Make common BitVector operations inline-able.

Change-Id: Ie25de4fae56c6712539f04172c42e3eff57df7ca
diff --git a/runtime/base/bit_vector.h b/runtime/base/bit_vector.h
index fb1646f..1e28a27 100644
--- a/runtime/base/bit_vector.h
+++ b/runtime/base/bit_vector.h
@@ -18,235 +18,237 @@
 #define ART_RUNTIME_BASE_BIT_VECTOR_H_
 
 #include <stdint.h>
-#include <stddef.h>
-
-#include "allocator.h"
-#include "base/logging.h"
-#include "utils.h"
+#include <iterator>
 
 namespace art {
 
+class Allocator;
+
 /*
  * Expanding bitmap, used for tracking resources.  Bits are numbered starting
  * from zero.  All operations on a BitVector are unsynchronized.
  */
 class BitVector {
-  public:
-    class IndexContainer;
+ public:
+  class IndexContainer;
 
-    /**
-     * @brief Convenient iterator across the indexes of the BitVector's set bits.
-     *
-     * @details IndexIterator is a Forward iterator (C++11: 24.2.5) from the lowest
-     * to the highest index of the BitVector's set bits. Instances can be retrieved
-     * only through BitVector::Indexes() which returns an IndexContainer wrapper
-     * object with begin() and end() suitable for range-based loops:
-     *   for (uint32_t idx : bit_vector.Indexes()) {
-     *     // Use idx.
-     *   }
-     */
-    class IndexIterator
-        : std::iterator<std::forward_iterator_tag, uint32_t, ptrdiff_t, void, uint32_t> {
-      public:
-        bool operator==(const IndexIterator& other) const {
-          DCHECK(bit_storage_ == other.bit_storage_);
-          DCHECK_EQ(storage_size_, other.storage_size_);
-          return bit_index_ == other.bit_index_;
-        }
+  /**
+   * @brief Convenient iterator across the indexes of the BitVector's set bits.
+   *
+   * @details IndexIterator is a Forward iterator (C++11: 24.2.5) from the lowest
+   * to the highest index of the BitVector's set bits. Instances can be retrieved
+   * only through BitVector::Indexes() which returns an IndexContainer wrapper
+   * object with begin() and end() suitable for range-based loops:
+   *   for (uint32_t idx : bit_vector.Indexes()) {
+   *     // Use idx.
+   *   }
+   */
+  class IndexIterator :
+      std::iterator<std::forward_iterator_tag, uint32_t, ptrdiff_t, void, uint32_t> {
+   public:
+    bool operator==(const IndexIterator& other) const;
 
