text: /*
   * Copyright (c) 2004-2005 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.
   */
  
  #include "cpu/pred/ras.hh"
  
  namespace gem5
  {
  
  namespace branch_prediction
  {
  
  void
  ReturnAddrStack::init(unsigned _numEntries)
  {
      numEntries = _numEntries;
      addrStack.resize(numEntries);
      reset();
  }
  
  void
  ReturnAddrStack::reset()
  {
      usedEntries = 0;
      tos = 0;
      for (unsigned i = 0; i < numEntries; ++i)
          addrStack[i].set(0);
  }
  
  void
  ReturnAddrStack::push(const TheISA::PCState &return_addr)
  {
      incrTos();
  
      addrStack[tos] = return_addr;
  
      if (usedEntries != numEntries) {
          ++usedEntries;
      }
  }
  
  void
  ReturnAddrStack::pop()
  {
      if (usedEntries > 0) {
          --usedEntries;
      }
  
      decrTos();
  }
  
  void
  ReturnAddrStack::restore(unsigned top_entry_idx,
                           const TheISA::PCState &restored)
  {
      tos = top_entry_idx;
  
      addrStack[tos] = restored;
  
      if (usedEntries != numEntries) {
          ++usedEntries;
      }
  }
  
  } // namespace branch_prediction
  } // namespace gem5
  