X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FAllocator.h;h=de317719714da0196261b5173b83a501687792d6;hb=d09c631f071640130c0c91f8f8c219ea31a23f32;hp=d9cb8ba428ba01b4d5ada95b201eb6d308327fa8;hpb=34bc6b6e787f27b5c9e05c82de4c1b4ac9b117bc;p=oota-llvm.git

diff --git a/include/llvm/Support/Allocator.h b/include/llvm/Support/Allocator.h
index d9cb8ba428b..de317719714 100644
--- a/include/llvm/Support/Allocator.h
+++ b/include/llvm/Support/Allocator.h
@@ -6,14 +6,22 @@
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// This file defines the MallocAllocator and BumpPtrAllocator interfaces.
-//
+/// \file
+///
+/// This file defines the MallocAllocator and BumpPtrAllocator interfaces. Both
+/// of these conform to an LLVM "Allocator" concept which consists of an
+/// Allocate method accepting a size and alignment, and a Deallocate accepting
+/// a pointer and size. Further, the LLVM "Allocator" concept has overloads of
+/// Allocate and Deallocate for setting size and alignment based on the final
+/// type. These overloads are typically provided by a base class template \c
+/// AllocatorBase.
+///
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_SUPPORT_ALLOCATOR_H
 #define LLVM_SUPPORT_ALLOCATOR_H
 
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/AlignOf.h"
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/MathExtras.h"
@@ -24,106 +32,109 @@
 #include <cstdlib>
 
 namespace llvm {
-template <typename T> struct ReferenceAdder {
-  typedef T &result;
-};
-template <typename T> struct ReferenceAdder<T &> {
-  typedef T result;
-};
 
-class MallocAllocator {
+/// \brief CRTP base class providing obvious overloads for the core \c
+/// Allocate() methods of LLVM-style allocators.
+///
+/// This base class both documents the full public interface exposed by all
+/// LLVM-style allocators, and redirects all of the overloads to a single core
+/// set of methods which the derived class must define.
+template <typename DerivedT> class AllocatorBase {
 public:
-  MallocAllocator() {}
-  ~MallocAllocator() {}
-
-  void Reset() {}
-
-  void *Allocate(size_t Size, size_t /*Alignment*/) { return malloc(Size); }
-
-  template <typename T> T *Allocate() {
-    return static_cast<T *>(malloc(sizeof(T)));
+  /// \brief Allocate \a Size bytes of \a Alignment aligned memory. This method
+  /// must be implemented by \c DerivedT.
+  void *Allocate(size_t Size, size_t Alignment) {
+#ifdef __clang__
+    static_assert(static_cast<void *(AllocatorBase::*)(size_t, size_t)>(
+                      &AllocatorBase::Allocate) !=
+                      static_cast<void *(DerivedT::*)(size_t, size_t)>(
+                          &DerivedT::Allocate),
+                  "Class derives from AllocatorBase without implementing the "
+                  "core Allocate(size_t, size_t) overload!");
+#endif
+    return static_cast<DerivedT *>(this)->Allocate(Size, Alignment);
   }
 
-  template <typename T> T *Allocate(size_t Num) {
-    return static_cast<T *>(malloc(sizeof(T) * Num));
+  /// \brief Deallocate \a Ptr to \a Size bytes of memory allocated by this
+  /// allocator.
+  void Deallocate(const void *Ptr, size_t Size) {
+#ifdef __clang__
+    static_assert(static_cast<void (AllocatorBase::*)(const void *, size_t)>(
+                      &AllocatorBase::Deallocate) !=
+                      static_cast<void (DerivedT::*)(const void *, size_t)>(
+                          &DerivedT::Deallocate),
+                  "Class derives from AllocatorBase without implementing the "
+                  "core Deallocate(void *) overload!");
+#endif
+    return static_cast<DerivedT *>(this)->Deallocate(Ptr, Size);
   }
 
-  void Deallocate(const void *Ptr) { free(const_cast<void *>(Ptr)); }
+  // The rest of these methods are helpers that redirect to one of the above
+  // core methods.
 
