62#include "params/DerivO3CPU.hh"
63#include "sim/faults.hh"
64#include "sim/full_system.hh"
65
66using namespace std;
67
68template <class Impl>
69DefaultCommit<Impl>::TrapEvent::TrapEvent(DefaultCommit<Impl> *_commit,
70 ThreadID _tid)
71 : Event(CPU_Tick_Pri, AutoDelete), commit(_commit), tid(_tid)
72{
73}
74
75template <class Impl>
76void
77DefaultCommit<Impl>::TrapEvent::process()
78{
79 // This will get reset by commit if it was switched out at the
80 // time of this event processing.
81 commit->trapSquash[tid] = true;
82}
83
84template <class Impl>
85const char *
86DefaultCommit<Impl>::TrapEvent::description() const
87{
88 return "Trap";
89}
90
91template <class Impl>
92DefaultCommit<Impl>::DefaultCommit(O3CPU *_cpu, DerivO3CPUParams *params)
93 : cpu(_cpu),
94 squashCounter(0),
95 iewToCommitDelay(params->iewToCommitDelay),
96 commitToIEWDelay(params->commitToIEWDelay),
97 renameToROBDelay(params->renameToROBDelay),
98 fetchToCommitDelay(params->commitToFetchDelay),
99 renameWidth(params->renameWidth),
100 commitWidth(params->commitWidth),
101 numThreads(params->numThreads),
102 drainPending(false),
103 switchedOut(false),
104 trapLatency(params->trapLatency),
105 canHandleInterrupts(true)
106{
107 _status = Active;
108 _nextStatus = Inactive;
109 std::string policy = params->smtCommitPolicy;
110
111 //Convert string to lowercase
112 std::transform(policy.begin(), policy.end(), policy.begin(),
113 (int(*)(int)) tolower);
114
115 //Assign commit policy
116 if (policy == "aggressive"){
117 commitPolicy = Aggressive;
118
119 DPRINTF(Commit,"Commit Policy set to Aggressive.\n");
120 } else if (policy == "roundrobin"){
121 commitPolicy = RoundRobin;
122
123 //Set-Up Priority List
124 for (ThreadID tid = 0; tid < numThreads; tid++) {
125 priority_list.push_back(tid);
126 }
127
128 DPRINTF(Commit,"Commit Policy set to Round Robin.\n");
129 } else if (policy == "oldestready"){
130 commitPolicy = OldestReady;
131
132 DPRINTF(Commit,"Commit Policy set to Oldest Ready.");
133 } else {
134 assert(0 && "Invalid SMT Commit Policy. Options Are: {Aggressive,"
135 "RoundRobin,OldestReady}");
136 }
137
138 for (ThreadID tid = 0; tid < numThreads; tid++) {
139 commitStatus[tid] = Idle;
140 changedROBNumEntries[tid] = false;
141 checkEmptyROB[tid] = false;
142 trapInFlight[tid] = false;
143 committedStores[tid] = false;
144 trapSquash[tid] = false;
145 tcSquash[tid] = false;
146 pc[tid].set(0);
147 lastCommitedSeqNum[tid] = 0;
148 }
149 interrupt = NoFault;
150}
151
152template <class Impl>
153std::string
154DefaultCommit<Impl>::name() const
155{
156 return cpu->name() + ".commit";
157}
158
159template <class Impl>
160void
161DefaultCommit<Impl>::regStats()
162{
163 using namespace Stats;
164 commitSquashedInsts
165 .name(name() + ".commitSquashedInsts")
166 .desc("The number of squashed insts skipped by commit")
167 .prereq(commitSquashedInsts);
168 commitSquashEvents
169 .name(name() + ".commitSquashEvents")
170 .desc("The number of times commit is told to squash")
171 .prereq(commitSquashEvents);
172 commitNonSpecStalls
173 .name(name() + ".commitNonSpecStalls")
174 .desc("The number of times commit has been forced to stall to "
175 "communicate backwards")
176 .prereq(commitNonSpecStalls);
177 branchMispredicts
178 .name(name() + ".branchMispredicts")
179 .desc("The number of times a branch was mispredicted")
180 .prereq(branchMispredicts);
181 numCommittedDist
182 .init(0,commitWidth,1)
183 .name(name() + ".committed_per_cycle")
184 .desc("Number of insts commited each cycle")
185 .flags(Stats::pdf)
186 ;
187
188 instsCommitted
189 .init(cpu->numThreads)
190 .name(name() + ".committedInsts")
191 .desc("Number of instructions committed")
192 .flags(total)
193 ;
194
195 opsCommitted
196 .init(cpu->numThreads)
197 .name(name() + ".committedOps")
198 .desc("Number of ops (including micro ops) committed")
199 .flags(total)
200 ;
201
202 statComSwp
203 .init(cpu->numThreads)
204 .name(name() + ".swp_count")
205 .desc("Number of s/w prefetches committed")
206 .flags(total)
207 ;
208
209 statComRefs
210 .init(cpu->numThreads)
211 .name(name() + ".refs")
212 .desc("Number of memory references committed")
213 .flags(total)
214 ;
215
216 statComLoads
217 .init(cpu->numThreads)
218 .name(name() + ".loads")
219 .desc("Number of loads committed")
220 .flags(total)
221 ;
222
223 statComMembars
224 .init(cpu->numThreads)
225 .name(name() + ".membars")
226 .desc("Number of memory barriers committed")
227 .flags(total)
228 ;
229
230 statComBranches
231 .init(cpu->numThreads)
232 .name(name() + ".branches")
233 .desc("Number of branches committed")
234 .flags(total)
235 ;
236
237 statComFloating
238 .init(cpu->numThreads)
239 .name(name() + ".fp_insts")
240 .desc("Number of committed floating point instructions.")
241 .flags(total)
242 ;
243
244 statComInteger
245 .init(cpu->numThreads)
246 .name(name()+".int_insts")
247 .desc("Number of committed integer instructions.")
248 .flags(total)
249 ;
250
251 statComFunctionCalls
252 .init(cpu->numThreads)
253 .name(name()+".function_calls")
254 .desc("Number of function calls committed.")
255 .flags(total)
256 ;
257
258 commitEligible
259 .init(cpu->numThreads)
260 .name(name() + ".bw_limited")
261 .desc("number of insts not committed due to BW limits")
262 .flags(total)
263 ;
264
265 commitEligibleSamples
266 .name(name() + ".bw_lim_events")
267 .desc("number cycles where commit BW limit reached")
268 ;
269}
270
271template <class Impl>
272void
273DefaultCommit<Impl>::setThreads(std::vector<Thread *> &threads)
274{
275 thread = threads;
276}
277
278template <class Impl>
279void
280DefaultCommit<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr)
281{
282 timeBuffer = tb_ptr;
283
284 // Setup wire to send information back to IEW.
285 toIEW = timeBuffer->getWire(0);
286
287 // Setup wire to read data from IEW (for the ROB).
288 robInfoFromIEW = timeBuffer->getWire(-iewToCommitDelay);
289}
290
291template <class Impl>
292void
293DefaultCommit<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr)
294{
295 fetchQueue = fq_ptr;
296
297 // Setup wire to get instructions from rename (for the ROB).
298 fromFetch = fetchQueue->getWire(-fetchToCommitDelay);
299}
300
301template <class Impl>
302void
303DefaultCommit<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr)
304{
305 renameQueue = rq_ptr;
306
307 // Setup wire to get instructions from rename (for the ROB).
308 fromRename = renameQueue->getWire(-renameToROBDelay);
309}
310
311template <class Impl>
312void
313DefaultCommit<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr)
314{
315 iewQueue = iq_ptr;
316
317 // Setup wire to get instructions from IEW.
318 fromIEW = iewQueue->getWire(-iewToCommitDelay);
319}
320
321template <class Impl>
322void
323DefaultCommit<Impl>::setIEWStage(IEW *iew_stage)
324{
325 iewStage = iew_stage;
326}
327
328template<class Impl>
329void
330DefaultCommit<Impl>::setActiveThreads(list<ThreadID> *at_ptr)
331{
332 activeThreads = at_ptr;
333}
334
335template <class Impl>
336void
337DefaultCommit<Impl>::setRenameMap(RenameMap rm_ptr[])
338{
339 for (ThreadID tid = 0; tid < numThreads; tid++)
340 renameMap[tid] = &rm_ptr[tid];
341}
342
343template <class Impl>
344void
345DefaultCommit<Impl>::setROB(ROB *rob_ptr)
346{
347 rob = rob_ptr;
348}
349
350template <class Impl>
351void
352DefaultCommit<Impl>::initStage()
353{
354 rob->setActiveThreads(activeThreads);
355 rob->resetEntries();
356
357 // Broadcast the number of free entries.
358 for (ThreadID tid = 0; tid < numThreads; tid++) {
359 toIEW->commitInfo[tid].usedROB = true;
360 toIEW->commitInfo[tid].freeROBEntries = rob->numFreeEntries(tid);
361 toIEW->commitInfo[tid].emptyROB = true;
362 }
363
364 // Commit must broadcast the number of free entries it has at the
365 // start of the simulation, so it starts as active.
366 cpu->activateStage(O3CPU::CommitIdx);
367
368 cpu->activityThisCycle();
369}
370
371template <class Impl>
372bool
373DefaultCommit<Impl>::drain()
374{
375 drainPending = true;
376
377 return false;
378}
379
380template <class Impl>
381void
382DefaultCommit<Impl>::switchOut()
383{
384 switchedOut = true;
385 drainPending = false;
386 rob->switchOut();
387}
388
389template <class Impl>
390void
391DefaultCommit<Impl>::resume()
392{
393 drainPending = false;
394}
395
396template <class Impl>
397void
398DefaultCommit<Impl>::takeOverFrom()
399{
400 switchedOut = false;
401 _status = Active;
402 _nextStatus = Inactive;
403 for (ThreadID tid = 0; tid < numThreads; tid++) {
404 commitStatus[tid] = Idle;
405 changedROBNumEntries[tid] = false;
406 trapSquash[tid] = false;
407 tcSquash[tid] = false;
408 }
409 squashCounter = 0;
410 rob->takeOverFrom();
411}
412
413template <class Impl>
414void
415DefaultCommit<Impl>::updateStatus()
416{
417 // reset ROB changed variable
418 list<ThreadID>::iterator threads = activeThreads->begin();
419 list<ThreadID>::iterator end = activeThreads->end();
420
421 while (threads != end) {
422 ThreadID tid = *threads++;
423
424 changedROBNumEntries[tid] = false;
425
426 // Also check if any of the threads has a trap pending
427 if (commitStatus[tid] == TrapPending ||
428 commitStatus[tid] == FetchTrapPending) {
429 _nextStatus = Active;
430 }
431 }
432
433 if (_nextStatus == Inactive && _status == Active) {
434 DPRINTF(Activity, "Deactivating stage.\n");
435 cpu->deactivateStage(O3CPU::CommitIdx);
436 } else if (_nextStatus == Active && _status == Inactive) {
437 DPRINTF(Activity, "Activating stage.\n");
438 cpu->activateStage(O3CPU::CommitIdx);
439 }
440
441 _status = _nextStatus;
442}
443
444template <class Impl>
445void
446DefaultCommit<Impl>::setNextStatus()
447{
448 int squashes = 0;
449
450 list<ThreadID>::iterator threads = activeThreads->begin();
451 list<ThreadID>::iterator end = activeThreads->end();
452
453 while (threads != end) {
454 ThreadID tid = *threads++;
455
456 if (commitStatus[tid] == ROBSquashing) {
457 squashes++;
458 }
459 }
460
461 squashCounter = squashes;
462
463 // If commit is currently squashing, then it will have activity for the
464 // next cycle. Set its next status as active.
