blob: 35b039a3551931050a44001d957cfbbd7f36fc3f [file] [log] [blame]
/*
* Copyright (C) 2011-2022 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include <wtf/BitVector.h>
#include <algorithm>
#include <string.h>
#include <wtf/Assertions.h>
#include <wtf/MathExtras.h>
#include <wtf/NeverDestroyed.h>
namespace WTF {
DECLARE_ALLOCATOR_WITH_HEAP_IDENTIFIER(BitVector);
DEFINE_ALLOCATOR_WITH_HEAP_IDENTIFIER(BitVector);
void BitVector::setSlow(const BitVector& other)
{
uintptr_t newBitsOrPointer;
if (other.isInline() || other.isEmptyOrDeletedValue())
newBitsOrPointer = other.m_bitsOrPointer;
else {
OutOfLineBits* newOutOfLineBits = OutOfLineBits::create(other.size());
memcpy(newOutOfLineBits->bits(), other.bits(), byteCount(other.size()));
newBitsOrPointer = bitwise_cast<uintptr_t>(newOutOfLineBits) >> 1;
}
if (!isInline() && !isEmptyOrDeletedValue())
OutOfLineBits::destroy(outOfLineBits());
m_bitsOrPointer = newBitsOrPointer;
}
void BitVector::resize(size_t numBits)
{
if (numBits <= maxInlineBits()) {
if (isInline())
return;
OutOfLineBits* myOutOfLineBits = outOfLineBits();
m_bitsOrPointer = makeInlineBits(*myOutOfLineBits->bits());
OutOfLineBits::destroy(myOutOfLineBits);
return;
}
resizeOutOfLine(numBits);
}
void BitVector::clearAll()
{
if (isInline())
m_bitsOrPointer = makeInlineBits(0);
else
memset(outOfLineBits()->bits(), 0, byteCount(size()));
}
BitVector::OutOfLineBits* BitVector::OutOfLineBits::create(size_t numBits)
{
numBits = (numBits + bitsInPointer() - 1) & ~(static_cast<size_t>(bitsInPointer()) - 1);
size_t size = sizeof(OutOfLineBits) + sizeof(uintptr_t) * (numBits / bitsInPointer());
OutOfLineBits* result = new (NotNull, BitVectorMalloc::malloc(size)) OutOfLineBits(numBits);
return result;
}
void BitVector::OutOfLineBits::destroy(OutOfLineBits* outOfLineBits)
{
BitVectorMalloc::free(outOfLineBits);
}
void BitVector::shiftRightByMultipleOf64(size_t shiftInBits)
{
RELEASE_ASSERT(!(shiftInBits % 64));
static_assert(!(8 % sizeof(void*)), "BitVector::shiftRightByMultipleOf64 assumes that word size is a divisor of 64");
size_t shiftInWords = shiftInBits / (8 * sizeof(void*));
size_t numBits = size() + shiftInBits;
resizeOutOfLine(numBits, shiftInWords);
}
void BitVector::resizeOutOfLine(size_t numBits, size_t shiftInWords)
{
ASSERT(numBits > maxInlineBits());
OutOfLineBits* newOutOfLineBits = OutOfLineBits::create(numBits);
size_t newNumWords = newOutOfLineBits->numWords();
if (isInline()) {
memset(newOutOfLineBits->bits(), 0, shiftInWords * sizeof(void*));
// Make sure that all of the bits are zero in case we do a no-op resize.
