1/*
2 * Copyright (c) 2004-2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Kevin Lim
29 * Korey Sewell
30 */
31
32#include <list>
33
34#include "config/full_system.hh"
35#include "cpu/o3/rename.hh"
36
37template <class Impl>
38DefaultRename<Impl>::DefaultRename(Params *params)
39 : iewToRenameDelay(params->iewToRenameDelay),
40 decodeToRenameDelay(params->decodeToRenameDelay),
41 commitToRenameDelay(params->commitToRenameDelay),
42 renameWidth(params->renameWidth),
43 commitWidth(params->commitWidth),
44 numThreads(params->numberOfThreads),
45 maxPhysicalRegs(params->numPhysIntRegs + params->numPhysFloatRegs)
46{
47 _status = Inactive;
48
49 for (int i=0; i< numThreads; i++) {
50 renameStatus[i] = Idle;
51
52 freeEntries[i].iqEntries = 0;
53 freeEntries[i].lsqEntries = 0;
54 freeEntries[i].robEntries = 0;
55
56 stalls[i].iew = false;
57 stalls[i].commit = false;
58 serializeInst[i] = NULL;
59
60 instsInProgress[i] = 0;
61
62 emptyROB[i] = true;
63
64 serializeOnNextInst[i] = false;
65 }
66
67 // @todo: Make into a parameter.
68 skidBufferMax = (2 * (iewToRenameDelay * params->decodeWidth)) + renameWidth;
69}
70
71template <class Impl>
72std::string
73DefaultRename<Impl>::name() const
74{
75 return cpu->name() + ".rename";
76}
77
78template <class Impl>
79void
80DefaultRename<Impl>::regStats()
81{
82 renameSquashCycles
83 .name(name() + ".RENAME:SquashCycles")
84 .desc("Number of cycles rename is squashing")
85 .prereq(renameSquashCycles);
86 renameIdleCycles
87 .name(name() + ".RENAME:IdleCycles")
88 .desc("Number of cycles rename is idle")
89 .prereq(renameIdleCycles);
90 renameBlockCycles
91 .name(name() + ".RENAME:BlockCycles")
92 .desc("Number of cycles rename is blocking")
93 .prereq(renameBlockCycles);
94 renameSerializeStallCycles
95 .name(name() + ".RENAME:serializeStallCycles")
96 .desc("count of cycles rename stalled for serializing inst")
97 .flags(Stats::total);
98 renameRunCycles
99 .name(name() + ".RENAME:RunCycles")
100 .desc("Number of cycles rename is running")
101 .prereq(renameIdleCycles);
102 renameUnblockCycles
103 .name(name() + ".RENAME:UnblockCycles")
104 .desc("Number of cycles rename is unblocking")
105 .prereq(renameUnblockCycles);
106 renameRenamedInsts
107 .name(name() + ".RENAME:RenamedInsts")
108 .desc("Number of instructions processed by rename")
109 .prereq(renameRenamedInsts);
110 renameSquashedInsts
111 .name(name() + ".RENAME:SquashedInsts")
112 .desc("Number of squashed instructions processed by rename")
113 .prereq(renameSquashedInsts);
114 renameROBFullEvents
115 .name(name() + ".RENAME:ROBFullEvents")
116 .desc("Number of times rename has blocked due to ROB full")
117 .prereq(renameROBFullEvents);
118 renameIQFullEvents
119 .name(name() + ".RENAME:IQFullEvents")
120 .desc("Number of times rename has blocked due to IQ full")
121 .prereq(renameIQFullEvents);
122 renameLSQFullEvents
123 .name(name() + ".RENAME:LSQFullEvents")
124 .desc("Number of times rename has blocked due to LSQ full")
125 .prereq(renameLSQFullEvents);
126 renameFullRegistersEvents
127 .name(name() + ".RENAME:FullRegisterEvents")
128 .desc("Number of times there has been no free registers")
129 .prereq(renameFullRegistersEvents);
130 renameRenamedOperands
131 .name(name() + ".RENAME:RenamedOperands")
132 .desc("Number of destination operands rename has renamed")
133 .prereq(renameRenamedOperands);
134 renameRenameLookups
135 .name(name() + ".RENAME:RenameLookups")
136 .desc("Number of register rename lookups that rename has made")
137 .prereq(renameRenameLookups);
138 renameCommittedMaps
139 .name(name() + ".RENAME:CommittedMaps")
140 .desc("Number of HB maps that are committed")
141 .prereq(renameCommittedMaps);
142 renameUndoneMaps
143 .name(name() + ".RENAME:UndoneMaps")
144 .desc("Number of HB maps that are undone due to squashing")
145 .prereq(renameUndoneMaps);
146 renamedSerializing
147 .name(name() + ".RENAME:serializingInsts")
148 .desc("count of serializing insts renamed")
149 .flags(Stats::total)
150 ;
151 renamedTempSerializing
152 .name(name() + ".RENAME:tempSerializingInsts")
153 .desc("count of temporary serializing insts renamed")
154 .flags(Stats::total)
155 ;
156 renameSkidInsts
157 .name(name() + ".RENAME:skidInsts")
158 .desc("count of insts added to the skid buffer")
159 .flags(Stats::total)
160 ;
161}
162
163template <class Impl>
164void
165DefaultRename<Impl>::setCPU(O3CPU *cpu_ptr)
166{
167 DPRINTF(Rename, "Setting CPU pointer.\n");
168 cpu = cpu_ptr;
169}
170
171template <class Impl>
172void
173DefaultRename<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr)
174{
175 DPRINTF(Rename, "Setting time buffer pointer.\n");
176 timeBuffer = tb_ptr;
177
178 // Setup wire to read information from time buffer, from IEW stage.