465 if (squashCounter) {
466 _nextStatus = Active;
467 }
468}
469
470template <class Impl>
471bool
472DefaultCommit<Impl>::changedROBEntries()
473{
474 list<ThreadID>::iterator threads = activeThreads->begin();
475 list<ThreadID>::iterator end = activeThreads->end();
476
477 while (threads != end) {
478 ThreadID tid = *threads++;
479
480 if (changedROBNumEntries[tid]) {
481 return true;
482 }
483 }
484
485 return false;
486}
487
488template <class Impl>
489size_t
490DefaultCommit<Impl>::numROBFreeEntries(ThreadID tid)
491{
492 return rob->numFreeEntries(tid);
493}
494
495template <class Impl>
496void
497DefaultCommit<Impl>::generateTrapEvent(ThreadID tid)
498{
499 DPRINTF(Commit, "Generating trap event for [tid:%i]\n", tid);
500
501 TrapEvent *trap = new TrapEvent(this, tid);
502
503 cpu->schedule(trap, cpu->clockEdge(trapLatency));
504 trapInFlight[tid] = true;
505 thread[tid]->trapPending = true;
506}
507
508template <class Impl>
509void
510DefaultCommit<Impl>::generateTCEvent(ThreadID tid)
511{
512 assert(!trapInFlight[tid]);
513 DPRINTF(Commit, "Generating TC squash event for [tid:%i]\n", tid);
514
515 tcSquash[tid] = true;
516}
517
518template <class Impl>
519void
520DefaultCommit<Impl>::squashAll(ThreadID tid)
521{
522 // If we want to include the squashing instruction in the squash,
523 // then use one older sequence number.
524 // Hopefully this doesn't mess things up. Basically I want to squash
525 // all instructions of this thread.
526 InstSeqNum squashed_inst = rob->isEmpty() ?
527 lastCommitedSeqNum[tid] : rob->readHeadInst(tid)->seqNum - 1;
528
529 // All younger instructions will be squashed. Set the sequence
530 // number as the youngest instruction in the ROB (0 in this case.
531 // Hopefully nothing breaks.)
532 youngestSeqNum[tid] = lastCommitedSeqNum[tid];
533
534 rob->squash(squashed_inst, tid);
535 changedROBNumEntries[tid] = true;
536
537 // Send back the sequence number of the squashed instruction.
538 toIEW->commitInfo[tid].doneSeqNum = squashed_inst;
539
540 // Send back the squash signal to tell stages that they should
541 // squash.
542 toIEW->commitInfo[tid].squash = true;
543
544 // Send back the rob squashing signal so other stages know that
545 // the ROB is in the process of squashing.
546 toIEW->commitInfo[tid].robSquashing = true;
547
548 toIEW->commitInfo[tid].mispredictInst = NULL;
549 toIEW->commitInfo[tid].squashInst = NULL;
550
551 toIEW->commitInfo[tid].pc = pc[tid];
552}
553
554template <class Impl>
555void
556DefaultCommit<Impl>::squashFromTrap(ThreadID tid)
557{
558 squashAll(tid);
559
560 DPRINTF(Commit, "Squashing from trap, restarting at PC %s\n", pc[tid]);
561
562 thread[tid]->trapPending = false;
563 thread[tid]->inSyscall = false;
564 trapInFlight[tid] = false;
565
566 trapSquash[tid] = false;
567
568 commitStatus[tid] = ROBSquashing;
569 cpu->activityThisCycle();
570}
571
572template <class Impl>
573void
574DefaultCommit<Impl>::squashFromTC(ThreadID tid)
575{
576 squashAll(tid);
577
578 DPRINTF(Commit, "Squashing from TC, restarting at PC %s\n", pc[tid]);
579
580 thread[tid]->inSyscall = false;
581 assert(!thread[tid]->trapPending);
582
583 commitStatus[tid] = ROBSquashing;
584 cpu->activityThisCycle();
585
586 tcSquash[tid] = false;
587}
588
589template <class Impl>
590void
591DefaultCommit<Impl>::squashAfter(ThreadID tid, DynInstPtr &head_inst,
592 uint64_t squash_after_seq_num)
593{
594 youngestSeqNum[tid] = squash_after_seq_num;
595
596 rob->squash(squash_after_seq_num, tid);
597 changedROBNumEntries[tid] = true;
598
599 // Send back the sequence number of the squashed instruction.
600 toIEW->commitInfo[tid].doneSeqNum = squash_after_seq_num;
601
602 toIEW->commitInfo[tid].squashInst = head_inst;
603 // Send back the squash signal to tell stages that they should squash.
604 toIEW->commitInfo[tid].squash = true;
605
606 // Send back the rob squashing signal so other stages know that
607 // the ROB is in the process of squashing.
608 toIEW->commitInfo[tid].robSquashing = true;
609
610 toIEW->commitInfo[tid].mispredictInst = NULL;
611
612 toIEW->commitInfo[tid].pc = pc[tid];
613 DPRINTF(Commit, "Executing squash after for [tid:%i] inst [sn:%lli]\n",
614 tid, squash_after_seq_num);
615 commitStatus[tid] = ROBSquashing;
616}
617
618template <class Impl>
619void
620DefaultCommit<Impl>::tick()
621{
622 wroteToTimeBuffer = false;
623 _nextStatus = Inactive;
624
625 if (drainPending && cpu->instList.empty() && !iewStage->hasStoresToWB() &&
626 interrupt == NoFault) {
627 cpu->signalDrained();
628 drainPending = false;
629 return;
630 }
631
632 if (activeThreads->empty())
633 return;
634
635 list<ThreadID>::iterator threads = activeThreads->begin();
636 list<ThreadID>::iterator end = activeThreads->end();
637
638 // Check if any of the threads are done squashing. Change the
639 // status if they are done.
640 while (threads != end) {
641 ThreadID tid = *threads++;
642
643 // Clear the bit saying if the thread has committed stores
644 // this cycle.
645 committedStores[tid] = false;
646
647 if (commitStatus[tid] == ROBSquashing) {
648
649 if (rob->isDoneSquashing(tid)) {
650 commitStatus[tid] = Running;
651 } else {
652 DPRINTF(Commit,"[tid:%u]: Still Squashing, cannot commit any"
653 " insts this cycle.\n", tid);
654 rob->doSquash(tid);
655 toIEW->commitInfo[tid].robSquashing = true;
656 wroteToTimeBuffer = true;
657 }
658 }
659 }
660
661 commit();
662
663 markCompletedInsts();
664
665 threads = activeThreads->begin();
666
667 while (threads != end) {
668 ThreadID tid = *threads++;
669
670 if (!rob->isEmpty(tid) && rob->readHeadInst(tid)->readyToCommit()) {
671 // The ROB has more instructions it can commit. Its next status
672 // will be active.
673 _nextStatus = Active;
674
675 DynInstPtr inst = rob->readHeadInst(tid);
676
677 DPRINTF(Commit,"[tid:%i]: Instruction [sn:%lli] PC %s is head of"
678 " ROB and ready to commit\n",
679 tid, inst->seqNum, inst->pcState());
680
681 } else if (!rob->isEmpty(tid)) {
682 DynInstPtr inst = rob->readHeadInst(tid);
683
684 DPRINTF(Commit,"[tid:%i]: Can't commit, Instruction [sn:%lli] PC "
685 "%s is head of ROB and not ready\n",
686 tid, inst->seqNum, inst->pcState());
687 }
688
689 DPRINTF(Commit, "[tid:%i]: ROB has %d insts & %d free entries.\n",
690 tid, rob->countInsts(tid), rob->numFreeEntries(tid));
691 }
692
693
694 if (wroteToTimeBuffer) {
695 DPRINTF(Activity, "Activity This Cycle.\n");
696 cpu->activityThisCycle();
697 }
698
699 updateStatus();
700}
701
702template <class Impl>
703void
704DefaultCommit<Impl>::handleInterrupt()
705{
706 // Verify that we still have an interrupt to handle
707 if (!cpu->checkInterrupts(cpu->tcBase(0))) {
708 DPRINTF(Commit, "Pending interrupt is cleared by master before "
709 "it got handled. Restart fetching from the orig path.\n");
710 toIEW->commitInfo[0].clearInterrupt = true;
711 interrupt = NoFault;
712 return;
713 }
714
715 // Wait until all in flight instructions are finished before enterring
716 // the interrupt.
717 if (canHandleInterrupts && cpu->instList.empty()) {
718 // Squash or record that I need to squash this cycle if
719 // an interrupt needed to be handled.
720 DPRINTF(Commit, "Interrupt detected.\n");
721
722 // Clear the interrupt now that it's going to be handled
723 toIEW->commitInfo[0].clearInterrupt = true;
724
725 assert(!thread[0]->inSyscall);
726 thread[0]->inSyscall = true;
727
728 if (cpu->checker) {
729 cpu->checker->handlePendingInt();
730 }
731
732 // CPU will handle interrupt.
733 cpu->processInterrupts(interrupt);
734
735 thread[0]->inSyscall = false;
736
737 commitStatus[0] = TrapPending;
738
739 // Generate trap squash event.
740 generateTrapEvent(0);
741
742 interrupt = NoFault;
743 } else {
744 DPRINTF(Commit, "Interrupt pending: instruction is %sin "
745 "flight, ROB is %sempty\n",
746 canHandleInterrupts ? "not " : "",
747 cpu->instList.empty() ? "" : "not " );
748 }
749}
750
751template <class Impl>
752void
753DefaultCommit<Impl>::propagateInterrupt()
754{
755 if (commitStatus[0] == TrapPending || interrupt || trapSquash[0] ||
756 tcSquash[0])
757 return;
758
759 // Process interrupts if interrupts are enabled, not in PAL
760 // mode, and no other traps or external squashes are currently
761 // pending.
762 // @todo: Allow other threads to handle interrupts.
763
764 // Get any interrupt that happened
765 interrupt = cpu->getInterrupts();
766
767 // Tell fetch that there is an interrupt pending. This
768 // will make fetch wait until it sees a non PAL-mode PC,
769 // at which point it stops fetching instructions.
770 if (interrupt != NoFault)
771 toIEW->commitInfo[0].interruptPending = true;
772}
773
774template <class Impl>
775void
776DefaultCommit<Impl>::commit()
777{
778 if (FullSystem) {
779 // Check if we have a interrupt and get read to handle it
780 if (cpu->checkInterrupts(cpu->tcBase(0)))
781 propagateInterrupt();
782 }
783
784 ////////////////////////////////////
785 // Check for any possible squashes, handle them first
786 ////////////////////////////////////
787 list<ThreadID>::iterator threads = activeThreads->begin();
788 list<ThreadID>::iterator end = activeThreads->end();
789
790 while (threads != end) {
791 ThreadID tid = *threads++;
792
793 // Not sure which one takes priority. I think if we have
794 // both, that's a bad sign.
795 if (trapSquash[tid] == true) {
796 assert(!tcSquash[tid]);
797 squashFromTrap(tid);
798 } else if (tcSquash[tid] == true) {
799 assert(commitStatus[tid] != TrapPending);
800 squashFromTC(tid);
801 }
802
803 // Squashed sequence number must be older than youngest valid
804 // instruction in the ROB. This prevents squashes from younger
805 // instructions overriding squashes from older instructions.
