mem-cache: Create BIP Replacement Policy

Implementation of a Bimodal Insertion Policy replacement policy.

Change-Id: Ife058d0d4310dbcb35858348006189f0b2bf7c37
Reviewed-on: https://gem5-review.googlesource.com/9003
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/src/mem/cache/replacement_policies/bip_rp.cc b/src/mem/cache/replacement_policies/bip_rp.cc
new file mode 100644
index 000000000..215711bb9
--- /dev/null
+++ b/src/mem/cache/replacement_policies/bip_rp.cc
@@ -0,0 +1,59 @@
+/**
+ * Copyright (c) 2018 Inria
+ * 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 "mem/cache/replacement_policies/bip_rp.hh"
+
+#include "base/random.hh"
+#include "debug/CacheRepl.hh"
+
+BIPRP::BIPRP(const Params *p)
+    : LRURP(p), btp(p->btp)
+{
+}
+
+void
+BIPRP::reset(CacheBlk *blk)
+{
+    BaseReplacementPolicy::reset(blk);
+
+    // Blocks are inserted as MRU if lower than btp, LRU otherwise
+    if (random_mt.random<unsigned>(1, 100) <= btp) {
+        blk->lastTouchTick = curTick();
+    } else {
+        // Make their timestamps as old as possible, so that they become LRU
+        blk->lastTouchTick = 0;
+    }
+}
+
+BIPRP*
+BIPRPParams::create()
+{
+    return new BIPRP(this);
+}