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diff --git a/libartbase/base/memory_region.h b/libartbase/base/memory_region.h
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+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_LIBARTBASE_BASE_MEMORY_REGION_H_
+#define ART_LIBARTBASE_BASE_MEMORY_REGION_H_
+
+#include <stdint.h>
+#include <type_traits>
+
+#include <android-base/logging.h>
+
+#include "base/bit_utils.h"
+#include "base/casts.h"
+#include "base/enums.h"
+#include "base/macros.h"
+#include "base/value_object.h"
+#include "globals.h"
+
+namespace art {
+
+// Memory regions are useful for accessing memory with bounds check in
+// debug mode. They can be safely passed by value and do not assume ownership
+// of the region.
+class MemoryRegion FINAL : public ValueObject {
+ public:
+  struct ContentEquals {
+    constexpr bool operator()(const MemoryRegion& lhs, const MemoryRegion& rhs) const {
+      return lhs.size() == rhs.size() && memcmp(lhs.begin(), rhs.begin(), lhs.size()) == 0;
+    }
+  };
+
+  MemoryRegion() : pointer_(nullptr), size_(0) {}
+  MemoryRegion(void* pointer_in, uintptr_t size_in) : pointer_(pointer_in), size_(size_in) {}
+
+  void* pointer() const { return pointer_; }
+  size_t size() const { return size_; }
+  size_t size_in_bits() const { return size_ * kBitsPerByte; }
+
+  static size_t pointer_offset() {
+    return OFFSETOF_MEMBER(MemoryRegion, pointer_);
+  }
+
+  uint8_t* begin() const { return reinterpret_cast<uint8_t*>(pointer_); }
+  uint8_t* end() const { return begin() + size_; }
+
+  // Load value of type `T` at `offset`.  The memory address corresponding
+  // to `offset` should be word-aligned (on ARM, this is a requirement).
+  template<typename T>
+  ALWAYS_INLINE T Load(uintptr_t offset) const {
+    T* address = ComputeInternalPointer<T>(offset);
+    DCHECK(IsWordAligned(address));
+    return *address;
+  }
+
+  // Store `value` (of type `T`) at `offset`.  The memory address
+  // corresponding to `offset` should be word-aligned (on ARM, this is
+  // a requirement).
+  template<typename T>
+  ALWAYS_INLINE void Store(uintptr_t offset, T value) const {
+    T* address = ComputeInternalPointer<T>(offset);
+    DCHECK(IsWordAligned(address));
+    *address = value;
+  }
+
+  // Load value of type `T` at `offset`.  The memory address corresponding
+  // to `offset` does not need to be word-aligned.
+  template<typename T>
+  ALWAYS_INLINE T LoadUnaligned(uintptr_t offset) const {
+    // Equivalent unsigned integer type corresponding to T.
+    typedef typename std::make_unsigned<T>::type U;
+    U equivalent_unsigned_integer_value = 0;
+    // Read the value byte by byte in a little-endian fashion.
+    for (size_t i = 0; i < sizeof(U); ++i) {
+      equivalent_unsigned_integer_value +=
+          *ComputeInternalPointer<uint8_t>(offset + i) << (i * kBitsPerByte);
+    }
+    return bit_cast<T, U>(equivalent_unsigned_integer_value);
+  }
+
+  // Store `value` (of type `T`) at `offset`.  The memory address
+  // corresponding to `offset` does not need to be word-aligned.
+  template<typename T>
+  ALWAYS_INLINE void StoreUnaligned(uintptr_t offset, T value) const {
+    // Equivalent unsigned integer type corresponding to T.
+    typedef typename std::make_unsigned<T>::type U;
+    U equivalent_unsigned_integer_value = bit_cast<U, T>(value);
+    // Write the value byte by byte in a little-endian fashion.
+    for (size_t i = 0; i < sizeof(U); ++i) {
+      *ComputeInternalPointer<uint8_t>(offset + i) =
+          (equivalent_unsigned_integer_value >> (i * kBitsPerByte)) & 0xFF;
+    }
+  }
+
+  template<typename T>
+  ALWAYS_INLINE T* PointerTo(uintptr_t offset) const {
+    return ComputeInternalPointer<T>(offset);
+  }
+
+  // Load a single bit in the region. The bit at offset 0 is the least
+  // significant bit in the first byte.
+  ALWAYS_INLINE bool LoadBit(uintptr_t bit_offset) const {
+    uint8_t bit_mask;
+    uint8_t byte = *ComputeBitPointer(bit_offset, &bit_mask);
+    return byte & bit_mask;
+  }
+
+  ALWAYS_INLINE void StoreBit(uintptr_t bit_offset, bool value) const {
+    uint8_t bit_mask;
+    uint8_t* byte = ComputeBitPointer(bit_offset, &bit_mask);
+    if (value) {
+      *byte |= bit_mask;
+    } else {
+      *byte &= ~bit_mask;
+    }
+  }
+
+  // Load `length` bits from the region starting at bit offset `bit_offset`.