806 if (fromIEW->squash[tid] &&
807 commitStatus[tid] != TrapPending &&
808 fromIEW->squashedSeqNum[tid] <= youngestSeqNum[tid]) {
809
810 if (fromIEW->mispredictInst[tid]) {
811 DPRINTF(Commit,
812 "[tid:%i]: Squashing due to branch mispred PC:%#x [sn:%i]\n",
813 tid,
814 fromIEW->mispredictInst[tid]->instAddr(),
815 fromIEW->squashedSeqNum[tid]);
816 } else {
817 DPRINTF(Commit,
818 "[tid:%i]: Squashing due to order violation [sn:%i]\n",
819 tid, fromIEW->squashedSeqNum[tid]);
820 }
821
822 DPRINTF(Commit, "[tid:%i]: Redirecting to PC %#x\n",
823 tid,
824 fromIEW->pc[tid].nextInstAddr());
825
826 commitStatus[tid] = ROBSquashing;
827
828 // If we want to include the squashing instruction in the squash,
829 // then use one older sequence number.
830 InstSeqNum squashed_inst = fromIEW->squashedSeqNum[tid];
831
832 if (fromIEW->includeSquashInst[tid] == true) {
833 squashed_inst--;
834 }
835
836 // All younger instructions will be squashed. Set the sequence
837 // number as the youngest instruction in the ROB.
838 youngestSeqNum[tid] = squashed_inst;
839
840 rob->squash(squashed_inst, tid);
841 changedROBNumEntries[tid] = true;
842
843 toIEW->commitInfo[tid].doneSeqNum = squashed_inst;
844
845 toIEW->commitInfo[tid].squash = true;
846
847 // Send back the rob squashing signal so other stages know that
848 // the ROB is in the process of squashing.
849 toIEW->commitInfo[tid].robSquashing = true;
850
851 toIEW->commitInfo[tid].mispredictInst =
852 fromIEW->mispredictInst[tid];
853 toIEW->commitInfo[tid].branchTaken =
854 fromIEW->branchTaken[tid];
855 toIEW->commitInfo[tid].squashInst =
856 rob->findInst(tid, squashed_inst);
857 if (toIEW->commitInfo[tid].mispredictInst) {
858 if (toIEW->commitInfo[tid].mispredictInst->isUncondCtrl()) {
859 toIEW->commitInfo[tid].branchTaken = true;
860 }
861 }
862
863 toIEW->commitInfo[tid].pc = fromIEW->pc[tid];
864
865 if (toIEW->commitInfo[tid].mispredictInst) {
866 ++branchMispredicts;
867 }
868 }
869
870 }
871
872 setNextStatus();
873
874 if (squashCounter != numThreads) {
875 // If we're not currently squashing, then get instructions.
876 getInsts();
877
878 // Try to commit any instructions.
879 commitInsts();
880 }
881
882 //Check for any activity
883 threads = activeThreads->begin();
884
885 while (threads != end) {
886 ThreadID tid = *threads++;
887
888 if (changedROBNumEntries[tid]) {
889 toIEW->commitInfo[tid].usedROB = true;
890 toIEW->commitInfo[tid].freeROBEntries = rob->numFreeEntries(tid);
891
892 wroteToTimeBuffer = true;
893 changedROBNumEntries[tid] = false;
894 if (rob->isEmpty(tid))
895 checkEmptyROB[tid] = true;
896 }
897
898 // ROB is only considered "empty" for previous stages if: a)
899 // ROB is empty, b) there are no outstanding stores, c) IEW
900 // stage has received any information regarding stores that
901 // committed.
902 // c) is checked by making sure to not consider the ROB empty
903 // on the same cycle as when stores have been committed.
904 // @todo: Make this handle multi-cycle communication between
905 // commit and IEW.
906 if (checkEmptyROB[tid] && rob->isEmpty(tid) &&
907 !iewStage->hasStoresToWB(tid) && !committedStores[tid]) {
908 checkEmptyROB[tid] = false;
909 toIEW->commitInfo[tid].usedROB = true;
910 toIEW->commitInfo[tid].emptyROB = true;
911 toIEW->commitInfo[tid].freeROBEntries = rob->numFreeEntries(tid);
912 wroteToTimeBuffer = true;
913 }
914
915 }
916}
917
918template <class Impl>
919void
920DefaultCommit<Impl>::commitInsts()
921{
922 ////////////////////////////////////
923 // Handle commit
924 // Note that commit will be handled prior to putting new
925 // instructions in the ROB so that the ROB only tries to commit
926 // instructions it has in this current cycle, and not instructions
927 // it is writing in during this cycle. Can't commit and squash
928 // things at the same time...
929 ////////////////////////////////////
930
931 DPRINTF(Commit, "Trying to commit instructions in the ROB.\n");
932
933 unsigned num_committed = 0;
934
935 DynInstPtr head_inst;
936
937 // Commit as many instructions as possible until the commit bandwidth
938 // limit is reached, or it becomes impossible to commit any more.
939 while (num_committed < commitWidth) {
940 // Check for any interrupt that we've already squashed for
941 // and start processing it.
942 if (interrupt != NoFault)
943 handleInterrupt();
944
945 int commit_thread = getCommittingThread();
946
947 if (commit_thread == -1 || !rob->isHeadReady(commit_thread))
948 break;
949
950 head_inst = rob->readHeadInst(commit_thread);
951
952 ThreadID tid = head_inst->threadNumber;
953
954 assert(tid == commit_thread);
955
956 DPRINTF(Commit, "Trying to commit head instruction, [sn:%i] [tid:%i]\n",
957 head_inst->seqNum, tid);
958
959 // If the head instruction is squashed, it is ready to retire
960 // (be removed from the ROB) at any time.
961 if (head_inst->isSquashed()) {
962
963 DPRINTF(Commit, "Retiring squashed instruction from "
964 "ROB.\n");
965
966 rob->retireHead(commit_thread);
967
968 ++commitSquashedInsts;
969
970 // Record that the number of ROB entries has changed.
971 changedROBNumEntries[tid] = true;
972 } else {
973 pc[tid] = head_inst->pcState();
974
975 // Increment the total number of non-speculative instructions
976 // executed.
977 // Hack for now: it really shouldn't happen until after the
978 // commit is deemed to be successful, but this count is needed
979 // for syscalls.
980 thread[tid]->funcExeInst++;
981
982 // Try to commit the head instruction.
983 bool commit_success = commitHead(head_inst, num_committed);
984
985 if (commit_success) {
986 ++num_committed;
987
988 changedROBNumEntries[tid] = true;
989
990 // Set the doneSeqNum to the youngest committed instruction.
991 toIEW->commitInfo[tid].doneSeqNum = head_inst->seqNum;
992
993 if (tid == 0) {
994 canHandleInterrupts = (!head_inst->isDelayedCommit()) &&
995 ((THE_ISA != ALPHA_ISA) ||
996 (!(pc[0].instAddr() & 0x3)));
997 }
998
999 // Updates misc. registers.
1000 head_inst->updateMiscRegs();
1001
1002 cpu->traceFunctions(pc[tid].instAddr());
1003
1004 TheISA::advancePC(pc[tid], head_inst->staticInst);
1005
1006 // Keep track of the last sequence number commited
1007 lastCommitedSeqNum[tid] = head_inst->seqNum;
1008
1009 // If this is an instruction that doesn't play nicely with
1010 // others squash everything and restart fetch
1011 if (head_inst->isSquashAfter())
1012 squashAfter(tid, head_inst, head_inst->seqNum);
1013
1014 int count = 0;
1015 Addr oldpc;
1016 // Debug statement. Checks to make sure we're not
1017 // currently updating state while handling PC events.
1018 assert(!thread[tid]->inSyscall && !thread[tid]->trapPending);
1019 do {
1020 oldpc = pc[tid].instAddr();
1021 cpu->system->pcEventQueue.service(thread[tid]->getTC());
1022 count++;
1023 } while (oldpc != pc[tid].instAddr());
1024 if (count > 1) {
1025 DPRINTF(Commit,
1026 "PC skip function event, stopping commit\n");
1027 break;
1028 }
1029 } else {
1030 DPRINTF(Commit, "Unable to commit head instruction PC:%s "
1031 "[tid:%i] [sn:%i].\n",
1032 head_inst->pcState(), tid ,head_inst->seqNum);
1033 break;
1034 }
1035 }
1036 }
1037
1038 DPRINTF(CommitRate, "%i\n", num_committed);
1039 numCommittedDist.sample(num_committed);
1040
1041 if (num_committed == commitWidth) {
1042 commitEligibleSamples++;
1043 }
1044}
1045
1046template <class Impl>
1047bool
1048DefaultCommit<Impl>::commitHead(DynInstPtr &head_inst, unsigned inst_num)
1049{
1050 assert(head_inst);
1051
1052 ThreadID tid = head_inst->threadNumber;
1053
1054 // If the instruction is not executed yet, then it will need extra
1055 // handling. Signal backwards that it should be executed.
1056 if (!head_inst->isExecuted()) {
1057 // Keep this number correct. We have not yet actually executed
1058 // and committed this instruction.
1059 thread[tid]->funcExeInst--;
1060
1061 if (head_inst->isNonSpeculative() ||
1062 head_inst->isStoreConditional() ||
1063 head_inst->isMemBarrier() ||
1064 head_inst->isWriteBarrier()) {
1065
1066 DPRINTF(Commit, "Encountered a barrier or non-speculative "
1067 "instruction [sn:%lli] at the head of the ROB, PC %s.\n",
1068 head_inst->seqNum, head_inst->pcState());
1069
1070 if (inst_num > 0 || iewStage->hasStoresToWB(tid)) {
1071 DPRINTF(Commit, "Waiting for all stores to writeback.\n");
1072 return false;
1073 }
1074
1075 toIEW->commitInfo[tid].nonSpecSeqNum = head_inst->seqNum;
1076
1077 // Change the instruction so it won't try to commit again until
1078 // it is executed.
1079 head_inst->clearCanCommit();
1080
1081 ++commitNonSpecStalls;
1082
1083 return false;
1084 } else if (head_inst->isLoad()) {
1085 if (inst_num > 0 || iewStage->hasStoresToWB(tid)) {
1086 DPRINTF(Commit, "Waiting for all stores to writeback.\n");
1087 return false;
1088 }
1089
1090 assert(head_inst->uncacheable());
1091 DPRINTF(Commit, "[sn:%lli]: Uncached load, PC %s.\n",
1092 head_inst->seqNum, head_inst->pcState());
1093
1094 // Send back the non-speculative instruction's sequence
1095 // number. Tell the lsq to re-execute the load.
1096 toIEW->commitInfo[tid].nonSpecSeqNum = head_inst->seqNum;
1097 toIEW->commitInfo[tid].uncached = true;
1098 toIEW->commitInfo[tid].uncachedLoad = head_inst;
1099
1100 head_inst->clearCanCommit();
1101
1102 return false;
1103 } else {
1104 panic("Trying to commit un-executed instruction "
1105 "of unknown type!\n");
1106 }
1107 }
1108
1109 if (head_inst->isThreadSync()) {
1110 // Not handled for now.
1111 panic("Thread sync instructions are not handled yet.\n");
1112 }
1113
1114 // Check if the instruction caused a fault. If so, trap.
1115 Fault inst_fault = head_inst->getFault();
1116
1117 // Stores mark themselves as completed.
1118 if (!head_inst->isStore() && inst_fault == NoFault) {
1119 head_inst->setCompleted();
1120 }
1121
1122 // Use checker prior to updating anything due to traps or PC
1123 // based events.
1124 if (cpu->checker) {
1125 cpu->checker->verify(head_inst);
1126 }
1127
1128 if (inst_fault != NoFault) {
1129 DPRINTF(Commit, "Inst [sn:%lli] PC %s has a fault\n",
1130 head_inst->seqNum, head_inst->pcState());
1131
1132 if (iewStage->hasStoresToWB(tid) || inst_num > 0) {
1133 DPRINTF(Commit, "Stores outstanding, fault must wait.\n");
1134 return false;
1135 }
1136
1137 head_inst->setCompleted();
1138
1139 if (cpu->checker) {
1140 // Need to check the instruction before its fault is processed
1141 cpu->checker->verify(head_inst);
1142 }
1143
1144 assert(!thread[tid]->inSyscall);
1145
1146 // Mark that we're in state update mode so that the trap's
1147 // execution doesn't generate extra squashes.
