getOpcode() == Instruction::GetElementPtr) {
+    // Cannot compute this if the element type of the pointer is missing size
+    // info.
+    if (!cast<PointerType>(CE->getOperand(0)->getType())->getElementType()->isSized())
+      return false;
+    
+    // If the base isn't a global+constant, we aren't either.
+    if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, TD))
+      return false;
+    
+    // Otherwise, add any offset that our operands provide.
+    gep_type_iterator GTI = gep_type_begin(CE);
+    for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i, ++GTI) {
+      ConstantInt *CI = dyn_cast<ConstantInt>(CE->getOperand(i));
+      if (!CI) return false;  // Index isn't a simple constant?
+      if (CI->getZExtValue() == 0) continue;  // Not adding anything.
+      
+      if (const StructType *ST = dyn_cast<StructType>(*GTI)) {
+        // N = N + Offset
+        Offset += TD.getStructLayout(ST)->getElementOffset(CI->getZExtValue());
+      } else {
+        const SequentialType *SQT = cast<SequentialType>(*GTI);
+        Offset += TD.getTypeSize(SQT->getElementType())*CI->getSExtValue();
+      }
+    }
+    return true;
+  }
+  
+  return false;
+}
+
+
+/// SymbolicallyEvaluateBinop - One of Op0/Op1 is a constant expression.
+/// Attempt to symbolically evaluate the result of  a binary operator merging
+/// these together.  If target data info is available, it is provided as TD, 
+/// otherwise TD is null.
+static Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0,
+                                           Constant *Op1, const TargetData *TD){
+  // SROA
+  
+  // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
+  // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
+  // bits.
+  
+  
+  // If the constant expr is something like &A[123] - &A[4].f, fold this into a
+  // constant.  This happens frequently when iterating over a global array.
+  if (Opc == Instruction::Sub && TD) {
+    GlobalValue *GV1, *GV2;
+    int64_t Offs1, Offs2;
+    
+    if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, *TD))
+      if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, *TD) &&
+          GV1 == GV2) {
+        // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
+        return ConstantInt::get(Op0->getType(), Offs1-Offs2);
+      }
+  }
+    
+  // TODO: Fold icmp setne/seteq as well.
+  return 0;
+}
+
+/// SymbolicallyEvaluateGEP - If we can symbolically evaluate the specified GEP
+/// constant expression, do so.
+static Constant *SymbolicallyEvaluateGEP(Constant** Ops, unsigned NumOps,
+                                         const Type *ResultTy,
+                                         const TargetData *TD) {
+  Constant *Ptr = Ops[0];
+  if (!cast<PointerType>(Ptr->getType())->getElementType()->isSized())
+    return 0;
+  
+  if (TD && Ptr->isNullValue()) {
+    // If this is a constant expr gep that is effectively computing an
+    // "offsetof", fold it into 'cast int Size to T*' instead of 'gep 0, 0, 12'
+    bool isFoldableGEP = true;
+    for (unsigned i = 1; i != NumOps; ++i)
+      if (!isa<ConstantInt>(Ops[i])) {
+        isFoldableGEP = false;
+        break;
+      }
+    if (isFoldableGEP) {
+      uint64_t Offset = TD->getIndexedOffset(Ptr->getType(),
+                                             (Value**)Ops+1, NumOps-1);
+      Constant *C = ConstantInt::get(TD->getIntPtrType(), Offset);
+      return ConstantExpr::getIntToPtr(C, ResultTy);
+    }
+  }
+  
+  return 0;
+}
+
+
+//===----------------------------------------------------------------------===//
+// Constant Folding public APIs
+//===----------------------------------------------------------------------===//
+
+
+/// ConstantFoldInstruction - Attempt to constant fold the specified
+/// instruction.  If successful, the constant result is returned, if not, null
+/// is returned.  Note that this function can only fail when attempting to fold
+/// instructions like loads and stores, which have no constant expression form.
+///
+Constant *llvm::ConstantFoldInstruction(Instruction *I, const TargetData *TD) {
+  if (PHINode *PN = dyn_cast<PHINode>(I)) {
+    if (PN->getNumIncomingValues() == 0)
+      return Constant::getNullValue(PN->getType());
+
+    Constant *Result = dyn_cast<Constant>(PN->getIncomingValue(0));
+    if (Result == 0) return 0;
+
+    // Handle PHI nodes specially here...
