src/cpu/inorder/first_stage.hh

   1 /*
   2  * Copyright (c) 2007 MIPS Technologies, Inc.
   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  * Authors: Korey Sewell
  29  *
  30  */
  31
  32 #ifndef __CPU_INORDER_FIRST_STAGE_HH__
  33 #define __CPU_INORDER_FIRST_STAGE_HH__
  34
  35 #include <queue>
  36 #include <vector>
  37
  38 #include "base/statistics.hh"
  39 #include "cpu/inorder/comm.hh"
  40 #include "cpu/inorder/inorder_dyn_inst.hh"
  41 #include "cpu/inorder/pipeline_stage.hh"
  42 #include "cpu/inorder/pipeline_traits.hh"
  43 #include "cpu/timebuf.hh"
  44
  45 class InOrderCPU;
  46
  47 class FirstStage : public PipelineStage {
  48   public:
  49     FirstStage(ThePipeline::Params *params, unsigned stage_num);
  50
  51     /** Set Pointer to CPU */
  52     void setCPU(InOrderCPU *cpu_ptr);
  53
  54     /** Evaluate Stage Info. & Execute Stage */
  55     void processStage(bool &status_change);
  56
  57     /** Process All Instructions Available */
  58     void processInsts(ThreadID tid);
  59
  60     /** Squash Instructions Above a Seq. Num */
  61     void squash(InstSeqNum squash_seq_num, ThreadID tid);
  62
  63     void squashDueToMemStall(InstSeqNum seq_num, ThreadID tid);
  64
  65     /** There are no insts. coming from previous stages, so there is
  66      *  no need to sort insts here
  67      */
  68     void sortInsts() {}
  69
  70     /** The number of fetching threads in the CPU */
  71     int numFetchingThreads;
  72
  73     //@TODO: Add fetch priority information to a resource class...
  74     /** Fetching Policy, Add new policies here.*/
  75     enum FetchPriority {
  76         SingleThread,
  77         RoundRobin
  78     };
  79
  80     /** Fetch policy. */
  81     FetchPriority fetchPolicy;
  82
  83     /** List that has the threads organized by priority. */
  84     std::list<ThreadID> *fetchPriorityList;
  85
  86     /** Return the next fetching thread */
  87     ThreadID getFetchingThread(FetchPriority &fetch_priority);
  88
  89     /** Return next thread given Round Robin Policy for Thread Fetching */
  90     ThreadID roundRobin();
  91 };
  92
  93 #endif // __CPU_INORDER_FIRST_STAGE_HH__