1// Copyright 2015 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "src/compiler/js-inlining-heuristic.h"
6
7#include "src/compiler/common-operator.h"
8#include "src/compiler/compiler-source-position-table.h"
9#include "src/compiler/node-matchers.h"
10#include "src/compiler/simplified-operator.h"
11#include "src/objects-inl.h"
12#include "src/optimized-compilation-info.h"
13
14namespace v8 {
15namespace internal {
16namespace compiler {
17
18#define TRACE(...) \
19 do { \
20 if (FLAG_trace_turbo_inlining) PrintF(__VA_ARGS__); \
21 } while (false)
22
23namespace {
24
25bool IsSmallInlineFunction(BytecodeArrayRef bytecode) {
26 // Forcibly inline small functions.
27 if (bytecode.length() <= FLAG_max_inlined_bytecode_size_small) {
28 return true;
29 }
30 return false;
31}
32
33} // namespace
34
35JSInliningHeuristic::Candidate JSInliningHeuristic::CollectFunctions(
36 Node* node, int functions_size) {
37 DCHECK_NE(0, functions_size);
38 Node* callee = node->InputAt(0);
39 Candidate out;
40 out.node = node;
41
42 HeapObjectMatcher m(callee);
43 if (m.HasValue() && m.Ref(broker()).IsJSFunction()) {
44 out.functions[0] = m.Ref(broker()).AsJSFunction();
45 JSFunctionRef function = out.functions[0].value();
46 if (function.IsSerializedForCompilation()) {
47 out.bytecode[0] = function.shared().GetBytecodeArray();
48 }
49 out.num_functions = 1;
50 return out;
51 }
52 if (m.IsPhi()) {
53 int const value_input_count = m.node()->op()->ValueInputCount();
54 if (value_input_count > functions_size) {
55 out.num_functions = 0;
56 return out;
57 }
58 for (int n = 0; n < value_input_count; ++n) {
59 HeapObjectMatcher m(callee->InputAt(n));
60 if (!m.HasValue() || !m.Ref(broker()).IsJSFunction()) {
61 out.num_functions = 0;
62 return out;
63 }
64
65 out.functions[n] = m.Ref(broker()).AsJSFunction();
66 JSFunctionRef function = out.functions[n].value();
67 if (function.IsSerializedForCompilation()) {
68 out.bytecode[n] = function.shared().GetBytecodeArray(), isolate();
69 }
70 }
71 out.num_functions = value_input_count;
72 return out;
73 }
74 if (m.IsJSCreateClosure()) {
75 CreateClosureParameters const& p = CreateClosureParametersOf(m.op());
76 DCHECK(!out.functions[0].has_value());
77 out.shared_info = SharedFunctionInfoRef(broker(), p.shared_info());
78 SharedFunctionInfoRef shared_info = out.shared_info.value();
79 if (shared_info.HasBytecodeArray()) {
80 out.bytecode[0] = shared_info.GetBytecodeArray();
81 }
82 out.num_functions = 1;
83 return out;
84 }
85 out.num_functions = 0;
86 return out;
87}
88
89Reduction JSInliningHeuristic::Reduce(Node* node) {
90 DisallowHeapAccessIf no_heap_acess(FLAG_concurrent_inlining);
91
92 if (!IrOpcode::IsInlineeOpcode(node->opcode())) return NoChange();
93
94 // Check if we already saw that {node} before, and if so, just skip it.
95 if (seen_.find(node->id()) != seen_.end()) return NoChange();
96 seen_.insert(node->id());
97
98 // Check if the {node} is an appropriate candidate for inlining.
99 Candidate candidate = CollectFunctions(node, kMaxCallPolymorphism);
100 if (candidate.num_functions == 0) {
101 return NoChange();
102 } else if (candidate.num_functions > 1 && !FLAG_polymorphic_inlining) {
103 TRACE(
104 "Not considering call site #%d:%s, because polymorphic inlining "
105 "is disabled\n",
106 node->id(), node->op()->mnemonic());
107 return NoChange();
108 }
109
110 bool can_inline = false, force_inline_small = true;
111 candidate.total_size = 0;
112 Node* frame_state = NodeProperties::GetFrameStateInput(node);
113 FrameStateInfo const& frame_info = FrameStateInfoOf(frame_state->op());
114 Handle<SharedFunctionInfo> frame_shared_info;
115 for (int i = 0; i < candidate.num_functions; ++i) {
116 if (!candidate.bytecode[i].has_value()) {
117 // We're already missing critical data which wouldn't allow us to
118 // continue the inlining checks. Log a warning and continue.
119 if (candidate.functions[i].has_value()) {
120 TRACE_BROKER(broker(),
121 "Missing bytecode array trying to inline function "
122 << candidate.functions[i].value().object().address());
123 } else {
124 TRACE_BROKER(
125 broker(),
126 "Missing bytecode array trying to inline function with SFI "
127 << candidate.shared_info.value().object().address());
128 }
129 // Those functions that don't have their bytecode serialized probably
130 // don't have the SFI either, so we exit the loop early.