179 fromIEW = timeBuffer->getWire(-iewToRenameDelay);
180
181 // Setup wire to read infromation from time buffer, from commit stage.
182 fromCommit = timeBuffer->getWire(-commitToRenameDelay);
183
184 // Setup wire to write information to previous stages.
185 toDecode = timeBuffer->getWire(0);
186}
187
188template <class Impl>
189void
190DefaultRename<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr)
191{
192 DPRINTF(Rename, "Setting rename queue pointer.\n");
193 renameQueue = rq_ptr;
194
195 // Setup wire to write information to future stages.
196 toIEW = renameQueue->getWire(0);
197}
198
199template <class Impl>
200void
201DefaultRename<Impl>::setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr)
202{
203 DPRINTF(Rename, "Setting decode queue pointer.\n");
204 decodeQueue = dq_ptr;
205
206 // Setup wire to get information from decode.
207 fromDecode = decodeQueue->getWire(-decodeToRenameDelay);
208}
209
210template <class Impl>
211void
212DefaultRename<Impl>::initStage()
213{
214 // Grab the number of free entries directly from the stages.
215 for (int tid=0; tid < numThreads; tid++) {
216 freeEntries[tid].iqEntries = iew_ptr->instQueue.numFreeEntries(tid);
217 freeEntries[tid].lsqEntries = iew_ptr->ldstQueue.numFreeEntries(tid);
218 freeEntries[tid].robEntries = commit_ptr->numROBFreeEntries(tid);
219 emptyROB[tid] = true;
220 }
221}
222
223template<class Impl>
224void
225DefaultRename<Impl>::setActiveThreads(std::list<unsigned> *at_ptr)
226{
227 DPRINTF(Rename, "Setting active threads list pointer.\n");
228 activeThreads = at_ptr;
229}
230
231
232template <class Impl>
233void
234DefaultRename<Impl>::setRenameMap(RenameMap rm_ptr[])
235{
236 DPRINTF(Rename, "Setting rename map pointers.\n");
237
238 for (int i=0; i<numThreads; i++) {
239 renameMap[i] = &rm_ptr[i];
240 }
241}
242
243template <class Impl>
244void
245DefaultRename<Impl>::setFreeList(FreeList *fl_ptr)
246{
247 DPRINTF(Rename, "Setting free list pointer.\n");
248 freeList = fl_ptr;
249}
250
251template<class Impl>
252void
253DefaultRename<Impl>::setScoreboard(Scoreboard *_scoreboard)
254{
255 DPRINTF(Rename, "Setting scoreboard pointer.\n");
256 scoreboard = _scoreboard;
257}
258
259template <class Impl>
260bool
261DefaultRename<Impl>::drain()
262{
263 // Rename is ready to switch out at any time.
264 cpu->signalDrained();
265 return true;
266}
267
268template <class Impl>
269void
270DefaultRename<Impl>::switchOut()
271{
272 // Clear any state, fix up the rename map.
273 for (int i = 0; i < numThreads; i++) {
274 typename std::list<RenameHistory>::iterator hb_it =
275 historyBuffer[i].begin();
276
277 while (!historyBuffer[i].empty()) {
278 assert(hb_it != historyBuffer[i].end());
279
280 DPRINTF(Rename, "[tid:%u]: Removing history entry with sequence "
281 "number %i.\n", i, (*hb_it).instSeqNum);
282
283 // Tell the rename map to set the architected register to the
284 // previous physical register that it was renamed to.
285 renameMap[i]->setEntry(hb_it->archReg, hb_it->prevPhysReg);
286
287 // Put the renamed physical register back on the free list.
288 freeList->addReg(hb_it->newPhysReg);
289
290 // Be sure to mark its register as ready if it's a misc register.
291 if (hb_it->newPhysReg >= maxPhysicalRegs) {
292 scoreboard->setReg(hb_it->newPhysReg);
293 }
294
295 historyBuffer[i].erase(hb_it++);
296 }
297 insts[i].clear();
298 skidBuffer[i].clear();
299 }
300}
301
302template <class Impl>
303void
304DefaultRename<Impl>::takeOverFrom()
305{
306 _status = Inactive;
307 initStage();
308
309 // Reset all state prior to taking over from the other CPU.
310 for (int i=0; i< numThreads; i++) {
311 renameStatus[i] = Idle;
312
313 stalls[i].iew = false;
314 stalls[i].commit = false;
315 serializeInst[i] = NULL;
316
317 instsInProgress[i] = 0;
318
319 emptyROB[i] = true;
320
321 serializeOnNextInst[i] = false;
322 }
323}
324
325template <class Impl>
326void
327DefaultRename<Impl>::squash(const InstSeqNum &squash_seq_num, unsigned tid)
328{
329 DPRINTF(Rename, "[tid:%u]: Squashing instructions.\n",tid);
330
331 // Clear the stall signal if rename was blocked or unblocking before.
332 // If it still needs to block, the blocking should happen the next
333 // cycle and there should be space to hold everything due to the squash.
334 if (renameStatus[tid] == Blocked ||
335 renameStatus[tid] == Unblocking ||
336 renameStatus[tid] == SerializeStall) {
337
338 toDecode->renameUnblock[tid] = 1;
339
340 serializeInst[tid] = NULL;
341 }
342
343 // Set the status to Squashing.
344 renameStatus[tid] = Squashing;
345
346 // Squash any instructions from decode.
