1 files changed, 74 insertions, 0 deletions
diff --git a/src/mem/cache/prefetch/ghb.cc b/src/mem/cache/prefetch/ghb.cc
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+++ b/src/mem/cache/prefetch/ghb.cc
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+/*
+ * Copyright (c) 2005 The Regents of The University of Michigan
+ * 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: Ron Dreslinski
+ *          Steve Reinhardt
+ */
+
+/**
+ * @file
+ * GHB Prefetcher implementation.
+ */
+
+#include "mem/cache/prefetch/ghb_prefetcher.hh"
+#include "arch/isa_traits.hh"
+
+void
+GHBPrefetcher::calculatePrefetch(PacketPtr &pkt, std::list<Addr> &addresses,
+                                 std::list<Tick> &delays)
+{
+    Addr blkAddr = pkt->getAddr() & ~(Addr)(this->blkSize-1);
+    int cpuID = pkt->req->getCpuNum();
+    if (!useCPUId) cpuID = 0;
+
+
+    int new_stride = blkAddr - last_miss_addr[cpuID];
+    int old_stride = last_miss_addr[cpuID] -
+        second_last_miss_addr[cpuID];
+
+    second_last_miss_addr[cpuID] = last_miss_addr[cpuID];
+    last_miss_addr[cpuID] = blkAddr;
+
+    if (new_stride == old_stride) {
+        for (int d=1; d <= degree; d++) {
+            Addr newAddr = blkAddr + d * new_stride;
+            if (this->pageStop &&
+                (blkAddr & ~(TheISA::VMPageSize - 1)) !=
+                (newAddr & ~(TheISA::VMPageSize - 1)))
+            {
+                //Spanned the page, so now stop
+                this->pfSpanPage += degree - d + 1;
+                return;
+            }
+            else
+            {
+                addresses.push_back(newAddr);
+                delays.push_back(latency);
+            }
+        }
+    }
+}