| /* |
| * 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/MultiBitSelBloomFilter.hh" |
| |
| #include <limits> |
| |
| #include "base/bitfield.hh" |
| #include "params/MultiBitSelBloomFilter.hh" |
| |
| MultiBitSelBloomFilter::MultiBitSelBloomFilter( |
| const MultiBitSelBloomFilterParams* p) |
| : AbstractBloomFilter(p), numHashes(p->num_hashes), |
| skipBits(p->skip_bits), |
| parFilterSize(p->size / numHashes), |
| isParallel(p->is_parallel) |
| { |
| } |
| |
| MultiBitSelBloomFilter::~MultiBitSelBloomFilter() |
| { |
| } |
| |
| void |
| MultiBitSelBloomFilter::merge(const AbstractBloomFilter *other) |
| { |
| auto cast_other = static_cast<const MultiBitSelBloomFilter*>(other); |
| assert(filter.size() == cast_other->filter.size()); |
| for (int i = 0; i < filter.size(); ++i){ |
| filter[i] |= cast_other->filter[i]; |
| } |
| } |
| |
| void |
| MultiBitSelBloomFilter::set(Addr addr) |
| { |
| for (int i = 0; i < numHashes; i++) { |
| int idx = hash(addr, i); |
| filter[idx] = 1; |
| } |
| } |
| |
| int |
| MultiBitSelBloomFilter::getCount(Addr addr) const |
| { |
| int count = 0; |
| for (int i=0; i < numHashes; i++) { |
| count += filter[hash(addr, i)]; |
| } |
| return count; |
| } |
| |
| int |
| MultiBitSelBloomFilter::hash(Addr addr, int hash_number) const |
| { |
| uint64_t x = bits(addr, std::numeric_limits<Addr>::digits - 1, |
| offsetBits) >> skipBits; |
| int y = hashBitsel(x, hash_number, numHashes, 30, sizeBits); |
| //36-bit addresses, 6-bit cache lines |
| |
| if (isParallel) { |
| return (y % parFilterSize) + hash_number * parFilterSize; |
| } else { |
| return y % filter.size(); |
| } |
| } |
| |
| int |
| MultiBitSelBloomFilter::hashBitsel(uint64_t value, int index, int jump, |
| int maxBits, int numBits) const |
| { |
| uint64_t mask = 1; |
| int result = 0; |
| int bit, i; |
| |
| for (i = 0; i < numBits; i++) { |
| bit = (index + jump*i) % maxBits; |
| if (value & (mask << bit)) result += mask << i; |
| } |
| return result; |
| } |
| |
| MultiBitSelBloomFilter* |
| MultiBitSelBloomFilterParams::create() |
| { |
| return new MultiBitSelBloomFilter(this); |
| } |