347 unsigned squashCount = 0;
348
349 for (int i=0; i<fromDecode->size; i++) {
350 if (fromDecode->insts[i]->threadNumber == tid &&
351 fromDecode->insts[i]->seqNum > squash_seq_num) {
352 fromDecode->insts[i]->setSquashed();
353 wroteToTimeBuffer = true;
354 squashCount++;
355 }
356
357 }
358
359 // Clear the instruction list and skid buffer in case they have any
360 // insts in them. Since we support multiple ISAs, we cant just:
361 // "insts[tid].clear();" or "skidBuffer[tid].clear()" since there is
362 // a possible delay slot inst for different architectures
363 // insts[tid].clear();
364#if ISA_HAS_DELAY_SLOT
365 DPRINTF(Rename, "[tid:%i] Squashing incoming decode instructions until "
366 "[sn:%i].\n",tid, squash_seq_num);
367 ListIt ilist_it = insts[tid].begin();
368 while (ilist_it != insts[tid].end()) {
369 if ((*ilist_it)->seqNum > squash_seq_num) {
370 (*ilist_it)->setSquashed();
371 DPRINTF(Rename, "Squashing incoming decode instruction, "
372 "[tid:%i] [sn:%i] PC %08p.\n", tid, (*ilist_it)->seqNum, (*ilist_it)->PC);
373 }
374 ilist_it++;
375 }
376#else
377 insts[tid].clear();
378#endif
379
380 // Clear the skid buffer in case it has any data in it.
381 // See comments above.
382 // skidBuffer[tid].clear();
383#if ISA_HAS_DELAY_SLOT
384 DPRINTF(Rename, "[tid:%i] Squashing incoming skidbuffer instructions "
385 "until [sn:%i].\n", tid, squash_seq_num);
386 ListIt slist_it = skidBuffer[tid].begin();
387 while (slist_it != skidBuffer[tid].end()) {
388 if ((*slist_it)->seqNum > squash_seq_num) {
389 (*slist_it)->setSquashed();
390 DPRINTF(Rename, "Squashing skidbuffer instruction, [tid:%i] [sn:%i]"
391 "PC %08p.\n", tid, (*slist_it)->seqNum, (*slist_it)->PC);
392 }
393 slist_it++;
394 }
395#else
396 skidBuffer[tid].clear();
397#endif
398 doSquash(squash_seq_num, tid);
399}
400
401template <class Impl>
402void
403DefaultRename<Impl>::tick()
404{
405 wroteToTimeBuffer = false;
406
407 blockThisCycle = false;
408
409 bool status_change = false;
410
411 toIEWIndex = 0;
412
413 sortInsts();
414
415 std::list<unsigned>::iterator threads = (*activeThreads).begin();
416
417 // Check stall and squash signals.
418 while (threads != (*activeThreads).end()) {
419 unsigned tid = *threads++;
420
421 DPRINTF(Rename, "Processing [tid:%i]\n", tid);
422
423 status_change = checkSignalsAndUpdate(tid) || status_change;
424
425 rename(status_change, tid);
426 }
427
428 if (status_change) {
429 updateStatus();
430 }
431
432 if (wroteToTimeBuffer) {
433 DPRINTF(Activity, "Activity this cycle.\n");
434 cpu->activityThisCycle();
435 }
436
437 threads = (*activeThreads).begin();
438
439 while (threads != (*activeThreads).end()) {
440 unsigned tid = *threads++;
441
442 // If we committed this cycle then doneSeqNum will be > 0
443 if (fromCommit->commitInfo[tid].doneSeqNum != 0 &&
444 !fromCommit->commitInfo[tid].squash &&
445 renameStatus[tid] != Squashing) {
446
447 removeFromHistory(fromCommit->commitInfo[tid].doneSeqNum,
448 tid);
449 }
450 }
451
452 // @todo: make into updateProgress function
453 for (int tid=0; tid < numThreads; tid++) {
454 instsInProgress[tid] -= fromIEW->iewInfo[tid].dispatched;
455
456 assert(instsInProgress[tid] >=0);
457 }
458
459}
460
461template<class Impl>
462void
463DefaultRename<Impl>::rename(bool &status_change, unsigned tid)
464{
465 // If status is Running or idle,
466 // call renameInsts()
467 // If status is Unblocking,
468 // buffer any instructions coming from decode
469 // continue trying to empty skid buffer
470 // check if stall conditions have passed
471
472 if (renameStatus[tid] == Blocked) {
473 ++renameBlockCycles;
474 } else if (renameStatus[tid] == Squashing) {
475 ++renameSquashCycles;
476 } else if (renameStatus[tid] == SerializeStall) {
477 ++renameSerializeStallCycles;
478 }
479
480 if (renameStatus[tid] == Running ||
481 renameStatus[tid] == Idle) {
482 DPRINTF(Rename, "[tid:%u]: Not blocked, so attempting to run "
483 "stage.\n", tid);
484
485 renameInsts(tid);
486 } else if (renameStatus[tid] == Unblocking) {
487 renameInsts(tid);
488
489 if (validInsts()) {
490 // Add the current inputs to the skid buffer so they can be
491 // reprocessed when this stage unblocks.
492 skidInsert(tid);
493 }
494
495 // If we switched over to blocking, then there's a potential for
496 // an overall status change.
497 status_change = unblock(tid) || status_change || blockThisCycle;
498 }
499}
500
501template <class Impl>
502void
503DefaultRename<Impl>::renameInsts(unsigned tid)
504{
505 // Instructions can be either in the skid buffer or the queue of
506 // instructions coming from decode, depending on the status.
507 int insts_available = renameStatus[tid] == Unblocking ?
508 skidBuffer[tid].size() : insts[tid].size();
509
510 // Check the decode queue to see if instructions are available.
511 // If there are no available instructions to rename, then do nothing.
512 if (insts_available == 0) {
513 DPRINTF(Rename, "[tid:%u]: Nothing to do, breaking out early.\n",
514 tid);
515 // Should I change status to idle?
