1/*
2 * Copyright (C) 2011 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include <wtf/BitVector.h>
28
29#include <algorithm>
30#include <string.h>
31#include <wtf/Assertions.h>
32#include <wtf/FastMalloc.h>
33#include <wtf/StdLibExtras.h>
34
35namespace WTF {
36
37void BitVector::setSlow(const BitVector& other)
38{
39 uintptr_t newBitsOrPointer;
40 if (other.isInline() || other.isEmptyOrDeletedValue())
41 newBitsOrPointer = other.m_bitsOrPointer;
42 else {
43 OutOfLineBits* newOutOfLineBits = OutOfLineBits::create(other.size());
44 memcpy(newOutOfLineBits->bits(), other.bits(), byteCount(other.size()));
45 newBitsOrPointer = bitwise_cast<uintptr_t>(newOutOfLineBits) >> 1;
46 }
47 if (!isInline() && !isEmptyOrDeletedValue())
48 OutOfLineBits::destroy(outOfLineBits());
49 m_bitsOrPointer = newBitsOrPointer;
50}
51
52void BitVector::resize(size_t numBits)
53{
54 if (numBits <= maxInlineBits()) {
55 if (isInline())
56 return;
57
58 OutOfLineBits* myOutOfLineBits = outOfLineBits();
59 m_bitsOrPointer = makeInlineBits(*myOutOfLineBits->bits());
60 OutOfLineBits::destroy(myOutOfLineBits);
61 return;
62 }
63
64 resizeOutOfLine(numBits);
65}
66
67void BitVector::clearAll()
68{
69 if (isInline())
70 m_bitsOrPointer = makeInlineBits(0);
71 else
72 memset(outOfLineBits()->bits(), 0, byteCount(size()));
73}
74
75BitVector::OutOfLineBits* BitVector::OutOfLineBits::create(size_t numBits)
76{
77 numBits = (numBits + bitsInPointer() - 1) & ~(static_cast<size_t>(bitsInPointer()) - 1);
78 size_t size = sizeof(OutOfLineBits) + sizeof(uintptr_t) * (numBits / bitsInPointer());
79 OutOfLineBits* result = new (NotNull, fastMalloc(size)) OutOfLineBits(numBits);
80 return result;
81}
82
83void BitVector::OutOfLineBits::destroy(OutOfLineBits* outOfLineBits)
84{
85 fastFree(outOfLineBits);
86}
87
88void BitVector::resizeOutOfLine(size_t numBits)
89{
90 ASSERT(numBits > maxInlineBits());
91 OutOfLineBits* newOutOfLineBits = OutOfLineBits::create(numBits);
92 size_t newNumWords = newOutOfLineBits->numWords();
93 if (isInline()) {
94 // Make sure that all of the bits are zero in case we do a no-op resize.
95 *newOutOfLineBits->bits() = m_bitsOrPointer & ~(static_cast<uintptr_t>(1) << maxInlineBits());
96 memset(newOutOfLineBits->bits() + 1, 0, (newNumWords - 1) * sizeof(void*));
97 } else {
98 if (numBits > size()) {
99 size_t oldNumWords = outOfLineBits()->numWords();
100 memcpy(newOutOfLineBits->bits(), outOfLineBits()->bits(), oldNumWords * sizeof(void*));
101 memset(newOutOfLineBits->bits() + oldNumWords, 0, (newNumWords - oldNumWords) * sizeof(void*));
102 } else
103 memcpy(newOutOfLineBits->bits(), outOfLineBits()->bits(), newOutOfLineBits->numWords() * sizeof(void*));
104 OutOfLineBits::destroy(outOfLineBits());
105 }
106 m_bitsOrPointer = bitwise_cast<uintptr_t>(newOutOfLineBits) >> 1;
107}
108
109void BitVector::mergeSlow(const BitVector& other)
110{
111 if (other.isInline()) {
112 ASSERT(!isInline());
113 *bits() |= cleanseInlineBits(other.m_bitsOrPointer);
114 return;
115 }
116
117 ensureSize(other.size());
118 ASSERT(!isInline());
119 ASSERT(!other.isInline());
120
121 OutOfLineBits* a = outOfLineBits();
122 const OutOfLineBits* b = other.outOfLineBits();
123 for (unsigned i = a->numWords(); i--;)
124 a->bits()[i] |= b->bits()[i];
125}
126
127void BitVector::filterSlow(const BitVector& other)
128{
129 if (other.isInline()) {
130 ASSERT(!isInline());
131 *bits() &= cleanseInlineBits(other.m_bitsOrPointer);
132 return;
133 }
134
135 if (isInline()) {
