1 /*
2 * Copyright (c) 2021-2023 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include "optimizer/ir/inst.h"
17 #include "optimizer/ir/basicblock.h"
18 #include "optimizer/ir/graph.h"
19 #include "liveness_analyzer.h"
20 #include "optimizer/analysis/dominators_tree.h"
21 #include "optimizer/analysis/loop_analyzer.h"
22 #include "optimizer/optimizations/locations_builder.h"
23 #include "optimizer/optimizations/regalloc/reg_type.h"
24
25 namespace panda::compiler {
LivenessAnalyzer(Graph * graph)26 LivenessAnalyzer::LivenessAnalyzer(Graph *graph)
27 : Analysis(graph),
28 allocator_(graph->GetAllocator()),
29 linearBlocks_(graph->GetAllocator()->Adapter()),
30 instLifeNumbers_(graph->GetAllocator()->Adapter()),
31 instLifeIntervals_(graph->GetAllocator()->Adapter()),
32 instsByLifeNumber_(graph->GetAllocator()->Adapter()),
33 blockLiveRanges_(graph->GetAllocator()->Adapter()),
34 blockLiveSets_(graph->GetLocalAllocator()->Adapter()),
35 pendingCatchPhiInputs_(graph->GetAllocator()->Adapter()),
36 physicalGeneralIntervals_(graph->GetAllocator()->Adapter()),
37 physicalVectorIntervals_(graph->GetAllocator()->Adapter()),
38 intervalsForTemps_(graph->GetAllocator()->Adapter()),
39 useTable_(graph->GetAllocator()),
40 hasSafepointDuringCall_(graph->GetRuntime()->HasSafepointDuringCall())
41 {
42 }
43
RunImpl()44 bool LivenessAnalyzer::RunImpl()
45 {
46 if (!RunLocationsBuilder(GetGraph())) {
47 return false;
48 }
49 GetGraph()->RunPass<DominatorsTree>();
50 GetGraph()->RunPass<LoopAnalyzer>();
51 ResetLiveness();
52 BuildBlocksLinearOrder();
53 BuildInstLifeNumbers();
54 BuildInstLifeIntervals();
55 Finalize();
56 if (!pendingCatchPhiInputs_.empty()) {
57 COMPILER_LOG(ERROR, LIVENESS_ANALYZER)
58 << "Graph contains CatchPhi instructions whose inputs were not processed";
59 return false;
60 }
61 std::copy_if(physicalGeneralIntervals_.begin(), physicalGeneralIntervals_.end(),
62 std::back_inserter(instLifeIntervals_), [](auto li) { return li != nullptr; });
63 std::copy_if(physicalVectorIntervals_.begin(), physicalVectorIntervals_.end(),
64 std::back_inserter(instLifeIntervals_), [](auto li) { return li != nullptr; });
65 std::copy(intervalsForTemps_.begin(), intervalsForTemps_.end(), std::back_inserter(instLifeIntervals_));
66 COMPILER_LOG(DEBUG, LIVENESS_ANALYZER) << "Liveness analysis is constructed";
67 return true;
68 }
69
ResetLiveness()70 void LivenessAnalyzer::ResetLiveness()
71 {
72 instLifeNumbers_.clear();
73 instLifeIntervals_.clear();
74 blockLiveSets_.clear();
75 blockLiveRanges_.clear();
76 physicalGeneralIntervals_.clear();
77 physicalVectorIntervals_.clear();
78 intervalsForTemps_.clear();
79 if (GetGraph()->GetArch() != Arch::NONE) {
80 physicalGeneralIntervals_.resize(REGISTERS_NUM);
81 physicalVectorIntervals_.resize(VREGISTERS_NUM);
82 }
83 #ifndef NDEBUG
84 finalized_ = false;
85 #endif
86 }
87
88 /*
89 * Linear blocks order means:
90 * - all dominators of a block are visiting before this block;
91 * - all blocks belonging to the same loop are contiguous;
92 */
BuildBlocksLinearOrder()93 void LivenessAnalyzer::BuildBlocksLinearOrder()
94 {
95 ASSERT_PRINT(GetGraph()->IsAnalysisValid<DominatorsTree>(), "Liveness Analyzer needs valid Dom Tree");
96 auto size = GetGraph()->GetBlocksRPO().size();
97 linearBlocks_.reserve(size);
98 linearBlocks_.clear();
99 marker_ = GetGraph()->NewMarker();
100 ASSERT_PRINT(marker_ != UNDEF_MARKER, "There are no free markers");
101 if (GetGraph()->IsBytecodeOptimizer() && !GetGraph()->GetTryBeginBlocks().empty()) {
102 LinearizeBlocks<true>();
103 } else {
104 LinearizeBlocks<false>();
105 }
106 ASSERT(linearBlocks_.size() == size);
107 GetGraph()->EraseMarker(marker_);
108 ASSERT_PRINT(CheckLinearOrder(), "Linear block order isn't correct");
109
110 blockLiveSets_.resize(GetGraph()->GetVectorBlocks().size());
111 blockLiveRanges_.resize(GetGraph()->GetVectorBlocks().size());
112 }
113
114 /*
115 * Check if all forward edges of loop header were visited to get the resulting block order in RPO.
116 * Predecessors which are not in the same loop with a header - are forward edges.