516 ++renameIdleCycles;
517 return;
518 } else if (renameStatus[tid] == Unblocking) {
519 ++renameUnblockCycles;
520 } else if (renameStatus[tid] == Running) {
521 ++renameRunCycles;
522 }
523
524 DynInstPtr inst;
525
526 // Will have to do a different calculation for the number of free
527 // entries.
528 int free_rob_entries = calcFreeROBEntries(tid);
529 int free_iq_entries = calcFreeIQEntries(tid);
530 int free_lsq_entries = calcFreeLSQEntries(tid);
531 int min_free_entries = free_rob_entries;
532
533 FullSource source = ROB;
534
535 if (free_iq_entries < min_free_entries) {
536 min_free_entries = free_iq_entries;
537 source = IQ;
538 }
539
540 if (free_lsq_entries < min_free_entries) {
541 min_free_entries = free_lsq_entries;
542 source = LSQ;
543 }
544
545 // Check if there's any space left.
546 if (min_free_entries <= 0) {
547 DPRINTF(Rename, "[tid:%u]: Blocking due to no free ROB/IQ/LSQ "
548 "entries.\n"
549 "ROB has %i free entries.\n"
550 "IQ has %i free entries.\n"
551 "LSQ has %i free entries.\n",
552 tid,
553 free_rob_entries,
554 free_iq_entries,
555 free_lsq_entries);
556
557 blockThisCycle = true;
558
559 block(tid);
560
561 incrFullStat(source);
562
563 return;
564 } else if (min_free_entries < insts_available) {
565 DPRINTF(Rename, "[tid:%u]: Will have to block this cycle."
566 "%i insts available, but only %i insts can be "
567 "renamed due to ROB/IQ/LSQ limits.\n",
568 tid, insts_available, min_free_entries);
569
570 insts_available = min_free_entries;
571
572 blockThisCycle = true;
573
574 incrFullStat(source);
575 }
576
577 InstQueue &insts_to_rename = renameStatus[tid] == Unblocking ?
578 skidBuffer[tid] : insts[tid];
579
580 DPRINTF(Rename, "[tid:%u]: %i available instructions to "
581 "send iew.\n", tid, insts_available);
582
583 DPRINTF(Rename, "[tid:%u]: %i insts pipelining from Rename | %i insts "
584 "dispatched to IQ last cycle.\n",
585 tid, instsInProgress[tid], fromIEW->iewInfo[tid].dispatched);
586
587 // Handle serializing the next instruction if necessary.
588 if (serializeOnNextInst[tid]) {
589 if (emptyROB[tid] && instsInProgress[tid] == 0) {
590 // ROB already empty; no need to serialize.
591 serializeOnNextInst[tid] = false;
592 } else if (!insts_to_rename.empty()) {
593 insts_to_rename.front()->setSerializeBefore();
594 }
595 }
596
597 int renamed_insts = 0;
598
599 while (insts_available > 0 && toIEWIndex < renameWidth) {
600 DPRINTF(Rename, "[tid:%u]: Sending instructions to IEW.\n", tid);
601
602 assert(!insts_to_rename.empty());
603
604 inst = insts_to_rename.front();
605
606 insts_to_rename.pop_front();
607
608 if (renameStatus[tid] == Unblocking) {
609 DPRINTF(Rename,"[tid:%u]: Removing [sn:%lli] PC:%#x from rename "
610 "skidBuffer\n",
611 tid, inst->seqNum, inst->readPC());
612 }
613
614 if (inst->isSquashed()) {
615 DPRINTF(Rename, "[tid:%u]: instruction %i with PC %#x is "
616 "squashed, skipping.\n",
617 tid, inst->seqNum, inst->readPC());
618
619 ++renameSquashedInsts;
620
621 // Decrement how many instructions are available.
622 --insts_available;
623
624 continue;
625 }
626
627 DPRINTF(Rename, "[tid:%u]: Processing instruction [sn:%lli] with "
628 "PC %#x.\n",
629 tid, inst->seqNum, inst->readPC());
630
631 // Handle serializeAfter/serializeBefore instructions.
632 // serializeAfter marks the next instruction as serializeBefore.
633 // serializeBefore makes the instruction wait in rename until the ROB
634 // is empty.
635
636 // In this model, IPR accesses are serialize before
637 // instructions, and store conditionals are serialize after
638 // instructions. This is mainly due to lack of support for
639 // out-of-order operations of either of those classes of
640 // instructions.
641 if ((inst->isIprAccess() || inst->isSerializeBefore()) &&
642 !inst->isSerializeHandled()) {
643 DPRINTF(Rename, "Serialize before instruction encountered.\n");
644
645 if (!inst->isTempSerializeBefore()) {
646 renamedSerializing++;
647 inst->setSerializeHandled();
648 } else {
649 renamedTempSerializing++;
650 }
651
652 // Change status over to SerializeStall so that other stages know
653 // what this is blocked on.
654 renameStatus[tid] = SerializeStall;
655
656 serializeInst[tid] = inst;
657
658 blockThisCycle = true;
659
660 break;
661 } else if ((inst->isStoreConditional() || inst->isSerializeAfter()) &&
662 !inst->isSerializeHandled()) {
663 DPRINTF(Rename, "Serialize after instruction encountered.\n");
664
665 renamedSerializing++;
666
667 inst->setSerializeHandled();
668
669 serializeAfter(insts_to_rename, tid);
670 }
671
672 // Check here to make sure there are enough destination registers
673 // to rename to. Otherwise block.