*(newOutOfLineBits->bits() + shiftInWords) = m_bitsOrPointer & ~(static_cast<uintptr_t>(1) << maxInlineBits());
RELEASE_ASSERT(shiftInWords + 1 <= newNumWords);
memset(newOutOfLineBits->bits() + shiftInWords + 1, 0, (newNumWords - 1 - shiftInWords) * sizeof(void*));
} else {
if (numBits > size()) {
size_t oldNumWords = outOfLineBits()->numWords();
memset(newOutOfLineBits->bits(), 0, shiftInWords * sizeof(void*));
memcpy(newOutOfLineBits->bits() + shiftInWords, outOfLineBits()->bits(), oldNumWords * sizeof(void*));
RELEASE_ASSERT(shiftInWords + oldNumWords <= newNumWords);
memset(newOutOfLineBits->bits() + shiftInWords + oldNumWords, 0, (newNumWords - oldNumWords - shiftInWords) * sizeof(void*));
} else
memcpy(newOutOfLineBits->bits(), outOfLineBits()->bits(), newOutOfLineBits->numWords() * sizeof(void*));
OutOfLineBits::destroy(outOfLineBits());
}
m_bitsOrPointer = bitwise_cast<uintptr_t>(newOutOfLineBits) >> 1;
}
void BitVector::mergeSlow(const BitVector& other)
{
if (other.isInline()) {
ASSERT(!isInline());
*bits() |= cleanseInlineBits(other.m_bitsOrPointer);
return;
}
ensureSize(other.size());
ASSERT(!isInline());
ASSERT(!other.isInline());
OutOfLineBits* a = outOfLineBits();
const OutOfLineBits* b = other.outOfLineBits();
for (unsigned i = a->numWords(); i--;)
a->bits()[i] |= b->bits()[i];
}
void BitVector::filterSlow(const BitVector& other)
{
if (other.isInline()) {
ASSERT(!isInline());
*bits() &= cleanseInlineBits(other.m_bitsOrPointer);
return;
}
if (isInline()) {
ASSERT(!other.isInline());
m_bitsOrPointer &= *other.outOfLineBits()->bits();
m_bitsOrPointer |= (static_cast<uintptr_t>(1) << maxInlineBits());
ASSERT(isInline());
return;
}
OutOfLineBits* a = outOfLineBits();
const OutOfLineBits* b = other.outOfLineBits();
for (unsigned i = std::min(a->numWords(), b->numWords()); i--;)
a->bits()[i] &= b->bits()[i];
for (unsigned i = b->numWords(); i < a->numWords(); ++i)
a->bits()[i] = 0;
}
void BitVector::excludeSlow(const BitVector& other)
{
if (other.isInline()) {
ASSERT(!isInline());
*bits() &= ~cleanseInlineBits(other.m_bitsOrPointer);
return;
}
if (isInline()) {
ASSERT(!other.isInline());
m_bitsOrPointer &= ~*other.outOfLineBits()->bits();
m_bitsOrPointer |= (static_cast<uintptr_t>(1) << maxInlineBits());
ASSERT(isInline());
return;
}
OutOfLineBits* a = outOfLineBits();
const OutOfLineBits* b = other.outOfLineBits();
for (unsigned i = std::min(a->numWords(), b->numWords()); i--;)
a->bits()[i] &= ~b->bits()[i];
}
size_t BitVector::bitCountSlow() const
{
ASSERT(!isInline());
const OutOfLineBits* bits = outOfLineBits();
size_t result = 0;
for (unsigned i = bits->numWords(); i--;)
result += bitCount(bits->bits()[i]);
return result;
}
bool BitVector::isEmptySlow() const
{
ASSERT(!isInline());
const OutOfLineBits* bits = outOfLineBits();
for (unsigned i = bits->numWords(); i--;) {
if (bits->bits()[i])
return false;
}
return true;
}
bool BitVector::equalsSlowCase(const BitVector& other) const
{
bool result = equalsSlowCaseFast(other);
ASSERT(result == equalsSlowCaseSimple(other));
return result;
}
bool BitVector::equalsSlowCaseFast(const BitVector& other) const
{
if (isInline() != other.isInline())
return equalsSlowCaseSimple(other);
const OutOfLineBits* myBits = outOfLineBits();
const OutOfLineBits* otherBits = other.outOfLineBits();
size_t myNumWords = myBits->numWords();
size_t otherNumWords = otherBits->numWords();
size_t minNumWords;
size_t maxNumWords;
const OutOfLineBits* longerBits;
if (myNumWords < otherNumWords) {
minNumWords = myNumWords;
maxNumWords = otherNumWords;
longerBits = otherBits;
} else {
minNumWords = otherNumWords;
maxNumWords = myNumWords;
longerBits = myBits;
}
for (size_t i = minNumWords; i < maxNumWords; ++i) {
if (longerBits->bits()[i])
return false;
}
for (size_t i = minNumWords; i--;) {
if (myBits->bits()[i] != otherBits->bits()[i])
return false;
}
return true;
}
bool BitVector::equalsSlowCaseSimple(const BitVector& other) const
{
// This is really cheesy, but probably good enough for now.
for (unsigned i = std::max(size(), other.size()); i--;) {
if (get(i) != other.get(i))
return false;
}
return true;
}
uintptr_t BitVector::hashSlowCase() const
{
ASSERT(!isInline());
const OutOfLineBits* bits = outOfLineBits();
uintptr_t result = 0;
for (unsigned i = bits->numWords(); i--;)
result ^= bits->bits()[i];
return result;
}
void BitVector::dump(PrintStream& out) const
{
for (size_t i = 0; i < size(); ++i)
out.print(get(i) ? "1" : "-");
}
} // namespace WTF