-        bool operator!=(const IndexIterator& other) const {
-          return !(*this == other);
-        }
-
-        int operator*() const {
-          DCHECK_LT(bit_index_, BitSize());
-          return bit_index_;
-        }
-
-        IndexIterator& operator++() {
-          DCHECK_LT(bit_index_, BitSize());
-          bit_index_ = FindIndex(bit_index_ + 1u);
-          return *this;
-        }
-
-        IndexIterator operator++(int) {
-          IndexIterator result(*this);
-          ++*this;
-          return result;
-        }
-
-        // Helper function to check for end without comparing with bit_vector.Indexes().end().
-        bool Done() const {
-          return bit_index_ == BitSize();
-        }
-
-      private:
-        struct begin_tag { };
-        struct end_tag { };
-
-        IndexIterator(const BitVector* bit_vector, begin_tag)
-          : bit_storage_(bit_vector->GetRawStorage()),
-            storage_size_(bit_vector->storage_size_),
-            bit_index_(FindIndex(0u)) { }
-
-        IndexIterator(const BitVector* bit_vector, end_tag)
-          : bit_storage_(bit_vector->GetRawStorage()),
-            storage_size_(bit_vector->storage_size_),
-            bit_index_(BitSize()) { }
-
-        uint32_t BitSize() const {
-          return storage_size_ * kWordBits;
-        }
-
-        uint32_t FindIndex(uint32_t start_index) const {
-          DCHECK_LE(start_index, BitSize());
-          uint32_t word_index = start_index / kWordBits;
-          if (UNLIKELY(word_index == storage_size_)) {
-            return start_index;
-          }
-          uint32_t word = bit_storage_[word_index];
-          // Mask out any bits in the first word we've already considered.
-          word &= static_cast<uint32_t>(-1) << (start_index & 0x1f);
-          while (word == 0u) {
-            ++word_index;
-            if (UNLIKELY(word_index == storage_size_)) {
-              return BitSize();
-            }
-            word = bit_storage_[word_index];
-          }
-          return word_index * 32u + CTZ(word);
-        }
-
-        const uint32_t* const bit_storage_;
-        const uint32_t storage_size_;  // Size of vector in words.
-        uint32_t bit_index_;           // Current index (size in bits).
-
-        friend class BitVector::IndexContainer;
-    };
-
-    /**
-     * @brief BitVector wrapper class for iteration across indexes of set bits.
-     */
-    class IndexContainer {
-     public:
-      explicit IndexContainer(const BitVector* bit_vector) : bit_vector_(bit_vector) { }
-
-      IndexIterator begin() const {
-        return IndexIterator(bit_vector_, IndexIterator::begin_tag());
-      }
-
-      IndexIterator end() const {
-        return IndexIterator(bit_vector_, IndexIterator::end_tag());
-      }
-
-     private:
-      const BitVector* const bit_vector_;
-    };
-
-    BitVector(uint32_t start_bits,
-              bool expandable,
-              Allocator* allocator,
-              uint32_t storage_size = 0,
-              uint32_t* storage = nullptr);
-
-    virtual ~BitVector();
-
-    void SetBit(uint32_t num);
-    void ClearBit(uint32_t num);
-    bool IsBitSet(uint32_t num) const;
-    void ClearAllBits();
-    void SetInitialBits(uint32_t num_bits);
-
-    void Copy(const BitVector* src);
-    void Intersect(const BitVector* src2);
-    bool Union(const BitVector* src);
-
-    // Set bits of union_with that are not in not_in.
-    bool UnionIfNotIn(const BitVector* union_with, const BitVector* not_in);
-
-    void Subtract(const BitVector* src);
-    // Are we equal to another bit vector?  Note: expandability attributes must also match.
-    bool Equal(const BitVector* src) {
-      return (storage_size_ == src->GetStorageSize()) &&
-        (expandable_ == src->IsExpandable()) &&
-        (memcmp(storage_, src->GetRawStorage(), storage_size_ * sizeof(uint32_t)) == 0);
+    bool operator!=(const IndexIterator& other) const {
+      return !(*this == other);
     }
 
-    /**
-     * @brief Are all the bits set the same?
-     * @details expandability and size can differ as long as the same bits are set.
-     */
-    bool SameBitsSet(const BitVector *src);
+    int operator*() const;
 
-    uint32_t NumSetBits() const;
+    IndexIterator& operator++();
 
-    // Number of bits set in range [0, end).
-    uint32_t NumSetBits(uint32_t end) const;
+    IndexIterator operator++(int);
 
-    IndexContainer Indexes() const {
-      return IndexContainer(this);
+    // Helper function to check for end without comparing with bit_vector.Indexes().end().
+    bool Done() const {
+      return bit_index_ == BitSize();
     }
 
-    uint32_t GetStorageSize() const { return storage_size_; }
-    bool IsExpandable() const { return expandable_; }
-    uint32_t GetRawStorageWord(size_t idx) const { return storage_[idx]; }
-    uint32_t* GetRawStorage() { return storage_; }
-    const uint32_t* GetRawStorage() const { return storage_; }
-    size_t GetSizeOf() const { return storage_size_ * kWordBytes; }
+   private:
+    struct begin_tag { };
+    struct end_tag { };
 