674 if (renameMap[tid]->numFreeEntries() < inst->numDestRegs()) {
675 DPRINTF(Rename, "Blocking due to lack of free "
676 "physical registers to rename to.\n");
677 blockThisCycle = true;
678
679 ++renameFullRegistersEvents;
680
681 break;
682 }
683
684 renameSrcRegs(inst, inst->threadNumber);
685
686 renameDestRegs(inst, inst->threadNumber);
687
688 ++renamed_insts;
689
690 // Put instruction in rename queue.
691 toIEW->insts[toIEWIndex] = inst;
692 ++(toIEW->size);
693
694 // Increment which instruction we're on.
695 ++toIEWIndex;
696
697 // Decrement how many instructions are available.
698 --insts_available;
699 }
700
701 instsInProgress[tid] += renamed_insts;
702 renameRenamedInsts += renamed_insts;
703
704 // If we wrote to the time buffer, record this.
705 if (toIEWIndex) {
706 wroteToTimeBuffer = true;
707 }
708
709 // Check if there's any instructions left that haven't yet been renamed.
710 // If so then block.
711 if (insts_available) {
712 blockThisCycle = true;
713 }
714
715 if (blockThisCycle) {
716 block(tid);
717 toDecode->renameUnblock[tid] = false;
718 }
719}
720
721template<class Impl>
722void
723DefaultRename<Impl>::skidInsert(unsigned tid)
724{
725 DynInstPtr inst = NULL;
726
727 while (!insts[tid].empty()) {
728 inst = insts[tid].front();
729
730 insts[tid].pop_front();
731
732 assert(tid == inst->threadNumber);
733
734 DPRINTF(Rename, "[tid:%u]: Inserting [sn:%lli] PC:%#x into Rename "
735 "skidBuffer\n", tid, inst->seqNum, inst->readPC());
736
737 ++renameSkidInsts;
738
739 skidBuffer[tid].push_back(inst);
740 }
741
742 if (skidBuffer[tid].size() > skidBufferMax)
743 panic("Skidbuffer Exceeded Max Size");
744}
745
746template <class Impl>
747void
748DefaultRename<Impl>::sortInsts()
749{
750 int insts_from_decode = fromDecode->size;
751#ifdef DEBUG
752#if !ISA_HAS_DELAY_SLOT
753 for (int i=0; i < numThreads; i++)
754 assert(insts[i].empty());
755#endif
756#endif
757 for (int i = 0; i < insts_from_decode; ++i) {
758 DynInstPtr inst = fromDecode->insts[i];
759 insts[inst->threadNumber].push_back(inst);
760 }
761}
762
763template<class Impl>
764bool
765DefaultRename<Impl>::skidsEmpty()
766{
767 std::list<unsigned>::iterator threads = (*activeThreads).begin();
768
769 while (threads != (*activeThreads).end()) {
770 if (!skidBuffer[*threads++].empty())
771 return false;
772 }
773
774 return true;
775}
776
777template<class Impl>
778void
779DefaultRename<Impl>::updateStatus()
780{
781 bool any_unblocking = false;
782
783 std::list<unsigned>::iterator threads = (*activeThreads).begin();
784
785 threads = (*activeThreads).begin();
786
787 while (threads != (*activeThreads).end()) {
788 unsigned tid = *threads++;
789
790 if (renameStatus[tid] == Unblocking) {
791 any_unblocking = true;
792 break;
793 }
794 }
795
796 // Rename will have activity if it's unblocking.
797 if (any_unblocking) {
798 if (_status == Inactive) {
799 _status = Active;
800
801 DPRINTF(Activity, "Activating stage.\n");
802
803 cpu->activateStage(O3CPU::RenameIdx);
804 }
805 } else {
806 // If it's not unblocking, then rename will not have any internal
807 // activity. Switch it to inactive.
808 if (_status == Active) {
809 _status = Inactive;
810 DPRINTF(Activity, "Deactivating stage.\n");
811
812 cpu->deactivateStage(O3CPU::RenameIdx);
813 }
814 }
815}
816
817template <class Impl>
818bool
819DefaultRename<Impl>::block(unsigned tid)
820{
821 DPRINTF(Rename, "[tid:%u]: Blocking.\n", tid);
822
823 // Add the current inputs onto the skid buffer, so they can be
824 // reprocessed when this stage unblocks.
825 skidInsert(tid);
826
827 // Only signal backwards to block if the previous stages do not think
828 // rename is already blocked.
829 if (renameStatus[tid] != Blocked) {
830 if (renameStatus[tid] != Unblocking) {
831 toDecode->renameBlock[tid] = true;
832 toDecode->renameUnblock[tid] = false;
833 wroteToTimeBuffer = true;
834 }
835
836 // Rename can not go from SerializeStall to Blocked, otherwise
837 // it would not know to complete the serialize stall.
838 if (renameStatus[tid] != SerializeStall) {
839 // Set status to Blocked.
840 renameStatus[tid] = Blocked;
841 return true;
842 }
843 }
844
845 return false;
846}
847
848template <class Impl>
849bool
850DefaultRename<Impl>::unblock(unsigned tid)
851{
852 DPRINTF(Rename, "[tid:%u]: Trying to unblock.\n", tid);
853
854 // Rename is done unblocking if the skid buffer is empty.
855 if (skidBuffer[tid].empty() && renameStatus[tid] != SerializeStall) {
856
857 DPRINTF(Rename, "[tid:%u]: Done unblocking.\n", tid);
858
859 toDecode->renameUnblock[tid] = true;
860 wroteToTimeBuffer = true;
861
862 renameStatus[tid] = Running;
863 return true;
864 }
865
866 return false;
867}
868
869template <class Impl>
870void
871DefaultRename<Impl>::doSquash(const InstSeqNum &squashed_seq_num, unsigned tid)
872{
873 typename std::list<RenameHistory>::iterator hb_it =
874 historyBuffer[tid].begin();
875
876 // After a syscall squashes everything, the history buffer may be empty
877 // but the ROB may still be squashing instructions.
