Sink InlineCost.cpp into IPA -- it is now officially an interprocedural

analysis. How cute that it wasn't previously. ;]

Part of this confusion stems from the flattened header file tree. Thanks
to Benjamin for pointing out the goof on IRC, and we're considering
un-flattening the headers, so speak now if that would bug you.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173033 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 1238 insertions, 0 deletions

diff --git a/lib/Analysis/IPA/CMakeLists.txt b/lib/Analysis/IPA/CMakeLists.txt
index 318119b92f..67b4135779 100644
--- a/lib/Analysis/IPA/CMakeLists.txt
+++ b/lib/Analysis/IPA/CMakeLists.txt
@@ -5,6 +5,7 @@ add_llvm_library(LLVMipa
   FindUsedTypes.cpp
   GlobalsModRef.cpp
   IPA.cpp
+  InlineCost.cpp
   )
 
 add_dependencies(LLVMipa intrinsics_gen)
diff --git a/lib/Analysis/IPA/InlineCost.cpp b/lib/Analysis/IPA/InlineCost.cpp
new file mode 100644
index 0000000000..cd211c408d
--- /dev/null
+++ b/lib/Analysis/IPA/InlineCost.cpp
@@ -0,0 +1,1237 @@
+//===- InlineCost.cpp - Cost analysis for inliner -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements inline cost analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "inline-cost"
+#include "llvm/Analysis/InlineCost.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/IR/CallingConv.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/GlobalAlias.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Operator.h"
+#include "llvm/InstVisitor.h"
+#include "llvm/Support/CallSite.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+STATISTIC(NumCallsAnalyzed, "Number of call sites analyzed");
+
+namespace {
+
+class CallAnalyzer : public InstVisitor<CallAnalyzer, bool> {
+  typedef InstVisitor<CallAnalyzer, bool> Base;
+  friend class InstVisitor<CallAnalyzer, bool>;
+
+  // DataLayout if available, or null.
+  const DataLayout *const TD;
+
+  /// The TargetTransformInfo available for this compilation.
+  const TargetTransformInfo &TTI;
+
+  // The called function.
+  Function &F;
+
+  int Threshold;
+  int Cost;
+
+  bool IsCallerRecursive;
+  bool IsRecursiveCall;
+  bool ExposesReturnsTwice;
+  bool HasDynamicAlloca;
+  bool ContainsNoDuplicateCall;
+
+  /// Number of bytes allocated statically by the callee.
+  uint64_t AllocatedSize;
+  unsigned NumInstructions, NumVectorInstructions;
+  int FiftyPercentVectorBonus, TenPercentVectorBonus;
+  int VectorBonus;
+
+  // While we walk the potentially-inlined instructions, we build up and
+  // maintain a mapping of simplified values specific to this callsite. The
+  // idea is to propagate any special information we have about arguments to
+  // this call through the inlinable section of the function, and account for
+  // likely simplifications post-inlining. The most important aspect we track
+  // is CFG altering simplifications -- when we prove a basic block dead, that
+  // can cause dramatic shifts in the cost of inlining a function.
+  DenseMap<Value *, Constant *> SimplifiedValues;
+
+  // Keep track of the values which map back (through function arguments) to
+  // allocas on the caller stack which could be simplified through SROA.
+  DenseMap<Value *, Value *> SROAArgValues;
+
+  // The mapping of caller Alloca values to their accumulated cost savings. If
+  // we have to disable SROA for one of the allocas, this tells us how much
+  // cost must be added.
+  DenseMap<Value *, int> SROAArgCosts;
+
+  // Keep track of values which map to a pointer base and constant offset.
+  DenseMap<Value *, std::pair<Value *, APInt> > ConstantOffsetPtrs;
+
+  // Custom simplification helper routines.
+  bool isAllocaDerivedArg(Value *V);
+  bool lookupSROAArgAndCost(Value *V, Value *&Arg,
+                            DenseMap<Value *, int>::iterator &CostIt);
+  void disableSROA(DenseMap<Value *, int>::iterator CostIt);
+  void disableSROA(Value *V);
+  void accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
+                          int InstructionCost);
+  bool handleSROACandidate(bool IsSROAValid,
+                           DenseMap<Value *, int>::iterator CostIt,
+                           int InstructionCost);
+  bool isGEPOffsetConstant(GetElementPtrInst &GEP);
+  bool accumulateGEPOffset(GEPOperator &GEP, APInt &Offset);
+  bool simplifyCallSite(Function *F, CallSite CS);
+  ConstantInt *stripAndComputeInBoundsConstantOffsets(Value *&V);
+
+  // Custom analysis routines.
+  bool analyzeBlock(BasicBlock *BB);
+
+  // Disable several entry points to the visitor so we don't accidentally use
+  // them by declaring but not defining them here.
+  void visit(Module *);     void visit(Module &);
+  void visit(Function *);   void visit(Function &);
+  void visit(BasicBlock *); void visit(BasicBlock &);
+
+  // Provide base case for our instruction visit.
+  bool visitInstruction(Instruction &I);
+
+  // Our visit overrides.