+    for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i)
+      if (PN->getIncomingValue(i) != Result && PN->getIncomingValue(i) != PN)
+        return 0;   // Not all the same incoming constants...
+
+    // If we reach here, all incoming values are the same constant.
+    return Result;
+  }
+
+  // Scan the operand list, checking to see if they are all constants, if so,
+  // hand off to ConstantFoldInstOperands.
+  SmallVector<Constant*, 8> Ops;
+  for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
+    if (Constant *Op = dyn_cast<Constant>(I->getOperand(i)))
+      Ops.push_back(Op);
+    else
+      return 0;  // All operands not constant!
+
+  return ConstantFoldInstOperands(I, &Ops[0], Ops.size(), TD);
+}
+
+/// ConstantFoldInstOperands - Attempt to constant fold an instruction with the
+/// specified opcode and operands.  If successful, the constant result is
+/// returned, if not, null is returned.  Note that this function can fail when
+/// attempting to fold instructions like loads and stores, which have no
+/// constant expression form.
+///
+Constant *llvm::ConstantFoldInstOperands(const Instruction* I, 
+                                         Constant** Ops, unsigned NumOps,
+                                         const TargetData *TD) {
+  unsigned Opc = I->getOpcode();
+  const Type *DestTy = I->getType();
+
+  // Handle easy binops first.
+  if (isa<BinaryOperator>(I)) {
+    if (isa<ConstantExpr>(Ops[0]) || isa<ConstantExpr>(Ops[1]))
+      if (Constant *C = SymbolicallyEvaluateBinop(I->getOpcode(), Ops[0],
+                                                  Ops[1], TD))
+        return C;
+    
+    return ConstantExpr::get(Opc, Ops[0], Ops[1]);
+  }
+  
+  switch (Opc) {
+  default: return 0;
+  case Instruction::Call:
+    if (Function *F = dyn_cast<Function>(Ops[0]))
+      if (canConstantFoldCallTo(F))
+        return ConstantFoldCall(F, Ops+1, NumOps-1);
+    return 0;
+  case Instruction::ICmp:
+  case Instruction::FCmp:
+    return ConstantExpr::getCompare(cast<CmpInst>(I)->getPredicate(), Ops[0], 
+                                    Ops[1]);
+  case Instruction::Trunc:
+  case Instruction::ZExt:
+  case Instruction::SExt:
+  case Instruction::FPTrunc:
+  case Instruction::FPExt:
+  case Instruction::UIToFP:
+  case Instruction::SIToFP:
+  case Instruction::FPToUI:
+  case Instruction::FPToSI:
+  case Instruction::PtrToInt:
+  case Instruction::IntToPtr:
+  case Instruction::BitCast:
+    return ConstantExpr::getCast(Opc, Ops[0], DestTy);
+  case Instruction::Select:
+    return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]);
+  case Instruction::ExtractElement:
+    return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
+  case Instruction::InsertElement:
+    return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
+  case Instruction::ShuffleVector:
+    return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2]);
+  case Instruction::GetElementPtr:
+    if (Constant *C = SymbolicallyEvaluateGEP(Ops, NumOps, I->getType(), TD))
+      return C;
+    
+    return ConstantExpr::getGetElementPtr(Ops[0], Ops+1, NumOps-1);
+  }
+}
+
+/// ConstantFoldLoadThroughGEPConstantExpr - Given a constant and a
+/// getelementptr constantexpr, return the constant value being addressed by the
+/// constant expression, or null if something is funny and we can't decide.
+Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, 
+                                                       ConstantExpr *CE) {
+  if (CE->getOperand(1) != Constant::getNullValue(CE->getOperand(1)->getType()))
+    return 0;  // Do not allow stepping over the value!
+  
+  // Loop over all of the operands, tracking down which value we are
+  // addressing...
