src/cpu/inorder/resources/graduation_unit.cc

   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 #include "cpu/inorder/resources/graduation_unit.hh"
  33
  34 using namespace ThePipeline;
  35
  36 GraduationUnit::GraduationUnit(std::string res_name, int res_id, int res_width,
  37                        int res_latency, InOrderCPU *_cpu, ThePipeline::Params *params)
  38     : Resource(res_name, res_id, res_width, res_latency, _cpu),
  39       lastCycleGrad(0), numCycleGrad(0)
  40
  41 {
  42     for (ThreadID tid = 0; tid < ThePipeline::MaxThreads; tid++) {
  43         nonSpecInstActive[tid] = &cpu->nonSpecInstActive[tid];
  44         nonSpecSeqNum[tid] = &cpu->nonSpecSeqNum[tid];
  45     }
  46 }
  47
  48 void
  49 GraduationUnit::execute(int slot_num)
  50 {
  51     ResourceRequest* grad_req = reqMap[slot_num];
  52     DynInstPtr inst = reqMap[slot_num]->inst;
  53     Fault fault = reqMap[slot_num]->fault;
  54     ThreadID tid = inst->readTid();
  55     int stage_num = inst->resSched.top()->stageNum;
  56
  57     grad_req->fault = NoFault;
  58
  59     switch (grad_req->cmd)
  60     {
  61       case GraduateInst:
  62         {
  63             // @TODO: Instructions should never really get to this point since this should be handled
  64             // through the request interface. Check to make sure this happens and delete this
  65             // code.
  66             if (lastCycleGrad != curTick) {
  67                 lastCycleGrad = curTick;
  68                 numCycleGrad = 0;
  69             } else if (numCycleGrad > width) {
  70                 DPRINTF(InOrderGraduation,
  71                         "Graduation bandwidth reached for this cycle.\n");
  72                 return;
  73             }
  74
  75             // Make sure this is the last thing on the resource schedule
  76             assert(inst->resSched.size() == 1);
  77
  78             DPRINTF(InOrderGraduation,
  79                     "[tid:%i] Graduating instruction [sn:%i].\n",
  80                     tid, inst->seqNum);
  81
  82             // Release Non-Speculative "Block" on instructions that could not execute
  83             // because there was a non-speculative inst. active.
  84             // @TODO: Fix this functionality. Probably too conservative.
  85             if (inst->isNonSpeculative()) {
  86                 *nonSpecInstActive[tid] = false;
  87                 DPRINTF(InOrderGraduation,
  88                         "[tid:%i] Non-speculative inst [sn:%i] graduated\n",
  89                         tid, inst->seqNum);
  90             }
  91
  92             if (inst->traceData) {
  93                 inst->traceData->setStageCycle(stage_num, curTick);
  94             }
  95
  96             // Tell CPU that instruction is finished processing
  97             cpu->instDone(inst, tid);
  98
  99             //cpu->pipelineStage[stage_num]->toPrevStages->
 100             //stageInfo[stage_num][tid].doneSeqNum = inst->seqNum;
 101
 102             grad_req->done();
 103         }
 104         break;
 105
 106       default:
 107         fatal("Unrecognized command to %s", resName);
 108     }
 109
 110 }