+  bool visitAlloca(AllocaInst &I);
+  bool visitPHI(PHINode &I);
+  bool visitGetElementPtr(GetElementPtrInst &I);
+  bool visitBitCast(BitCastInst &I);
+  bool visitPtrToInt(PtrToIntInst &I);
+  bool visitIntToPtr(IntToPtrInst &I);
+  bool visitCastInst(CastInst &I);
+  bool visitUnaryInstruction(UnaryInstruction &I);
+  bool visitICmp(ICmpInst &I);
+  bool visitSub(BinaryOperator &I);
+  bool visitBinaryOperator(BinaryOperator &I);
+  bool visitLoad(LoadInst &I);
+  bool visitStore(StoreInst &I);
+  bool visitExtractValue(ExtractValueInst &I);
+  bool visitInsertValue(InsertValueInst &I);
+  bool visitCallSite(CallSite CS);
+
+public:
+  CallAnalyzer(const DataLayout *TD, const TargetTransformInfo &TTI,
+               Function &Callee, int Threshold)
+      : TD(TD), TTI(TTI), F(Callee), Threshold(Threshold), Cost(0),
+        IsCallerRecursive(false), IsRecursiveCall(false),
+        ExposesReturnsTwice(false), HasDynamicAlloca(false),
+        ContainsNoDuplicateCall(false), AllocatedSize(0), NumInstructions(0),
+        NumVectorInstructions(0), FiftyPercentVectorBonus(0),
+        TenPercentVectorBonus(0), VectorBonus(0), NumConstantArgs(0),
+        NumConstantOffsetPtrArgs(0), NumAllocaArgs(0), NumConstantPtrCmps(0),
+        NumConstantPtrDiffs(0), NumInstructionsSimplified(0),
+        SROACostSavings(0), SROACostSavingsLost(0) {}
+
+  bool analyzeCall(CallSite CS);
+
+  int getThreshold() { return Threshold; }
+  int getCost() { return Cost; }
+
+  // Keep a bunch of stats about the cost savings found so we can print them
+  // out when debugging.
+  unsigned NumConstantArgs;
+  unsigned NumConstantOffsetPtrArgs;
+  unsigned NumAllocaArgs;
+  unsigned NumConstantPtrCmps;
+  unsigned NumConstantPtrDiffs;
+  unsigned NumInstructionsSimplified;
+  unsigned SROACostSavings;
+  unsigned SROACostSavingsLost;
+
+  void dump();
+};
+
+} // namespace
+
+/// \brief Test whether the given value is an Alloca-derived function argument.
+bool CallAnalyzer::isAllocaDerivedArg(Value *V) {
+  return SROAArgValues.count(V);
+}
+
+/// \brief Lookup the SROA-candidate argument and cost iterator which V maps to.
+/// Returns false if V does not map to a SROA-candidate.
+bool CallAnalyzer::lookupSROAArgAndCost(
+    Value *V, Value *&Arg, DenseMap<Value *, int>::iterator &CostIt) {
+  if (SROAArgValues.empty() || SROAArgCosts.empty())
+    return false;
+
+  DenseMap<Value *, Value *>::iterator ArgIt = SROAArgValues.find(V);
+  if (ArgIt == SROAArgValues.end())
+    return false;
+
+  Arg = ArgIt->second;
+  CostIt = SROAArgCosts.find(Arg);
+  return CostIt != SROAArgCosts.end();
+}
+
+/// \brief Disable SROA for the candidate marked by this cost iterator.
+///
+/// This marks the candidate as no longer viable for SROA, and adds the cost
+/// savings associated with it back into the inline cost measurement.
+void CallAnalyzer::disableSROA(DenseMap<Value *, int>::iterator CostIt) {
+  // If we're no longer able to perform SROA we need to undo its cost savings
+  // and prevent subsequent analysis.
+  Cost += CostIt->second;
+  SROACostSavings -= CostIt->second;
+  SROACostSavingsLost += CostIt->second;
+  SROAArgCosts.erase(CostIt);
+}
+
+/// \brief If 'V' maps to a SROA candidate, disable SROA for it.
+void CallAnalyzer::disableSROA(Value *V) {
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(V, SROAArg, CostIt))
+    disableSROA(CostIt);
+}
+
+/// \brief Accumulate the given cost for a particular SROA candidate.
+void CallAnalyzer::accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
+                                      int InstructionCost) {
+  CostIt->second += InstructionCost;
+  SROACostSavings += InstructionCost;
+}
+
+/// \brief Helper for the common pattern of handling a SROA candidate.
+/// Either accumulates the cost savings if the SROA remains valid, or disables
+/// SROA for the candidate.
+bool CallAnalyzer::handleSROACandidate(bool IsSROAValid,
+                                       DenseMap<Value *, int>::iterator CostIt,
+                                       int InstructionCost) {
+  if (IsSROAValid) {
+    accumulateSROACost(CostIt, InstructionCost);
+    return true;
+  }
+
+  disableSROA(CostIt);
+  return false;
+}
+
+/// \brief Check whether a GEP's indices are all constant.
+///
+/// Respects any simplified values known during the analysis of this callsite.
+bool CallAnalyzer::isGEPOffsetConstant(GetElementPtrInst &GEP) {
+  for (User::op_iterator I = GEP.idx_begin(), E = GEP.idx_end(); I != E; ++I)
+    if (!isa<Constant>(*I) && !SimplifiedValues.lookup(*I))
+      return false;
+
+  return true;
+}
+
+/// \brief Accumulate a constant GEP offset into an APInt if possible.
+///
+/// Returns false if unable to compute the offset for any reason. Respects any
+/// simplified values known during the analysis of this callsite.
+bool CallAnalyzer::accumulateGEPOffset(GEPOperator &GEP, APInt &Offset) {
+  if (!TD)
+    return false;
+
+  unsigned IntPtrWidth = TD->getPointerSizeInBits();
+  assert(IntPtrWidth == Offset.getBitWidth());
+
+  for (gep_type_iterator GTI = gep_type_begin(GEP), GTE = gep_type_end(GEP);
+       GTI != GTE; ++GTI) {
+    ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
+    if (!OpC)
+      if (Constant *SimpleOp = SimplifiedValues.lookup(GTI.getOperand()))
+        OpC = dyn_cast<ConstantInt>(SimpleOp);
+    if (!OpC)
+      return false;
+    if (OpC->isZero()) continue;
+
+    // Handle a struct index, which adds its field offset to the pointer.
+    if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+      unsigned ElementIdx = OpC->getZExtValue();
+      const StructLayout *SL = TD->getStructLayout(STy);
+      Offset += APInt(IntPtrWidth, SL->getElementOffset(ElementIdx));
+      continue;
+    }
+
+    APInt TypeSize(IntPtrWidth, TD->getTypeAllocSize(GTI.getIndexedType()));
+    Offset += OpC->getValue().sextOrTrunc(IntPtrWidth) * TypeSize;
+  }
+  return true;
+}
+
+bool CallAnalyzer::visitAlloca(AllocaInst &I) {
+  // FIXME: Check whether inlining will turn a dynamic alloca into a static
+  // alloca, and handle that case.