-  void PrintStats() const {}
-};
+  /// \brief Allocate space for a sequence of objects without constructing them.
+  template <typename T> T *Allocate(size_t Num = 1) {
+    return static_cast<T *>(Allocate(Num * sizeof(T), AlignOf<T>::Alignment));
+  }
 
-/// MemSlab - This structure lives at the beginning of every slab allocated by
-/// the bump allocator.
-class MemSlab {
-public:
-  size_t Size;
-  MemSlab *NextPtr;
+  /// \brief Deallocate space for a sequence of objects without constructing them.
+  template <typename T>
+  typename std::enable_if<
+      !std::is_same<typename std::remove_cv<T>::type, void>::value, void>::type
+  Deallocate(T *Ptr, size_t Num = 1) {
+    Deallocate(static_cast<const void *>(Ptr), Num * sizeof(T));
+  }
 };
 
-/// SlabAllocator - This class can be used to parameterize the underlying
-/// allocation strategy for the bump allocator.  In particular, this is used
-/// by the JIT to allocate contiguous swathes of executable memory.  The
-/// interface uses MemSlab's instead of void *'s so that the allocator
-/// doesn't have to remember the size of the pointer it allocated.
-class SlabAllocator {
+class MallocAllocator : public AllocatorBase<MallocAllocator> {
 public:
-  virtual ~SlabAllocator();
-  virtual MemSlab *Allocate(size_t Size) = 0;
-  virtual void Deallocate(MemSlab *Slab) = 0;
-};
+  void Reset() {}
 
-/// MallocSlabAllocator - The default slab allocator for the bump allocator
-/// is an adapter class for MallocAllocator that just forwards the method
-/// calls and translates the arguments.
-class MallocSlabAllocator : public SlabAllocator {
-  /// Allocator - The underlying allocator that we forward to.
-  ///
-  MallocAllocator Allocator;
+  LLVM_ATTRIBUTE_RETURNS_NONNULL void *Allocate(size_t Size,
+                                                size_t /*Alignment*/) {
+    return malloc(Size);
+  }
 
-public:
-  MallocSlabAllocator() : Allocator() {}
-  virtual ~MallocSlabAllocator();
-  MemSlab *Allocate(size_t Size) override;
-  void Deallocate(MemSlab *Slab) override;
-};
+  // Pull in base class overloads.
+  using AllocatorBase<MallocAllocator>::Allocate;
 
-/// \brief Non-templated base class for the \c BumpPtrAllocatorImpl template.
-class BumpPtrAllocatorBase {
-public:
-  void Deallocate(const void * /*Ptr*/) {}
-  void PrintStats() const;
+  void Deallocate(const void *Ptr, size_t /*Size*/) {
+    free(const_cast<void *>(Ptr));
+  }
 
-  /// \brief Returns the total physical memory allocated by this allocator.
-  size_t getTotalMemory() const;
+  // Pull in base class overloads.
+  using AllocatorBase<MallocAllocator>::Deallocate;
 
-protected:
-  /// \brief The slab that we are currently allocating into.
-  MemSlab *CurSlab;
+  void PrintStats() const {}
+};
 
-  /// \brief How many bytes we've allocated.
-  ///
-  /// Used so that we can compute how much space was wasted.
-  size_t BytesAllocated;
+namespace detail {
 
-  BumpPtrAllocatorBase() : CurSlab(nullptr), BytesAllocated(0) {}
-};
+// We call out to an external function to actually print the message as the
+// printing code uses Allocator.h in its implementation.
+void printBumpPtrAllocatorStats(unsigned NumSlabs, size_t BytesAllocated,
+                                size_t TotalMemory);
+} // End namespace detail.
 