1148 thread[tid]->inSyscall = true;
1149
1150 // Execute the trap. Although it's slightly unrealistic in
1151 // terms of timing (as it doesn't wait for the full timing of
1152 // the trap event to complete before updating state), it's
1153 // needed to update the state as soon as possible. This
1154 // prevents external agents from changing any specific state
1155 // that the trap need.
1156 cpu->trap(inst_fault, tid, head_inst->staticInst);
1157
1158 // Exit state update mode to avoid accidental updating.
1159 thread[tid]->inSyscall = false;
1160
1161 commitStatus[tid] = TrapPending;
1162
1163 DPRINTF(Commit, "Committing instruction with fault [sn:%lli]\n",
1164 head_inst->seqNum);
1165 if (head_inst->traceData) {
1166 if (DTRACE(ExecFaulting)) {
1167 head_inst->traceData->setFetchSeq(head_inst->seqNum);
1168 head_inst->traceData->setCPSeq(thread[tid]->numOp);
1169 head_inst->traceData->dump();
1170 }
1171 delete head_inst->traceData;
1172 head_inst->traceData = NULL;
1173 }
1174
1175 // Generate trap squash event.
1176 generateTrapEvent(tid);
1177 return false;
1178 }
1179
1180 updateComInstStats(head_inst);
1181
1182 if (FullSystem) {
1183 if (thread[tid]->profile) {
1184 thread[tid]->profilePC = head_inst->instAddr();
1185 ProfileNode *node = thread[tid]->profile->consume(
1186 thread[tid]->getTC(), head_inst->staticInst);
1187
1188 if (node)
1189 thread[tid]->profileNode = node;
1190 }
1191 if (CPA::available()) {
1192 if (head_inst->isControl()) {
1193 ThreadContext *tc = thread[tid]->getTC();
1194 CPA::cpa()->swAutoBegin(tc, head_inst->nextInstAddr());
1195 }
1196 }
1197 }
1198 DPRINTF(Commit, "Committing instruction with [sn:%lli] PC %s\n",
1199 head_inst->seqNum, head_inst->pcState());
1200 if (head_inst->traceData) {
1201 head_inst->traceData->setFetchSeq(head_inst->seqNum);
1202 head_inst->traceData->setCPSeq(thread[tid]->numOp);
1203 head_inst->traceData->dump();
1204 delete head_inst->traceData;
1205 head_inst->traceData = NULL;
1206 }
1207 if (head_inst->isReturn()) {
1208 DPRINTF(Commit,"Return Instruction Committed [sn:%lli] PC %s \n",
1209 head_inst->seqNum, head_inst->pcState());
1210 }
1211
1212 // Update the commit rename map
1213 for (int i = 0; i < head_inst->numDestRegs(); i++) {
1214 renameMap[tid]->setEntry(head_inst->flattenedDestRegIdx(i),
1215 head_inst->renamedDestRegIdx(i));
1216 }
1217
1218 // Finally clear the head ROB entry.
1219 rob->retireHead(tid);
1220
1221#if TRACING_ON
| 61#include "params/DerivO3CPU.hh"
62#include "sim/faults.hh"
63#include "sim/full_system.hh"
64
65using namespace std;
66
67template <class Impl>
68DefaultCommit<Impl>::TrapEvent::TrapEvent(DefaultCommit<Impl> *_commit,
69 ThreadID _tid)
70 : Event(CPU_Tick_Pri, AutoDelete), commit(_commit), tid(_tid)
71{
72}
73
74template <class Impl>
75void
76DefaultCommit<Impl>::TrapEvent::process()
77{
78 // This will get reset by commit if it was switched out at the
79 // time of this event processing.
80 commit->trapSquash[tid] = true;
81}
82
83template <class Impl>
84const char *
85DefaultCommit<Impl>::TrapEvent::description() const
86{
87 return "Trap";
88}
89
90template <class Impl>
91DefaultCommit<Impl>::DefaultCommit(O3CPU *_cpu, DerivO3CPUParams *params)
92 : cpu(_cpu),
93 squashCounter(0),
94 iewToCommitDelay(params->iewToCommitDelay),
95 commitToIEWDelay(params->commitToIEWDelay),
96 renameToROBDelay(params->renameToROBDelay),
97 fetchToCommitDelay(params->commitToFetchDelay),
98 renameWidth(params->renameWidth),
99 commitWidth(params->commitWidth),
100 numThreads(params->numThreads),
101 drainPending(false),
102 switchedOut(false),
103 trapLatency(params->trapLatency),
104 canHandleInterrupts(true)
105{
106 _status = Active;
107 _nextStatus = Inactive;
108 std::string policy = params->smtCommitPolicy;
109
110 //Convert string to lowercase
111 std::transform(policy.begin(), policy.end(), policy.begin(),
112 (int(*)(int)) tolower);
113
114 //Assign commit policy
115 if (policy == "aggressive"){
116 commitPolicy = Aggressive;
117
118 DPRINTF(Commit,"Commit Policy set to Aggressive.\n");
119 } else if (policy == "roundrobin"){
120 commitPolicy = RoundRobin;
121
122 //Set-Up Priority List
123 for (ThreadID tid = 0; tid < numThreads; tid++) {
124 priority_list.push_back(tid);
125 }
126
127 DPRINTF(Commit,"Commit Policy set to Round Robin.\n");
128 } else if (policy == "oldestready"){
129 commitPolicy = OldestReady;
130
131 DPRINTF(Commit,"Commit Policy set to Oldest Ready.");
132 } else {
133 assert(0 && "Invalid SMT Commit Policy. Options Are: {Aggressive,"
134 "RoundRobin,OldestReady}");
135 }
136
137 for (ThreadID tid = 0; tid < numThreads; tid++) {
138 commitStatus[tid] = Idle;
139 changedROBNumEntries[tid] = false;
140 checkEmptyROB[tid] = false;
141 trapInFlight[tid] = false;
142 committedStores[tid] = false;
143 trapSquash[tid] = false;
144 tcSquash[tid] = false;
145 pc[tid].set(0);
146 lastCommitedSeqNum[tid] = 0;
147 }
148 interrupt = NoFault;
149}
150
151template <class Impl>
152std::string
153DefaultCommit<Impl>::name() const
154{
155 return cpu->name() + ".commit";
156}
157
158template <class Impl>
159void
160DefaultCommit<Impl>::regStats()
161{
162 using namespace Stats;
163 commitSquashedInsts
164 .name(name() + ".commitSquashedInsts")
165 .desc("The number of squashed insts skipped by commit")
166 .prereq(commitSquashedInsts);
167 commitSquashEvents
168 .name(name() + ".commitSquashEvents")
169 .desc("The number of times commit is told to squash")
170 .prereq(commitSquashEvents);
171 commitNonSpecStalls
172 .name(name() + ".commitNonSpecStalls")
173 .desc("The number of times commit has been forced to stall to "
174 "communicate backwards")
175 .prereq(commitNonSpecStalls);
176 branchMispredicts
177 .name(name() + ".branchMispredicts")
178 .desc("The number of times a branch was mispredicted")
179 .prereq(branchMispredicts);
180 numCommittedDist
181 .init(0,commitWidth,1)
182 .name(name() + ".committed_per_cycle")
183 .desc("Number of insts commited each cycle")
184 .flags(Stats::pdf)
185 ;
186
187 instsCommitted
188 .init(cpu->numThreads)
189 .name(name() + ".committedInsts")
190 .desc("Number of instructions committed")
191 .flags(total)
192 ;
193
194 opsCommitted
195 .init(cpu->numThreads)
196 .name(name() + ".committedOps")
197 .desc("Number of ops (including micro ops) committed")
198 .flags(total)
199 ;
200
201 statComSwp
202 .init(cpu->numThreads)
203 .name(name() + ".swp_count")
204 .desc("Number of s/w prefetches committed")
205 .flags(total)
206 ;
207
208 statComRefs
209 .init(cpu->numThreads)
210 .name(name() + ".refs")
211 .desc("Number of memory references committed")
212 .flags(total)
213 ;
214
215 statComLoads
216 .init(cpu->numThreads)
217 .name(name() + ".loads")
218 .desc("Number of loads committed")
219 .flags(total)
220 ;
221
222 statComMembars
223 .init(cpu->numThreads)
224 .name(name() + ".membars")
225 .desc("Number of memory barriers committed")
226 .flags(total)
227 ;
228
229 statComBranches
230 .init(cpu->numThreads)
231 .name(name() + ".branches")
232 .desc("Number of branches committed")
233 .flags(total)
234 ;
235
236 statComFloating
237 .init(cpu->numThreads)
238 .name(name() + ".fp_insts")
239 .desc("Number of committed floating point instructions.")
240 .flags(total)
241 ;
242
243 statComInteger
244 .init(cpu->numThreads)
245 .name(name()+".int_insts")
246 .desc("Number of committed integer instructions.")
247 .flags(total)
248 ;
249
250 statComFunctionCalls
251 .init(cpu->numThreads)
252 .name(name()+".function_calls")
253 .desc("Number of function calls committed.")
254 .flags(total)
255 ;
256
257 commitEligible
258 .init(cpu->numThreads)
259 .name(name() + ".bw_limited")
260 .desc("number of insts not committed due to BW limits")
261 .flags(total)
262 ;
263
264 commitEligibleSamples
265 .name(name() + ".bw_lim_events")
266 .desc("number cycles where commit BW limit reached")
267 ;
268}
269
270template <class Impl>
271void
272DefaultCommit<Impl>::setThreads(std::vector<Thread *> &threads)
273{
274 thread = threads;
275}
276
277template <class Impl>
278void
279DefaultCommit<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr)
280{
281 timeBuffer = tb_ptr;
282
283 // Setup wire to send information back to IEW.
284 toIEW = timeBuffer->getWire(0);
285
286 // Setup wire to read data from IEW (for the ROB).
287 robInfoFromIEW = timeBuffer->getWire(-iewToCommitDelay);
288}
289
290template <class Impl>
291void
292DefaultCommit<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr)
293{
294 fetchQueue = fq_ptr;
295
296 // Setup wire to get instructions from rename (for the ROB).
297 fromFetch = fetchQueue->getWire(-fetchToCommitDelay);
298}
299
300template <class Impl>
301void
302DefaultCommit<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr)
303{
304 renameQueue = rq_ptr;
305
306 // Setup wire to get instructions from rename (for the ROB).
307 fromRename = renameQueue->getWire(-renameToROBDelay);
308}
309
310template <class Impl>
311void
312DefaultCommit<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr)
313{
314 iewQueue = iq_ptr;
315
316 // Setup wire to get instructions from IEW.
317 fromIEW = iewQueue->getWire(-iewToCommitDelay);
318}
319
320template <class Impl>
321void
322DefaultCommit<Impl>::setIEWStage(IEW *iew_stage)
323{
324 iewStage = iew_stage;
325}
326
327template<class Impl>
328void
329DefaultCommit<Impl>::setActiveThreads(list<ThreadID> *at_ptr)
330{
331 activeThreads = at_ptr;
332}
333
334template <class Impl>
335void
336DefaultCommit<Impl>::setRenameMap(RenameMap rm_ptr[])
337{
338 for (ThreadID tid = 0; tid < numThreads; tid++)
339 renameMap[tid] = &rm_ptr[tid];
340}
341
342template <class Impl>
343void
344DefaultCommit<Impl>::setROB(ROB *rob_ptr)
345{
346 rob = rob_ptr;
347}
348
349template <class Impl>
350void
351DefaultCommit<Impl>::initStage()
352{
353 rob->setActiveThreads(activeThreads);
354 rob->resetEntries();
355
356 // Broadcast the number of free entries.