117 */
AllForwardEdgesVisited(BasicBlock * block)118 bool LivenessAnalyzer::AllForwardEdgesVisited(BasicBlock *block)
119 {
120 if (!block->IsLoopHeader()) {
121 for (auto pred : block->GetPredsBlocks()) {
122 if (!pred->IsMarked(marker_)) {
123 return false;
124 }
125 }
126 } else {
127 // Head of irreducible loop can not dominate other blocks in the loop
128 if (block->GetLoop()->IsIrreducible()) {
129 return true;
130 }
131 // Predecessors which are not dominated - are forward edges,
132 for (auto pred : block->GetPredsBlocks()) {
133 if (!block->IsDominate(pred) && !pred->IsMarked(marker_)) {
134 return false;
135 }
136 }
137 }
138 return true;
139 }
140
141 template <bool USE_PC_ORDER>
LinearizeBlocks()142 void LivenessAnalyzer::LinearizeBlocks()
143 {
144 ArenaList<BasicBlock *> pending {GetGraph()->GetLocalAllocator()->Adapter()};
145 pending.push_back(GetGraph()->GetStartBlock());
146
147 while (!pending.empty()) {
148 auto current = pending.front();
149 pending.pop_front();
150
151 linearBlocks_.push_back(current);
152 current->SetMarker(marker_);
153
154 auto succs = current->GetSuccsBlocks();
155 // Each block is inserted into pending list before all already inserted blocks
156 // from the same loop. To process edges forwarding to a "true" branches successors
157 // should be processed in reversed order.
158 for (auto it = succs.rbegin(); it != succs.rend(); ++it) {
159 auto succ = *it;
160 if (succ->IsMarked(marker_) || !AllForwardEdgesVisited(succ)) {
161 continue;
162 }
163
164 if constexpr (USE_PC_ORDER) { // NOLINT(readability-braces-around-statements)
165 auto pcCompare = [succ](auto block) { return block->GetGuestPc() > succ->GetGuestPc(); };
166 auto insertBefore = std::find_if(pending.begin(), pending.end(), pcCompare);
167 pending.insert(insertBefore, succ);
168 } else {
169 // Insert successor right before the first block not from an inner loop.
170 // Such ordering guarantee that a loop and all it's inner loops will be processed
171 // before following edges leading to outer loop blocks.
172 auto isNotInnerLoop = [succ](auto block) { return !block->GetLoop()->IsInside(succ->GetLoop()); };
173 auto insertBefore = std::find_if(pending.begin(), pending.end(), isNotInnerLoop);
174 pending.insert(insertBefore, succ);
175 }
176 }
177 }
178 }
179
180 /*
181 * Check linear order correctness, using dominators tree
182 */
CheckLinearOrder()183 bool LivenessAnalyzer::CheckLinearOrder()
184 {
185 ArenaVector<size_t> blockPos(GetGraph()->GetVectorBlocks().size(), 0, GetAllocator()->Adapter());
186 size_t position = 0;
187 for (auto block : linearBlocks_) {
188 blockPos[block->GetId()] = position++;
189 }
190
191 for (auto block : linearBlocks_) {
192 if (block->GetDominator() != nullptr) {
193 ASSERT_PRINT(blockPos[block->GetDominator()->GetId()] < blockPos[block->GetId()],
194 "Each block should be visited after its dominator");
195 }
196 if (!block->IsTryEnd()) {
197 continue;
198 }
199 ASSERT(block->GetTryId() != INVALID_ID);
200 for (auto bb : linearBlocks_) {
201 if (bb->IsTry() && bb->GetTryId() == block->GetTryId()) {
202 ASSERT_PRINT(blockPos[bb->GetId()] < blockPos[block->GetId()],
203 "Each try-block should be visited before its try-end block");
204 }
205 }
206 }
207
208 return true;
209 }
210
211 /*
212 * Set lifetime number and visiting number for each instruction
213 */
BuildInstLifeNumbers()214 void LivenessAnalyzer::BuildInstLifeNumbers()
215 {
216 LifeNumber blockBegin;
217 LifeNumber lifeNumber = 0;
218 LinearNumber linearNumber = 0;
219
220 for (auto block : GetLinearizedBlocks()) {
221 blockBegin = lifeNumber;
222 // set the same number for each phi in the block
223 for (auto phi : block->PhiInsts()) {
224 phi->SetLinearNumber(linearNumber++);
225 SetInstLifeNumber(phi, lifeNumber);
226 CreateLifeIntervals(phi);
227 }
228 // ignore PHI instructions
229 instsByLifeNumber_.push_back(nullptr);
230 // set a unique number for each instruction in the block, differing by 2
231 // for the reason of adding spill/fill instructions
232 for (auto inst : block->Insts()) {
233 inst->SetLinearNumber(linearNumber++);
234 CreateLifeIntervals(inst);
235 if (IsPseudoUserOfMultiOutput(inst)) {
236 // Should be the same life number as pseudo-user, since actually they have the same definition
237 SetInstLifeNumber(inst, lifeNumber);
238 GetInstLifeIntervals(inst)->AddUsePosition(lifeNumber);
239 continue;
240 }
241 lifeNumber += LIFE_NUMBER_GAP;
242 SetInstLifeNumber(inst, lifeNumber);
243 SetUsePositions(inst, lifeNumber);
244 instsByLifeNumber_.push_back(inst);
245
246 if (inst->RequireTmpReg()) {
247 CreateIntervalForTemp(lifeNumber);
248 }
249 }
250 lifeNumber += LIFE_NUMBER_GAP;
251 SetBlockLiveRange(block, {blockBegin, lifeNumber});
252 }
253 }
254
SetUsePositions(Inst * userInst,LifeNumber lifeNumber)255 void LivenessAnalyzer::SetUsePositions(Inst *userInst, LifeNumber lifeNumber)
256 {