 /// \brief Allocate memory in an ever growing pool, as if by bump-pointer.
 ///
 /// This isn't strictly a bump-pointer allocator as it uses backing slabs of
-/// memory rather than relying on boundless contiguous heap. However, it has
-/// bump-pointer semantics in that is a monotonically growing pool of memory
+/// memory rather than relying on a boundless contiguous heap. However, it has
+/// bump-pointer semantics in that it is a monotonically growing pool of memory
 /// where every allocation is found by merely allocating the next N bytes in
 /// the slab, or the next N bytes in the next slab.
 ///
 /// Note that this also has a threshold for forcing allocations above a certain
 /// size into their own slab.
-template <size_t SlabSize = 4096, size_t SizeThreshold = SlabSize>
-class BumpPtrAllocatorImpl : public BumpPtrAllocatorBase {
-  BumpPtrAllocatorImpl(const BumpPtrAllocatorImpl &) LLVM_DELETED_FUNCTION;
-  void operator=(const BumpPtrAllocatorImpl &) LLVM_DELETED_FUNCTION;
-
+///
+/// The BumpPtrAllocatorImpl template defaults to using a MallocAllocator
+/// object, which wraps malloc, to allocate memory, but it can be changed to
+/// use a custom allocator.
+template <typename AllocatorT = MallocAllocator, size_t SlabSize = 4096,
+          size_t SizeThreshold = SlabSize>
+class BumpPtrAllocatorImpl
+    : public AllocatorBase<
+          BumpPtrAllocatorImpl<AllocatorT, SlabSize, SizeThreshold>> {
 public:
   static_assert(SizeThreshold <= SlabSize,
                 "The SizeThreshold must be at most the SlabSize to ensure "
@@ -131,104 +142,136 @@ public:
                 "allocation.");
 
   BumpPtrAllocatorImpl()
-      : Allocator(DefaultSlabAllocator), NumSlabs(0) {}
-  BumpPtrAllocatorImpl(SlabAllocator &Allocator)
-      : Allocator(Allocator), NumSlabs(0) {}
-  ~BumpPtrAllocatorImpl() { DeallocateSlabs(CurSlab); }
+      : CurPtr(nullptr), End(nullptr), BytesAllocated(0), Allocator() {}
+  template <typename T>
+  BumpPtrAllocatorImpl(T &&Allocator)
+      : CurPtr(nullptr), End(nullptr), BytesAllocated(0),
+        Allocator(std::forward<T &&>(Allocator)) {}
+
+  // Manually implement a move constructor as we must clear the old allocators
+  // slabs as a matter of correctness.
+  BumpPtrAllocatorImpl(BumpPtrAllocatorImpl &&Old)
+      : CurPtr(Old.CurPtr), End(Old.End), Slabs(std::move(Old.Slabs)),
+        CustomSizedSlabs(std::move(Old.CustomSizedSlabs)),
+        BytesAllocated(Old.BytesAllocated),
+        Allocator(std::move(Old.Allocator)) {
+    Old.CurPtr = Old.End = nullptr;
+    Old.BytesAllocated = 0;
+    Old.Slabs.clear();
+    Old.CustomSizedSlabs.clear();
+  }
+
+  ~BumpPtrAllocatorImpl() {
+    DeallocateSlabs(Slabs.begin(), Slabs.end());
+    DeallocateCustomSizedSlabs();
+  }
+
+  BumpPtrAllocatorImpl &operator=(BumpPtrAllocatorImpl &&RHS) {
+    DeallocateSlabs(Slabs.begin(), Slabs.end());
+    DeallocateCustomSizedSlabs();
+
+    CurPtr = RHS.CurPtr;
+    End = RHS.End;
+    BytesAllocated = RHS.BytesAllocated;
+    Slabs = std::move(RHS.Slabs);
+    CustomSizedSlabs = std::move(RHS.CustomSizedSlabs);
+    Allocator = std::move(RHS.Allocator);
+
+    RHS.CurPtr = RHS.End = nullptr;
+    RHS.BytesAllocated = 0;
+    RHS.Slabs.clear();
+    RHS.CustomSizedSlabs.clear();
+    return *this;
+  }
 
