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/*
* Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* 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;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 THE COPYRIGHT
* OWNER 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 "mem/ruby/filters/BulkBloomFilter.hh"
#include <cassert>
#include "base/intmath.hh"
#include "base/str.hh"
#include "mem/ruby/system/RubySystem.hh"
using namespace std;
BulkBloomFilter::BulkBloomFilter(int size)
{
m_filter_size = size;
m_filter_size_bits = floorLog2(m_filter_size);
// split the filter bits in half, c0 and c1
m_sector_bits = m_filter_size_bits - 1;
m_temp_filter.resize(m_filter_size);
m_filter.resize(m_filter_size);
clear();
// clear temp filter
for (int i = 0; i < m_filter_size; ++i) {
m_temp_filter[i] = 0;
}
}
BulkBloomFilter::~BulkBloomFilter()
{
}
void
BulkBloomFilter::clear()
{
for (int i = 0; i < m_filter_size; i++) {
m_filter[i] = 0;
}
}
void
BulkBloomFilter::merge(AbstractBloomFilter * other_filter)
{
// TODO
}
void
BulkBloomFilter::set(Addr addr)
{
// c0 contains the cache index bits
int set_bits = m_sector_bits;
int block_bits = RubySystem::getBlockSizeBits();
int c0 = bitSelect(addr, block_bits, block_bits + set_bits - 1);
// c1 contains the lower m_sector_bits permuted bits
//Address permuted_bits = permute(addr);
//int c1 = permuted_bits.bitSelect(0, set_bits-1);
int c1 = bitSelect(addr, block_bits+set_bits, (block_bits+2*set_bits) - 1);
//assert(c0 < (m_filter_size/2));
//assert(c0 + (m_filter_size/2) < m_filter_size);
//assert(c1 < (m_filter_size/2));
// set v0 bit
m_filter[c0 + (m_filter_size/2)] = 1;
// set v1 bit
m_filter[c1] = 1;
}
bool
BulkBloomFilter::isSet(Addr addr)
{
// c0 contains the cache index bits
int set_bits = m_sector_bits;
int block_bits = RubySystem::getBlockSizeBits();
int c0 = bitSelect(addr, block_bits, block_bits + set_bits - 1);
// c1 contains the lower 10 permuted bits
//Address permuted_bits = permute(addr);
//int c1 = permuted_bits.bitSelect(0, set_bits-1);
int c1 = bitSelect(addr, block_bits+set_bits, (block_bits+2*set_bits) - 1);
//assert(c0 < (m_filter_size/2));
//assert(c0 + (m_filter_size/2) < m_filter_size);
//assert(c1 < (m_filter_size/2));
// set v0 bit
m_temp_filter[c0 + (m_filter_size/2)] = 1;
// set v1 bit
m_temp_filter[c1] = 1;
// perform filter intersection. If any c part is 0, no possibility
// of address being in signature. get first c intersection part
bool zero = false;
for (int i = 0; i < m_filter_size/2; ++i){
// get intersection of signatures
m_temp_filter[i] = m_temp_filter[i] && m_filter[i];
zero = zero || m_temp_filter[i];
}
zero = !zero;
if (zero) {
// one section is zero, no possiblility of address in signature
// reset bits we just set
m_temp_filter[c0 + (m_filter_size / 2)] = 0;
m_temp_filter[c1] = 0;
return false;
}
// check second section
zero = false;
for (int i = m_filter_size / 2; i < m_filter_size; ++i) {
// get intersection of signatures
m_temp_filter[i] = m_temp_filter[i] && m_filter[i];
zero = zero || m_temp_filter[i];
}
zero = !zero;
if (zero) {
// one section is zero, no possiblility of address in signature
m_temp_filter[c0 + (m_filter_size / 2)] = 0;
m_temp_filter[c1] = 0;
return false;
}
// one section has at least one bit set
m_temp_filter[c0 + (m_filter_size / 2)] = 0;
m_temp_filter[c1] = 0;
return true;
}
int
BulkBloomFilter::getCount(Addr addr)
{
// not used
return 0;
}
int
BulkBloomFilter::getTotalCount()
{
int count = 0;
for (int i = 0; i < m_filter_size; i++) {
if (m_filter[i]) {
count++;
}
}
return count;
}
int
BulkBloomFilter::getIndex(Addr addr)
{
return get_index(addr);
}
int
BulkBloomFilter::readBit(const int index)
{
return 0;
// TODO
}
void
BulkBloomFilter::writeBit(const int index, const int value)
{
// TODO
}
void
BulkBloomFilter::print(ostream& out) const
{
}
int
BulkBloomFilter::get_index(Addr addr)
{
return bitSelect(addr, RubySystem::getBlockSizeBits(),
RubySystem::getBlockSizeBits() +
m_filter_size_bits - 1);
}
Addr
BulkBloomFilter::permute(Addr addr)
{
// permutes the original address bits according to Table 5
int block_offset = RubySystem::getBlockSizeBits();
Addr part1 = bitSelect(addr, block_offset, block_offset + 6),
part2 = bitSelect(addr, block_offset + 9, block_offset + 9),
part3 = bitSelect(addr, block_offset + 11, block_offset + 11),
part4 = bitSelect(addr, block_offset + 17, block_offset + 17),
part5 = bitSelect(addr, block_offset + 7, block_offset + 8),
part6 = bitSelect(addr, block_offset + 10, block_offset + 10),
part7 = bitSelect(addr, block_offset + 12, block_offset + 12),
part8 = bitSelect(addr, block_offset + 13, block_offset + 13),
part9 = bitSelect(addr, block_offset + 15, block_offset + 16),
part10 = bitSelect(addr, block_offset + 18, block_offset + 20),
part11 = bitSelect(addr, block_offset + 14, block_offset + 14);
Addr result =
(part1 << 14) | (part2 << 13) | (part3 << 12) | (part4 << 11) |
(part5 << 9) | (part6 << 8) | (part7 << 7) | (part8 << 6) |
(part9 << 4) | (part10 << 1) | (part11);
// assume 32 bit addresses (both virtual and physical)
// select the remaining high-order 11 bits
Addr remaining_bits =
bitSelect(addr, block_offset + 21, 31) << 21;
result = result | remaining_bits;
return result;
}