257 if (GetGraph()->IsBytecodeOptimizer()) {
258 return;
259 }
260 if (userInst->IsCatchPhi() || userInst->IsSaveState()) {
261 return;
262 }
263 for (size_t i = 0; i < userInst->GetInputsCount(); i++) {
264 auto location = userInst->GetLocation(i);
265 if (!location.IsAnyRegister()) {
266 continue;
267 }
268 auto inputInst = userInst->GetDataFlowInput(i);
269 auto li = GetInstLifeIntervals(inputInst);
270 if (location.IsRegisterValid()) {
271 useTable_.AddUseOnFixedLocation(inputInst, location, lifeNumber);
272 } else if (location.IsUnallocatedRegister()) {
273 li->AddUsePosition(lifeNumber);
274 }
275 }
276
277 // Constant can be defined without register
278 if (userInst->IsConst() && g_options.IsCompilerRematConst()) {
279 return;
280 }
281
282 // If instruction required dst register, set use position in the beginning of the interval
283 auto li = GetInstLifeIntervals(userInst);
284 if (!li->NoDest()) {
285 li->AddUsePosition(lifeNumber);
286 }
287 }
288
289 /*
290 * Get lifetime intervals for each instruction
291 */
BuildInstLifeIntervals()292 void LivenessAnalyzer::BuildInstLifeIntervals()
293 {
294 for (auto it = GetLinearizedBlocks().rbegin(); it != GetLinearizedBlocks().rend(); it++) {
295 auto block = *it;
296 auto liveSet = GetInitInstLiveSet(block);
297 ProcessBlockLiveInstructions(block, liveSet);
298 }
299 }
300
301 /*
302 * The initial set of live instructions in the `block` is the the union of all live instructions at the beginning of
303 * the block's successors.
304 * Also for each phi-instruction of the successors: input corresponding to the `block` is added to the live set.
305 */
GetInitInstLiveSet(BasicBlock * block)306 InstLiveSet *LivenessAnalyzer::GetInitInstLiveSet(BasicBlock *block)
307 {
308 unsigned instructionCount = instLifeIntervals_.size();
309 auto liveSet = GetAllocator()->New<InstLiveSet>(instructionCount, GetAllocator());
310 for (auto succ : block->GetSuccsBlocks()) {
311 // catch-begin is pseudo successor, its live set will be processed for blocks with throwable instructions
312 if (succ->IsCatchBegin()) {
313 continue;
314 }
315 liveSet->Union(GetBlockLiveSet(succ));
316 for (auto phi : succ->PhiInsts()) {
317 auto phiInput = phi->CastToPhi()->GetPhiDataflowInput(block);
318 liveSet->Add(phiInput->GetLinearNumber());
319 }
320 }
321
322 // if basic block contains throwable instruction, all instructions live in the catch-handlers should be live in this
323 // block
324 if (auto inst = block->GetFistThrowableInst(); inst != nullptr) {
325 auto handlers = GetGraph()->GetThrowableInstHandlers(inst);
326 for (auto catchHandler : handlers) {
327 liveSet->Union(GetBlockLiveSet(catchHandler));
328 }
329 }
330 return liveSet;
331 }
332
GetLoopEnd(Loop * loop)333 LifeNumber LivenessAnalyzer::GetLoopEnd(Loop *loop)
334 {
335 LifeNumber loopEnd = 0;
336 // find max LifeNumber of inner loops
337 for (auto inner : loop->GetInnerLoops()) {
338 loopEnd = std::max(loopEnd, GetLoopEnd(inner));
339 }
340 // find max LifeNumber of back_edges
341 for (auto backEdge : loop->GetBackEdges()) {
342 loopEnd = std::max(loopEnd, GetBlockLiveRange(backEdge).GetEnd());
343 }
344 return loopEnd;
345 }
346
347 /*
348 * Append and adjust the lifetime intervals for each instruction live in the block and for their inputs
349 */
ProcessBlockLiveInstructions(BasicBlock * block,InstLiveSet * liveSet)350 void LivenessAnalyzer::ProcessBlockLiveInstructions(BasicBlock *block, InstLiveSet *liveSet)
351 {
352 // For each live instruction set initial life range equals to the block life range
353 for (auto &interval : instLifeIntervals_) {
354 if (liveSet->IsSet(interval->GetInst()->GetLinearNumber())) {
355 interval->AppendRange(GetBlockLiveRange(block));
356 }
357 }
358
359 for (Inst *inst : block->InstsSafeReverse()) {
360 // Shorten instruction lifetime to the position where its defined
361 // and remove from the block's live set
362 auto instLifeNumber = GetInstLifeNumber(inst);
363 auto interval = GetInstLifeIntervals(inst);
364 interval->StartFrom(instLifeNumber);
365 liveSet->Remove(inst->GetLinearNumber());
366 if (inst->IsCatchPhi()) {
367 // catch-phi's liveness should overlap all linked try blocks' livenesses
368 for (auto pred : inst->GetBasicBlock()->GetPredsBlocks()) {
369 instLifeNumber = std::min(instLifeNumber, GetBlockLiveRange(pred).GetBegin());
370 }
371 interval->StartFrom(instLifeNumber);
372 AdjustCatchPhiInputsLifetime(inst);
373 } else {
374 if (inst->GetOpcode() == Opcode::LiveOut) {
375 if (block->GetSuccsBlocks().size() == 1 && block->GetSuccessor(0)->IsEndBlock()) {
376 interval->AppendRange({instLifeNumber, GetBlockLiveRange(block).GetEnd()});
377 } else {
378 interval->AppendRange({instLifeNumber, GetBlockLiveRange(GetGraph()->GetEndBlock()).GetBegin()});
379 }
380 }
381 auto currentLiveRange = LiveRange {GetBlockLiveRange(block).GetBegin(), instLifeNumber};
382 AdjustInputsLifetime(inst, currentLiveRange, liveSet);
