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bitvec.cpp
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1 /******************************************************************************
2  ** Filename: bitvec.c
3  ** Purpose: Routines for manipulating bit vectors
4  ** Author: Dan Johnson
5  ** History: Thu Mar 15 10:37:27 1990, DSJ, Created.
6  **
7  ** (c) Copyright Hewlett-Packard Company, 1988.
8  ** Licensed under the Apache License, Version 2.0 (the "License");
9  ** you may not use this file except in compliance with the License.
10  ** You may obtain a copy of the License at
11  ** http://www.apache.org/licenses/LICENSE-2.0
12  ** Unless required by applicable law or agreed to in writing, software
13  ** distributed under the License is distributed on an "AS IS" BASIS,
14  ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  ** See the License for the specific language governing permissions and
16  ** limitations under the License.
17  ******************************************************************************/
18 
19 /*-----------------------------------------------------------------------------
20  Include Files and Type Defines
21 -----------------------------------------------------------------------------*/
22 #include "bitvec.h"
23 
24 #include <stdio.h>
25 
26 #include "emalloc.h"
27 #include "freelist.h"
28 #include "tprintf.h"
29 
30 /*-----------------------------------------------------------------------------
31  Public Code
32 -----------------------------------------------------------------------------*/
33 /*---------------------------------------------------------------------------*/
48 BIT_VECTOR ExpandBitVector(BIT_VECTOR Vector, int NewNumBits) {
49  return ((BIT_VECTOR) Erealloc(Vector,
50  sizeof(Vector[0]) * WordsInVectorOfSize(NewNumBits)));
51 } /* ExpandBitVector */
52 
53 
54 /*---------------------------------------------------------------------------*/
55 void FreeBitVector(BIT_VECTOR BitVector) {
70  if (BitVector) {
71  Efree(BitVector);
72  }
73 } /* FreeBitVector */
74 
75 
80 /*--------------------------------------------------------------------------*/
81 int hamming_distance(uinT32* array1, uinT32* array2, int length) {
82  register uinT32 diff; /*bit difference */
83  register int dist; /*total distance */
84 
85  dist = 0;
86  for (; length > 0; length--) {
87  diff = *array1++ ^ *array2++;/*different bits */
88  while (diff) {
89  diff &= diff - 1; /*lose a bit */
90  dist++;
91  }
92  }
93  return dist; /*total distance */
94 }
95 
96 
97 /*---------------------------------------------------------------------------*/
111 BIT_VECTOR NewBitVector(int NumBits) {
112  return ((BIT_VECTOR) Emalloc(sizeof(uinT32) *
113  WordsInVectorOfSize(NumBits)));
114 } /* NewBitVector */