878 if (historyBuffer[tid].empty()) {
879 return;
880 }
881
882 // Go through the most recent instructions, undoing the mappings
883 // they did and freeing up the registers.
884 while (!historyBuffer[tid].empty() &&
885 (*hb_it).instSeqNum > squashed_seq_num) {
886 assert(hb_it != historyBuffer[tid].end());
887
888 DPRINTF(Rename, "[tid:%u]: Removing history entry with sequence "
889 "number %i.\n", tid, (*hb_it).instSeqNum);
890
891 // Tell the rename map to set the architected register to the
892 // previous physical register that it was renamed to.
893 renameMap[tid]->setEntry(hb_it->archReg, hb_it->prevPhysReg);
894
895 // Put the renamed physical register back on the free list.
896 freeList->addReg(hb_it->newPhysReg);
897
898 // Be sure to mark its register as ready if it's a misc register.
899 if (hb_it->newPhysReg >= maxPhysicalRegs) {
900 scoreboard->setReg(hb_it->newPhysReg);
901 }
902
903 historyBuffer[tid].erase(hb_it++);
904
905 ++renameUndoneMaps;
906 }
907}
908
909template<class Impl>
910void
911DefaultRename<Impl>::removeFromHistory(InstSeqNum inst_seq_num, unsigned tid)
912{
913 DPRINTF(Rename, "[tid:%u]: Removing a committed instruction from the "
914 "history buffer %u (size=%i), until [sn:%lli].\n",
915 tid, tid, historyBuffer[tid].size(), inst_seq_num);
916
917 typename std::list<RenameHistory>::iterator hb_it =
918 historyBuffer[tid].end();
919
920 --hb_it;
921
922 if (historyBuffer[tid].empty()) {
923 DPRINTF(Rename, "[tid:%u]: History buffer is empty.\n", tid);
924 return;
925 } else if (hb_it->instSeqNum > inst_seq_num) {
926 DPRINTF(Rename, "[tid:%u]: Old sequence number encountered. Ensure "
927 "that a syscall happened recently.\n", tid);
928 return;
929 }
930
931 // Commit all the renames up until (and including) the committed sequence
932 // number. Some or even all of the committed instructions may not have
933 // rename histories if they did not have destination registers that were
934 // renamed.
935 while (!historyBuffer[tid].empty() &&
936 hb_it != historyBuffer[tid].end() &&
937 (*hb_it).instSeqNum <= inst_seq_num) {
938
939 DPRINTF(Rename, "[tid:%u]: Freeing up older rename of reg %i, "
940 "[sn:%lli].\n",
941 tid, (*hb_it).prevPhysReg, (*hb_it).instSeqNum);
942
943 freeList->addReg((*hb_it).prevPhysReg);
944 ++renameCommittedMaps;
945
946 historyBuffer[tid].erase(hb_it--);
947 }
948}
949
950template <class Impl>
951inline void
952DefaultRename<Impl>::renameSrcRegs(DynInstPtr &inst,unsigned tid)
953{
954 assert(renameMap[tid] != 0);
955
956 unsigned num_src_regs = inst->numSrcRegs();
957
958 // Get the architectual register numbers from the source and
959 // destination operands, and redirect them to the right register.
960 // Will need to mark dependencies though.
961 for (int src_idx = 0; src_idx < num_src_regs; src_idx++) {
962 RegIndex src_reg = inst->srcRegIdx(src_idx);
963
964 // Look up the source registers to get the phys. register they've
965 // been renamed to, and set the sources to those registers.
966 PhysRegIndex renamed_reg = renameMap[tid]->lookup(src_reg);
967
968 DPRINTF(Rename, "[tid:%u]: Looking up arch reg %i, got "
969 "physical reg %i.\n", tid, (int)src_reg,
970 (int)renamed_reg);
971
972 inst->renameSrcReg(src_idx, renamed_reg);
973
974 // See if the register is ready or not.
975 if (scoreboard->getReg(renamed_reg) == true) {
976 DPRINTF(Rename, "[tid:%u]: Register is ready.\n", tid);
977
978 inst->markSrcRegReady(src_idx);
979 }
980
981 ++renameRenameLookups;
982 }
983}
984
985template <class Impl>
986inline void
987DefaultRename<Impl>::renameDestRegs(DynInstPtr &inst,unsigned tid)
988{
989 typename RenameMap::RenameInfo rename_result;
990
991 unsigned num_dest_regs = inst->numDestRegs();
992
993 // Rename the destination registers.
994 for (int dest_idx = 0; dest_idx < num_dest_regs; dest_idx++) {
995 RegIndex dest_reg = inst->destRegIdx(dest_idx);
996
997 // Get the physical register that the destination will be
998 // renamed to.
999 rename_result = renameMap[tid]->rename(dest_reg);
1000
1001 //Mark Scoreboard entry as not ready
1002 scoreboard->unsetReg(rename_result.first);
1003
1004 DPRINTF(Rename, "[tid:%u]: Renaming arch reg %i to physical "
1005 "reg %i.\n", tid, (int)dest_reg,
1006 (int)rename_result.first);
1007
1008 // Record the rename information so that a history can be kept.
