gecko-dev/ef/Utilities/General/NewFastBitSet.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#include "Fundamentals.h"
#include "FastBitSet.h"
#include "Pool.h"
//
// Resize the bitset to sizeInBits. All the bits present in the bitset will be lost.
// The bitset will be unitialized. A call to clear() or set() is needed after sizeTo() !!!
//
void FastBitSet::sizeTo(Pool& pool, Uint32 sizeInBits)
{
PR_ASSERT(sizeInBits);
Uint32 newSizeInWords = getNumberOfWords(sizeInBits);
if (newSizeInWords > sizeInWords) {
sizeInWords = newSizeInWords;
bits = new(pool) Uint32[newSizeInWords];
}
#ifdef DEBUG_LOG
this->sizeInBits = sizeInBits;
#endif /* DEBUG_LOG */
}
//
// Set the bits (in this bitset) that are defined in x and return true if this bitset changed.
//
bool FastBitSet::set(const FastBitSet& x)
{
PR_ASSERT(sizeInWords == x.sizeInWords);
bool differ = false;
Uint32* dst = bits;
Uint32* src = x.bits;
Int32 count = sizeInWords - 1;
do {
Uint32 oldWord = dst[count];
Uint32 newWord = oldWord | src[count];
differ |= (newWord != oldWord);
dst[count] = newWord;
} while(--count >= 0);
return differ;
}
//
// Arithmetic operators.
//
#define FastBitSetOperation(x, op) \
PR_ASSERT(sizeInWords && sizeInWords == x.sizeInWords); \
Uint32* dst = bits; \
Uint32* src = x.bits; \
Int32 count = sizeInWords < x.sizeInWords ? sizeInWords - 1 : x.sizeInWords - 1; \
do { \
dst[count] op src[count]; \
} while(--count >= 0);
FastBitSet& FastBitSet::operator |= (const FastBitSet& x)
{
FastBitSetOperation(x, |=);
return *this;
}
FastBitSet& FastBitSet::operator &= (const FastBitSet& x)
{
FastBitSetOperation(x, &=);
return *this;
}
FastBitSet& FastBitSet::operator ^= (const FastBitSet& x)
{
FastBitSetOperation(x, ^=);
return *this;
}
FastBitSet& FastBitSet::operator -= (const FastBitSet& x)
{
FastBitSetOperation(x, &= ~);
return *this;
}
//
// Copy operator.
//
FastBitSet& FastBitSet::operator = (const FastBitSet& x)
{
FastBitSetOperation(x, = );
return *this;
}
#undef FastBitSetOperation
//
// Comparison operator.
//
bool operator == (const FastBitSet& x, const FastBitSet& y)
{
PR_ASSERT(x.sizeInWords == y.sizeInWords);
Uint32* srcX = x.bits;
Uint32* srcY = y.bits;
Uint32* limitX = &srcX[x.sizeInWords];
while (srcX < limitX)
if (*srcX++ != *srcY++)
return false;
return true;
}
//
// Return the next '1' bit just after pos or -1 if not found.
//
Int32 FastBitSet::nextOne(Int32 pos) const
{
PR_ASSERT(sizeInWords);
++pos; // Skip this bit.
Uint32 wordOffset = getWordOffset(pos);
if (wordOffset < sizeInWords) {
Uint32* ptr = &bits[wordOffset];
Uint8 bitOffset = getBitOffset(pos);
Uint32 word = *ptr++ >> bitOffset;
if (word != 0) {
while ((word & 3) == 0) {
bitOffset+=2;
word >>= 2;
}
if ((word & 1) == 0)
bitOffset++;
return (wordOffset << 5) + bitOffset;
}
Uint32* limit = &bits[sizeInWords];
for (++wordOffset; ptr < limit; ++wordOffset) {
word = *ptr++;
if (word != 0) {
bitOffset = 0;
while ((word & 3) == 0) {
bitOffset+=2;
word >>= 2;
}
if ((word & 1) == 0)
bitOffset++;
return (wordOffset << 5) + bitOffset;
}
}
}
return -1;
}
//
// Return the '1' bit just before pos or -1 if not found.
//
Int32 FastBitSet::previousOne(Int32 pos) const
{
PR_ASSERT(sizeInWords);
--pos; // Skip this bit.