+
+  // Accumulate the allocated size.
+  if (I.isStaticAlloca()) {
+    Type *Ty = I.getAllocatedType();
+    AllocatedSize += (TD ? TD->getTypeAllocSize(Ty) :
+                      Ty->getPrimitiveSizeInBits());
+  }
+
+  // We will happily inline static alloca instructions.
+  if (I.isStaticAlloca())
+    return Base::visitAlloca(I);
+
+  // FIXME: This is overly conservative. Dynamic allocas are inefficient for
+  // a variety of reasons, and so we would like to not inline them into
+  // functions which don't currently have a dynamic alloca. This simply
+  // disables inlining altogether in the presence of a dynamic alloca.
+  HasDynamicAlloca = true;
+  return false;
+}
+
+bool CallAnalyzer::visitPHI(PHINode &I) {
+  // FIXME: We should potentially be tracking values through phi nodes,
+  // especially when they collapse to a single value due to deleted CFG edges
+  // during inlining.
+
+  // FIXME: We need to propagate SROA *disabling* through phi nodes, even
+  // though we don't want to propagate it's bonuses. The idea is to disable
+  // SROA if it *might* be used in an inappropriate manner.
+
+  // Phi nodes are always zero-cost.
+  return true;
+}
+
+bool CallAnalyzer::visitGetElementPtr(GetElementPtrInst &I) {
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  bool SROACandidate = lookupSROAArgAndCost(I.getPointerOperand(),
+                                            SROAArg, CostIt);
+
+  // Try to fold GEPs of constant-offset call site argument pointers. This
+  // requires target data and inbounds GEPs.
+  if (TD && I.isInBounds()) {
+    // Check if we have a base + offset for the pointer.
+    Value *Ptr = I.getPointerOperand();
+    std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Ptr);
+    if (BaseAndOffset.first) {
+      // Check if the offset of this GEP is constant, and if so accumulate it
+      // into Offset.
+      if (!accumulateGEPOffset(cast<GEPOperator>(I), BaseAndOffset.second)) {
+        // Non-constant GEPs aren't folded, and disable SROA.
+        if (SROACandidate)
+          disableSROA(CostIt);
+        return false;
+      }
+
+      // Add the result as a new mapping to Base + Offset.
+      ConstantOffsetPtrs[&I] = BaseAndOffset;
+
+      // Also handle SROA candidates here, we already know that the GEP is
+      // all-constant indexed.
+      if (SROACandidate)
+        SROAArgValues[&I] = SROAArg;
+
+      return true;
+    }
+  }
+
+  if (isGEPOffsetConstant(I)) {
+    if (SROACandidate)
+      SROAArgValues[&I] = SROAArg;
+
+    // Constant GEPs are modeled as free.
+    return true;
+  }
+
+  // Variable GEPs will require math and will disable SROA.
+  if (SROACandidate)
+    disableSROA(CostIt);
+  return false;
+}
+
+bool CallAnalyzer::visitBitCast(BitCastInst &I) {
+  // Propagate constants through bitcasts.
+  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+  if (!COp)
+    COp = SimplifiedValues.lookup(I.getOperand(0));
+  if (COp)
+    if (Constant *C = ConstantExpr::getBitCast(COp, I.getType())) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Track base/offsets through casts
+  std::pair<Value *, APInt> BaseAndOffset
+    = ConstantOffsetPtrs.lookup(I.getOperand(0));
+  // Casts don't change the offset, just wrap it up.
+  if (BaseAndOffset.first)
+    ConstantOffsetPtrs[&I] = BaseAndOffset;
+
+  // Also look for SROA candidates here.
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
+    SROAArgValues[&I] = SROAArg;
+
+  // Bitcasts are always zero cost.
+  return true;
+}
+
+bool CallAnalyzer::visitPtrToInt(PtrToIntInst &I) {
+  // Propagate constants through ptrtoint.
+  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+  if (!COp)
+    COp = SimplifiedValues.lookup(I.getOperand(0));
+  if (COp)
+    if (Constant *C = ConstantExpr::getPtrToInt(COp, I.getType())) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Track base/offset pairs when converted to a plain integer provided the
+  // integer is large enough to represent the pointer.
+  unsigned IntegerSize = I.getType()->getScalarSizeInBits();
+  if (TD && IntegerSize >= TD->getPointerSizeInBits()) {
+    std::pair<Value *, APInt> BaseAndOffset
+      = ConstantOffsetPtrs.lookup(I.getOperand(0));
+    if (BaseAndOffset.first)
+      ConstantOffsetPtrs[&I] = BaseAndOffset;
+  }
+
+  // This is really weird. Technically, ptrtoint will disable SROA. However,
+  // unless that ptrtoint is *used* somewhere in the live basic blocks after
+  // inlining, it will be nuked, and SROA should proceed. All of the uses which
+  // would block SROA would also block SROA if applied directly to a pointer,
+  // and so we can just add the integer in here. The only places where SROA is
+  // preserved either cannot fire on an integer, or won't in-and-of themselves
+  // disable SROA (ext) w/o some later use that we would see and disable.
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
+    SROAArgValues[&I] = SROAArg;
+
+  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitIntToPtr(IntToPtrInst &I) {
+  // Propagate constants through ptrtoint.
+  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+  if (!COp)
+    COp = SimplifiedValues.lookup(I.getOperand(0));
+  if (COp)
+    if (Constant *C = ConstantExpr::getIntToPtr(COp, I.getType())) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Track base/offset pairs when round-tripped through a pointer without
+  // modifications provided the integer is not too large.