357 for (ThreadID tid = 0; tid < numThreads; tid++) {
358 toIEW->commitInfo[tid].usedROB = true;
359 toIEW->commitInfo[tid].freeROBEntries = rob->numFreeEntries(tid);
360 toIEW->commitInfo[tid].emptyROB = true;
361 }
362
363 // Commit must broadcast the number of free entries it has at the
364 // start of the simulation, so it starts as active.
365 cpu->activateStage(O3CPU::CommitIdx);
366
367 cpu->activityThisCycle();
368}
369
370template <class Impl>
371bool
372DefaultCommit<Impl>::drain()
373{
374 drainPending = true;
375
376 return false;
377}
378
379template <class Impl>
380void
381DefaultCommit<Impl>::switchOut()
382{
383 switchedOut = true;
384 drainPending = false;
385 rob->switchOut();
386}
387
388template <class Impl>
389void
390DefaultCommit<Impl>::resume()
391{
392 drainPending = false;
393}
394
395template <class Impl>
396void
397DefaultCommit<Impl>::takeOverFrom()
398{
399 switchedOut = false;
400 _status = Active;
401 _nextStatus = Inactive;
402 for (ThreadID tid = 0; tid < numThreads; tid++) {
403 commitStatus[tid] = Idle;
404 changedROBNumEntries[tid] = false;
405 trapSquash[tid] = false;
406 tcSquash[tid] = false;
407 }
408 squashCounter = 0;
409 rob->takeOverFrom();
410}
411
412template <class Impl>
413void
414DefaultCommit<Impl>::updateStatus()
415{
416 // reset ROB changed variable
417 list<ThreadID>::iterator threads = activeThreads->begin();
418 list<ThreadID>::iterator end = activeThreads->end();
419
420 while (threads != end) {
421 ThreadID tid = *threads++;
422
423 changedROBNumEntries[tid] = false;
424
425 // Also check if any of the threads has a trap pending
426 if (commitStatus[tid] == TrapPending ||
427 commitStatus[tid] == FetchTrapPending) {
428 _nextStatus = Active;
429 }
430 }
431
432 if (_nextStatus == Inactive && _status == Active) {
433 DPRINTF(Activity, "Deactivating stage.\n");
434 cpu->deactivateStage(O3CPU::CommitIdx);
435 } else if (_nextStatus == Active && _status == Inactive) {
436 DPRINTF(Activity, "Activating stage.\n");
437 cpu->activateStage(O3CPU::CommitIdx);
438 }
439
440 _status = _nextStatus;
441}
442
443template <class Impl>
444void
445DefaultCommit<Impl>::setNextStatus()
446{
447 int squashes = 0;
448
449 list<ThreadID>::iterator threads = activeThreads->begin();
450 list<ThreadID>::iterator end = activeThreads->end();
451
452 while (threads != end) {
453 ThreadID tid = *threads++;
454
455 if (commitStatus[tid] == ROBSquashing) {
456 squashes++;
457 }
458 }
459
460 squashCounter = squashes;
461
462 // If commit is currently squashing, then it will have activity for the
463 // next cycle. Set its next status as active.
464 if (squashCounter) {
465 _nextStatus = Active;
466 }
467}
468
469template <class Impl>
470bool
471DefaultCommit<Impl>::changedROBEntries()
472{
473 list<ThreadID>::iterator threads = activeThreads->begin();
474 list<ThreadID>::iterator end = activeThreads->end();
475
476 while (threads != end) {
477 ThreadID tid = *threads++;
478
479 if (changedROBNumEntries[tid]) {
480 return true;
481 }
482 }
483
484 return false;
485}
486
487template <class Impl>
488size_t
489DefaultCommit<Impl>::numROBFreeEntries(ThreadID tid)
490{
491 return rob->numFreeEntries(tid);
492}
493
494template <class Impl>
495void
496DefaultCommit<Impl>::generateTrapEvent(ThreadID tid)
497{
498 DPRINTF(Commit, "Generating trap event for [tid:%i]\n", tid);
499
500 TrapEvent *trap = new TrapEvent(this, tid);
501
502 cpu->schedule(trap, cpu->clockEdge(trapLatency));
503 trapInFlight[tid] = true;
504 thread[tid]->trapPending = true;
505}
506
507template <class Impl>
508void
509DefaultCommit<Impl>::generateTCEvent(ThreadID tid)
510{
511 assert(!trapInFlight[tid]);
512 DPRINTF(Commit, "Generating TC squash event for [tid:%i]\n", tid);
513
514 tcSquash[tid] = true;
515}
516
517template <class Impl>
518void
519DefaultCommit<Impl>::squashAll(ThreadID tid)
520{
521 // If we want to include the squashing instruction in the squash,
522 // then use one older sequence number.
523 // Hopefully this doesn't mess things up. Basically I want to squash
524 // all instructions of this thread.
525 InstSeqNum squashed_inst = rob->isEmpty() ?
526 lastCommitedSeqNum[tid] : rob->readHeadInst(tid)->seqNum - 1;
527
528 // All younger instructions will be squashed. Set the sequence
529 // number as the youngest instruction in the ROB (0 in this case.
530 // Hopefully nothing breaks.)
531 youngestSeqNum[tid] = lastCommitedSeqNum[tid];
532
533 rob->squash(squashed_inst, tid);
534 changedROBNumEntries[tid] = true;
535
536 // Send back the sequence number of the squashed instruction.
537 toIEW->commitInfo[tid].doneSeqNum = squashed_inst;
538
539 // Send back the squash signal to tell stages that they should
540 // squash.
541 toIEW->commitInfo[tid].squash = true;
542
543 // Send back the rob squashing signal so other stages know that
544 // the ROB is in the process of squashing.
545 toIEW->commitInfo[tid].robSquashing = true;
546
547 toIEW->commitInfo[tid].mispredictInst = NULL;
548 toIEW->commitInfo[tid].squashInst = NULL;
549
550 toIEW->commitInfo[tid].pc = pc[tid];
551}
552
553template <class Impl>
554void
555DefaultCommit<Impl>::squashFromTrap(ThreadID tid)
556{
557 squashAll(tid);
558
559 DPRINTF(Commit, "Squashing from trap, restarting at PC %s\n", pc[tid]);
560
561 thread[tid]->trapPending = false;
562 thread[tid]->inSyscall = false;
563 trapInFlight[tid] = false;
564
565 trapSquash[tid] = false;
566
567 commitStatus[tid] = ROBSquashing;
568 cpu->activityThisCycle();
569}
570
571template <class Impl>
572void
573DefaultCommit<Impl>::squashFromTC(ThreadID tid)
574{
575 squashAll(tid);
576
577 DPRINTF(Commit, "Squashing from TC, restarting at PC %s\n", pc[tid]);
578
579 thread[tid]->inSyscall = false;
580 assert(!thread[tid]->trapPending);
581
582 commitStatus[tid] = ROBSquashing;
583 cpu->activityThisCycle();
584
585 tcSquash[tid] = false;
586}
587
588template <class Impl>
589void
590DefaultCommit<Impl>::squashAfter(ThreadID tid, DynInstPtr &head_inst,
591 uint64_t squash_after_seq_num)
592{
593 youngestSeqNum[tid] = squash_after_seq_num;
594
595 rob->squash(squash_after_seq_num, tid);
596 changedROBNumEntries[tid] = true;
597
598 // Send back the sequence number of the squashed instruction.
599 toIEW->commitInfo[tid].doneSeqNum = squash_after_seq_num;
600
601 toIEW->commitInfo[tid].squashInst = head_inst;
602 // Send back the squash signal to tell stages that they should squash.
603 toIEW->commitInfo[tid].squash = true;
604
605 // Send back the rob squashing signal so other stages know that
606 // the ROB is in the process of squashing.
607 toIEW->commitInfo[tid].robSquashing = true;
608
609 toIEW->commitInfo[tid].mispredictInst = NULL;
610
611 toIEW->commitInfo[tid].pc = pc[tid];
612 DPRINTF(Commit, "Executing squash after for [tid:%i] inst [sn:%lli]\n",
613 tid, squash_after_seq_num);
614 commitStatus[tid] = ROBSquashing;
615}
616
617template <class Impl>
618void
619DefaultCommit<Impl>::tick()
620{
621 wroteToTimeBuffer = false;
622 _nextStatus = Inactive;
623
624 if (drainPending && cpu->instList.empty() && !iewStage->hasStoresToWB() &&
625 interrupt == NoFault) {
626 cpu->signalDrained();
627 drainPending = false;
628 return;
629 }
630
631 if (activeThreads->empty())
632 return;
633
634 list<ThreadID>::iterator threads = activeThreads->begin();
635 list<ThreadID>::iterator end = activeThreads->end();
636
637 // Check if any of the threads are done squashing. Change the
638 // status if they are done.
639 while (threads != end) {
640 ThreadID tid = *threads++;
641
642 // Clear the bit saying if the thread has committed stores
643 // this cycle.
644 committedStores[tid] = false;
645
646 if (commitStatus[tid] == ROBSquashing) {
647
648 if (rob->isDoneSquashing(tid)) {
649 commitStatus[tid] = Running;
650 } else {
651 DPRINTF(Commit,"[tid:%u]: Still Squashing, cannot commit any"
652 " insts this cycle.\n", tid);
653 rob->doSquash(tid);
654 toIEW->commitInfo[tid].robSquashing = true;
655 wroteToTimeBuffer = true;
656 }
657 }
658 }
659
660 commit();
661
662 markCompletedInsts();
663
664 threads = activeThreads->begin();
665
666 while (threads != end) {
667 ThreadID tid = *threads++;
668
669 if (!rob->isEmpty(tid) && rob->readHeadInst(tid)->readyToCommit()) {
670 // The ROB has more instructions it can commit. Its next status
671 // will be active.
672 _nextStatus = Active;
673
674 DynInstPtr inst = rob->readHeadInst(tid);
675
676 DPRINTF(Commit,"[tid:%i]: Instruction [sn:%lli] PC %s is head of"
677 " ROB and ready to commit\n",
678 tid, inst->seqNum, inst->pcState());
679
680 } else if (!rob->isEmpty(tid)) {
681 DynInstPtr inst = rob->readHeadInst(tid);
682
683 DPRINTF(Commit,"[tid:%i]: Can't commit, Instruction [sn:%lli] PC "
684 "%s is head of ROB and not ready\n",
685 tid, inst->seqNum, inst->pcState());
686 }
687
688 DPRINTF(Commit, "[tid:%i]: ROB has %d insts & %d free entries.\n",
689 tid, rob->countInsts(tid), rob->numFreeEntries(tid));
690 }
691
692
693 if (wroteToTimeBuffer) {
694 DPRINTF(Activity, "Activity This Cycle.\n");
695 cpu->activityThisCycle();
696 }
697
698 updateStatus();
699}
700
701template <class Impl>
702void
703DefaultCommit<Impl>::handleInterrupt()
704{
705 // Verify that we still have an interrupt to handle
706 if (!cpu->checkInterrupts(cpu->tcBase(0))) {
707 DPRINTF(Commit, "Pending interrupt is cleared by master before "
708 "it got handled. Restart fetching from the orig path.\n");
709 toIEW->commitInfo[0].clearInterrupt = true;
710 interrupt = NoFault;
711 return;
712 }
713
714 // Wait until all in flight instructions are finished before enterring
715 // the interrupt.
