InOrder: Import new inorder CPU model from MIPS.

This model currently only works in MIPS_SE mode, so it will take some effort
to clean it up and make it generally useful. Hopefully people are willing to
help make that happen!

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..97924d2d3
--- /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(Resource, "[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(Resource, "[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(Resource, "[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(Resource, "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(Resource, "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(Resource, "[tid:%i]: Inserting [sn:%i] into buffer.\n",
+                        tid, seq_num);
+                insert(inst);
+                inserted = true;
+            } else {
+                DPRINTF(Resource, "[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(Resource, "[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(Resource, "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(Resource, "[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);
+}