383 }
384
385 BlockFixedRegisters(inst);
386 }
387
388 // The lifetime interval of phis instructions starts at the beginning of the block
389 for (auto phi : block->PhiInsts()) {
390 liveSet->Remove(phi->GetLinearNumber());
391 }
392
393 // All instructions live at the beginning ot the loop header
394 // must be live for the entire loop
395 if (block->IsLoopHeader()) {
396 LifeNumber loopEndPosition = GetLoopEnd(block->GetLoop());
397
398 for (auto &interval : instLifeIntervals_) {
399 if (liveSet->IsSet(interval->GetInst()->GetLinearNumber())) {
400 interval->AppendGroupRange({GetBlockLiveRange(block).GetBegin(), loopEndPosition});
401 }
402 }
403 }
404 SetBlockLiveSet(block, liveSet);
405 }
406
407 /* static */
GetPropagatedLiveRange(Inst * inst,LiveRange liveRange)408 LiveRange LivenessAnalyzer::GetPropagatedLiveRange(Inst *inst, LiveRange liveRange)
409 {
410 /*
411 * Implicit null check encoded as no-op and if the reference to check is null
412 * then SIGSEGV will be raised at the first (closest) user. Regmap generated for
413 * NullCheck's SaveState should be valid at that user so we need to extend
414 * life intervals of SaveState's inputs until NullCheck user.
415 */
416 if (inst->IsNullCheck() && !inst->GetUsers().Empty() && inst->CastToNullCheck()->IsImplicit()) {
417 auto extendUntil = std::numeric_limits<LifeNumber>::max();
418 for (auto &user : inst->GetUsers()) {
419 // Skip the users dominating the NullCheck as their live ranges
420 // start earlier than NullCheck's live range.
421 if (!user.GetInst()->IsDominate(inst)) {
422 auto li = GetInstLifeIntervals(user.GetInst());
423 ASSERT(li != nullptr);
424 extendUntil = std::min<LifeNumber>(extendUntil, li->GetBegin() + 1);
425 }
426 }
427 liveRange.SetEnd(extendUntil);
428 return liveRange;
429 }
430 /*
431 * We need to propagate liveness for instruction with CallRuntime to save registers before call;
432 * Otherwise, we will not be able to restore the value of the virtual registers
433 */
434 if (inst->IsPropagateLiveness()) {
435 liveRange.SetEnd(liveRange.GetEnd() + 1);
436 } else if (inst->GetOpcode() == Opcode::ReturnInlined && inst->CastToReturnInlined()->IsExtendedLiveness()) {
437 /*
438 * [ReturnInlined]
439 * [ReturnInlined]
440 * ...
441 * [Deoptimize/Throw]
442 *
443 * In this case we propagate ReturnInlined inputs liveness up to the end of basic block
444 */
445 liveRange.SetEnd(GetBlockLiveRange(inst->GetBasicBlock()).GetEnd());
446 }
447 return liveRange;
448 }
449
450 /*
451 * Adjust instruction inputs lifetime and add them to the block's live set
452 */
AdjustInputsLifetime(Inst * inst,LiveRange liveRange,InstLiveSet * liveSet)453 void LivenessAnalyzer::AdjustInputsLifetime(Inst *inst, LiveRange liveRange, InstLiveSet *liveSet)
454 {
455 for (auto input : inst->GetInputs()) {
456 auto inputInst = inst->GetDataFlowInput(input.GetInst());
457 liveSet->Add(inputInst->GetLinearNumber());
458 SetInputRange(inst, inputInst, liveRange);
459 }
460
461 // Extend SaveState inputs lifetime to the end of SaveState's lifetime
462 if (inst->RequireState()) {
463 auto saveState = inst->GetSaveState();
464 auto propagatedRange = GetPropagatedLiveRange(inst, liveRange);
465 while (true) {
466 ASSERT(saveState != nullptr);
467 for (auto ssInput : saveState->GetInputs()) {
468 auto inputInst = saveState->GetDataFlowInput(ssInput.GetInst());
469 liveSet->Add(inputInst->GetLinearNumber());
470 GetInstLifeIntervals(inputInst)->AppendRange(propagatedRange);
471 }
472 auto callerInst = saveState->GetCallerInst();
473 if (callerInst == nullptr) {
474 break;
475 }
476 saveState = callerInst->GetSaveState();
477 }
478 }
479
480 // Handle CatchPhi inputs associated with inst
481 auto range = pendingCatchPhiInputs_.equal_range(inst);
482 for (auto it = range.first; it != range.second; ++it) {
483 auto throwableInput = it->second;
484 auto throwableInputInterval = GetInstLifeIntervals(throwableInput);
485 liveSet->Add(throwableInput->GetLinearNumber());
486 throwableInputInterval->AppendRange(liveRange);
487 }
488 pendingCatchPhiInputs_.erase(inst);
489 }
490
491 /*
492 * Increase ref-input liveness in the 'no-async-jit' mode, since GC can be triggered and delete ref during callee-method
493 * compilation
494 */
SetInputRange(const Inst * inst,const Inst * input,LiveRange liveRange) const495 void LivenessAnalyzer::SetInputRange(const Inst *inst, const Inst *input, LiveRange liveRange) const
496 {
497 if (hasSafepointDuringCall_ && inst->IsCall() && DataType::IsReference(input->GetType())) {
498 GetInstLifeIntervals(input)->AppendRange(liveRange.GetBegin(), liveRange.GetEnd() + 1U);
499 } else {
500 GetInstLifeIntervals(input)->AppendRange(liveRange);
501 }
502 }
503
504 /*
505 * CatchPhi does not handle inputs as regular instructions - instead of performing
506 * some action at CatchPhi's definition copy instruction are added before throwable instructions.