   /// \brief Deallocate all but the current slab and reset the current pointer
   /// to the beginning of it, freeing all memory allocated so far.
   void Reset() {
-    if (!CurSlab)
+    if (Slabs.empty())
       return;
-    DeallocateSlabs(CurSlab->NextPtr);
-    CurSlab->NextPtr = nullptr;
-    CurPtr = (char *)(CurSlab + 1);
-    End = ((char *)CurSlab) + CurSlab->Size;
+
+    // Reset the state.
     BytesAllocated = 0;
+    CurPtr = (char *)Slabs.front();
+    End = CurPtr + SlabSize;
+
+    // Deallocate all but the first slab, and all custome sized slabs.
+    DeallocateSlabs(std::next(Slabs.begin()), Slabs.end());
+    Slabs.erase(std::next(Slabs.begin()), Slabs.end());
+    DeallocateCustomSizedSlabs();
+    CustomSizedSlabs.clear();
   }
 
   /// \brief Allocate space at the specified alignment.
-  void *Allocate(size_t Size, size_t Alignment) {
-    if (!CurSlab) // Start a new slab if we haven't allocated one already.
-      StartNewSlab();
+  LLVM_ATTRIBUTE_RETURNS_NONNULL void *Allocate(size_t Size, size_t Alignment) {
+    assert(Alignment > 0 && "0-byte alignnment is not allowed. Use 1 instead.");
 
     // Keep track of how many bytes we've allocated.
     BytesAllocated += Size;
 
-    // 0-byte alignment means 1-byte alignment.
-    if (Alignment == 0)
-      Alignment = 1;
-
-    // Allocate the aligned space, going forwards from CurPtr.
-    char *Ptr = alignPtr(CurPtr, Alignment);
+    size_t Adjustment = alignmentAdjustment(CurPtr, Alignment);
+    assert(Adjustment + Size >= Size && "Adjustment + Size must not overflow");
 
-    // Check if we can hold it.
-    if (Ptr + Size <= End) {
-      CurPtr = Ptr + Size;
+    // Check if we have enough space.
+    if (Adjustment + Size <= size_t(End - CurPtr)) {
+      char *AlignedPtr = CurPtr + Adjustment;
+      CurPtr = AlignedPtr + Size;
       // Update the allocation point of this memory block in MemorySanitizer.
       // Without this, MemorySanitizer messages for values originated from here
       // will point to the allocation of the entire slab.
-      __msan_allocated_memory(Ptr, Size);
-      return Ptr;
+      __msan_allocated_memory(AlignedPtr, Size);
+      return AlignedPtr;
     }
 
     // If Size is really big, allocate a separate slab for it.
-    size_t PaddedSize = Size + sizeof(MemSlab) + Alignment - 1;
+    size_t PaddedSize = Size + Alignment - 1;
     if (PaddedSize > SizeThreshold) {
-      ++NumSlabs;
-      MemSlab *NewSlab = Allocator.Allocate(PaddedSize);
-
-      // Put the new slab after the current slab, since we are not allocating
-      // into it.
-      NewSlab->NextPtr = CurSlab->NextPtr;
-      CurSlab->NextPtr = NewSlab;
-
-      Ptr = alignPtr((char *)(NewSlab + 1), Alignment);
-      assert((uintptr_t)Ptr + Size <= (uintptr_t)NewSlab + NewSlab->Size);
-      __msan_allocated_memory(Ptr, Size);
-      return Ptr;
+      void *NewSlab = Allocator.Allocate(PaddedSize, 0);
+      CustomSizedSlabs.push_back(std::make_pair(NewSlab, PaddedSize));
+
+      uintptr_t AlignedAddr = alignAddr(NewSlab, Alignment);
+      assert(AlignedAddr + Size <= (uintptr_t)NewSlab + PaddedSize);
+      char *AlignedPtr = (char*)AlignedAddr;
+      __msan_allocated_memory(AlignedPtr, Size);
+      return AlignedPtr;
     }
 
