1 files changed, 105 insertions, 0 deletions
diff --git a/src/cpu/ozone/null_predictor.hh b/src/cpu/ozone/null_predictor.hh
new file mode 100644
index 000000000..0751338b7
--- /dev/null
+++ b/src/cpu/ozone/null_predictor.hh
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2006 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: Kevin Lim
+ */
+
+#ifndef __CPU_OZONE_NULL_PREDICTOR_HH__
+#define __CPU_OZONE_NULL_PREDICTOR_HH__
+
+#include "cpu/inst_seq.hh"
+#include "sim/host.hh"
+
+template <class Impl>
+class NullPredictor
+{
+  public:
+    typedef typename Impl::Params Params;
+    typedef typename Impl::DynInstPtr DynInstPtr;
+
+    NullPredictor(Params *p) { }
+
+    struct BPredInfo {
+        BPredInfo()
+            : PC(0), nextPC(0)
+        { }
+
+        BPredInfo(const Addr &pc, const Addr &next_pc)
+            : PC(pc), nextPC(next_pc)
+        { }
+
+        Addr PC;
+        Addr nextPC;
+    };
+
+    BPredInfo lookup(Addr &PC) { return BPredInfo(PC, PC+4); }
+
+    void undo(BPredInfo &bp_info) { return; }
+
+    /**
+     * Predicts whether or not the instruction is a taken branch, and the
+     * target of the branch if it is taken.
+     * @param inst The branch instruction.
+     * @param PC The predicted PC is passed back through this parameter.
+     * @param tid The thread id.
+     * @return Returns if the branch is taken or not.
+     */
+    bool predict(DynInstPtr &inst, Addr &PC, unsigned tid)
+    { return false; }
+
+    /**
+     * Tells the branch predictor to commit any updates until the given
+     * sequence number.
+     * @param done_sn The sequence number to commit any older updates up until.
+     * @param tid The thread id.
+     */
+    void update(const InstSeqNum &done_sn, unsigned tid) { }
+
+    /**
+     * Squashes all outstanding updates until a given sequence number.
+     * @param squashed_sn The sequence number to squash any younger updates up
+     * until.
+     * @param tid The thread id.
+     */
+    void squash(const InstSeqNum &squashed_sn, unsigned tid) { }
+
+    /**
+     * Squashes all outstanding updates until a given sequence number, and
+     * corrects that sn's update with the proper address and taken/not taken.
+     * @param squashed_sn The sequence number to squash any younger updates up
+     * until.
+     * @param corr_target The correct branch target.
+     * @param actually_taken The correct branch direction.
+     * @param tid The thread id.
+     */
+    void squash(const InstSeqNum &squashed_sn, const Addr &corr_target,
+                bool actually_taken, unsigned tid)
+    { }
+
+};
+
+#endif // __CPU_OZONE_NULL_PREDICTOR_HH__