507 * Instead of extending input life interval until CatchPhi it is extended until throwable instruction.
508 */
AdjustCatchPhiInputsLifetime(Inst * inst)509 void LivenessAnalyzer::AdjustCatchPhiInputsLifetime(Inst *inst)
510 {
511 auto catchPhi = inst->CastToCatchPhi();
512
513 for (ssize_t inputIdx = catchPhi->GetInputsCount() - 1; inputIdx >= 0; inputIdx--) {
514 auto inputInst = catchPhi->GetDataFlowInput(inputIdx);
515 auto throwableInst = const_cast<Inst *>(catchPhi->GetThrowableInst(inputIdx));
516
517 pendingCatchPhiInputs_.insert({throwableInst, inputInst});
518 }
519 }
520
SetInstLifeNumber(const Inst * inst,LifeNumber number)521 void LivenessAnalyzer::SetInstLifeNumber([[maybe_unused]] const Inst *inst, LifeNumber number)
522 {
523 ASSERT(instLifeNumbers_.size() == inst->GetLinearNumber());
524 instLifeNumbers_.push_back(number);
525 }
526
GetInstLifeNumber(const Inst * inst) const527 LifeNumber LivenessAnalyzer::GetInstLifeNumber(const Inst *inst) const
528 {
529 return instLifeNumbers_[inst->GetLinearNumber()];
530 }
531
532 /*
533 * Create new lifetime intervals for instruction, check that instruction linear number is equal to intervals
534 * position in vector
535 */
CreateLifeIntervals(Inst * inst)536 void LivenessAnalyzer::CreateLifeIntervals(Inst *inst)
537 {
538 ASSERT(!finalized_);
539 ASSERT(inst->GetLinearNumber() == instLifeIntervals_.size());
540 auto interval = GetAllocator()->New<LifeIntervals>(GetAllocator(), inst);
541 instLifeIntervals_.push_back(interval);
542 }
543
CreateIntervalForTemp(LifeNumber ln)544 void LivenessAnalyzer::CreateIntervalForTemp(LifeNumber ln)
545 {
546 ASSERT(!finalized_);
547 auto interval = GetAllocator()->New<LifeIntervals>(GetAllocator());
548 interval->AppendRange({ln - 1, ln});
549 interval->AddUsePosition(ln);
550 // DataType is INT64, since general register is reserved (for 32-bits arch will be converted to INT32)
551 interval->SetType(ConvertRegType(GetGraph(), DataType::INT64));
552 intervalsForTemps_.push_back(interval);
553 }
554
GetInstLifeIntervals(const Inst * inst) const555 LifeIntervals *LivenessAnalyzer::GetInstLifeIntervals(const Inst *inst) const
556 {
557 ASSERT(inst->GetLinearNumber() != INVALID_LINEAR_NUM);
558 return instLifeIntervals_[inst->GetLinearNumber()];
559 }
560
SetBlockLiveRange(BasicBlock * block,LiveRange lifeRange)561 void LivenessAnalyzer::SetBlockLiveRange(BasicBlock *block, LiveRange lifeRange)
562 {
563 blockLiveRanges_[block->GetId()] = lifeRange;
564 }
565
GetBlockLiveRange(const BasicBlock * block) const566 LiveRange LivenessAnalyzer::GetBlockLiveRange(const BasicBlock *block) const
567 {
568 return blockLiveRanges_[block->GetId()];
569 }
570
SetBlockLiveSet(BasicBlock * block,InstLiveSet * liveSet)571 void LivenessAnalyzer::SetBlockLiveSet(BasicBlock *block, InstLiveSet *liveSet)
572 {
573 blockLiveSets_[block->GetId()] = liveSet;
574 }
575
GetBlockLiveSet(BasicBlock * block) const576 InstLiveSet *LivenessAnalyzer::GetBlockLiveSet(BasicBlock *block) const
577 {
578 return blockLiveSets_[block->GetId()];
579 }
580
DumpLifeIntervals(std::ostream & out) const581 void LivenessAnalyzer::DumpLifeIntervals(std::ostream &out) const
582 {
583 for (auto bb : GetGraph()->GetBlocksRPO()) {
584 if (bb->GetId() >= GetBlocksCount()) {
585 continue;
586 }
587 auto blockRange = GetBlockLiveRange(bb);
588 out << "BB " << bb->GetId() << "\t" << blockRange.ToString() << std::endl;
589
590 for (auto inst : bb->AllInsts()) {
591 if (inst->GetLinearNumber() == INVALID_LINEAR_NUM) {
592 continue;
593 }
594 auto interval = GetInstLifeIntervals(inst);
595
596 out << "v" << inst->GetId() << "\t";
