cpu/o3/ras.hh

   1 /*
   2  * Copyright (c) 2004-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef __CPU_O3_CPU_RAS_HH__
  30 #define __CPU_O3_CPU_RAS_HH__
  31
  32 // For Addr type.
  33 #include "arch/isa_traits.hh"
  34
  35 class ReturnAddrStack
  36 {
  37   public:
  38     ReturnAddrStack(unsigned numEntries);
  39
  40     Addr top()
  41     { return addrStack[tos]; }
  42
  43     unsigned topIdx()
  44     { return tos; }
  45
  46     void push(const Addr &return_addr);
  47
  48     void pop();
  49
  50     void restore(unsigned top_entry_idx, const Addr &restored_target);
  51
  52   private:
  53     inline void incrTos()
  54     { if (++tos == numEntries) tos = 0; }
  55
  56     inline void decrTos()
  57     { tos = (tos == 0 ? numEntries - 1 : tos - 1); }
  58
  59     Addr *addrStack;
  60
  61     unsigned numEntries;
  62
  63     unsigned usedEntries;
  64
  65     unsigned tos;
  66 };
  67
  68 #endif // __CPU_O3_CPU_RAS_HH__