-    /**
-     * @return the highest bit set, -1 if none are set
+    IndexIterator(const BitVector* bit_vector, begin_tag)
+      : bit_storage_(bit_vector->GetRawStorage()),
+        storage_size_(bit_vector->storage_size_),
+        bit_index_(FindIndex(0u)) { }
+
+    IndexIterator(const BitVector* bit_vector, end_tag)
+      : bit_storage_(bit_vector->GetRawStorage()),
+        storage_size_(bit_vector->storage_size_),
+        bit_index_(BitSize()) { }
+
+    uint32_t BitSize() const {
+      return storage_size_ * kWordBits;
+    }
+
+    uint32_t FindIndex(uint32_t start_index) const;
+    const uint32_t* const bit_storage_;
+    const uint32_t storage_size_;  // Size of vector in words.
+    uint32_t bit_index_;           // Current index (size in bits).
+
+    friend class BitVector::IndexContainer;
+  };
+
+  /**
+   * @brief BitVector wrapper class for iteration across indexes of set bits.
+   */
+  class IndexContainer {
+   public:
+    explicit IndexContainer(const BitVector* bit_vector) : bit_vector_(bit_vector) { }
+
+    IndexIterator begin() const {
+      return IndexIterator(bit_vector_, IndexIterator::begin_tag());
+    }
+
+    IndexIterator end() const {
+      return IndexIterator(bit_vector_, IndexIterator::end_tag());
+    }
+
+   private:
+    const BitVector* const bit_vector_;
+  };
+
+  BitVector(uint32_t start_bits,
+            bool expandable,
+            Allocator* allocator,
+            uint32_t storage_size = 0,
+            uint32_t* storage = nullptr);
+
+  virtual ~BitVector();
+
+  // Mark the specified bit as "set".
+  void SetBit(uint32_t idx) {
+    /*
+     * TUNING: this could have pathologically bad growth/expand behavior.  Make sure we're
+     * not using it badly or change resize mechanism.
      */
-    int GetHighestBitSet() const;
+    if (idx >= storage_size_ * kWordBits) {
+      EnsureSize(idx);
+    }
+    storage_[WordIndex(idx)] |= BitMask(idx);
+  }
 
-    // Is bit set in storage. (No range check.)
-    static bool IsBitSet(const uint32_t* storage, uint32_t num);
-    // Number of bits set in range [0, end) in storage. (No range check.)
-    static uint32_t NumSetBits(const uint32_t* storage, uint32_t end);
+  // Mark the specified bit as "unset".
+  void ClearBit(uint32_t idx) {
+    // If the index is over the size, we don't have to do anything, it is cleared.
+    if (idx < storage_size_ * kWordBits) {
+      // Otherwise, go ahead and clear it.
+      storage_[WordIndex(idx)] &= ~BitMask(idx);
+    }
+  }
 
-    bool EnsureSizeAndClear(unsigned int num);
+  // Determine whether or not the specified bit is set.
+  bool IsBitSet(uint32_t idx) const {
+    // If the index is over the size, whether it is expandable or not, this bit does not exist:
+    // thus it is not set.
+    return (idx < (storage_size_ * kWordBits)) && IsBitSet(storage_, idx);
+  }
 
-    void Dump(std::ostream& os, const char* prefix) const;
+  // Mark all bits bit as "clear".
+  void ClearAllBits();
 
-    /**
-     * @brief last_entry is this the last entry for the dot dumping
-     * @details if not, a "|" is appended to the dump.
-     */
-    void DumpDot(FILE* file, const char* prefix, bool last_entry = false) const;
+  // Mark specified number of bits as "set". Cannot set all bits like ClearAll since there might
+  // be unused bits - setting those to one will confuse the iterator.
+  void SetInitialBits(uint32_t num_bits);
 
-    /**
-     * @brief last_entry is this the last entry for the dot dumping
-     * @details if not, a "|" is appended to the dump.
-     */
-    void DumpIndicesDot(FILE* file, const char* prefix, bool last_entry = false) const;
+  void Copy(const BitVector* src);
 
-  protected:
-    /**
-     * @brief Dump the bitvector into buffer in a 00101..01 format.
-     * @param buffer the ostringstream used to dump the bitvector into.
-     */
-    void DumpHelper(const char* prefix, std::ostringstream& buffer) const;
+  // Intersect with another bit vector.
+  void Intersect(const BitVector* src2);
 