     // Otherwise, start a new slab and try again.
     StartNewSlab();
-    Ptr = alignPtr(CurPtr, Alignment);
-    CurPtr = Ptr + Size;
-    assert(CurPtr <= End && "Unable to allocate memory!");
-    __msan_allocated_memory(Ptr, Size);
-    return Ptr;
+    uintptr_t AlignedAddr = alignAddr(CurPtr, Alignment);
+    assert(AlignedAddr + Size <= (uintptr_t)End &&
+           "Unable to allocate memory!");
+    char *AlignedPtr = (char*)AlignedAddr;
+    CurPtr = AlignedPtr + Size;
+    __msan_allocated_memory(AlignedPtr, Size);
+    return AlignedPtr;
   }
 
-  /// \brief Allocate space for one object without constructing it.
-  template <typename T> T *Allocate() {
-    return static_cast<T *>(Allocate(sizeof(T), AlignOf<T>::Alignment));
-  }
+  // Pull in base class overloads.
+  using AllocatorBase<BumpPtrAllocatorImpl>::Allocate;
 
-  /// \brief Allocate space for an array of objects without constructing them.
-  template <typename T> T *Allocate(size_t Num) {
-    return static_cast<T *>(Allocate(Num * sizeof(T), AlignOf<T>::Alignment));
-  }
+  void Deallocate(const void * /*Ptr*/, size_t /*Size*/) {}
 
-  /// \brief Allocate space for an array of objects with the specified alignment
-  /// and without constructing them.
-  template <typename T> T *Allocate(size_t Num, size_t Alignment) {
-    // Round EltSize up to the specified alignment.
-    size_t EltSize = (sizeof(T) + Alignment - 1) & (-Alignment);
-    return static_cast<T *>(Allocate(Num * EltSize, Alignment));
-  }
+  // Pull in base class overloads.
+  using AllocatorBase<BumpPtrAllocatorImpl>::Deallocate;
 
-  size_t GetNumSlabs() const { return NumSlabs; }
+  size_t GetNumSlabs() const { return Slabs.size() + CustomSizedSlabs.size(); }
 
-private:
-  /// \brief The default allocator used if one is not provided.
-  MallocSlabAllocator DefaultSlabAllocator;
+  size_t getTotalMemory() const {
+    size_t TotalMemory = 0;
+    for (auto I = Slabs.begin(), E = Slabs.end(); I != E; ++I)
+      TotalMemory += computeSlabSize(std::distance(Slabs.begin(), I));
+    for (auto &PtrAndSize : CustomSizedSlabs)
+      TotalMemory += PtrAndSize.second;
+    return TotalMemory;
+  }
 
-  /// \brief The underlying allocator we use to get slabs of memory.
-  ///
-  /// This defaults to MallocSlabAllocator, which wraps malloc, but it could be
-  /// changed to use a custom allocator.
-  SlabAllocator &Allocator;
+  void PrintStats() const {
+    detail::printBumpPtrAllocatorStats(Slabs.size(), BytesAllocated,
+                                       getTotalMemory());
+  }
 
+private:
   /// \brief The current pointer into the current slab.
   ///
   /// This points to the next free byte in the slab.
@@ -237,46 +280,69 @@ private:
   /// \brief The end of the current slab.
   char *End;
 
-  /// \brief How many slabs we've allocated.
+  /// \brief The slabs allocated so far.
+  SmallVector<void *, 4> Slabs;
+
+  /// \brief Custom-sized slabs allocated for too-large allocation requests.
+  SmallVector<std::pair<void *, size_t>, 0> CustomSizedSlabs;
+
+  /// \brief How many bytes we've allocated.
   ///
-  /// Used to scale the size of each slab and reduce the number of allocations
-  /// for extremely heavy memory use scenarios.
-  size_t NumSlabs;
+  /// Used so that we can compute how much space was wasted.
+  size_t BytesAllocated;
 
