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diff --git a/lib/Target/JSBackend/AllocaManager.h b/lib/Target/JSBackend/AllocaManager.h
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+//===-- AllocaManager.h ---------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass declares the AllocaManager class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef JSBACKEND_ALLOCAMANAGER_H
+#define JSBACKEND_ALLOCAMANAGER_H
+
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/SetVector.h"
+
+namespace llvm {
+
+class AllocaInst;
+class BasicBlock;
+class CallInst;
+class DataLayout;
+class Function;
+
+/// Compute frame layout for allocas.
+class AllocaManager {
+  const DataLayout *DL;
+  const Function *LifetimeStart;
+  const Function *LifetimeEnd;
+  const Function *F;
+
+  // Per-block lifetime information.
+  struct BlockLifetimeInfo {
+    BitVector Start;
+    BitVector End;
+    BitVector LiveIn;
+    BitVector LiveOut;
+  };
+  typedef DenseMap<const BasicBlock *, BlockLifetimeInfo> LivenessMap;
+  LivenessMap BlockLiveness;
+
+  // Worklist for inter-block liveness analysis.
+  typedef SmallSetVector<const BasicBlock *, 8> InterBlockWorklistVec;
+  InterBlockWorklistVec InterBlockWorklist;
+
+  // Map allocas to their index in AllocasByIndex.
+  typedef DenseMap<const AllocaInst *, size_t> AllocaMap;
+  AllocaMap Allocas;
+
+  // Information about an alloca. Note that the size and alignment may vary
+  // from what's in the actual AllocaInst when an alloca is also representing
+  // another with perhaps greater size and/or alignment needs.
+  //
+  // When an alloca is represented by another, its AllocaInfo is marked as
+  // "forwarded", at which point it no longer holds a size and alignment, but
+  // the index of the representative AllocaInfo.
+  class AllocaInfo {
+    const AllocaInst *Inst;
+    uint64_t Size;
+    unsigned Alignment;
+
+  public:
+    AllocaInfo(const AllocaInst *I, uint64_t S, unsigned A)
+      : Inst(I), Size(S), Alignment(A) {
+      assert(I != NULL);
+      assert(A != 0);
+      assert(!isForwarded());
+    }
+
+    bool isForwarded() const { return Alignment == 0; }
+
+    size_t getForwardedID() const {
+      assert(isForwarded());
+      return static_cast<size_t>(Size);
+    }
+
+    void forward(size_t i) {
+      assert(!isForwarded());
+      Alignment = 0;
+      Size = i;
+      assert(isForwarded());
+      assert(getForwardedID() == i);
+    }
+
+    const AllocaInst *getInst() const { return Inst; }
+
+    uint64_t getSize() const { assert(!isForwarded()); return Size; }
+    unsigned getAlignment() const { assert(!isForwarded()); return Alignment; }
+
+    void mergeSize(uint64_t S) {
+      assert(!isForwarded());
+      Size = std::max(Size, S);
+      assert(!isForwarded());
+    }
+    void mergeAlignment(unsigned A) {
+      assert(A != 0);
+      assert(!isForwarded());
+      Alignment = std::max(Alignment, A);
+      assert(!isForwarded());
+    }
+  };
+  typedef SmallVector<AllocaInfo, 32> AllocaVec;
+  AllocaVec AllocasByIndex;
+
+  // For each alloca, which allocas can it safely represent? Allocas are
+  // identified by AllocasByIndex index.
+  // TODO: Vector-of-vectors isn't the fastest data structure possible here.
+  typedef SmallVector<BitVector, 32> AllocaCompatibilityVec;
+  AllocaCompatibilityVec AllocaCompatibility;
+
+  // This is for allocas that will eventually be sorted.
+  SmallVector<AllocaInfo, 32> SortedAllocas;
+
+  // Static allocation results.
+  struct StaticAllocation {
+    const AllocaInst *Representative;
+    uint64_t Offset;
+    StaticAllocation() {}
+    StaticAllocation(const AllocaInst *A, uint64_t O)
+      : Representative(A), Offset(O) {}
+  };
+  typedef DenseMap<const AllocaInst *, StaticAllocation> StaticAllocaMap;
+  StaticAllocaMap StaticAllocas;
+  uint64_t FrameSize;
+
+  uint64_t getSize(const AllocaInst *AI);
+  unsigned getAlignment(const AllocaInst *AI);
+  AllocaInfo getInfo(const AllocaInst *AI);
+  const AllocaInst *getAllocaFromIntrinsic(const CallInst *CI);
+  static int AllocaSort(const void *l, const void *r);
+
+  void collectMarkedAllocas();
+  void collectBlocks();
+  void computeInterBlockLiveness();
+  void computeIntraBlockLiveness();
+  void computeRepresentatives();
+  void computeFrameOffsets();
+
+public:
+  AllocaManager();
+
+  /// Analyze the given function and prepare for getReplacement queries.
+  void analyze(const Function &Func, const DataLayout &Layout);
+
+  /// Reset all stored state.
+  void clear();
+
+  /// Return the representative alloca for the given alloca. When allocas are
+  /// merged, one is chosen as the representative to stand for the rest.
+  /// References to the alloca should take the form of references to the
+  /// representative.
+  const AllocaInst *getRepresentative(const AllocaInst *AI) const;
+
+  /// Set *offset to the frame offset for the given alloca. Return true if the
+  /// given alloca is representative, meaning that it needs an explicit
+  /// definition in the function entry. Return false if some other alloca
+  /// represents this one.
+  bool getFrameOffset(const AllocaInst *AI, uint64_t *offset) const;
+
+  /// Return the total frame size for all static allocas and associated padding.
+  uint64_t getFrameSize() const { return FrameSize; }
+};
+
+} // namespace llvm
+
+#endif