+  gep_type_iterator I = gep_type_begin(CE), E = gep_type_end(CE);
+  for (++I; I != E; ++I)
+    if (const StructType *STy = dyn_cast<StructType>(*I)) {
+      ConstantInt *CU = cast<ConstantInt>(I.getOperand());
+      assert(CU->getZExtValue() < STy->getNumElements() &&
+             "Struct index out of range!");
+      unsigned El = (unsigned)CU->getZExtValue();
+      if (ConstantStruct *CS = dyn_cast<ConstantStruct>(C)) {
+        C = CS->getOperand(El);
+      } else if (isa<ConstantAggregateZero>(C)) {
+        C = Constant::getNullValue(STy->getElementType(El));
+      } else if (isa<UndefValue>(C)) {
+        C = UndefValue::get(STy->getElementType(El));
+      } else {
+        return 0;
+      }
+    } else if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand())) {
+      if (const ArrayType *ATy = dyn_cast<ArrayType>(*I)) {
+        if (CI->getZExtValue() >= ATy->getNumElements())
+         return 0;
+        if (ConstantArray *CA = dyn_cast<ConstantArray>(C))
+          C = CA->getOperand(CI->getZExtValue());
+        else if (isa<ConstantAggregateZero>(C))
+          C = Constant::getNullValue(ATy->getElementType());
+        else if (isa<UndefValue>(C))
+          C = UndefValue::get(ATy->getElementType());
+        else
+          return 0;
+      } else if (const VectorType *PTy = dyn_cast<VectorType>(*I)) {
+        if (CI->getZExtValue() >= PTy->getNumElements())
+          return 0;
+        if (ConstantVector *CP = dyn_cast<ConstantVector>(C))
+          C = CP->getOperand(CI->getZExtValue());
+        else if (isa<ConstantAggregateZero>(C))
+          C = Constant::getNullValue(PTy->getElementType());
+        else if (isa<UndefValue>(C))
+          C = UndefValue::get(PTy->getElementType());
+        else
+          return 0;
+      } else {
+        return 0;
+      }
+    } else {
+      return 0;
+    }
+  return C;
+}
+
+
+//===----------------------------------------------------------------------===//
+//  Constant Folding for Calls
+//
+
+/// canConstantFoldCallTo - Return true if its even possible to fold a call to
+/// the specified function.
+bool
+llvm::canConstantFoldCallTo(Function *F) {
+  const std::string &Name = F->getName();
+
+  switch (F->getIntrinsicID()) {
+  case Intrinsic::sqrt_f32:
+  case Intrinsic::sqrt_f64:
+  case Intrinsic::powi_f32:
+  case Intrinsic::powi_f64:
+  case Intrinsic::bswap:
+  case Intrinsic::ctpop:
+  case Intrinsic::ctlz:
+  case Intrinsic::cttz:
+    return true;
+  default: break;
+  }
+
+  switch (Name[0])
+  {
+    case 'a':
+      return Name == "acos" || Name == "asin" || Name == "atan" ||
+             Name == "atan2";
+    case 'c':
+      return Name == "ceil" || Name == "cos" || Name == "cosf" ||
+             Name == "cosh";
+    case 'e':
+      return Name == "exp";
+    case 'f':
+      return Name == "fabs" || Name == "fmod" || Name == "floor";
+    case 'l':
+      return Name == "log" || Name == "log10";
+    case 'p':
+      return Name == "pow";
+    case 's':
+      return Name == "sin" || Name == "sinh" || 
+             Name == "sqrt" || Name == "sqrtf";
+    case 't':
+      return Name == "tan" || Name == "tanh";
+    default:
+      return false;
+  }
+}
+
+static Constant *ConstantFoldFP(double (*NativeFP)(double), double V, 
+                                const Type *Ty) {
+  errno = 0;
+  V = NativeFP(V);
+  if (errno == 0)
+    return ConstantFP::get(Ty, V);
+  errno = 0;
+  return 0;
+}
+
+static Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
+                                      double V, double W,
+                                      const Type *Ty) {
+  errno = 0;
+  V = NativeFP(V, W);
+  if (errno == 0)
+    return ConstantFP::get(Ty, V);
+  errno = 0;
+  return 0;
+}
+
+/// ConstantFoldCall - Attempt to constant fold a call to the specified function
+/// with the specified arguments, returning null if unsuccessful.