1009 RenameHistory hb_entry(inst->seqNum, dest_reg,
1010 rename_result.first,
1011 rename_result.second);
1012
1013 historyBuffer[tid].push_front(hb_entry);
1014
1015 DPRINTF(Rename, "[tid:%u]: Adding instruction to history buffer "
1016 "(size=%i), [sn:%lli].\n",tid,
1017 historyBuffer[tid].size(),
1018 (*historyBuffer[tid].begin()).instSeqNum);
1019
1020 // Tell the instruction to rename the appropriate destination
1021 // register (dest_idx) to the new physical register
1022 // (rename_result.first), and record the previous physical
1023 // register that the same logical register was renamed to
1024 // (rename_result.second).
1025 inst->renameDestReg(dest_idx,
1026 rename_result.first,
1027 rename_result.second);
1028
1029 ++renameRenamedOperands;
1030 }
1031}
1032
1033template <class Impl>
1034inline int
1035DefaultRename<Impl>::calcFreeROBEntries(unsigned tid)
1036{
1037 int num_free = freeEntries[tid].robEntries -
1038 (instsInProgress[tid] - fromIEW->iewInfo[tid].dispatched);
1039
1040 //DPRINTF(Rename,"[tid:%i]: %i rob free\n",tid,num_free);
1041
1042 return num_free;
1043}
1044
1045template <class Impl>
1046inline int
1047DefaultRename<Impl>::calcFreeIQEntries(unsigned tid)
1048{
1049 int num_free = freeEntries[tid].iqEntries -
1050 (instsInProgress[tid] - fromIEW->iewInfo[tid].dispatched);
1051
1052 //DPRINTF(Rename,"[tid:%i]: %i iq free\n",tid,num_free);
1053
1054 return num_free;
1055}
1056
1057template <class Impl>
1058inline int
1059DefaultRename<Impl>::calcFreeLSQEntries(unsigned tid)
1060{
1061 int num_free = freeEntries[tid].lsqEntries -
1062 (instsInProgress[tid] - fromIEW->iewInfo[tid].dispatchedToLSQ);
1063
1064 //DPRINTF(Rename,"[tid:%i]: %i lsq free\n",tid,num_free);
1065
1066 return num_free;
1067}
1068
1069template <class Impl>
1070unsigned
1071DefaultRename<Impl>::validInsts()
1072{
1073 unsigned inst_count = 0;
1074
1075 for (int i=0; i<fromDecode->size; i++) {
1076 if (!fromDecode->insts[i]->isSquashed())
1077 inst_count++;
1078 }
1079
1080 return inst_count;
1081}
1082
1083template <class Impl>
1084void
1085DefaultRename<Impl>::readStallSignals(unsigned tid)
1086{
1087 if (fromIEW->iewBlock[tid]) {
1088 stalls[tid].iew = true;
1089 }
1090
1091 if (fromIEW->iewUnblock[tid]) {
1092 assert(stalls[tid].iew);
1093 stalls[tid].iew = false;
1094 }
1095
1096 if (fromCommit->commitBlock[tid]) {
1097 stalls[tid].commit = true;
1098 }
1099
1100 if (fromCommit->commitUnblock[tid]) {
1101 assert(stalls[tid].commit);
1102 stalls[tid].commit = false;
1103 }
1104}
1105
1106template <class Impl>
1107bool
1108DefaultRename<Impl>::checkStall(unsigned tid)
1109{
1110 bool ret_val = false;
1111
1112 if (stalls[tid].iew) {
1113 DPRINTF(Rename,"[tid:%i]: Stall from IEW stage detected.\n", tid);
1114 ret_val = true;
1115 } else if (stalls[tid].commit) {
1116 DPRINTF(Rename,"[tid:%i]: Stall from Commit stage detected.\n", tid);
1117 ret_val = true;
1118 } else if (calcFreeROBEntries(tid) <= 0) {
1119 DPRINTF(Rename,"[tid:%i]: Stall: ROB has 0 free entries.\n", tid);
1120 ret_val = true;
1121 } else if (calcFreeIQEntries(tid) <= 0) {
1122 DPRINTF(Rename,"[tid:%i]: Stall: IQ has 0 free entries.\n", tid);
1123 ret_val = true;
1124 } else if (calcFreeLSQEntries(tid) <= 0) {
1125 DPRINTF(Rename,"[tid:%i]: Stall: LSQ has 0 free entries.\n", tid);
1126 ret_val = true;
1127 } else if (renameMap[tid]->numFreeEntries() <= 0) {
1128 DPRINTF(Rename,"[tid:%i]: Stall: RenameMap has 0 free entries.\n", tid);
1129 ret_val = true;
1130 } else if (renameStatus[tid] == SerializeStall &&
1131 (!emptyROB[tid] || instsInProgress[tid])) {
1132 DPRINTF(Rename,"[tid:%i]: Stall: Serialize stall and ROB is not "
1133 "empty.\n",
1134 tid);
1135 ret_val = true;
1136 }
1137
1138 return ret_val;
1139}
1140
1141template <class Impl>
1142void
1143DefaultRename<Impl>::readFreeEntries(unsigned tid)
1144{
1145 bool updated = false;
1146 if (fromIEW->iewInfo[tid].usedIQ) {
1147 freeEntries[tid].iqEntries =
1148 fromIEW->iewInfo[tid].freeIQEntries;
1149 updated = true;
1150 }
1151
1152 if (fromIEW->iewInfo[tid].usedLSQ) {
1153 freeEntries[tid].lsqEntries =
1154 fromIEW->iewInfo[tid].freeLSQEntries;
1155 updated = true;
1156 }
1157
1158 if (fromCommit->commitInfo[tid].usedROB) {
1159 freeEntries[tid].robEntries =
1160 fromCommit->commitInfo[tid].freeROBEntries;
1161 emptyROB[tid] = fromCommit->commitInfo[tid].emptyROB;
1162 updated = true;
1163 }
1164
1165 DPRINTF(Rename, "[tid:%i]: Free IQ: %i, Free ROB: %i, Free LSQ: %i\n",
1166 tid,
1167 freeEntries[tid].iqEntries,
1168 freeEntries[tid].robEntries,
1169 freeEntries[tid].lsqEntries);
1170
1171 DPRINTF(Rename, "[tid:%i]: %i instructions not yet in ROB\n",
1172 tid, instsInProgress[tid]);
1173}
1174
1175template <class Impl>
1176bool
1177DefaultRename<Impl>::checkSignalsAndUpdate(unsigned tid)
1178{
1179 // Check if there's a squash signal, squash if there is
1180 // Check stall signals, block if necessary.