+  // The bit at the smallest offset is the least significant bit in the
+  // loaded value.  `length` must not be larger than the number of bits
+  // contained in the return value (32).
+  ALWAYS_INLINE uint32_t LoadBits(uintptr_t bit_offset, size_t length) const {
+    DCHECK_LE(length, BitSizeOf<uint32_t>());
+    DCHECK_LE(bit_offset + length, size_in_bits());
+    if (UNLIKELY(length == 0)) {
+      // Do not touch any memory if the range is empty.
+      return 0;
+    }
+    const uint8_t* address = begin() + bit_offset / kBitsPerByte;
+    const uint32_t shift = bit_offset & (kBitsPerByte - 1);
+    // Load the value (reading only the strictly needed bytes).
+    const uint32_t load_bit_count = shift + length;
+    uint32_t value = address[0] >> shift;
+    if (load_bit_count > 8) {
+      value |= static_cast<uint32_t>(address[1]) << (8 - shift);
+      if (load_bit_count > 16) {
+        value |= static_cast<uint32_t>(address[2]) << (16 - shift);
+        if (load_bit_count > 24) {
+          value |= static_cast<uint32_t>(address[3]) << (24 - shift);
+          if (load_bit_count > 32) {
+            value |= static_cast<uint32_t>(address[4]) << (32 - shift);
+          }
+        }
+      }
+    }
+    // Clear unwanted most significant bits.
+    uint32_t clear_bit_count = BitSizeOf(value) - length;
+    value = (value << clear_bit_count) >> clear_bit_count;
+    for (size_t i = 0; i < length; ++i) {
+      DCHECK_EQ((value >> i) & 1, LoadBit(bit_offset + i));
+    }
+    return value;
+  }
+
+  // Store `value` on `length` bits in the region starting at bit offset
+  // `bit_offset`.  The bit at the smallest offset is the least significant
+  // bit of the stored `value`.  `value` must not be larger than `length`
+  // bits.
+  void StoreBits(uintptr_t bit_offset, uint32_t value, size_t length);
+
+  void CopyFrom(size_t offset, const MemoryRegion& from) const;
+
+  template<class Vector>
+  void CopyFromVector(size_t offset, Vector& vector) const {
+    if (!vector.empty()) {
+      CopyFrom(offset, MemoryRegion(vector.data(), vector.size()));
+    }
+  }
+
+  // Compute a sub memory region based on an existing one.
+  ALWAYS_INLINE MemoryRegion Subregion(uintptr_t offset, uintptr_t size_in) const {
+    CHECK_GE(this->size(), size_in);
+    CHECK_LE(offset,  this->size() - size_in);
+    return MemoryRegion(reinterpret_cast<void*>(begin() + offset), size_in);
+  }
+
+  // Compute an extended memory region based on an existing one.
+  ALWAYS_INLINE void Extend(const MemoryRegion& region, uintptr_t extra) {
+    pointer_ = region.pointer();
+    size_ = (region.size() + extra);
+  }
+
+ private:
+  template<typename T>
+  ALWAYS_INLINE T* ComputeInternalPointer(size_t offset) const {
+    CHECK_GE(size(), sizeof(T));
+    CHECK_LE(offset, size() - sizeof(T));
+    return reinterpret_cast<T*>(begin() + offset);
+  }
+
+  // Locate the bit with the given offset. Returns a pointer to the byte
+  // containing the bit, and sets bit_mask to the bit within that byte.
+  ALWAYS_INLINE uint8_t* ComputeBitPointer(uintptr_t bit_offset, uint8_t* bit_mask) const {
+    uintptr_t bit_remainder = (bit_offset & (kBitsPerByte - 1));
+    *bit_mask = (1U << bit_remainder);
+    uintptr_t byte_offset = (bit_offset >> kBitsPerByteLog2);
+    return ComputeInternalPointer<uint8_t>(byte_offset);
+  }
+
+  // Is `address` aligned on a machine word?
+  template<typename T> static constexpr bool IsWordAligned(const T* address) {
+    // Word alignment in bytes.  Determined from pointer size.
+    return IsAligned<kRuntimePointerSize>(address);
+  }
+
+  void* pointer_;
+  size_t size_;
+};
+
+}  // namespace art
+
+#endif  // ART_LIBARTBASE_BASE_MEMORY_REGION_H_