-  /// \brief Allocate a new slab and move the bump pointers over into the new
-  /// slab, modifying CurPtr and End.
-  void StartNewSlab() {
-    ++NumSlabs;
+  /// \brief The allocator instance we use to get slabs of memory.
+  AllocatorT Allocator;
+
+  static size_t computeSlabSize(unsigned SlabIdx) {
     // Scale the actual allocated slab size based on the number of slabs
     // allocated. Every 128 slabs allocated, we double the allocated size to
     // reduce allocation frequency, but saturate at multiplying the slab size by
     // 2^30.
-    // FIXME: Currently, this count includes special slabs for objects above the
-    // size threshold. That will be fixed in a subsequent commit to make the
-    // growth even more predictable.
-    size_t AllocatedSlabSize =
-        SlabSize * ((size_t)1 << std::min<size_t>(30, NumSlabs / 128));
-
-    MemSlab *NewSlab = Allocator.Allocate(AllocatedSlabSize);
-    NewSlab->NextPtr = CurSlab;
-    CurSlab = NewSlab;
-    CurPtr = (char *)(CurSlab + 1);
-    End = ((char *)CurSlab) + CurSlab->Size;
+    return SlabSize * ((size_t)1 << std::min<size_t>(30, SlabIdx / 128));
   }
 
-  /// \brief Deallocate all memory slabs after and including this one.
-  void DeallocateSlabs(MemSlab *Slab) {
-    while (Slab) {
-      MemSlab *NextSlab = Slab->NextPtr;
+  /// \brief Allocate a new slab and move the bump pointers over into the new
+  /// slab, modifying CurPtr and End.
+  void StartNewSlab() {
+    size_t AllocatedSlabSize = computeSlabSize(Slabs.size());
+
+    void *NewSlab = Allocator.Allocate(AllocatedSlabSize, 0);
+    Slabs.push_back(NewSlab);
+    CurPtr = (char *)(NewSlab);
+    End = ((char *)NewSlab) + AllocatedSlabSize;
+  }
+
+  /// \brief Deallocate a sequence of slabs.
+  void DeallocateSlabs(SmallVectorImpl<void *>::iterator I,
+                       SmallVectorImpl<void *>::iterator E) {
+    for (; I != E; ++I) {
+      size_t AllocatedSlabSize =
+          computeSlabSize(std::distance(Slabs.begin(), I));
 #ifndef NDEBUG
       // Poison the memory so stale pointers crash sooner.  Note we must
       // preserve the Size and NextPtr fields at the beginning.
-      sys::Memory::setRangeWritable(Slab + 1, Slab->Size - sizeof(MemSlab));
-      memset(Slab + 1, 0xCD, Slab->Size - sizeof(MemSlab));
+      if (AllocatedSlabSize != 0) {
+        sys::Memory::setRangeWritable(*I, AllocatedSlabSize);
+        memset(*I, 0xCD, AllocatedSlabSize);
+      }
 #endif
-      Allocator.Deallocate(Slab);
-      Slab = NextSlab;
-      --NumSlabs;
+      Allocator.Deallocate(*I, AllocatedSlabSize);
+    }
+  }
+
+  /// \brief Deallocate all memory for custom sized slabs.
+  void DeallocateCustomSizedSlabs() {
+    for (auto &PtrAndSize : CustomSizedSlabs) {
+      void *Ptr = PtrAndSize.first;
+      size_t Size = PtrAndSize.second;
+#ifndef NDEBUG
+      // Poison the memory so stale pointers crash sooner.  Note we must
+      // preserve the Size and NextPtr fields at the beginning.
+      sys::Memory::setRangeWritable(Ptr, Size);
+      memset(Ptr, 0xCD, Size);
+#endif
+      Allocator.Deallocate(Ptr, Size);
     }
   }
 