+  Value *Op = I.getOperand(0);
+  unsigned IntegerSize = Op->getType()->getScalarSizeInBits();
+  if (TD && IntegerSize <= TD->getPointerSizeInBits()) {
+    std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Op);
+    if (BaseAndOffset.first)
+      ConstantOffsetPtrs[&I] = BaseAndOffset;
+  }
+
+  // "Propagate" SROA here in the same manner as we do for ptrtoint above.
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(Op, SROAArg, CostIt))
+    SROAArgValues[&I] = SROAArg;
+
+  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitCastInst(CastInst &I) {
+  // Propagate constants through ptrtoint.
+  Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+  if (!COp)
+    COp = SimplifiedValues.lookup(I.getOperand(0));
+  if (COp)
+    if (Constant *C = ConstantExpr::getCast(I.getOpcode(), COp, I.getType())) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Disable SROA in the face of arbitrary casts we don't whitelist elsewhere.
+  disableSROA(I.getOperand(0));
+
+  return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitUnaryInstruction(UnaryInstruction &I) {
+  Value *Operand = I.getOperand(0);
+  Constant *Ops[1] = { dyn_cast<Constant>(Operand) };
+  if (Ops[0] || (Ops[0] = SimplifiedValues.lookup(Operand)))
+    if (Constant *C = ConstantFoldInstOperands(I.getOpcode(), I.getType(),
+                                               Ops, TD)) {
+      SimplifiedValues[&I] = C;
+      return true;
+    }
+
+  // Disable any SROA on the argument to arbitrary unary operators.
+  disableSROA(Operand);
+
+  return false;
+}
+
+bool CallAnalyzer::visitICmp(ICmpInst &I) {
+  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+  // First try to handle simplified comparisons.
+  if (!isa<Constant>(LHS))
+    if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
+      LHS = SimpleLHS;
+  if (!isa<Constant>(RHS))
+    if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
+      RHS = SimpleRHS;
+  if (Constant *CLHS = dyn_cast<Constant>(LHS))
+    if (Constant *CRHS = dyn_cast<Constant>(RHS))
+      if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) {
+        SimplifiedValues[&I] = C;
+        return true;
+      }
+
+  // Otherwise look for a comparison between constant offset pointers with
+  // a common base.
+  Value *LHSBase, *RHSBase;
+  APInt LHSOffset, RHSOffset;
+  llvm::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
+  if (LHSBase) {
+    llvm::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
+    if (RHSBase && LHSBase == RHSBase) {
+      // We have common bases, fold the icmp to a constant based on the
+      // offsets.
+      Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
+      Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
+      if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) {
+        SimplifiedValues[&I] = C;
+        ++NumConstantPtrCmps;
+        return true;
+      }
+    }
+  }
+
+  // If the comparison is an equality comparison with null, we can simplify it
+  // for any alloca-derived argument.
+  if (I.isEquality() && isa<ConstantPointerNull>(I.getOperand(1)))
+    if (isAllocaDerivedArg(I.getOperand(0))) {
+      // We can actually predict the result of comparisons between an
+      // alloca-derived value and null. Note that this fires regardless of
+      // SROA firing.
+      bool IsNotEqual = I.getPredicate() == CmpInst::ICMP_NE;
+      SimplifiedValues[&I] = IsNotEqual ? ConstantInt::getTrue(I.getType())
+                                        : ConstantInt::getFalse(I.getType());
+      return true;
+    }
+
+  // Finally check for SROA candidates in comparisons.
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) {
+    if (isa<ConstantPointerNull>(I.getOperand(1))) {
+      accumulateSROACost(CostIt, InlineConstants::InstrCost);
+      return true;
+    }
+
+    disableSROA(CostIt);
+  }
+
+  return false;
+}
+
+bool CallAnalyzer::visitSub(BinaryOperator &I) {
+  // Try to handle a special case: we can fold computing the difference of two
+  // constant-related pointers.
+  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+  Value *LHSBase, *RHSBase;
+  APInt LHSOffset, RHSOffset;
+  llvm::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
+  if (LHSBase) {
+    llvm::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
+    if (RHSBase && LHSBase == RHSBase) {
+      // We have common bases, fold the subtract to a constant based on the
+      // offsets.
+      Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
+      Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
+      if (Constant *C = ConstantExpr::getSub(CLHS, CRHS)) {
+        SimplifiedValues[&I] = C;
+        ++NumConstantPtrDiffs;
+        return true;
+      }
+    }
+  }
+
+  // Otherwise, fall back to the generic logic for simplifying and handling
+  // instructions.
+  return Base::visitSub(I);
+}
+
+bool CallAnalyzer::visitBinaryOperator(BinaryOperator &I) {
+  Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+  if (!isa<Constant>(LHS))
+    if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
+      LHS = SimpleLHS;
+  if (!isa<Constant>(RHS))
+    if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
+      RHS = SimpleRHS;
+  Value *SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, TD);
+  if (Constant *C = dyn_cast_or_null<Constant>(SimpleV)) {
+    SimplifiedValues[&I] = C;
+    return true;
+  }
+
+  // Disable any SROA on arguments to arbitrary, unsimplified binary operators.
+  disableSROA(LHS);
+  disableSROA(RHS);
+
+  return false;
+}
+
+bool CallAnalyzer::visitLoad(LoadInst &I) {
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) {
+    if (I.isSimple()) {
+      accumulateSROACost(CostIt, InlineConstants::InstrCost);
+      return true;
+    }
+
+    disableSROA(CostIt);
+  }
+
+  return false;
+}
+
+bool CallAnalyzer::visitStore(StoreInst &I) {
+  Value *SROAArg;
+  DenseMap<Value *, int>::iterator CostIt;
+  if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) {
+    if (I.isSimple()) {
+      accumulateSROACost(CostIt, InlineConstants::InstrCost);
+      return true;
+    }
+
+    disableSROA(CostIt);
+  }
+
+  return false;
+}
+
+bool CallAnalyzer::visitExtractValue(ExtractValueInst &I) {
+  // Constant folding for extract value is trivial.