136 ASSERT(!other.isInline());
137 m_bitsOrPointer &= *other.outOfLineBits()->bits();
138 m_bitsOrPointer |= (static_cast<uintptr_t>(1) << maxInlineBits());
139 ASSERT(isInline());
140 return;
141 }
142
143 OutOfLineBits* a = outOfLineBits();
144 const OutOfLineBits* b = other.outOfLineBits();
145 for (unsigned i = std::min(a->numWords(), b->numWords()); i--;)
146 a->bits()[i] &= b->bits()[i];
147
148 for (unsigned i = b->numWords(); i < a->numWords(); ++i)
149 a->bits()[i] = 0;
150}
151
152void BitVector::excludeSlow(const BitVector& other)
153{
154 if (other.isInline()) {
155 ASSERT(!isInline());
156 *bits() &= ~cleanseInlineBits(other.m_bitsOrPointer);
157 return;
158 }
159
160 if (isInline()) {
161 ASSERT(!other.isInline());
162 m_bitsOrPointer &= ~*other.outOfLineBits()->bits();
163 m_bitsOrPointer |= (static_cast<uintptr_t>(1) << maxInlineBits());
164 ASSERT(isInline());
165 return;
166 }
167
168 OutOfLineBits* a = outOfLineBits();
169 const OutOfLineBits* b = other.outOfLineBits();
170 for (unsigned i = std::min(a->numWords(), b->numWords()); i--;)
171 a->bits()[i] &= ~b->bits()[i];
172}
173
174size_t BitVector::bitCountSlow() const
175{
176 ASSERT(!isInline());
177 const OutOfLineBits* bits = outOfLineBits();
178 size_t result = 0;
179 for (unsigned i = bits->numWords(); i--;)
180 result += bitCount(bits->bits()[i]);
181 return result;
182}
183
184bool BitVector::isEmptySlow() const
185{
186 ASSERT(!isInline());
187 const OutOfLineBits* bits = outOfLineBits();
188 for (unsigned i = bits->numWords(); i--;) {
189 if (bits->bits()[i])
190 return false;
191 }
192 return true;
193}
194
195bool BitVector::equalsSlowCase(const BitVector& other) const
196{
197 bool result = equalsSlowCaseFast(other);
198 ASSERT(result == equalsSlowCaseSimple(other));
199 return result;
200}
201
202bool BitVector::equalsSlowCaseFast(const BitVector& other) const
203{
204 if (isInline() != other.isInline())
205 return equalsSlowCaseSimple(other);
206
207 const OutOfLineBits* myBits = outOfLineBits();
208 const OutOfLineBits* otherBits = other.outOfLineBits();
209
210 size_t myNumWords = myBits->numWords();
211 size_t otherNumWords = otherBits->numWords();
212 size_t minNumWords;
213 size_t maxNumWords;
214
215 const OutOfLineBits* longerBits;
216 if (myNumWords < otherNumWords) {
217 minNumWords = myNumWords;
218 maxNumWords = otherNumWords;
219 longerBits = otherBits;
220 } else {
221 minNumWords = otherNumWords;
222 maxNumWords = myNumWords;
223 longerBits = myBits;
224 }
225
226 for (size_t i = minNumWords; i < maxNumWords; ++i) {
227 if (longerBits->bits()[i])
228 return false;
229 }
230
231 for (size_t i = minNumWords; i--;) {
232 if (myBits->bits()[i] != otherBits->bits()[i])
233 return false;
234 }
235
236 return true;
237}
238
239bool BitVector::equalsSlowCaseSimple(const BitVector& other) const
240{
241 // This is really cheesy, but probably good enough for now.
242 for (unsigned i = std::max(size(), other.size()); i--;) {
243 if (get(i) != other.get(i))
244 return false;
245 }
246 return true;
247}
248
249uintptr_t BitVector::hashSlowCase() const
250{
251 ASSERT(!isInline());
252 const OutOfLineBits* bits = outOfLineBits();
253 uintptr_t result = 0;
254 for (unsigned i = bits->numWords(); i--;)
255 result ^= bits->bits()[i];
256 return result;
257}
258
259void BitVector::dump(PrintStream& out) const
260{
261 for (size_t i = 0; i < size(); ++i) {
262 if (get(i))
263 out.printf("1");
264 else
265 out.printf("-");
266 }
267}
268
269} // namespace WTF
270