1181 // If status was blocked
1182 // check if stall conditions have passed
1183 // if so then go to unblocking
1184 // If status was Squashing
1185 // check if squashing is not high. Switch to running this cycle.
1186 // If status was serialize stall
1187 // check if ROB is empty and no insts are in flight to the ROB
1188
1189 readFreeEntries(tid);
1190 readStallSignals(tid);
1191
1192 if (fromCommit->commitInfo[tid].squash) {
1193 DPRINTF(Rename, "[tid:%u]: Squashing instructions due to squash from "
1194 "commit.\n", tid);
1195
1196#if ISA_HAS_DELAY_SLOT
1197 InstSeqNum squashed_seq_num = fromCommit->commitInfo[tid].bdelayDoneSeqNum;
1198#else
1199 InstSeqNum squashed_seq_num = fromCommit->commitInfo[tid].doneSeqNum;
1200#endif
1201
1202 squash(squashed_seq_num, tid);
1203
1204 return true;
1205 }
1206
1207 if (fromCommit->commitInfo[tid].robSquashing) {
1208 DPRINTF(Rename, "[tid:%u]: ROB is still squashing.\n", tid);
1209
1210 renameStatus[tid] = Squashing;
1211
1212 return true;
1213 }
1214
1215 if (checkStall(tid)) {
1216 return block(tid);
1217 }
1218
1219 if (renameStatus[tid] == Blocked) {
1220 DPRINTF(Rename, "[tid:%u]: Done blocking, switching to unblocking.\n",
1221 tid);
1222
1223 renameStatus[tid] = Unblocking;
1224
1225 unblock(tid);
1226
1227 return true;
1228 }
1229
1230 if (renameStatus[tid] == Squashing) {
1231 // Switch status to running if rename isn't being told to block or
1232 // squash this cycle.
1233 DPRINTF(Rename, "[tid:%u]: Done squashing, switching to running.\n",
1234 tid);
1235
1236 renameStatus[tid] = Running;
1237
1238 return false;
1239 }
1240
1241 if (renameStatus[tid] == SerializeStall) {
1242 // Stall ends once the ROB is free.
1243 DPRINTF(Rename, "[tid:%u]: Done with serialize stall, switching to "
1244 "unblocking.\n", tid);
1245
1246 DynInstPtr serial_inst = serializeInst[tid];
1247
1248 renameStatus[tid] = Unblocking;
1249
1250 unblock(tid);
1251
1252 DPRINTF(Rename, "[tid:%u]: Processing instruction [%lli] with "
1253 "PC %#x.\n",
1254 tid, serial_inst->seqNum, serial_inst->readPC());
1255
1256 // Put instruction into queue here.
1257 serial_inst->clearSerializeBefore();
1258
1259 if (!skidBuffer[tid].empty()) {
1260 skidBuffer[tid].push_front(serial_inst);
1261 } else {
1262 insts[tid].push_front(serial_inst);
1263 }
1264
1265 DPRINTF(Rename, "[tid:%u]: Instruction must be processed by rename."
1266 " Adding to front of list.\n", tid);
1267
1268 serializeInst[tid] = NULL;
1269
1270 return true;
1271 }
1272
1273 // If we've reached this point, we have not gotten any signals that
1274 // cause rename to change its status. Rename remains the same as before.
1275 return false;
1276}
1277
1278template<class Impl>
1279void
1280DefaultRename<Impl>::serializeAfter(InstQueue &inst_list,
1281 unsigned tid)
1282{
1283 if (inst_list.empty()) {
1284 // Mark a bit to say that I must serialize on the next instruction.
1285 serializeOnNextInst[tid] = true;
1286 return;
1287 }
1288
1289 // Set the next instruction as serializing.
1290 inst_list.front()->setSerializeBefore();
1291}
1292
1293template <class Impl>
1294inline void
1295DefaultRename<Impl>::incrFullStat(const FullSource &source)
1296{
1297 switch (source) {
1298 case ROB:
1299 ++renameROBFullEvents;
1300 break;
1301 case IQ:
1302 ++renameIQFullEvents;
1303 break;
1304 case LSQ:
1305 ++renameLSQFullEvents;
1306 break;
1307 default:
1308 panic("Rename full stall stat should be incremented for a reason!");
1309 break;
1310 }
1311}
1312
1313template <class Impl>
1314void
1315DefaultRename<Impl>::dumpHistory()
1316{
1317 typename std::list<RenameHistory>::iterator buf_it;
1318
1319 for (int i = 0; i < numThreads; i++) {
1320
1321 buf_it = historyBuffer[i].begin();
1322
1323 while (buf_it != historyBuffer[i].end()) {
1324 cprintf("Seq num: %i\nArch reg: %i New phys reg: %i Old phys "
1325 "reg: %i\n", (*buf_it).instSeqNum, (int)(*buf_it).archReg,
1326 (int)(*buf_it).newPhysReg, (int)(*buf_it).prevPhysReg);
1327
1328 buf_it++;
1329 }
1330 }
1331}