Uint32 wordOffset = getWordOffset(pos);
if (wordOffset < sizeInWords) {
Uint32* ptr = &bits[wordOffset];
Uint8 bitOffset = getBitOffset(pos);
Uint32 word = *ptr-- << (31 - bitOffset);
if (word != 0) {
while ((word & 0x80000000) == 0) {
bitOffset--;
word <<= 1;
}
return (wordOffset << 5) + bitOffset;
}
Uint32* limit = bits;
for (--wordOffset; ptr >= limit; --wordOffset) {
word = *ptr--;
if (word != 0) {
bitOffset = 31;
while ((word & 0x80000000) == 0) {
bitOffset--;
word <<= 1;
}
return (wordOffset << 5) + bitOffset;
}
}
}
return -1;
}
//
// Return the next '0' bit just after pos or -1 if not found.
//
Int32 FastBitSet::nextZero(Int32 pos) const
{
PR_ASSERT(sizeInWords);
++pos; // Skip this bit.
Uint32 wordOffset = getWordOffset(pos);
if (wordOffset < sizeInWords) {
Uint32* ptr = &bits[wordOffset];
Uint8 bitOffset = getBitOffset(pos);
Uint32 word = *ptr++ >> bitOffset;
if (word != Uint32(~0)) {
while (word & 1) {
bitOffset++;
word >>= 1;
}
return (wordOffset << 5) + bitOffset;
}
Uint32* limit = &bits[sizeInWords];
for (++wordOffset; ptr < limit; ++wordOffset) {
word = *ptr++;
if (word != Uint32(~0)) {
bitOffset = 0;
while (word & 1) {
bitOffset++;
word >>= 1;
}
return (wordOffset << 5) + bitOffset;
}
}
}
return -1;
}
//
// Return the '0' bit just before pos or -1 if not found.
//
Int32 FastBitSet::previousZero(Int32 pos) const
{
PR_ASSERT(sizeInWords);
--pos; // Skip this bit.
Uint32 wordOffset = getWordOffset(pos);
if (wordOffset < sizeInWords) {
Uint32* ptr = &bits[wordOffset];
Uint8 bitOffset = getBitOffset(pos);
Uint8 shift = (31 - bitOffset);
Uint32 word = *ptr-- << shift;
if (word != (Uint32(~0) << shift)) {
while (word & 0x80000000) {
bitOffset--;
word <<= 1;
}
return (wordOffset << 5) + bitOffset;
}
Uint32* limit = bits;
for (--wordOffset; ptr >= limit; --wordOffset) {
word = *ptr--;
if (word != Uint32(~0)) {
bitOffset = 31;
while (word & 0x80000000) {
bitOffset--;
word <<= 1;
}
return (wordOffset << 5) + bitOffset;
}
}
}
return -1;
}
//
// Set the bits from position 'from' to position 'to'.
//
void FastBitSet::set(Uint32 from, Uint32 to)
{
Uint32* ptr = &bits[getWordOffset(from)];
Uint32* limit = &bits[getWordOffset(to)];
Uint32 beginMask = ~((1 << getBitOffset(from)) - 1); // 11..(32 - from) times..1100..from times..00
Uint32 endMask = (2 << getBitOffset(to)) - 1; // 00..(32 - to) times..0011..to times..11
if (ptr == limit) {
*ptr |= (beginMask & endMask);
} else {
register Uint32 val = ~0;
*ptr++ |= beginMask;
while (ptr < limit)
*ptr++ = val;
*limit |= endMask;
}
}
#ifdef DEBUG_LOG
//
// Print the bitset.
//
void FastBitSet::printPretty(FILE* f) const
{
PR_ASSERT(sizeInWords);
fprintf(f, "[");
for (PRUint32 bit = 0; bit < sizeInBits; bit++)
fprintf(f, test(bit) ? "1" : "0");
fprintf(f, "]\n");
}
//
// Print the difference between this bitset and the given biset.
//
void FastBitSet::printDiff(FILE *f, const FastBitSet& x) const
{
fprintf(f, "[");
for (Uint32 i = 0; i < sizeInBits; i++)
if (test(i) != x.test(i))
fprintf(f, test(i) ? "-" : "+");
else
fprintf(f, test(i) ? "1" : "0");
fprintf(f, "]\n");
}
//
// Print all the '1' bits.
//
void FastBitSet::printPrettyOnes(FILE* f) const
{
PR_ASSERT(sizeInWords);
fprintf(f, "[ ");
for (Int32 bit = firstOne(); !done(bit); bit = nextOne(bit))
fprintf(f, "%d ", bit);
fprintf(f, "]\n");
}
//
// Print all the '0' bits.
//
void FastBitSet::printPrettyZeros(FILE* f) const
{
PR_ASSERT(sizeInWords);
fprintf(f, "[ ");
for (Int32 bit = firstZero(); !done(bit); bit = nextZero(bit))
fprintf(f, "%d ", bit);
fprintf(f, "]\n");
}
#endif /* DEBUG_LOG */