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BitUtil.h
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1 // Copyright (c) 2009-2014 Alan Wright. All rights reserved.
3 // Distributable under the terms of either the Apache License (Version 2.0)
4 // or the GNU Lesser General Public License.
6 
7 #ifndef BITUTIL_H
8 #define BITUTIL_H
9 
10 #include "LuceneObject.h"
11 
12 namespace Lucene {
13 
15 class LPPAPI BitUtil : public LuceneObject {
16 public:
17  virtual ~BitUtil();
19 
20 public:
22  static const uint8_t ntzTable[];
23 
24 public:
26  static int32_t pop(int64_t x);
27 
29  static int64_t pop_array(const int64_t* A, int32_t wordOffset, int32_t numWords);
30 
32  static int64_t pop_intersect(const int64_t* A, const int64_t* B, int32_t wordOffset, int32_t numWords);
33 
35  static int64_t pop_union(const int64_t* A, const int64_t* B, int32_t wordOffset, int32_t numWords);
36 
38  static int64_t pop_andnot(const int64_t* A, const int64_t* B, int32_t wordOffset, int32_t numWords);
39 
41  static int64_t pop_xor(const int64_t* A, const int64_t* B, int32_t wordOffset, int32_t numWords);
42 
44  static int32_t ntz(int64_t val);
45 
47  static int32_t ntz(int32_t val);
48 
51  static int32_t ntz2(int64_t x);
52 
55  static int32_t ntz3(int64_t x);
56 
58  static bool isPowerOfTwo(int32_t v);
59 
61  static bool isPowerOfTwo(int64_t v);
62 
64  static int32_t nextHighestPowerOfTwo(int32_t v);
65 
67  static int64_t nextHighestPowerOfTwo(int64_t v);
68 
69 protected:
70  inline static void CSA(int64_t& h, int64_t& l, int64_t a, int64_t b, int64_t c);
71 };
72 
73 }
74 
75 #endif
#define LUCENE_CLASS(Name)
Definition: LuceneObject.h:24
A variety of high efficiency bit twiddling routines.
Definition: BitUtil.h:15
static int32_t ntz2(int64_t x)
Returns 0 based index of first set bit (only works for x!=0) This is an alternate implementation of n...
static int64_t nextHighestPowerOfTwo(int64_t v)
Returns the next highest power of two, or the current value if it's already a power of two or zero.
static bool isPowerOfTwo(int32_t v)
Returns true if v is a power of two or zero.
static int64_t pop_union(const int64_t *A, const int64_t *B, int32_t wordOffset, int32_t numWords)
Returns the popcount or cardinality of the union of two sets. Neither array is modified.
static int32_t ntz(int64_t val)
Returns number of trailing zeros in a 64 bit long value.
static int32_t nextHighestPowerOfTwo(int32_t v)
Returns the next highest power of two, or the current value if it's already a power of two or zero.
static int64_t pop_xor(const int64_t *A, const int64_t *B, int32_t wordOffset, int32_t numWords)
Returns the popcount or cardinality of A ^ B. Neither array is modified.
static int64_t pop_intersect(const int64_t *A, const int64_t *B, int32_t wordOffset, int32_t numWords)
Returns the popcount or cardinality of the two sets after an intersection. Neither array is modified.
virtual ~BitUtil()
static bool isPowerOfTwo(int64_t v)
Returns true if v is a power of two or zero.
static int32_t ntz(int32_t val)
Returns number of trailing zeros in a 32 bit int value.
static int32_t pop(int64_t x)
Returns the number of bits set in the long.
static int64_t pop_array(const int64_t *A, int32_t wordOffset, int32_t numWords)
Returns the number of set bits in an array of longs.
static int32_t ntz3(int64_t x)
Returns 0 based index of first set bit. This is an alternate implementation of ntz()
static int64_t pop_andnot(const int64_t *A, const int64_t *B, int32_t wordOffset, int32_t numWords)
Returns the popcount or cardinality of A & ~B. Neither array is modified.
static void CSA(int64_t &h, int64_t &l, int64_t a, int64_t b, int64_t c)
Base class for all Lucene classes.
Definition: LuceneObject.h:31
Definition: AbstractAllTermDocs.h:12

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