716 if (canHandleInterrupts && cpu->instList.empty()) {
717 // Squash or record that I need to squash this cycle if
718 // an interrupt needed to be handled.
719 DPRINTF(Commit, "Interrupt detected.\n");
720
721 // Clear the interrupt now that it's going to be handled
722 toIEW->commitInfo[0].clearInterrupt = true;
723
724 assert(!thread[0]->inSyscall);
725 thread[0]->inSyscall = true;
726
727 if (cpu->checker) {
728 cpu->checker->handlePendingInt();
729 }
730
731 // CPU will handle interrupt.
732 cpu->processInterrupts(interrupt);
733
734 thread[0]->inSyscall = false;
735
736 commitStatus[0] = TrapPending;
737
738 // Generate trap squash event.
739 generateTrapEvent(0);
740
741 interrupt = NoFault;
742 } else {
743 DPRINTF(Commit, "Interrupt pending: instruction is %sin "
744 "flight, ROB is %sempty\n",
745 canHandleInterrupts ? "not " : "",
746 cpu->instList.empty() ? "" : "not " );
747 }
748}
749
750template <class Impl>
751void
752DefaultCommit<Impl>::propagateInterrupt()
753{
754 if (commitStatus[0] == TrapPending || interrupt || trapSquash[0] ||
755 tcSquash[0])
756 return;
757
758 // Process interrupts if interrupts are enabled, not in PAL
759 // mode, and no other traps or external squashes are currently
760 // pending.
761 // @todo: Allow other threads to handle interrupts.
762
763 // Get any interrupt that happened
764 interrupt = cpu->getInterrupts();
765
766 // Tell fetch that there is an interrupt pending. This
767 // will make fetch wait until it sees a non PAL-mode PC,
768 // at which point it stops fetching instructions.
769 if (interrupt != NoFault)
770 toIEW->commitInfo[0].interruptPending = true;
771}
772
773template <class Impl>
774void
775DefaultCommit<Impl>::commit()
776{
777 if (FullSystem) {
778 // Check if we have a interrupt and get read to handle it
779 if (cpu->checkInterrupts(cpu->tcBase(0)))
780 propagateInterrupt();
781 }
782
783 ////////////////////////////////////
784 // Check for any possible squashes, handle them first
785 ////////////////////////////////////
786 list<ThreadID>::iterator threads = activeThreads->begin();
787 list<ThreadID>::iterator end = activeThreads->end();
788
789 while (threads != end) {
790 ThreadID tid = *threads++;
791
792 // Not sure which one takes priority. I think if we have
793 // both, that's a bad sign.
794 if (trapSquash[tid] == true) {
795 assert(!tcSquash[tid]);
796 squashFromTrap(tid);
797 } else if (tcSquash[tid] == true) {
798 assert(commitStatus[tid] != TrapPending);
799 squashFromTC(tid);
800 }
801
802 // Squashed sequence number must be older than youngest valid
803 // instruction in the ROB. This prevents squashes from younger
804 // instructions overriding squashes from older instructions.
805 if (fromIEW->squash[tid] &&
806 commitStatus[tid] != TrapPending &&
807 fromIEW->squashedSeqNum[tid] <= youngestSeqNum[tid]) {
808
809 if (fromIEW->mispredictInst[tid]) {
810 DPRINTF(Commit,
811 "[tid:%i]: Squashing due to branch mispred PC:%#x [sn:%i]\n",
812 tid,
813 fromIEW->mispredictInst[tid]->instAddr(),
814 fromIEW->squashedSeqNum[tid]);
815 } else {
816 DPRINTF(Commit,
817 "[tid:%i]: Squashing due to order violation [sn:%i]\n",
818 tid, fromIEW->squashedSeqNum[tid]);
819 }
820
821 DPRINTF(Commit, "[tid:%i]: Redirecting to PC %#x\n",
822 tid,
823 fromIEW->pc[tid].nextInstAddr());
824
825 commitStatus[tid] = ROBSquashing;
826
827 // If we want to include the squashing instruction in the squash,
828 // then use one older sequence number.
829 InstSeqNum squashed_inst = fromIEW->squashedSeqNum[tid];
830
831 if (fromIEW->includeSquashInst[tid] == true) {
832 squashed_inst--;
833 }
834
835 // All younger instructions will be squashed. Set the sequence
836 // number as the youngest instruction in the ROB.
837 youngestSeqNum[tid] = squashed_inst;
838
839 rob->squash(squashed_inst, tid);
840 changedROBNumEntries[tid] = true;
841
842 toIEW->commitInfo[tid].doneSeqNum = squashed_inst;
843
844 toIEW->commitInfo[tid].squash = true;
845
846 // Send back the rob squashing signal so other stages know that
847 // the ROB is in the process of squashing.
848 toIEW->commitInfo[tid].robSquashing = true;
849
850 toIEW->commitInfo[tid].mispredictInst =
851 fromIEW->mispredictInst[tid];
852 toIEW->commitInfo[tid].branchTaken =
853 fromIEW->branchTaken[tid];
854 toIEW->commitInfo[tid].squashInst =
855 rob->findInst(tid, squashed_inst);
856 if (toIEW->commitInfo[tid].mispredictInst) {
857 if (toIEW->commitInfo[tid].mispredictInst->isUncondCtrl()) {
858 toIEW->commitInfo[tid].branchTaken = true;
859 }
860 }
861
862 toIEW->commitInfo[tid].pc = fromIEW->pc[tid];
863
864 if (toIEW->commitInfo[tid].mispredictInst) {
865 ++branchMispredicts;
866 }
867 }
868
869 }
870
871 setNextStatus();
872
873 if (squashCounter != numThreads) {
874 // If we're not currently squashing, then get instructions.
875 getInsts();
876
877 // Try to commit any instructions.
878 commitInsts();
879 }
880
881 //Check for any activity
882 threads = activeThreads->begin();
883
884 while (threads != end) {
885 ThreadID tid = *threads++;
886
887 if (changedROBNumEntries[tid]) {
888 toIEW->commitInfo[tid].usedROB = true;
889 toIEW->commitInfo[tid].freeROBEntries = rob->numFreeEntries(tid);
890
891 wroteToTimeBuffer = true;
892 changedROBNumEntries[tid] = false;
893 if (rob->isEmpty(tid))
894 checkEmptyROB[tid] = true;
895 }
896
897 // ROB is only considered "empty" for previous stages if: a)
898 // ROB is empty, b) there are no outstanding stores, c) IEW
899 // stage has received any information regarding stores that
900 // committed.
901 // c) is checked by making sure to not consider the ROB empty
902 // on the same cycle as when stores have been committed.
903 // @todo: Make this handle multi-cycle communication between
904 // commit and IEW.
905 if (checkEmptyROB[tid] && rob->isEmpty(tid) &&
906 !iewStage->hasStoresToWB(tid) && !committedStores[tid]) {
907 checkEmptyROB[tid] = false;
908 toIEW->commitInfo[tid].usedROB = true;
909 toIEW->commitInfo[tid].emptyROB = true;
910 toIEW->commitInfo[tid].freeROBEntries = rob->numFreeEntries(tid);
911 wroteToTimeBuffer = true;
912 }
913
914 }
915}
916
917template <class Impl>
918void
919DefaultCommit<Impl>::commitInsts()
920{
921 ////////////////////////////////////
922 // Handle commit
923 // Note that commit will be handled prior to putting new
924 // instructions in the ROB so that the ROB only tries to commit
925 // instructions it has in this current cycle, and not instructions
926 // it is writing in during this cycle. Can't commit and squash
927 // things at the same time...
928 ////////////////////////////////////
929
930 DPRINTF(Commit, "Trying to commit instructions in the ROB.\n");
931
932 unsigned num_committed = 0;
933
934 DynInstPtr head_inst;
935
936 // Commit as many instructions as possible until the commit bandwidth
937 // limit is reached, or it becomes impossible to commit any more.
938 while (num_committed < commitWidth) {
939 // Check for any interrupt that we've already squashed for
940 // and start processing it.
941 if (interrupt != NoFault)
942 handleInterrupt();
943
944 int commit_thread = getCommittingThread();
945
946 if (commit_thread == -1 || !rob->isHeadReady(commit_thread))
947 break;
948
949 head_inst = rob->readHeadInst(commit_thread);
950
951 ThreadID tid = head_inst->threadNumber;
952
953 assert(tid == commit_thread);
954
955 DPRINTF(Commit, "Trying to commit head instruction, [sn:%i] [tid:%i]\n",
956 head_inst->seqNum, tid);
957
958 // If the head instruction is squashed, it is ready to retire
959 // (be removed from the ROB) at any time.
960 if (head_inst->isSquashed()) {
961
962 DPRINTF(Commit, "Retiring squashed instruction from "
963 "ROB.\n");
964
965 rob->retireHead(commit_thread);
966
967 ++commitSquashedInsts;
968
969 // Record that the number of ROB entries has changed.
970 changedROBNumEntries[tid] = true;
971 } else {
972 pc[tid] = head_inst->pcState();
973
974 // Increment the total number of non-speculative instructions
975 // executed.
976 // Hack for now: it really shouldn't happen until after the
977 // commit is deemed to be successful, but this count is needed
978 // for syscalls.
979 thread[tid]->funcExeInst++;
980
981 // Try to commit the head instruction.
982 bool commit_success = commitHead(head_inst, num_committed);
983
984 if (commit_success) {
985 ++num_committed;
986
987 changedROBNumEntries[tid] = true;
988
989 // Set the doneSeqNum to the youngest committed instruction.
990 toIEW->commitInfo[tid].doneSeqNum = head_inst->seqNum;
991
992 if (tid == 0) {
993 canHandleInterrupts = (!head_inst->isDelayedCommit()) &&
994 ((THE_ISA != ALPHA_ISA) ||
995 (!(pc[0].instAddr() & 0x3)));
996 }
997
998 // Updates misc. registers.
999 head_inst->updateMiscRegs();
1000
1001 cpu->traceFunctions(pc[tid].instAddr());
1002
1003 TheISA::advancePC(pc[tid], head_inst->staticInst);
1004
1005 // Keep track of the last sequence number commited
1006 lastCommitedSeqNum[tid] = head_inst->seqNum;
1007
1008 // If this is an instruction that doesn't play nicely with
1009 // others squash everything and restart fetch
1010 if (head_inst->isSquashAfter())
1011 squashAfter(tid, head_inst, head_inst->seqNum);
1012
1013 int count = 0;
1014 Addr oldpc;
1015 // Debug statement. Checks to make sure we're not
1016 // currently updating state while handling PC events.
1017 assert(!thread[tid]->inSyscall && !thread[tid]->trapPending);
1018 do {
1019 oldpc = pc[tid].instAddr();
1020 cpu->system->pcEventQueue.service(thread[tid]->getTC());
1021 count++;
1022 } while (oldpc != pc[tid].instAddr());
1023 if (count > 1) {
1024 DPRINTF(Commit,
1025 "PC skip function event, stopping commit\n");
1026 break;
1027 }
1028 } else {
1029 DPRINTF(Commit, "Unable to commit head instruction PC:%s "
1030 "[tid:%i] [sn:%i].\n",
1031 head_inst->pcState(), tid ,head_inst->seqNum);
1032 break;
1033 }
1034 }
1035 }
1036
1037 DPRINTF(CommitRate, "%i\n", num_committed);
1038 numCommittedDist.sample(num_committed);
1039
1040 if (num_committed == commitWidth) {
1041 commitEligibleSamples++;
1042 }
1043}
1044
1045template <class Impl>
1046bool
1047DefaultCommit<Impl>::commitHead(DynInstPtr &head_inst, unsigned inst_num)
1048{
1049 assert(head_inst);
1050
1051 ThreadID tid = head_inst->threadNumber;
1052
1053 // If the instruction is not executed yet, then it will need extra
1054 // handling. Signal backwards that it should be executed.