+  Constant *C = dyn_cast<Constant>(I.getAggregateOperand());
+  if (!C)
+    C = SimplifiedValues.lookup(I.getAggregateOperand());
+  if (C) {
+    SimplifiedValues[&I] = ConstantExpr::getExtractValue(C, I.getIndices());
+    return true;
+  }
+
+  // SROA can look through these but give them a cost.
+  return false;
+}
+
+bool CallAnalyzer::visitInsertValue(InsertValueInst &I) {
+  // Constant folding for insert value is trivial.
+  Constant *AggC = dyn_cast<Constant>(I.getAggregateOperand());
+  if (!AggC)
+    AggC = SimplifiedValues.lookup(I.getAggregateOperand());
+  Constant *InsertedC = dyn_cast<Constant>(I.getInsertedValueOperand());
+  if (!InsertedC)
+    InsertedC = SimplifiedValues.lookup(I.getInsertedValueOperand());
+  if (AggC && InsertedC) {
+    SimplifiedValues[&I] = ConstantExpr::getInsertValue(AggC, InsertedC,
+                                                        I.getIndices());
+    return true;
+  }
+
+  // SROA can look through these but give them a cost.
+  return false;
+}
+
+/// \brief Try to simplify a call site.
+///
+/// Takes a concrete function and callsite and tries to actually simplify it by
+/// analyzing the arguments and call itself with instsimplify. Returns true if
+/// it has simplified the callsite to some other entity (a constant), making it
+/// free.
+bool CallAnalyzer::simplifyCallSite(Function *F, CallSite CS) {
+  // FIXME: Using the instsimplify logic directly for this is inefficient
+  // because we have to continually rebuild the argument list even when no
+  // simplifications can be performed. Until that is fixed with remapping
+  // inside of instsimplify, directly constant fold calls here.
+  if (!canConstantFoldCallTo(F))
+    return false;
+
+  // Try to re-map the arguments to constants.
+  SmallVector<Constant *, 4> ConstantArgs;
+  ConstantArgs.reserve(CS.arg_size());
+  for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
+       I != E; ++I) {
+    Constant *C = dyn_cast<Constant>(*I);
+    if (!C)
+      C = dyn_cast_or_null<Constant>(SimplifiedValues.lookup(*I));
+    if (!C)
+      return false; // This argument doesn't map to a constant.
+
+    ConstantArgs.push_back(C);
+  }
+  if (Constant *C = ConstantFoldCall(F, ConstantArgs)) {
+    SimplifiedValues[CS.getInstruction()] = C;
+    return true;
+  }
+
+  return false;
+}
+
+bool CallAnalyzer::visitCallSite(CallSite CS) {
+  if (CS.isCall() && cast<CallInst>(CS.getInstruction())->canReturnTwice() &&
+      !F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                      Attribute::ReturnsTwice)) {
+    // This aborts the entire analysis.
+    ExposesReturnsTwice = true;
+    return false;
+  }
+  if (CS.isCall() &&
+      cast<CallInst>(CS.getInstruction())->hasFnAttr(Attribute::NoDuplicate))
+    ContainsNoDuplicateCall = true;
+
+  if (Function *F = CS.getCalledFunction()) {
+    // When we have a concrete function, first try to simplify it directly.
+    if (simplifyCallSite(F, CS))
+      return true;
+
+    // Next check if it is an intrinsic we know about.
+    // FIXME: Lift this into part of the InstVisitor.
+    if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
+      switch (II->getIntrinsicID()) {
+      default:
+        return Base::visitCallSite(CS);
+
+      case Intrinsic::memset:
+      case Intrinsic::memcpy:
+      case Intrinsic::memmove:
+        // SROA can usually chew through these intrinsics, but they aren't free.
+        return false;
+      }
+    }
+
+    if (F == CS.getInstruction()->getParent()->getParent()) {
+      // This flag will fully abort the analysis, so don't bother with anything
+      // else.
+      IsRecursiveCall = true;
+      return false;
+    }
+
+    if (!callIsSmall(CS)) {
+      // We account for the average 1 instruction per call argument setup
+      // here.
+      Cost += CS.arg_size() * InlineConstants::InstrCost;
+
+      // Everything other than inline ASM will also have a significant cost
+      // merely from making the call.
+      if (!isa<InlineAsm>(CS.getCalledValue()))
+        Cost += InlineConstants::CallPenalty;
+    }
+
+    return Base::visitCallSite(CS);
+  }
+
+  // Otherwise we're in a very special case -- an indirect function call. See
+  // if we can be particularly clever about this.
+  Value *Callee = CS.getCalledValue();
+
+  // First, pay the price of the argument setup. We account for the average
+  // 1 instruction per call argument setup here.
+  Cost += CS.arg_size() * InlineConstants::InstrCost;
+
+  // Next, check if this happens to be an indirect function call to a known
+  // function in this inline context. If not, we've done all we can.
+  Function *F = dyn_cast_or_null<Function>(SimplifiedValues.lookup(Callee));
+  if (!F)
+    return Base::visitCallSite(CS);
+
+  // If we have a constant that we are calling as a function, we can peer
+  // through it and see the function target. This happens not infrequently
+  // during devirtualization and so we want to give it a hefty bonus for
+  // inlining, but cap that bonus in the event that inlining wouldn't pan
+  // out. Pretend to inline the function, with a custom threshold.
+  CallAnalyzer CA(TD, TTI, *F, InlineConstants::IndirectCallThreshold);
+  if (CA.analyzeCall(CS)) {
+    // We were able to inline the indirect call! Subtract the cost from the
+    // bonus we want to apply, but don't go below zero.
+    Cost -= std::max(0, InlineConstants::IndirectCallThreshold - CA.getCost());
+  }
+
+  return Base::visitCallSite(CS);
+}
+
+bool CallAnalyzer::visitInstruction(Instruction &I) {
+  // Some instructions are free. All of the free intrinsics can also be
+  // handled by SROA, etc.
+  if (TargetTransformInfo::TCC_Free == TTI.getUserCost(&I))
+    return true;
+
+  // We found something we don't understand or can't handle. Mark any SROA-able
+  // values in the operand list as no longer viable.