-    /**
-     * @brief Dump the bitvector in a 1 2 5 8 format, where the numbers are the bit set.
-     * @param buffer the ostringstream used to dump the bitvector into.
-     */
-    void DumpIndicesHelper(const char* prefix, std::ostringstream& buffer) const;
+  // Union with another bit vector.
+  bool Union(const BitVector* src);
 
-    /**
-     * @brief Wrapper to perform the bitvector dumping with the .dot format.
-     * @param buffer the ostringstream used to dump the bitvector into.
-     */
-    void DumpDotHelper(bool last_entry, FILE* file, std::ostringstream& buffer) const;
+  // Set bits of union_with that are not in not_in.
+  bool UnionIfNotIn(const BitVector* union_with, const BitVector* not_in);
 
-  private:
-    static constexpr uint32_t kWordBytes = sizeof(uint32_t);
-    static constexpr uint32_t kWordBits = kWordBytes * 8;
+  void Subtract(const BitVector* src);
 
-    Allocator* const allocator_;
-    const bool expandable_;         // expand bitmap if we run out?
-    uint32_t   storage_size_;       // current size, in 32-bit words.
-    uint32_t*  storage_;
+  // Are we equal to another bit vector?  Note: expandability attributes must also match.
+  bool Equal(const BitVector* src) const;
+
+  /**
+   * @brief Are all the bits set the same?
+   * @details expandability and size can differ as long as the same bits are set.
+   */
+  bool SameBitsSet(const BitVector *src) const;
+
+  // Count the number of bits that are set.
+  uint32_t NumSetBits() const;
+
+  // Count the number of bits that are set in range [0, end).
+  uint32_t NumSetBits(uint32_t end) const;
+
+  IndexContainer Indexes() const {
+    return IndexContainer(this);
+  }
+
+  uint32_t GetStorageSize() const {
+    return storage_size_;
+  }
+
+  bool IsExpandable() const {
+    return expandable_;
+  }
+
+  uint32_t GetRawStorageWord(size_t idx) const {
+    return storage_[idx];
+  }
+
+  uint32_t* GetRawStorage() {
+    return storage_;
+  }
+
+  const uint32_t* GetRawStorage() const {
+    return storage_;
+  }
+
+  size_t GetSizeOf() const {
+    return storage_size_ * kWordBytes;
+  }
+
+  /**
+   * @return the highest bit set, -1 if none are set
+   */
+  int GetHighestBitSet() const;
+
+  // Is bit set in storage. (No range check.)
+  static bool IsBitSet(const uint32_t* storage, uint32_t idx) {
+    return (storage[WordIndex(idx)] & BitMask(idx)) != 0;
+  }
+
+  // Number of bits set in range [0, end) in storage. (No range check.)
+  static uint32_t NumSetBits(const uint32_t* storage, uint32_t end);
+
+  void Dump(std::ostream& os, const char* prefix) const;
+
+ private:
+  /**
+   * @brief Dump the bitvector into buffer in a 00101..01 format.
+   * @param buffer the ostringstream used to dump the bitvector into.
+   */
+  void DumpHelper(const char* prefix, std::ostringstream& buffer) const;
+
+  // Ensure there is space for a bit at idx.
+  void EnsureSize(uint32_t idx);
+
+  // The index of the word within storage.
+  static constexpr uint32_t WordIndex(uint32_t idx) {
+    return idx >> 5;
+  }
+
+  // A bit mask to extract the bit for the given index.
+  static constexpr uint32_t BitMask(uint32_t idx) {
+    return 1 << (idx & 0x1f);
+  }
+
+  static constexpr uint32_t kWordBytes = sizeof(uint32_t);
+  static constexpr uint32_t kWordBits = kWordBytes * 8;
+
+  uint32_t*  storage_;            // The storage for the bit vector.
+  uint32_t   storage_size_;       // Current size, in 32-bit words.
+  Allocator* const allocator_;    // Allocator if expandable.
+  const bool expandable_;         // Should the bitmap expand if too small?
 };