597 for (auto sibling = interval; sibling != nullptr; sibling = sibling->GetSibling()) {
598 out << sibling->ToString<false>() << "@ " << sibling->GetLocation().ToString(GetGraph()->GetArch())
599 << "; ";
600 }
601 out << std::endl;
602 }
603 }
604
605 out << "Temps:" << std::endl;
606 for (auto interval : intervalsForTemps_) {
607 out << interval->ToString<false>() << "@ " << interval->GetLocation().ToString(GetGraph()->GetArch())
608 << std::endl;
609 }
610 DumpLocationsUsage(out);
611 }
612
DumpLocationsUsage(std::ostream & out) const613 void LivenessAnalyzer::DumpLocationsUsage(std::ostream &out) const
614 {
615 std::map<Register, std::vector<LifeIntervals *>> regsIntervals;
616 std::map<Register, std::vector<LifeIntervals *>> vregsIntervals;
617 std::map<Register, std::vector<LifeIntervals *>> slotsIntervals;
618 for (auto &interval : instLifeIntervals_) {
619 for (auto sibling = interval; sibling != nullptr; sibling = sibling->GetSibling()) {
620 auto location = sibling->GetLocation();
621 if (location.IsFpRegister()) {
622 ASSERT(DataType::IsFloatType(interval->GetType()));
623 vregsIntervals[location.GetValue()].push_back(sibling);
624 } else if (location.IsRegister()) {
625 regsIntervals[location.GetValue()].push_back(sibling);
626 } else if (location.IsStack()) {
627 slotsIntervals[location.GetValue()].push_back(sibling);
628 }
629 }
630 }
631
632 for (auto intervalsMap : {®sIntervals, &vregsIntervals, &slotsIntervals}) {
633 std::string locSymbol;
634 if (intervalsMap == ®sIntervals) {
635 out << std::endl << "Registers intervals" << std::endl;
636 locSymbol = "r";
637 } else if (intervalsMap == &vregsIntervals) {
638 out << std::endl << "Vector registers intervals" << std::endl;
639 locSymbol = "vr";
640 } else {
641 ASSERT(intervalsMap == &slotsIntervals);
642 out << std::endl << "Stack slots intervals" << std::endl;
643 locSymbol = "s";
644 }
645
646 if (intervalsMap->empty()) {
647 out << "-" << std::endl;
648 continue;
649 }
650 for (auto &[reg, intervals] : *intervalsMap) {
651 std::sort(intervals.begin(), intervals.end(),
652 [](const auto &lhs, const auto &rhs) { return lhs->GetBegin() < rhs->GetBegin(); });
653 out << locSymbol << std::to_string(reg) << ": ";
654 auto delim = "";
655 for (auto &interval : intervals) {
656 out << delim << interval->ToString<false>();
657 delim = "; ";
658 }
659 out << std::endl;
660 }
661 }
662 }
663
BlockFixedRegisters(Inst * inst)664 void LivenessAnalyzer::BlockFixedRegisters(Inst *inst)
665 {
666 if (GetGraph()->IsBytecodeOptimizer() || GetGraph()->GetMode().IsFastPath()) {
667 return;
668 }
669
670 auto blockFrom = GetInstLifeNumber(inst);
671 if (IsCallBlockingRegisters(inst)) {
672 BlockPhysicalRegisters<false>(blockFrom);
673 BlockPhysicalRegisters<true>(blockFrom);
674 }
675 for (auto i = 0U; i < inst->GetInputsCount(); ++i) {
676 BlockFixedLocationRegister(inst->GetLocation(i), blockFrom);
677 }
678 BlockFixedLocationRegister(inst->GetDstLocation(), blockFrom);
679
680 if (inst->IsParameter()) {
681 // Block a register starting from the position preceding entry block start to
682 // correctly handle register blocked by "current" instruction from registers blocked
683 // by other instructions during register allocation.
684 constexpr auto FIRST_AVAILABLE_LIFE_NUMBER = LIFE_NUMBER_GAP - 1;
685 // Registers holding parameters should be blocked starting from the beginning of entry block
686 // to avoid its assignment to parameter instructions in case of high register pressure.
687 // The required interval is blocked using two calls to correctly mark first use position of a
688 // blocked register.