1055 if (!head_inst->isExecuted()) {
1056 // Keep this number correct. We have not yet actually executed
1057 // and committed this instruction.
1058 thread[tid]->funcExeInst--;
1059
1060 if (head_inst->isNonSpeculative() ||
1061 head_inst->isStoreConditional() ||
1062 head_inst->isMemBarrier() ||
1063 head_inst->isWriteBarrier()) {
1064
1065 DPRINTF(Commit, "Encountered a barrier or non-speculative "
1066 "instruction [sn:%lli] at the head of the ROB, PC %s.\n",
1067 head_inst->seqNum, head_inst->pcState());
1068
1069 if (inst_num > 0 || iewStage->hasStoresToWB(tid)) {
1070 DPRINTF(Commit, "Waiting for all stores to writeback.\n");
1071 return false;
1072 }
1073
1074 toIEW->commitInfo[tid].nonSpecSeqNum = head_inst->seqNum;
1075
1076 // Change the instruction so it won't try to commit again until
1077 // it is executed.
1078 head_inst->clearCanCommit();
1079
1080 ++commitNonSpecStalls;
1081
1082 return false;
1083 } else if (head_inst->isLoad()) {
1084 if (inst_num > 0 || iewStage->hasStoresToWB(tid)) {
1085 DPRINTF(Commit, "Waiting for all stores to writeback.\n");
1086 return false;
1087 }
1088
1089 assert(head_inst->uncacheable());
1090 DPRINTF(Commit, "[sn:%lli]: Uncached load, PC %s.\n",
1091 head_inst->seqNum, head_inst->pcState());
1092
1093 // Send back the non-speculative instruction's sequence
1094 // number. Tell the lsq to re-execute the load.
1095 toIEW->commitInfo[tid].nonSpecSeqNum = head_inst->seqNum;
1096 toIEW->commitInfo[tid].uncached = true;
1097 toIEW->commitInfo[tid].uncachedLoad = head_inst;
1098
1099 head_inst->clearCanCommit();
1100
1101 return false;
1102 } else {
1103 panic("Trying to commit un-executed instruction "
1104 "of unknown type!\n");
1105 }
1106 }
1107
1108 if (head_inst->isThreadSync()) {
1109 // Not handled for now.
1110 panic("Thread sync instructions are not handled yet.\n");
1111 }
1112
1113 // Check if the instruction caused a fault. If so, trap.
1114 Fault inst_fault = head_inst->getFault();
1115
1116 // Stores mark themselves as completed.
1117 if (!head_inst->isStore() && inst_fault == NoFault) {
1118 head_inst->setCompleted();
1119 }
1120
1121 // Use checker prior to updating anything due to traps or PC
1122 // based events.
1123 if (cpu->checker) {
1124 cpu->checker->verify(head_inst);
1125 }
1126
1127 if (inst_fault != NoFault) {
1128 DPRINTF(Commit, "Inst [sn:%lli] PC %s has a fault\n",
1129 head_inst->seqNum, head_inst->pcState());
1130
1131 if (iewStage->hasStoresToWB(tid) || inst_num > 0) {
1132 DPRINTF(Commit, "Stores outstanding, fault must wait.\n");
1133 return false;
1134 }
1135
1136 head_inst->setCompleted();
1137
1138 if (cpu->checker) {
1139 // Need to check the instruction before its fault is processed
1140 cpu->checker->verify(head_inst);
1141 }
1142
1143 assert(!thread[tid]->inSyscall);
1144
1145 // Mark that we're in state update mode so that the trap's
1146 // execution doesn't generate extra squashes.
1147 thread[tid]->inSyscall = true;
1148
1149 // Execute the trap. Although it's slightly unrealistic in
1150 // terms of timing (as it doesn't wait for the full timing of
1151 // the trap event to complete before updating state), it's
1152 // needed to update the state as soon as possible. This
1153 // prevents external agents from changing any specific state
1154 // that the trap need.
1155 cpu->trap(inst_fault, tid, head_inst->staticInst);
1156
1157 // Exit state update mode to avoid accidental updating.
1158 thread[tid]->inSyscall = false;
1159
1160 commitStatus[tid] = TrapPending;
1161
1162 DPRINTF(Commit, "Committing instruction with fault [sn:%lli]\n",
1163 head_inst->seqNum);
1164 if (head_inst->traceData) {
1165 if (DTRACE(ExecFaulting)) {
1166 head_inst->traceData->setFetchSeq(head_inst->seqNum);
1167 head_inst->traceData->setCPSeq(thread[tid]->numOp);
1168 head_inst->traceData->dump();
1169 }
1170 delete head_inst->traceData;
1171 head_inst->traceData = NULL;
1172 }
1173
1174 // Generate trap squash event.
1175 generateTrapEvent(tid);
1176 return false;
1177 }
1178
1179 updateComInstStats(head_inst);
1180
1181 if (FullSystem) {
1182 if (thread[tid]->profile) {
1183 thread[tid]->profilePC = head_inst->instAddr();
1184 ProfileNode *node = thread[tid]->profile->consume(
1185 thread[tid]->getTC(), head_inst->staticInst);
1186
1187 if (node)
1188 thread[tid]->profileNode = node;
1189 }
1190 if (CPA::available()) {
1191 if (head_inst->isControl()) {
1192 ThreadContext *tc = thread[tid]->getTC();
1193 CPA::cpa()->swAutoBegin(tc, head_inst->nextInstAddr());
1194 }
1195 }
1196 }
1197 DPRINTF(Commit, "Committing instruction with [sn:%lli] PC %s\n",
1198 head_inst->seqNum, head_inst->pcState());
1199 if (head_inst->traceData) {
1200 head_inst->traceData->setFetchSeq(head_inst->seqNum);
1201 head_inst->traceData->setCPSeq(thread[tid]->numOp);
1202 head_inst->traceData->dump();
1203 delete head_inst->traceData;
1204 head_inst->traceData = NULL;
1205 }
1206 if (head_inst->isReturn()) {
1207 DPRINTF(Commit,"Return Instruction Committed [sn:%lli] PC %s \n",
1208 head_inst->seqNum, head_inst->pcState());
1209 }
1210
1211 // Update the commit rename map
1212 for (int i = 0; i < head_inst->numDestRegs(); i++) {
1213 renameMap[tid]->setEntry(head_inst->flattenedDestRegIdx(i),
1214 head_inst->renamedDestRegIdx(i));
1215 }
1216
1217 // Finally clear the head ROB entry.
1218 rob->retireHead(tid);
1219
1220#if TRACING_ON
|
1235#endif
1236
1237 // If this was a store, record it for this cycle.
1238 if (head_inst->isStore())
1239 committedStores[tid] = true;
1240
1241 // Return true to indicate that we have committed an instruction.
1242 return true;
1243}
1244
1245template <class Impl>
1246void
1247DefaultCommit<Impl>::getInsts()
1248{
1249 DPRINTF(Commit, "Getting instructions from Rename stage.\n");
1250
1251 // Read any renamed instructions and place them into the ROB.
1252 int insts_to_process = std::min((int)renameWidth, fromRename->size);
1253
1254 for (int inst_num = 0; inst_num < insts_to_process; ++inst_num) {
1255 DynInstPtr inst;
1256
1257 inst = fromRename->insts[inst_num];
1258 ThreadID tid = inst->threadNumber;
1259
1260 if (!inst->isSquashed() &&
1261 commitStatus[tid] != ROBSquashing &&
1262 commitStatus[tid] != TrapPending) {
1263 changedROBNumEntries[tid] = true;
1264
1265 DPRINTF(Commit, "Inserting PC %s [sn:%i] [tid:%i] into ROB.\n",
1266 inst->pcState(), inst->seqNum, tid);
1267
1268 rob->insertInst(inst);
1269
1270 assert(rob->getThreadEntries(tid) <= rob->getMaxEntries(tid));
1271
1272 youngestSeqNum[tid] = inst->seqNum;
1273 } else {
1274 DPRINTF(Commit, "Instruction PC %s [sn:%i] [tid:%i] was "
1275 "squashed, skipping.\n",
1276 inst->pcState(), inst->seqNum, tid);
1277 }
1278 }
1279}
1280
1281template <class Impl>
1282void
1283DefaultCommit<Impl>::skidInsert()
1284{
1285 DPRINTF(Commit, "Attempting to any instructions from rename into "
1286 "skidBuffer.\n");
1287
1288 for (int inst_num = 0; inst_num < fromRename->size; ++inst_num) {
1289 DynInstPtr inst = fromRename->insts[inst_num];
1290
1291 if (!inst->isSquashed()) {
1292 DPRINTF(Commit, "Inserting PC %s [sn:%i] [tid:%i] into ",
1293 "skidBuffer.\n", inst->pcState(), inst->seqNum,
1294 inst->threadNumber);
1295 skidBuffer.push(inst);
1296 } else {
1297 DPRINTF(Commit, "Instruction PC %s [sn:%i] [tid:%i] was "
1298 "squashed, skipping.\n",
1299 inst->pcState(), inst->seqNum, inst->threadNumber);
1300 }
1301 }
1302}
1303
1304template <class Impl>
1305void
1306DefaultCommit<Impl>::markCompletedInsts()
1307{
1308 // Grab completed insts out of the IEW instruction queue, and mark
1309 // instructions completed within the ROB.
1310 for (int inst_num = 0;
1311 inst_num < fromIEW->size && fromIEW->insts[inst_num];
1312 ++inst_num)
1313 {
1314 if (!fromIEW->insts[inst_num]->isSquashed()) {
1315 DPRINTF(Commit, "[tid:%i]: Marking PC %s, [sn:%lli] ready "
1316 "within ROB.\n",
1317 fromIEW->insts[inst_num]->threadNumber,
1318 fromIEW->insts[inst_num]->pcState(),
1319 fromIEW->insts[inst_num]->seqNum);
1320
1321 // Mark the instruction as ready to commit.
1322 fromIEW->insts[inst_num]->setCanCommit();
1323 }
1324 }
1325}
1326
1327template <class Impl>
1328bool
1329DefaultCommit<Impl>::robDoneSquashing()
1330{
1331 list<ThreadID>::iterator threads = activeThreads->begin();
1332 list<ThreadID>::iterator end = activeThreads->end();
1333
1334 while (threads != end) {
1335 ThreadID tid = *threads++;
1336
1337 if (!rob->isDoneSquashing(tid))
1338 return false;
1339 }
1340
1341 return true;
1342}
1343
1344template <class Impl>
1345void
1346DefaultCommit<Impl>::updateComInstStats(DynInstPtr &inst)
1347{
1348 ThreadID tid = inst->threadNumber;
1349
1350 if (!inst->isMicroop() || inst->isLastMicroop())
1351 instsCommitted[tid]++;
1352 opsCommitted[tid]++;
1353
1354 // To match the old model, don't count nops and instruction
1355 // prefetches towards the total commit count.
