/* * Copyright (C) 2010 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 UTILS_BITSET_H #define UTILS_BITSET_H #include <stdint.h> /* * Contains some bit manipulation helpers. */ namespace android { // A simple set of 32 bits that can be individually marked or cleared. struct BitSet32 { uint32_t value; inline BitSet32() : value(0) { } explicit inline BitSet32(uint32_t value) : value(value) { } // Gets the value associated with a particular bit index. static inline uint32_t valueForBit(uint32_t n) { return 0x80000000 >> n; } // Clears the bit set. inline void clear() { value = 0; } // Returns the number of marked bits in the set. inline uint32_t count() const { return __builtin_popcount(value); } // Returns true if the bit set does not contain any marked bits. inline bool isEmpty() const { return ! value; } // Returns true if the specified bit is marked. inline bool hasBit(uint32_t n) const { return value & valueForBit(n); } // Marks the specified bit. inline void markBit(uint32_t n) { value |= valueForBit(n); } // Clears the specified bit. inline void clearBit(uint32_t n) { value &= ~ valueForBit(n); } // Finds the first marked bit in the set. // Result is undefined if all bits are unmarked. inline uint32_t firstMarkedBit() const { return __builtin_clz(value); } // Finds the first unmarked bit in the set. // Result is undefined if all bits are marked. inline uint32_t firstUnmarkedBit() const { return __builtin_clz(~ value); } inline bool operator== (const BitSet32& other) const { return value == other.value; } inline bool operator!= (const BitSet32& other) const { return value != other.value; } }; } // namespace android #endif // UTILS_BITSET_H