131 candidate.can_inline_function[i] = false;
132 continue;
133 }
134
135 SharedFunctionInfoRef shared = candidate.functions[i].has_value()
136 ? candidate.functions[i].value().shared()
137 : candidate.shared_info.value();
138 candidate.can_inline_function[i] = shared.IsInlineable();
139 // Do not allow direct recursion i.e. f() -> f(). We still allow indirect
140 // recurion like f() -> g() -> f(). The indirect recursion is helpful in
141 // cases where f() is a small dispatch function that calls the appropriate
142 // function. In the case of direct recursion, we only have some static
143 // information for the first level of inlining and it may not be that useful
144 // to just inline one level in recursive calls. In some cases like tail
145 // recursion we may benefit from recursive inlining, if we have additional
146 // analysis that converts them to iterative implementations. Though it is
147 // not obvious if such an anlysis is needed.
148 if (frame_info.shared_info().ToHandle(&frame_shared_info) &&
149 frame_shared_info.equals(shared.object())) {
150 TRACE("Not considering call site #%d:%s, because of recursive inlining\n",
151 node->id(), node->op()->mnemonic());
152 candidate.can_inline_function[i] = false;
153 }
154 // A function reaching this point should always have its bytecode
155 // serialized.
156 BytecodeArrayRef bytecode = candidate.bytecode[i].value();
157 if (candidate.can_inline_function[i]) {
158 can_inline = true;
159 candidate.total_size += bytecode.length();
160 }
161 // We don't force inline small functions if any of them is not inlineable.
162 if (!IsSmallInlineFunction(bytecode)) {
163 force_inline_small = false;
164 }
165 }
166 if (!can_inline) return NoChange();
167
168 // Gather feedback on how often this call site has been hit before.
169 if (node->opcode() == IrOpcode::kJSCall) {
170 CallParameters const p = CallParametersOf(node->op());
171 candidate.frequency = p.frequency();
172 } else {
173 ConstructParameters const p = ConstructParametersOf(node->op());
174 candidate.frequency = p.frequency();
175 }
176
177 // Handling of special inlining modes right away:
178 // - For restricted inlining: stop all handling at this point.
179 // - For stressing inlining: immediately handle all functions.
180 switch (mode_) {
181 case kRestrictedInlining:
182 return NoChange();
183 case kStressInlining:
184 return InlineCandidate(candidate, false);
185 case kGeneralInlining:
186 break;
187 }
188
189 // Don't consider a {candidate} whose frequency is below the
190 // threshold, i.e. a call site that is only hit once every N
191 // invocations of the caller.
192 if (candidate.frequency.IsKnown() &&
193 candidate.frequency.value() < FLAG_min_inlining_frequency) {
194 return NoChange();
195 }
196
197 // Forcibly inline small functions here. In the case of polymorphic inlining
198 // force_inline_small is set only when all functions are small.
199 if (force_inline_small &&
200 cumulative_count_ < FLAG_max_inlined_bytecode_size_absolute) {
201 TRACE("Inlining small function(s) at call site #%d:%s\n", node->id(),
202 node->op()->mnemonic());
203 return InlineCandidate(candidate, true);
204 }
205
206 // In the general case we remember the candidate for later.
207 candidates_.insert(candidate);
208 return NoChange();
209}
210
211void JSInliningHeuristic::Finalize() {
212 if (candidates_.empty()) return; // Nothing to do without candidates.
213 if (FLAG_trace_turbo_inlining) PrintCandidates();
214
215 // We inline at most one candidate in every iteration of the fixpoint.
216 // This is to ensure that we don't consume the full inlining budget
217 // on things that aren't called very often.
218 // TODO(bmeurer): Use std::priority_queue instead of std::set here.
219 while (!candidates_.empty()) {
220 auto i = candidates_.begin();
221 Candidate candidate = *i;
222 candidates_.erase(i);
223
224 // Make sure we have some extra budget left, so that any small functions
225 // exposed by this function would be given a chance to inline.
226 double size_of_candidate =
227 candidate.total_size * FLAG_reserve_inline_budget_scale_factor;
228 int total_size = cumulative_count_ + static_cast<int>(size_of_candidate);
229 if (total_size > FLAG_max_inlined_bytecode_size_cumulative) {
230 // Try if any smaller functions are available to inline.
231 continue;
232 }
233
234 // Make sure we don't try to inline dead candidate nodes.
235 if (!candidate.node->IsDead()) {
236 Reduction const reduction = InlineCandidate(candidate, false);
237 if (reduction.Changed()) return;
238 }
239 }
240}
241
242namespace {
243
244struct NodeAndIndex {
245 Node* node;
246 int index;
247};
248
249bool CollectStateValuesOwnedUses(Node* node, Node* state_values,
250 NodeAndIndex* uses_buffer, size_t* use_count,
251 size_t max_uses) {
252 // Only accumulate states that are not shared with other users.
