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Diffstat (limited to 'src/cpu/inorder/resources/inst_buffer.cc')
| -rw-r--r-- | src/cpu/inorder/resources/inst_buffer.cc | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/src/cpu/inorder/resources/inst_buffer.cc b/src/cpu/inorder/resources/inst_buffer.cc new file mode 100644 index 000000000..fafff1fa7 --- /dev/null +++ b/src/cpu/inorder/resources/inst_buffer.cc @@ -0,0 +1,222 @@ +/* + * Copyright (c) 2007 MIPS Technologies, Inc. + * 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. + * + * Authors: Korey Sewell + * + */ + +#include <vector> +#include <list> +#include "arch/isa_traits.hh" +#include "cpu/inorder/pipeline_traits.hh" +#include "cpu/inorder/resources/inst_buffer.hh" +#include "cpu/inorder/cpu.hh" + +using namespace std; +using namespace TheISA; +using namespace ThePipeline; + +InstBuffer::InstBuffer(string res_name, int res_id, int res_width, + int res_latency, InOrderCPU *_cpu, ThePipeline::Params *params) + : Resource(res_name, res_id, res_width, res_latency, _cpu) +{ } + +void +InstBuffer::regStats() +{ + instsBypassed + .name(name() + ".instsBypassed") + .desc("Number of Instructions Bypassed."); + + Resource::regStats(); +} + +void +InstBuffer::execute(int slot_idx) +{ + ResReqPtr ib_req = reqMap[slot_idx]; + DynInstPtr inst = ib_req->inst; + int tid, seq_num, stage_num; + + tid = inst->readTid(); + seq_num = inst->seqNum; + stage_num = ib_req->getStageNum(); + ib_req->fault = NoFault; + + switch (ib_req->cmd) + { + case ScheduleOrBypass: + { + int next_stage = stage_num + 1; + int bypass_stage = stage_num + 2; + bool do_bypass = true; + + if (!instList.empty()) { + DPRINTF(InOrderInstBuffer, "[sn:%i] cannot bypass stage %i because buffer isn't empty.\n", + inst->seqNum, next_stage); + do_bypass = false; + } else if(cpu->pipelineStage[bypass_stage]->isBlocked(tid)) { + DPRINTF(InOrderInstBuffer, "[sn:%i] cannot bypass stage %i because stage %i is blocking.\n", + inst->seqNum, next_stage); + do_bypass = false; + } else if(cpu->pipelineStage[bypass_stage]->stageBufferAvail() <= 0) { + DPRINTF(InOrderInstBuffer, "[sn:%i] cannot bypass stage %i because there is no room in " + "stage %i incoming stage buffer.\n", inst->seqNum, next_stage); + do_bypass = false; + } + + if (!do_bypass) { // SCHEDULE USAGE OF BUFFER + DPRINTF(InOrderInstBuffer, "Scheduling [sn:%i] for buffer insertion in stage %i\n", + inst->seqNum, next_stage); + + // Add to schedule: Insert into buffer in next stage + int stage_pri = ThePipeline::getNextPriority(inst, next_stage); + + inst->resSched.push(new ScheduleEntry(next_stage, stage_pri, id, + InstBuffer::InsertInst)); + + // Add to schedule: Remove from buffer in next next (bypass) stage + stage_pri = ThePipeline::getNextPriority(inst, bypass_stage); + + inst->resSched.push(new ScheduleEntry(bypass_stage, stage_pri, id, + InstBuffer::RemoveInst)); + } else { // BYPASS BUFFER & NEXT STAGE + DPRINTF(InOrderInstBuffer, "Setting [sn:%i] to bypass stage %i and enter stage %i.\n", + inst->seqNum, next_stage, bypass_stage); + inst->setNextStage(bypass_stage); + instsBypassed++; + } + + ib_req->done(); + } + break; + + case InsertInst: + { + bool inserted = false; + + if (instList.size() < width) { + DPRINTF(InOrderInstBuffer, "[tid:%i]: Inserting [sn:%i] into buffer.\n", + tid, seq_num); + insert(inst); + inserted = true; + } else { + DPRINTF(InOrderInstBuffer, "[tid:%i]: Denying [sn:%i] request because " + "buffer is full.\n", tid, seq_num); + + + std::list<DynInstPtr>::iterator list_it = instList.begin(); + std::list<DynInstPtr>::iterator list_end = instList.end(); + + while (list_it != list_end) { + DPRINTF(Resource,"Serving [tid:%i] [sn:%i].\n", (*list_it)->readTid(), (*list_it)->seqNum); + list_it++; + } + } + + ib_req->done(inserted); + } + break; + + case RemoveInst: + { + DPRINTF(InOrderInstBuffer, "[tid:%i]: Removing [sn:%i] from buffer.\n", + tid, seq_num); + remove(inst); + ib_req->done(); + } + break; + + default: + fatal("Unrecognized command to %s", resName); + } + + DPRINTF(InOrderInstBuffer, "Buffer now contains %i insts.\n", instList.size()); +} + +void +InstBuffer::insert(DynInstPtr inst) +{ + instList.push_back(inst); +} + +void +InstBuffer::remove(DynInstPtr inst) +{ + std::list<DynInstPtr>::iterator list_it = instList.begin(); + std::list<DynInstPtr>::iterator list_end = instList.end(); + + while (list_it != list_end) { + if((*list_it) == inst) { + instList.erase(list_it); + break; + } + list_it++; + } +} + +void +InstBuffer::pop(unsigned tid) +{ + instList.pop_front(); +} + +ThePipeline::DynInstPtr +InstBuffer::top(unsigned tid) +{ + return instList.front(); +} + +void +InstBuffer::squash(DynInstPtr inst, int stage_num, + InstSeqNum squash_seq_num, unsigned tid) +{ + queue<list<DynInstPtr>::iterator> remove_list; + list<DynInstPtr>::iterator list_it = instList.begin(); + list<DynInstPtr>::iterator list_end = instList.end(); + + // Collect All Instructions to be Removed in Remove List + while (list_it != list_end) { + if((*list_it)->readTid() == tid && + (*list_it)->seqNum > squash_seq_num) { + (*list_it)->setSquashed(); + remove_list.push(list_it); + } + + list_it++; + } + + // Removed Instructions from InstList & Clear Remove List + while (!remove_list.empty()) { + DPRINTF(InOrderInstBuffer, "[tid:%i]: Removing squashed [sn:%i] from buffer.\n", + tid, (*remove_list.front())->seqNum); + instList.erase(remove_list.front()); + remove_list.pop(); + } + + Resource::squash(inst, stage_num, squash_seq_num, tid); +} |