68 lines
2.2 KiB
C
68 lines
2.2 KiB
C
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/*
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* Copyright (C) 2010 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef UTILS_BITSET_H
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#define UTILS_BITSET_H
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#include <stdint.h>
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/*
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* Contains some bit manipulation helpers.
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*/
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namespace android {
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// A simple set of 32 bits that can be individually marked or cleared.
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struct BitSet32 {
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uint32_t value;
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inline BitSet32() : value(0) { }
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explicit inline BitSet32(uint32_t value) : value(value) { }
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// Gets the value associated with a particular bit index.
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static inline uint32_t valueForBit(uint32_t n) { return 0x80000000 >> n; }
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// Clears the bit set.
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inline void clear() { value = 0; }
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// Returns true if the bit set does not contain any marked bits.
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inline bool isEmpty() const { return ! value; }
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// Returns true if the specified bit is marked.
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inline bool hasBit(uint32_t n) const { return value & valueForBit(n); }
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// Marks the specified bit.
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inline void markBit(uint32_t n) { value |= valueForBit(n); }
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// Clears the specified bit.
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inline void clearBit(uint32_t n) { value &= ~ valueForBit(n); }
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// Finds the first marked bit in the set.
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// Result is undefined if all bits are unmarked.
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inline uint32_t firstMarkedBit() const { return __builtin_clz(value); }
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// Finds the first unmarked bit in the set.
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// Result is undefined if all bits are marked.
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inline uint32_t firstUnmarkedBit() const { return __builtin_clz(~ value); }
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inline bool operator== (const BitSet32& other) const { return value == other.value; }
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inline bool operator!= (const BitSet32& other) const { return value != other.value; }
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};
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} // namespace android
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#endif // UTILS_BITSET_H
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