689 BlockFixedLocationRegister(inst->CastToParameter()->GetLocationData().GetSrc(), blockFrom);
690 BlockFixedLocationRegister(inst->CastToParameter()->GetLocationData().GetSrc(), FIRST_AVAILABLE_LIFE_NUMBER,
691 blockFrom - 1, false);
692 // Block second parameter register that contains number of actual arguments in case of
693 // dynamic methods as it is used in parameter's code generation
694 if (GetGraph()->GetMode().IsDynamicMethod() &&
695 GetGraph()->FindParameter(ParameterInst::DYNAMIC_NUM_ARGS) == nullptr) {
696 BlockReg<false>(Target(GetGraph()->GetArch()).GetParamRegId(1), blockFrom, blockFrom + 1U, true);
697 BlockReg<false>(Target(GetGraph()->GetArch()).GetParamRegId(1), FIRST_AVAILABLE_LIFE_NUMBER, blockFrom - 1,
698 false);
699 }
700 }
701 }
702
703 template <bool IS_FP>
BlockPhysicalRegisters(LifeNumber blockFrom)704 void LivenessAnalyzer::BlockPhysicalRegisters(LifeNumber blockFrom)
705 {
706 auto arch = GetGraph()->GetArch();
707 RegMask callerRegs {GetCallerRegsMask(arch, IS_FP)};
708 for (auto reg = GetFirstCallerReg(arch, IS_FP); reg <= GetLastCallerReg(arch, IS_FP); ++reg) {
709 if (callerRegs.test(reg)) {
710 BlockReg<IS_FP>(reg, blockFrom, blockFrom + 1U, true);
711 }
712 }
713 }
714
BlockFixedLocationRegister(Location location,LifeNumber blockFrom,LifeNumber blockTo,bool isUse)715 void LivenessAnalyzer::BlockFixedLocationRegister(Location location, LifeNumber blockFrom, LifeNumber blockTo,
716 bool isUse)
717 {
718 if (location.IsRegister() && location.IsRegisterValid()) {
719 BlockReg<false>(location.GetValue(), blockFrom, blockTo, isUse);
720 } else if (location.IsFpRegister() && location.IsRegisterValid()) {
721 BlockReg<true>(location.GetValue(), blockFrom, blockTo, isUse);
722 }
723 }
724
725 template <bool IS_FP>
BlockReg(Register reg,LifeNumber blockFrom,LifeNumber blockTo,bool isUse)726 void LivenessAnalyzer::BlockReg(Register reg, LifeNumber blockFrom, LifeNumber blockTo, bool isUse)
727 {
728 ASSERT(!finalized_);
729 auto &intervals = IS_FP ? physicalVectorIntervals_ : physicalGeneralIntervals_;
730 auto interval = intervals.at(reg);
731 if (interval == nullptr) {
732 interval = GetGraph()->GetAllocator()->New<LifeIntervals>(GetGraph()->GetAllocator());
733 interval->SetPhysicalReg(reg, IS_FP ? DataType::FLOAT64 : DataType::UINT64);
734 intervals.at(reg) = interval;
735 }
736 interval->AppendRange(blockFrom, blockTo);
737 if (isUse) {
738 interval->AddUsePosition(blockFrom);
739 }
740 }
741
IsCallBlockingRegisters(Inst * inst) const742 bool LivenessAnalyzer::IsCallBlockingRegisters(Inst *inst) const
743 {
744 if (inst->IsCall() && !inst->IsLaunchCall() && !static_cast<CallInst *>(inst)->IsInlined()) {
745 return true;
746 }
747 if (inst->IsIntrinsic() && inst->CastToIntrinsic()->IsNativeCall()) {
748 return true;
749 }
750 return false;
751 }
752
SplitAt(LifeNumber ln,ArenaAllocator * alloc)753 LifeIntervals *LifeIntervals::SplitAt(LifeNumber ln, ArenaAllocator *alloc)
754 {
755 ASSERT(!IsPhysical());
756 ASSERT(ln > GetBegin() && ln <= GetEnd());
757 auto splitChild = alloc->New<LifeIntervals>(alloc, GetInst());
758 #ifndef NDEBUG
759 ASSERT(finalized_);
760 splitChild->finalized_ = true;
761 #endif
762 if (sibling_ != nullptr) {
763 splitChild->sibling_ = sibling_;
764 }
765 splitChild->isSplitSibling_ = true;
766
767 sibling_ = splitChild;
768 splitChild->SetType(GetType());
769
770 auto i = liveRanges_.size();
771 while (i > 0 && liveRanges_[i - 1].GetEnd() <= ln) {
772 i--;
773 }
774 if (i > 0) {
775 auto &range = liveRanges_[i - 1];
776 if (range.GetBegin() < ln) {
777 splitChild->AppendRange(range.GetBegin(), ln);
778 range.SetBegin(ln);
779 }
780 }
781 splitChild->liveRanges_.insert(splitChild->liveRanges_.end(), liveRanges_.begin() + i, liveRanges_.end());
782 liveRanges_.erase(liveRanges_.begin() + i, liveRanges_.end());
783 std::swap(liveRanges_, splitChild->liveRanges_);
784
785 // Move use positions to the child
786 auto it = std::lower_bound(usePositions_.begin(), usePositions_.end(), ln);
787 splitChild->usePositions_.insert(splitChild->usePositions_.end(), it, usePositions_.end());
788 usePositions_.erase(it, usePositions_.end());
789
790 return splitChild;
791 }
792
SplitAroundUses(ArenaAllocator * alloc)793 void LifeIntervals::SplitAroundUses(ArenaAllocator *alloc)
794 {
795 if (GetUsePositions().empty()) {
796 return;
797 }