+  for (User::op_iterator OI = I.op_begin(), OE = I.op_end(); OI != OE; ++OI)
+    disableSROA(*OI);
+
+  return false;
+}
+
+
+/// \brief Analyze a basic block for its contribution to the inline cost.
+///
+/// This method walks the analyzer over every instruction in the given basic
+/// block and accounts for their cost during inlining at this callsite. It
+/// aborts early if the threshold has been exceeded or an impossible to inline
+/// construct has been detected. It returns false if inlining is no longer
+/// viable, and true if inlining remains viable.
+bool CallAnalyzer::analyzeBlock(BasicBlock *BB) {
+  for (BasicBlock::iterator I = BB->begin(), E = llvm::prior(BB->end());
+       I != E; ++I) {
+    ++NumInstructions;
+    if (isa<ExtractElementInst>(I) || I->getType()->isVectorTy())
+      ++NumVectorInstructions;
+
+    // If the instruction simplified to a constant, there is no cost to this
+    // instruction. Visit the instructions using our InstVisitor to account for
+    // all of the per-instruction logic. The visit tree returns true if we
+    // consumed the instruction in any way, and false if the instruction's base
+    // cost should count against inlining.
+    if (Base::visit(I))
+      ++NumInstructionsSimplified;
+    else
+      Cost += InlineConstants::InstrCost;
+
+    // If the visit this instruction detected an uninlinable pattern, abort.
+    if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca)
+      return false;
+
+    // If the caller is a recursive function then we don't want to inline
+    // functions which allocate a lot of stack space because it would increase
+    // the caller stack usage dramatically.
+    if (IsCallerRecursive &&
+        AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
+      return false;
+
+    if (NumVectorInstructions > NumInstructions/2)
+      VectorBonus = FiftyPercentVectorBonus;
+    else if (NumVectorInstructions > NumInstructions/10)
+      VectorBonus = TenPercentVectorBonus;
+    else
+      VectorBonus = 0;
+
+    // Check if we've past the threshold so we don't spin in huge basic
+    // blocks that will never inline.
+    if (Cost > (Threshold + VectorBonus))
+      return false;
+  }
+
+  return true;
+}
+
+/// \brief Compute the base pointer and cumulative constant offsets for V.
+///
+/// This strips all constant offsets off of V, leaving it the base pointer, and
+/// accumulates the total constant offset applied in the returned constant. It
+/// returns 0 if V is not a pointer, and returns the constant '0' if there are
+/// no constant offsets applied.
+ConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) {
+  if (!TD || !V->getType()->isPointerTy())
+    return 0;
+
+  unsigned IntPtrWidth = TD->getPointerSizeInBits();
+  APInt Offset = APInt::getNullValue(IntPtrWidth);
+
+  // Even though we don't look through PHI nodes, we could be called on an
+  // instruction in an unreachable block, which may be on a cycle.
+  SmallPtrSet<Value *, 4> Visited;
+  Visited.insert(V);
+  do {
+    if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
+      if (!GEP->isInBounds() || !accumulateGEPOffset(*GEP, Offset))
+        return 0;
+      V = GEP->getPointerOperand();
+    } else if (Operator::getOpcode(V) == Instruction::BitCast) {
+      V = cast<Operator>(V)->getOperand(0);
+    } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
+      if (GA->mayBeOverridden())
+        break;
+      V = GA->getAliasee();
+    } else {
+      break;
+    }
+    assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+  } while (Visited.insert(V));
+
+  Type *IntPtrTy = TD->getIntPtrType(V->getContext());
+  return cast<ConstantInt>(ConstantInt::get(IntPtrTy, Offset));
+}
+
+/// \brief Analyze a call site for potential inlining.
+///
+/// Returns true if inlining this call is viable, and false if it is not
+/// viable. It computes the cost and adjusts the threshold based on numerous
+/// factors and heuristics. If this method returns false but the computed cost
+/// is below the computed threshold, then inlining was forcibly disabled by
+/// some artifact of the routine.
+bool CallAnalyzer::analyzeCall(CallSite CS) {
+  ++NumCallsAnalyzed;
+
+  // Track whether the post-inlining function would have more than one basic
+  // block. A single basic block is often intended for inlining. Balloon the
+  // threshold by 50% until we pass the single-BB phase.
+  bool SingleBB = true;
+  int SingleBBBonus = Threshold / 2;
+  Threshold += SingleBBBonus;
+
+  // Perform some tweaks to the cost and threshold based on the direct
+  // callsite information.
+
+  // We want to more aggressively inline vector-dense kernels, so up the
+  // threshold, and we'll lower it if the % of vector instructions gets too
+  // low.
+  assert(NumInstructions == 0);
+  assert(NumVectorInstructions == 0);
+  FiftyPercentVectorBonus = Threshold;
+  TenPercentVectorBonus = Threshold / 2;
+
+  // Give out bonuses per argument, as the instructions setting them up will
+  // be gone after inlining.
+  for (unsigned I = 0, E = CS.arg_size(); I != E; ++I) {
+    if (TD && CS.isByValArgument(I)) {
+      // We approximate the number of loads and stores needed by dividing the
+      // size of the byval type by the target's pointer size.
+      PointerType *PTy = cast<PointerType>(CS.getArgument(I)->getType());
+      unsigned TypeSize = TD->getTypeSizeInBits(PTy->getElementType());
+      unsigned PointerSize = TD->getPointerSizeInBits();
+      // Ceiling division.
+      unsigned NumStores = (TypeSize + PointerSize - 1) / PointerSize;
+
+      // If it generates more than 8 stores it is likely to be expanded as an
+      // inline memcpy so we take that as an upper bound. Otherwise we assume
+      // one load and one store per word copied.
+      // FIXME: The maxStoresPerMemcpy setting from the target should be used
+      // here instead of a magic number of 8, but it's not available via
+      // DataLayout.
