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 #include "debug/InOrderGraduation.hh"
  34
  35 using namespace ThePipeline;
  36
  37 GraduationUnit::GraduationUnit(std::string res_name, int res_id, int res_width,
  38                                int res_latency, InOrderCPU *_cpu,
  39                                ThePipeline::Params *params)
  40     : Resource(res_name, res_id, res_width, res_latency, _cpu),
  41       lastNonSpecTick(0)
  42 {
  43     for (ThreadID tid = 0; tid < ThePipeline::MaxThreads; tid++) {
  44         nonSpecInstActive[tid] = &cpu->nonSpecInstActive[tid];
  45         nonSpecSeqNum[tid] = &cpu->nonSpecSeqNum[tid];
  46     }
  47 }
  48
  49 void
  50 GraduationUnit::execute(int slot_num)
  51 {
  52     ResourceRequest* grad_req = reqs[slot_num];
  53     DynInstPtr inst = reqs[slot_num]->inst;
  54     ThreadID tid = inst->readTid();
  55     int stage_num = inst->curSkedEntry->stageNum;
  56
  57     switch (grad_req->cmd)
  58     {
  59       case GraduateInst:
  60         {
  61             if (lastNonSpecTick == curTick()) {
  62                 DPRINTF(InOrderGraduation, "Unable to graduate [sn:%i]. "
  63                         "Only 1 nonspec inst. per cycle can graduate.\n");
  64                 grad_req->done(false);
  65                 return;
  66             }
  67
  68             // Handle Any Faults Before Graduating Instruction
  69             if (inst->fault != NoFault) {
  70                 DPRINTF(Fault, "[sn:%i]: fault %s found for %s\n",
  71                         inst->seqNum, inst->fault->name(),
  72                         inst->instName());
  73                 inst->setSquashInfo(stage_num);
  74                 setupSquash(inst, stage_num, tid);
  75                 cpu->trapContext(inst->fault, tid, inst);
  76                 grad_req->done(false);
  77                 return;
  78             }
  79
  80             DPRINTF(InOrderGraduation,
  81                     "[tid:%i] Graduating instruction %s [sn:%i].\n",
  82                     tid, inst->instName(), inst->seqNum);
  83
  84             // Release Non-Speculative "Block" on instructions that could not
  85             // execute because there was a non-speculative inst. active.
  86             // @TODO: Fix this functionality. Probably too conservative.
  87             if (inst->isNonSpeculative()) {
  88                 *nonSpecInstActive[tid] = false;
  89                 DPRINTF(InOrderGraduation,
  90                         "[tid:%i] Non-speculative inst [sn:%i] graduated\n",
  91                         tid, inst->seqNum);
  92                 lastNonSpecTick = curTick();
  93             }
  94
  95             if (inst->traceData) {
  96                 inst->traceData->setStageCycle(stage_num, curTick());
  97             }
  98
  99             // Tell CPU that instruction is finished processing
 100             cpu->instDone(inst, tid);
 101
 102             grad_req->done();
 103         }
 104         break;
 105
 106       default:
 107         fatal("Unrecognized command to %s", resName);
 108     }
 109
 110 }