798 auto use = *GetUsePositions().begin();
799 if (use > GetBegin() + 1) {
800 auto split = SplitAt(use - 1, alloc);
801 split->SplitAroundUses(alloc);
802 } else if (use < GetEnd() - 1) {
803 auto split = SplitAt(use + 1, alloc);
804 split->SplitAroundUses(alloc);
805 }
806 }
807
MergeSibling()808 void LifeIntervals::MergeSibling()
809 {
810 ASSERT(sibling_ != nullptr);
811 #ifndef NDEBUG
812 ASSERT(finalized_);
813 ASSERT(sibling_->finalized_);
814 if (!usePositions_.empty() && !sibling_->usePositions_.empty()) {
815 ASSERT(usePositions_.back() <= sibling_->usePositions_.front());
816 }
817 #endif
818 for (auto range : liveRanges_) {
819 sibling_->AppendRange(range);
820 }
821 liveRanges_ = std::move(sibling_->liveRanges_);
822
823 for (auto &usePos : sibling_->usePositions_) {
824 AddUsePosition(usePos);
825 }
826 sibling_ = nullptr;
827 }
828
FindSiblingAt(LifeNumber ln)829 LifeIntervals *LifeIntervals::FindSiblingAt(LifeNumber ln)
830 {
831 ASSERT(!IsSplitSibling());
832 for (auto head = this; head != nullptr; head = head->GetSibling()) {
833 if (head->GetBegin() <= ln && ln <= head->GetEnd()) {
834 return head;
835 }
836 }
837 return nullptr;
838 }
839
Intersects(const LiveRange & range) const840 bool LifeIntervals::Intersects(const LiveRange &range) const
841 {
842 return // the interval starts within the range
843 (range.GetBegin() <= GetBegin() && GetBegin() <= range.GetEnd()) ||
844 // the interval ends within the range
845 (range.GetBegin() <= GetEnd() && GetEnd() <= range.GetEnd()) ||
846 // the range is fully covered by the interval
847 (GetBegin() <= range.GetBegin() && range.GetEnd() <= GetEnd());
848 }
849
GetFirstIntersectionWith(const LifeIntervals * other,LifeNumber searchFrom) const850 LifeNumber LifeIntervals::GetFirstIntersectionWith(const LifeIntervals *other, LifeNumber searchFrom) const
851 {
852 for (auto it = GetRanges().rbegin(); it != GetRanges().rend(); it++) {
853 auto range = *it;
854 if (range.GetEnd() <= searchFrom) {
855 continue;
856 }
857 for (auto otherIt = other->GetRanges().rbegin(); otherIt != other->GetRanges().rend(); otherIt++) {
858 auto otherRange = *otherIt;
859 if (otherRange.GetEnd() <= searchFrom) {
860 continue;
861 }
862 auto rangeBegin = std::max<LifeNumber>(searchFrom, range.GetBegin());
863 auto otherRangeBegin = std::max<LifeNumber>(searchFrom, otherRange.GetBegin());
864 if (rangeBegin <= otherRangeBegin && otherRangeBegin < range.GetEnd()) {
865 // [range]
866 // [other]
867 return otherRangeBegin;
868 // NOLINTNEXTLINE(readability-else-after-return)
869 } else if (rangeBegin > otherRangeBegin && rangeBegin < otherRange.GetEnd()) {
870 // [range]
871 // [other]
872 return rangeBegin;
873 }
874 }
875 }
876 return INVALID_LIFE_NUMBER;
877 }
878
FindRangeCoveringPosition(LifeNumber ln,LiveRange * dst) const879 bool LifeIntervals::FindRangeCoveringPosition(LifeNumber ln, LiveRange *dst) const
880 {
881 for (auto &range : GetRanges()) {
882 if (range.Contains(ln)) {
883 *dst = range;
884 return true;
885 }
886 }
887
888 return false;
889 }
890
GetSpillWeightAt(const LivenessAnalyzer & la,LifeNumber ln)891 static float GetSpillWeightAt(const LivenessAnalyzer &la, LifeNumber ln)
892 {
893 static constexpr float LOOP_MULT = 10.0;
894 auto block = la.GetBlockCoversPoint(ln);
895 return std::pow<float>(LOOP_MULT, block->GetLoop()->GetDepth());
896 }
897
CalcSpillWeight(const LivenessAnalyzer & la,LifeIntervals * interval)898 float CalcSpillWeight(const LivenessAnalyzer &la, LifeIntervals *interval)
899 {
900 if (interval->IsPhysical()) {
901 return std::numeric_limits<float>::max();
902 }
903
904 size_t length = interval->GetEnd() - interval->GetBegin();
905 // Interval can't be splitted
906 if (length <= LIFE_NUMBER_GAP) {
907 return std::numeric_limits<float>::max();
908 }
909
910 // Constant intervals are the first candidates to spill
911 if (interval->GetInst()->IsConst()) {
912 return std::numeric_limits<float>::min();
913 }
914
915 float useWeight = 0;
916 if (interval->GetInst()->IsPhi()) {
917 useWeight += GetSpillWeightAt(la, interval->GetBegin());
918 }
919
920 for (auto use : interval->GetUsePositions()) {
921 if (use == interval->GetBegin()) {
922 useWeight += GetSpillWeightAt(la, use + 1);
923 } else {
924 useWeight += GetSpillWeightAt(la, use - 1);
925 }
926 }
927 return useWeight;
928 }
929
930 } // namespace panda::compiler
931