@@ -297,25 +363,42 @@ template <typename T> class SpecificBumpPtrAllocator {
 
 public:
   SpecificBumpPtrAllocator() : Allocator() {}
-  SpecificBumpPtrAllocator(SlabAllocator &allocator) : Allocator(allocator) {}
-
+  SpecificBumpPtrAllocator(SpecificBumpPtrAllocator &&Old)
+      : Allocator(std::move(Old.Allocator)) {}
   ~SpecificBumpPtrAllocator() { DestroyAll(); }
 
+  SpecificBumpPtrAllocator &operator=(SpecificBumpPtrAllocator &&RHS) {
+    Allocator = std::move(RHS.Allocator);
+    return *this;
+  }
+
   /// Call the destructor of each allocated object and deallocate all but the
   /// current slab and reset the current pointer to the beginning of it, freeing
   /// all memory allocated so far.
   void DestroyAll() {
-    MemSlab *Slab = Allocator.CurSlab;
-    while (Slab) {
-      char *End = Slab == Allocator.CurSlab ? Allocator.CurPtr
-                                            : (char *)Slab + Slab->Size;
-      for (char *Ptr = (char *)(Slab + 1); Ptr < End; Ptr += sizeof(T)) {
-        Ptr = alignPtr(Ptr, alignOf<T>());
-        if (Ptr + sizeof(T) <= End)
-          reinterpret_cast<T *>(Ptr)->~T();
-      }
-      Slab = Slab->NextPtr;
+    auto DestroyElements = [](char *Begin, char *End) {
+      assert(Begin == (char*)alignAddr(Begin, alignOf<T>()));
+      for (char *Ptr = Begin; Ptr + sizeof(T) <= End; Ptr += sizeof(T))
+        reinterpret_cast<T *>(Ptr)->~T();
+    };
+
+    for (auto I = Allocator.Slabs.begin(), E = Allocator.Slabs.end(); I != E;
+         ++I) {
+      size_t AllocatedSlabSize = BumpPtrAllocator::computeSlabSize(
+          std::distance(Allocator.Slabs.begin(), I));
+      char *Begin = (char*)alignAddr(*I, alignOf<T>());
+      char *End = *I == Allocator.Slabs.back() ? Allocator.CurPtr
+                                               : (char *)*I + AllocatedSlabSize;
+
+      DestroyElements(Begin, End);
+    }
+
+    for (auto &PtrAndSize : Allocator.CustomSizedSlabs) {
+      void *Ptr = PtrAndSize.first;
+      size_t Size = PtrAndSize.second;
+      DestroyElements((char*)alignAddr(Ptr, alignOf<T>()), (char *)Ptr + Size);
     }
+
     Allocator.Reset();
   }
 
@@ -325,10 +408,10 @@ public:
 
 }  // end namespace llvm
 
-template <size_t SlabSize, size_t SizeThreshold>
-void *
-operator new(size_t Size,
-             llvm::BumpPtrAllocatorImpl<SlabSize, SizeThreshold> &Allocator) {
+template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold>
+void *operator new(size_t Size,
+                   llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize,
+                                              SizeThreshold> &Allocator) {
   struct S {
     char c;
     union {
@@ -342,8 +425,9 @@ operator new(size_t Size,
       Size, std::min((size_t)llvm::NextPowerOf2(Size), offsetof(S, x)));
 }
 
-template <size_t SlabSize, size_t SizeThreshold>
-void operator delete(void *,
-                     llvm::BumpPtrAllocatorImpl<SlabSize, SizeThreshold> &) {}
+template <typename AllocatorT, size_t SlabSize, size_t SizeThreshold>
+void operator delete(
+    void *, llvm::BumpPtrAllocatorImpl<AllocatorT, SlabSize, SizeThreshold> &) {
+}
 
 #endif // LLVM_SUPPORT_ALLOCATOR_H