1 files changed, 106 insertions, 0 deletions
diff --git a/src/base/filters/multi_bit_sel_bloom_filter.cc b/src/base/filters/multi_bit_sel_bloom_filter.cc
new file mode 100644
index 000000000..efd20c315
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+++ b/src/base/filters/multi_bit_sel_bloom_filter.cc
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2019 Inria
+ * 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.
+ *
+ * Authors: Daniel Carvalho
+ */
+
+#include "base/filters/multi_bit_sel_bloom_filter.hh"
+
+#include <limits>
+
+#include "base/bitfield.hh"
+#include "base/logging.hh"
+#include "params/BloomFilterMultiBitSel.hh"
+
+namespace BloomFilter {
+
+MultiBitSel::MultiBitSel(const BloomFilterMultiBitSelParams* p)
+    : Base(p), numHashes(p->num_hashes),
+      parFilterSize(p->size / numHashes),
+      isParallel(p->is_parallel), skipBits(p->skip_bits)
+{
+    if (p->size % numHashes) {
+        fatal("Can't divide filter (%d) in %d equal portions", p->size,
+              numHashes);
+    }
+}
+
+MultiBitSel::~MultiBitSel()
+{
+}
+
+void
+MultiBitSel::set(Addr addr)
+{
+    for (int i = 0; i < numHashes; i++) {
+        int idx = hash(addr, i);
+        filter[idx] = 1;
+    }
+}
+
+int
+MultiBitSel::getCount(Addr addr) const
+{
+    int count = 0;
+    for (int i=0; i < numHashes; i++) {
+        count += filter[hash(addr, i)];
+    }
+    return count;
+}
+
+int
+MultiBitSel::hash(Addr addr, int hash_number) const
+{
+    uint64_t value = bits(addr, std::numeric_limits<Addr>::digits - 1,
+        offsetBits) >> skipBits;
+    const int max_bits = std::numeric_limits<Addr>::digits - offsetBits;
+    int result = 0;
+    int bit, i;
+
+    for (i = 0; i < sizeBits; i++) {
+        bit = (hash_number + numHashes * i) % max_bits;
+        if (value & (1 << bit)) {
+            result += 1 << i;
+        }
+    }
+
+    if (isParallel) {
+        return (result % parFilterSize) + hash_number * parFilterSize;
+    } else {
+        return result % filter.size();
+    }
+}
+
+} // namespace BloomFilter
+
+BloomFilter::MultiBitSel*
+BloomFilterMultiBitSelParams::create()
+{
+    return new BloomFilter::MultiBitSel(this);
+}
+