+      NumStores = std::min(NumStores, 8U);
+
+      Cost -= 2 * NumStores * InlineConstants::InstrCost;
+    } else {
+      // For non-byval arguments subtract off one instruction per call
+      // argument.
+      Cost -= InlineConstants::InstrCost;
+    }
+  }
+
+  // If there is only one call of the function, and it has internal linkage,
+  // the cost of inlining it drops dramatically.
+  bool OnlyOneCallAndLocalLinkage = F.hasLocalLinkage() && F.hasOneUse() &&
+    &F == CS.getCalledFunction();
+  if (OnlyOneCallAndLocalLinkage)
+    Cost += InlineConstants::LastCallToStaticBonus;
+
+  // If the instruction after the call, or if the normal destination of the
+  // invoke is an unreachable instruction, the function is noreturn. As such,
+  // there is little point in inlining this unless there is literally zero
+  // cost.
+  Instruction *Instr = CS.getInstruction();
+  if (InvokeInst *II = dyn_cast<InvokeInst>(Instr)) {
+    if (isa<UnreachableInst>(II->getNormalDest()->begin()))
+      Threshold = 1;
+  } else if (isa<UnreachableInst>(++BasicBlock::iterator(Instr)))
+    Threshold = 1;
+
+  // If this function uses the coldcc calling convention, prefer not to inline
+  // it.
+  if (F.getCallingConv() == CallingConv::Cold)
+    Cost += InlineConstants::ColdccPenalty;
+
+  // Check if we're done. This can happen due to bonuses and penalties.
+  if (Cost > Threshold)
+    return false;
+
+  if (F.empty())
+    return true;
+
+  Function *Caller = CS.getInstruction()->getParent()->getParent();
+  // Check if the caller function is recursive itself.
+  for (Value::use_iterator U = Caller->use_begin(), E = Caller->use_end();
+       U != E; ++U) {
+    CallSite Site(cast<Value>(*U));
+    if (!Site)
+      continue;
+    Instruction *I = Site.getInstruction();
+    if (I->getParent()->getParent() == Caller) {
+      IsCallerRecursive = true;
+      break;
+    }
+  }
+
+  // Track whether we've seen a return instruction. The first return
+  // instruction is free, as at least one will usually disappear in inlining.
+  bool HasReturn = false;
+
+  // Populate our simplified values by mapping from function arguments to call
+  // arguments with known important simplifications.
+  CallSite::arg_iterator CAI = CS.arg_begin();
+  for (Function::arg_iterator FAI = F.arg_begin(), FAE = F.arg_end();
+       FAI != FAE; ++FAI, ++CAI) {
+    assert(CAI != CS.arg_end());
+    if (Constant *C = dyn_cast<Constant>(CAI))
+      SimplifiedValues[FAI] = C;
+
+    Value *PtrArg = *CAI;
+    if (ConstantInt *C = stripAndComputeInBoundsConstantOffsets(PtrArg)) {
+      ConstantOffsetPtrs[FAI] = std::make_pair(PtrArg, C->getValue());
+
+      // We can SROA any pointer arguments derived from alloca instructions.
+      if (isa<AllocaInst>(PtrArg)) {
+        SROAArgValues[FAI] = PtrArg;
+        SROAArgCosts[PtrArg] = 0;
+      }
+    }
+  }
+  NumConstantArgs = SimplifiedValues.size();
+  NumConstantOffsetPtrArgs = ConstantOffsetPtrs.size();
+  NumAllocaArgs = SROAArgValues.size();
+
+  // The worklist of live basic blocks in the callee *after* inlining. We avoid
+  // adding basic blocks of the callee which can be proven to be dead for this
+  // particular call site in order to get more accurate cost estimates. This
+  // requires a somewhat heavyweight iteration pattern: we need to walk the
+  // basic blocks in a breadth-first order as we insert live successors. To
+  // accomplish this, prioritizing for small iterations because we exit after
+  // crossing our threshold, we use a small-size optimized SetVector.
+  typedef SetVector<BasicBlock *, SmallVector<BasicBlock *, 16>,
+                                  SmallPtrSet<BasicBlock *, 16> > BBSetVector;
+  BBSetVector BBWorklist;
+  BBWorklist.insert(&F.getEntryBlock());
+  // Note that we *must not* cache the size, this loop grows the worklist.
+  for (unsigned Idx = 0; Idx != BBWorklist.size(); ++Idx) {
+    // Bail out the moment we cross the threshold. This means we'll under-count
+    // the cost, but only when undercounting doesn't matter.
+    if (Cost > (Threshold + VectorBonus))
+      break;
+
+    BasicBlock *BB = BBWorklist[Idx];
+    if (BB->empty())
+      continue;
+
+    // Handle the terminator cost here where we can track returns and other
+    // function-wide constructs.
+    TerminatorInst *TI = BB->getTerminator();
+
+    // We never want to inline functions that contain an indirectbr.  This is
+    // incorrect because all the blockaddress's (in static global initializers
+    // for example) would be referring to the original function, and this
+    // indirect jump would jump from the inlined copy of the function into the 
+    // original function which is extremely undefined behavior.
+    // FIXME: This logic isn't really right; we can safely inline functions
+    // with indirectbr's as long as no other function or global references the
+    // blockaddress of a block within the current function.  And as a QOI issue,
+    // if someone is using a blockaddress without an indirectbr, and that
+    // reference somehow ends up in another function or global, we probably
+    // don't want to inline this function.
+    if (isa<IndirectBrInst>(TI))
+      return false;
+
+    if (!HasReturn && isa<ReturnInst>(TI))
+      HasReturn = true;
+    else
+      Cost += InlineConstants::InstrCost;
+
+    // Analyze the cost of this block. If we blow through the threshold, this
+    // returns false, and we can bail on out.
+    if (!analyzeBlock(BB)) {
+      if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca)
+        return false;
+
+      // If the caller is a recursive function then we don't want to inline
+      // functions which allocate a lot of stack space because it would increase
+      // the caller stack usage dramatically.