+Constant *
+llvm::ConstantFoldCall(Function *F, Constant** Operands, unsigned NumOperands) {
+  const std::string &Name = F->getName();
+  const Type *Ty = F->getReturnType();
+
+  if (NumOperands == 1) {
+    if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) {
+      double V = Op->getValue();
+      switch (Name[0])
+      {
+        case 'a':
+          if (Name == "acos")
+            return ConstantFoldFP(acos, V, Ty);
+          else if (Name == "asin")
+            return ConstantFoldFP(asin, V, Ty);
+          else if (Name == "atan")
+            return ConstantFoldFP(atan, V, Ty);
+          break;
+        case 'c':
+          if (Name == "ceil")
+            return ConstantFoldFP(ceil, V, Ty);
+          else if (Name == "cos")
+            return ConstantFoldFP(cos, V, Ty);
+          else if (Name == "cosh")
+            return ConstantFoldFP(cosh, V, Ty);
+          break;
+        case 'e':
+          if (Name == "exp")
+            return ConstantFoldFP(exp, V, Ty);
+          break;
+        case 'f':
+          if (Name == "fabs")
+            return ConstantFP::get(Ty, fabs(V));
+          else if (Name == "floor")
+            return ConstantFoldFP(floor, V, Ty);
+          break;
+        case 'l':
+          if (Name == "log" && V > 0)
+            return ConstantFoldFP(log, V, Ty);
+          else if (Name == "log10" && V > 0)
+            return ConstantFoldFP(log10, V, Ty);
+          else if (Name == "llvm.sqrt.f32" || Name == "llvm.sqrt.f64") {
+            if (V >= -0.0)
+              return ConstantFP::get(Ty, sqrt(V));
+            else // Undefined
+              return ConstantFP::get(Ty, 0.0);
+          }
+          break;
+        case 's':
+          if (Name == "sin")
+            return ConstantFoldFP(sin, V, Ty);
+          else if (Name == "sinh")
+            return ConstantFoldFP(sinh, V, Ty);
+          else if (Name == "sqrt" && V >= 0)
+            return ConstantFoldFP(sqrt, V, Ty);
+          else if (Name == "sqrtf" && V >= 0)
+            return ConstantFoldFP(sqrt, V, Ty);
+          break;
+        case 't':
+          if (Name == "tan")
+            return ConstantFoldFP(tan, V, Ty);
+          else if (Name == "tanh")
+            return ConstantFoldFP(tanh, V, Ty);
+          break;
+        default:
+          break;
+      }
+    } else if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) {
+      if (Name.size() > 11 && !memcmp(&Name[0], "llvm.bswap", 10)) {
+        return ConstantInt::get(Op->getValue().byteSwap());
+      } else if (Name.size() > 11 && !memcmp(&Name[0],"llvm.ctpop",10)) {
+        uint64_t ctpop = Op->getValue().countPopulation();
+        return ConstantInt::get(Type::Int32Ty, ctpop);
+      } else if (Name.size() > 10 && !memcmp(&Name[0], "llvm.cttz", 9)) {
+        uint64_t cttz = Op->getValue().countTrailingZeros();
+        return ConstantInt::get(Type::Int32Ty, cttz);
+      } else if (Name.size() > 10 && !memcmp(&Name[0], "llvm.ctlz", 9)) {
+        uint64_t ctlz = Op->getValue().countLeadingZeros();
+        return ConstantInt::get(Type::Int32Ty, ctlz);
+      }
+    }
+  } else if (NumOperands == 2) {
+    if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
+      double Op1V = Op1->getValue();
+      if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
+        double Op2V = Op2->getValue();
+
+        if (Name == "pow") {
+          return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
+        } else if (Name == "fmod") {
+          return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty);
+        } else if (Name == "atan2") {
+          return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
+        }
+      } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
+        if (Name == "llvm.powi.f32") {
+          return ConstantFP::get(Ty, std::pow((float)Op1V,
+                                              (int)Op2C->getZExtValue()));
+        } else if (Name == "llvm.powi.f64") {
+          return ConstantFP::get(Ty, std::pow((double)Op1V,
+                                              (int)Op2C->getZExtValue()));
+        }
+      }
+    }
+  }
+  return 0;
+}
+