1356 if (!inst->isNop() && !inst->isInstPrefetch()) {
1357 cpu->instDone(tid, inst);
1358 }
1359
1360 //
1361 // Control Instructions
1362 //
1363 if (inst->isControl())
1364 statComBranches[tid]++;
1365
1366 //
1367 // Memory references
1368 //
1369 if (inst->isMemRef()) {
1370 statComRefs[tid]++;
1371
1372 if (inst->isLoad()) {
1373 statComLoads[tid]++;
1374 }
1375 }
1376
1377 if (inst->isMemBarrier()) {
1378 statComMembars[tid]++;
1379 }
1380
1381 // Integer Instruction
1382 if (inst->isInteger())
1383 statComInteger[tid]++;
1384
1385 // Floating Point Instruction
1386 if (inst->isFloating())
1387 statComFloating[tid]++;
1388
1389 // Function Calls
1390 if (inst->isCall())
1391 statComFunctionCalls[tid]++;
1392
1393}
1394
1395////////////////////////////////////////
1396// //
1397// SMT COMMIT POLICY MAINTAINED HERE //
1398// //
1399////////////////////////////////////////
1400template <class Impl>
1401ThreadID
1402DefaultCommit<Impl>::getCommittingThread()
1403{
1404 if (numThreads > 1) {
1405 switch (commitPolicy) {
1406
1407 case Aggressive:
1408 //If Policy is Aggressive, commit will call
1409 //this function multiple times per
1410 //cycle
1411 return oldestReady();
1412
1413 case RoundRobin:
1414 return roundRobin();
1415
1416 case OldestReady:
1417 return oldestReady();
1418
1419 default:
1420 return InvalidThreadID;
1421 }
1422 } else {
1423 assert(!activeThreads->empty());
1424 ThreadID tid = activeThreads->front();
1425
1426 if (commitStatus[tid] == Running ||
1427 commitStatus[tid] == Idle ||
1428 commitStatus[tid] == FetchTrapPending) {
1429 return tid;
1430 } else {
1431 return InvalidThreadID;
1432 }
1433 }
1434}
1435
1436template<class Impl>
1437ThreadID
1438DefaultCommit<Impl>::roundRobin()
1439{
1440 list<ThreadID>::iterator pri_iter = priority_list.begin();
1441 list<ThreadID>::iterator end = priority_list.end();
1442
1443 while (pri_iter != end) {
1444 ThreadID tid = *pri_iter;
1445
1446 if (commitStatus[tid] == Running ||
1447 commitStatus[tid] == Idle ||
1448 commitStatus[tid] == FetchTrapPending) {
1449
1450 if (rob->isHeadReady(tid)) {
1451 priority_list.erase(pri_iter);
1452 priority_list.push_back(tid);
1453
1454 return tid;
1455 }
1456 }
1457
1458 pri_iter++;
1459 }
1460
1461 return InvalidThreadID;
1462}
1463
1464template<class Impl>
1465ThreadID
1466DefaultCommit<Impl>::oldestReady()
1467{
1468 unsigned oldest = 0;
1469 bool first = true;
1470
1471 list<ThreadID>::iterator threads = activeThreads->begin();
1472 list<ThreadID>::iterator end = activeThreads->end();
1473
1474 while (threads != end) {
1475 ThreadID tid = *threads++;
1476
1477 if (!rob->isEmpty(tid) &&
1478 (commitStatus[tid] == Running ||
1479 commitStatus[tid] == Idle ||
1480 commitStatus[tid] == FetchTrapPending)) {
1481
1482 if (rob->isHeadReady(tid)) {
1483
1484 DynInstPtr head_inst = rob->readHeadInst(tid);
1485
1486 if (first) {
1487 oldest = tid;
1488 first = false;
1489 } else if (head_inst->seqNum < oldest) {
1490 oldest = tid;
1491 }
1492 }
1493 }
1494 }
1495
1496 if (!first) {
1497 return oldest;
1498 } else {
1499 return InvalidThreadID;
1500 }
1501}
| 1222#endif
1223
1224 // If this was a store, record it for this cycle.
1225 if (head_inst->isStore())
1226 committedStores[tid] = true;
1227
1228 // Return true to indicate that we have committed an instruction.
1229 return true;
1230}
1231
1232template <class Impl>
1233void
1234DefaultCommit<Impl>::getInsts()
1235{
1236 DPRINTF(Commit, "Getting instructions from Rename stage.\n");
1237
1238 // Read any renamed instructions and place them into the ROB.
1239 int insts_to_process = std::min((int)renameWidth, fromRename->size);
1240
1241 for (int inst_num = 0; inst_num < insts_to_process; ++inst_num) {
1242 DynInstPtr inst;
1243
1244 inst = fromRename->insts[inst_num];
1245 ThreadID tid = inst->threadNumber;
1246
1247 if (!inst->isSquashed() &&
1248 commitStatus[tid] != ROBSquashing &&
1249 commitStatus[tid] != TrapPending) {
1250 changedROBNumEntries[tid] = true;
1251
1252 DPRINTF(Commit, "Inserting PC %s [sn:%i] [tid:%i] into ROB.\n",
1253 inst->pcState(), inst->seqNum, tid);
1254
1255 rob->insertInst(inst);
1256
1257 assert(rob->getThreadEntries(tid) <= rob->getMaxEntries(tid));
1258
1259 youngestSeqNum[tid] = inst->seqNum;
1260 } else {
1261 DPRINTF(Commit, "Instruction PC %s [sn:%i] [tid:%i] was "
1262 "squashed, skipping.\n",
1263 inst->pcState(), inst->seqNum, tid);
1264 }
1265 }
1266}
1267
1268template <class Impl>
1269void
1270DefaultCommit<Impl>::skidInsert()
1271{
1272 DPRINTF(Commit, "Attempting to any instructions from rename into "
1273 "skidBuffer.\n");
1274
1275 for (int inst_num = 0; inst_num < fromRename->size; ++inst_num) {
1276 DynInstPtr inst = fromRename->insts[inst_num];
1277
1278 if (!inst->isSquashed()) {
1279 DPRINTF(Commit, "Inserting PC %s [sn:%i] [tid:%i] into ",
1280 "skidBuffer.\n", inst->pcState(), inst->seqNum,
1281 inst->threadNumber);
1282 skidBuffer.push(inst);
1283 } else {
1284 DPRINTF(Commit, "Instruction PC %s [sn:%i] [tid:%i] was "
1285 "squashed, skipping.\n",
1286 inst->pcState(), inst->seqNum, inst->threadNumber);
1287 }
1288 }
1289}
1290
1291template <class Impl>
1292void
1293DefaultCommit<Impl>::markCompletedInsts()
1294{
1295 // Grab completed insts out of the IEW instruction queue, and mark
1296 // instructions completed within the ROB.
1297 for (int inst_num = 0;
1298 inst_num < fromIEW->size && fromIEW->insts[inst_num];
1299 ++inst_num)
1300 {
1301 if (!fromIEW->insts[inst_num]->isSquashed()) {
1302 DPRINTF(Commit, "[tid:%i]: Marking PC %s, [sn:%lli] ready "
1303 "within ROB.\n",
1304 fromIEW->insts[inst_num]->threadNumber,
1305 fromIEW->insts[inst_num]->pcState(),
1306 fromIEW->insts[inst_num]->seqNum);
1307
1308 // Mark the instruction as ready to commit.
1309 fromIEW->insts[inst_num]->setCanCommit();
1310 }
1311 }
1312}
1313
1314template <class Impl>
1315bool
1316DefaultCommit<Impl>::robDoneSquashing()
1317{
1318 list<ThreadID>::iterator threads = activeThreads->begin();
1319 list<ThreadID>::iterator end = activeThreads->end();
1320
1321 while (threads != end) {
1322 ThreadID tid = *threads++;
1323
1324 if (!rob->isDoneSquashing(tid))
1325 return false;
1326 }
1327
1328 return true;
1329}
1330
1331template <class Impl>
1332void
1333DefaultCommit<Impl>::updateComInstStats(DynInstPtr &inst)
1334{
1335 ThreadID tid = inst->threadNumber;
1336
1337 if (!inst->isMicroop() || inst->isLastMicroop())
1338 instsCommitted[tid]++;
1339 opsCommitted[tid]++;
1340
1341 // To match the old model, don't count nops and instruction
1342 // prefetches towards the total commit count.
1343 if (!inst->isNop() && !inst->isInstPrefetch()) {
1344 cpu->instDone(tid, inst);
1345 }
1346
1347 //
1348 // Control Instructions
1349 //
1350 if (inst->isControl())
1351 statComBranches[tid]++;
1352
1353 //
1354 // Memory references
1355 //
1356 if (inst->isMemRef()) {
1357 statComRefs[tid]++;
1358
1359 if (inst->isLoad()) {
1360 statComLoads[tid]++;
1361 }
1362 }
1363
1364 if (inst->isMemBarrier()) {
1365 statComMembars[tid]++;
1366 }
1367
1368 // Integer Instruction
1369 if (inst->isInteger())
1370 statComInteger[tid]++;
1371
1372 // Floating Point Instruction
1373 if (inst->isFloating())
1374 statComFloating[tid]++;
1375
1376 // Function Calls
1377 if (inst->isCall())
1378 statComFunctionCalls[tid]++;
1379
1380}
1381
1382////////////////////////////////////////
1383// //
1384// SMT COMMIT POLICY MAINTAINED HERE //
1385// //
1386////////////////////////////////////////
1387template <class Impl>
1388ThreadID
1389DefaultCommit<Impl>::getCommittingThread()
1390{
1391 if (numThreads > 1) {
1392 switch (commitPolicy) {
1393
1394 case Aggressive:
1395 //If Policy is Aggressive, commit will call
1396 //this function multiple times per
1397 //cycle
1398 return oldestReady();
1399
1400 case RoundRobin:
1401 return roundRobin();
1402
1403 case OldestReady:
1404 return oldestReady();
1405
1406 default:
1407 return InvalidThreadID;
1408 }
1409 } else {
1410 assert(!activeThreads->empty());
1411 ThreadID tid = activeThreads->front();
1412
1413 if (commitStatus[tid] == Running ||
1414 commitStatus[tid] == Idle ||
1415 commitStatus[tid] == FetchTrapPending) {
1416 return tid;
1417 } else {
1418 return InvalidThreadID;
1419 }
1420 }
1421}
1422
1423template<class Impl>
1424ThreadID
1425DefaultCommit<Impl>::roundRobin()
1426{
1427 list<ThreadID>::iterator pri_iter = priority_list.begin();
1428 list<ThreadID>::iterator end = priority_list.end();
1429
1430 while (pri_iter != end) {
1431 ThreadID tid = *pri_iter;
1432
1433 if (commitStatus[tid] == Running ||
1434 commitStatus[tid] == Idle ||
1435 commitStatus[tid] == FetchTrapPending) {
1436
1437 if (rob->isHeadReady(tid)) {
1438 priority_list.erase(pri_iter);
1439 priority_list.push_back(tid);
1440
1441 return tid;
1442 }
1443 }
1444
1445 pri_iter++;
1446 }
1447
1448 return InvalidThreadID;
1449}
1450
1451template<class Impl>
1452ThreadID
1453DefaultCommit<Impl>::oldestReady()
1454{
1455 unsigned oldest = 0;
1456 bool first = true;
1457
1458 list<ThreadID>::iterator threads = activeThreads->begin();
1459 list<ThreadID>::iterator end = activeThreads->end();
1460
1461 while (threads != end) {
1462 ThreadID tid = *threads++;
1463
1464 if (!rob->isEmpty(tid) &&
1465 (commitStatus[tid] == Running ||
1466 commitStatus[tid] == Idle ||
1467 commitStatus[tid] == FetchTrapPending)) {
1468
1469 if (rob->isHeadReady(tid)) {
1470
1471 DynInstPtr head_inst = rob->readHeadInst(tid);
1472
1473 if (first) {
1474 oldest = tid;
1475 first = false;
1476 } else if (head_inst->seqNum < oldest) {
1477 oldest = tid;
1478 }
1479 }
1480 }
1481 }
1482
1483 if (!first) {
1484 return oldest;
1485 } else {
1486 return InvalidThreadID;
1487 }
1488}
|