+      if (IsCallerRecursive &&
+          AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
+        return false;
+
+      break;
+    }
+
+    // Add in the live successors by first checking whether we have terminator
+    // that may be simplified based on the values simplified by this call.
+    if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
+      if (BI->isConditional()) {
+        Value *Cond = BI->getCondition();
+        if (ConstantInt *SimpleCond
+              = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
+          BBWorklist.insert(BI->getSuccessor(SimpleCond->isZero() ? 1 : 0));
+          continue;
+        }
+      }
+    } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
+      Value *Cond = SI->getCondition();
+      if (ConstantInt *SimpleCond
+            = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
+        BBWorklist.insert(SI->findCaseValue(SimpleCond).getCaseSuccessor());
+        continue;
+      }
+    }
+
+    // If we're unable to select a particular successor, just count all of
+    // them.
+    for (unsigned TIdx = 0, TSize = TI->getNumSuccessors(); TIdx != TSize;
+         ++TIdx)
+      BBWorklist.insert(TI->getSuccessor(TIdx));
+
+    // If we had any successors at this point, than post-inlining is likely to
+    // have them as well. Note that we assume any basic blocks which existed
+    // due to branches or switches which folded above will also fold after
+    // inlining.
+    if (SingleBB && TI->getNumSuccessors() > 1) {
+      // Take off the bonus we applied to the threshold.
+      Threshold -= SingleBBBonus;
+      SingleBB = false;
+    }
+  }
+
+  // If this is a noduplicate call, we can still inline as long as 
+  // inlining this would cause the removal of the caller (so the instruction
+  // is not actually duplicated, just moved).
+  if (!OnlyOneCallAndLocalLinkage && ContainsNoDuplicateCall)
+    return false;
+
+  Threshold += VectorBonus;
+
+  return Cost < Threshold;
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+/// \brief Dump stats about this call's analysis.
+void CallAnalyzer::dump() {
+#define DEBUG_PRINT_STAT(x) llvm::dbgs() << "      " #x ": " << x << "\n"
+  DEBUG_PRINT_STAT(NumConstantArgs);
+  DEBUG_PRINT_STAT(NumConstantOffsetPtrArgs);
+  DEBUG_PRINT_STAT(NumAllocaArgs);
+  DEBUG_PRINT_STAT(NumConstantPtrCmps);
+  DEBUG_PRINT_STAT(NumConstantPtrDiffs);
+  DEBUG_PRINT_STAT(NumInstructionsSimplified);
+  DEBUG_PRINT_STAT(SROACostSavings);
+  DEBUG_PRINT_STAT(SROACostSavingsLost);
+  DEBUG_PRINT_STAT(ContainsNoDuplicateCall);
+#undef DEBUG_PRINT_STAT
+}
+#endif
+
+INITIALIZE_PASS_BEGIN(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
+                      true, true)
+INITIALIZE_AG_DEPENDENCY(TargetTransformInfo)
+INITIALIZE_PASS_END(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
+                    true, true)
+
+char InlineCostAnalysis::ID = 0;
+
+InlineCostAnalysis::InlineCostAnalysis() : CallGraphSCCPass(ID), TD(0) {}
+
+InlineCostAnalysis::~InlineCostAnalysis() {}
+
+void InlineCostAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  AU.addRequired<TargetTransformInfo>();
+  CallGraphSCCPass::getAnalysisUsage(AU);
+}
+
+bool InlineCostAnalysis::runOnSCC(CallGraphSCC &SCC) {
+  TD = getAnalysisIfAvailable<DataLayout>();
+  TTI = &getAnalysis<TargetTransformInfo>();
+  return false;
+}
+
+InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, int Threshold) {
+  return getInlineCost(CS, CS.getCalledFunction(), Threshold);
+}
+
+InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee,
+                                             int Threshold) {
+  // Cannot inline indirect calls.
+  if (!Callee)
+    return llvm::InlineCost::getNever();
+
+  // Calls to functions with always-inline attributes should be inlined
+  // whenever possible.
+  if (Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                           Attribute::AlwaysInline)) {
+    if (isInlineViable(*Callee))
+      return llvm::InlineCost::getAlways();
+    return llvm::InlineCost::getNever();
+  }
+
+  // Don't inline functions which can be redefined at link-time to mean
+  // something else.  Don't inline functions marked noinline or call sites
+  // marked noinline.
+  if (Callee->mayBeOverridden() ||
+      Callee->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                           Attribute::NoInline) ||
+      CS.isNoInline())
+    return llvm::InlineCost::getNever();
+
+  DEBUG(llvm::dbgs() << "      Analyzing call of " << Callee->getName()
+        << "...\n");
+
+  CallAnalyzer CA(TD, *TTI, *Callee, Threshold);
+  bool ShouldInline = CA.analyzeCall(CS);
+
+  DEBUG(CA.dump());
+
+  // Check if there was a reason to force inlining or no inlining.
+  if (!ShouldInline && CA.getCost() < CA.getThreshold())
+    return InlineCost::getNever();
+  if (ShouldInline && CA.getCost() >= CA.getThreshold())
+    return InlineCost::getAlways();
+
+  return llvm::InlineCost::get(CA.getCost(), CA.getThreshold());
+}
+
+bool InlineCostAnalysis::isInlineViable(Function &F) {
+  bool ReturnsTwice =
+    F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
+                                   Attribute::ReturnsTwice);
+  for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
+    // Disallow inlining of functions which contain an indirect branch.
+    if (isa<IndirectBrInst>(BI->getTerminator()))
+      return false;
+
+    for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
+         ++II) {
+      CallSite CS(II);
+      if (!CS)
+        continue;
+
+      // Disallow recursive calls.
+      if (&F == CS.getCalledFunction())
+        return false;
+
+      // Disallow calls which expose returns-twice to a function not previously
+      // attributed as such.
+      if (!ReturnsTwice && CS.isCall() &&
+          cast<CallInst>(CS.getInstruction())->canReturnTwice())
+        return false;
+    }
+  }
+
+  return true;
+}