253 if (state_values->UseCount() > 1) return true;
254 for (int i = 0; i < state_values->InputCount(); i++) {
255 Node* input = state_values->InputAt(i);
256 if (input->opcode() == IrOpcode::kStateValues) {
257 if (!CollectStateValuesOwnedUses(node, input, uses_buffer, use_count,
258 max_uses)) {
259 return false;
260 }
261 } else if (input == node) {
262 if (*use_count >= max_uses) return false;
263 uses_buffer[*use_count] = {state_values, i};
264 (*use_count)++;
265 }
266 }
267 return true;
268}
269
270} // namespace
271
272Node* JSInliningHeuristic::DuplicateStateValuesAndRename(Node* state_values,
273 Node* from, Node* to,
274 StateCloneMode mode) {
275 // Only rename in states that are not shared with other users. This needs to
276 // be in sync with the condition in {CollectStateValuesOwnedUses}.
277 if (state_values->UseCount() > 1) return state_values;
278 Node* copy = mode == kChangeInPlace ? state_values : nullptr;
279 for (int i = 0; i < state_values->InputCount(); i++) {
280 Node* input = state_values->InputAt(i);
281 Node* processed;
282 if (input->opcode() == IrOpcode::kStateValues) {
283 processed = DuplicateStateValuesAndRename(input, from, to, mode);
284 } else if (input == from) {
285 processed = to;
286 } else {
287 processed = input;
288 }
289 if (processed != input) {
290 if (!copy) {
291 copy = graph()->CloneNode(state_values);
292 }
293 copy->ReplaceInput(i, processed);
294 }
295 }
296 return copy ? copy : state_values;
297}
298
299namespace {
300
301bool CollectFrameStateUniqueUses(Node* node, Node* frame_state,
302 NodeAndIndex* uses_buffer, size_t* use_count,
303 size_t max_uses) {
304 // Only accumulate states that are not shared with other users.
305 if (frame_state->UseCount() > 1) return true;
306 if (frame_state->InputAt(kFrameStateStackInput) == node) {
307 if (*use_count >= max_uses) return false;
308 uses_buffer[*use_count] = {frame_state, kFrameStateStackInput};
309 (*use_count)++;
310 }
311 if (!CollectStateValuesOwnedUses(node,
312 frame_state->InputAt(kFrameStateLocalsInput),
313 uses_buffer, use_count, max_uses)) {
314 return false;
315 }
316 return true;
317}
318
319} // namespace
320
321Node* JSInliningHeuristic::DuplicateFrameStateAndRename(Node* frame_state,
322 Node* from, Node* to,
323 StateCloneMode mode) {
324 // Only rename in states that are not shared with other users. This needs to
325 // be in sync with the condition in {DuplicateFrameStateAndRename}.
326 if (frame_state->UseCount() > 1) return frame_state;
327 Node* copy = mode == kChangeInPlace ? frame_state : nullptr;
328 if (frame_state->InputAt(kFrameStateStackInput) == from) {
329 if (!copy) {
330 copy = graph()->CloneNode(frame_state);
331 }
332 copy->ReplaceInput(kFrameStateStackInput, to);
333 }
334 Node* locals = frame_state->InputAt(kFrameStateLocalsInput);
335 Node* new_locals = DuplicateStateValuesAndRename(locals, from, to, mode);
336 if (new_locals != locals) {
337 if (!copy) {
338 copy = graph()->CloneNode(frame_state);
339 }
340 copy->ReplaceInput(kFrameStateLocalsInput, new_locals);
341 }
342 return copy ? copy : frame_state;
343}
344
345bool JSInliningHeuristic::TryReuseDispatch(Node* node, Node* callee,
346 Candidate const& candidate,
347 Node** if_successes, Node** calls,
348 Node** inputs, int input_count) {
349 // We will try to reuse the control flow branch created for computing
350 // the {callee} target of the call. We only reuse the branch if there
351 // is no side-effect between the call and the branch, and if the callee is
352 // only used as the target (and possibly also in the related frame states).
353
354 int const num_calls = candidate.num_functions;
355
356 DCHECK_EQ(IrOpcode::kPhi, callee->opcode());
357 DCHECK_EQ(num_calls, callee->op()->ValueInputCount());
358
359 // We are trying to match the following pattern:
360 //
361 // C1 C2
362 // . .
363 // | |
364 // Merge(merge) <-----------------+
365 // ^ ^ |
366 // V1 V2 | | E1 E2 |
367 // . . | +----+ . . |
368 // | | | | | | |
369 // Phi(callee) EffectPhi(effect_phi) |
370 // ^ ^ |
371 // | | |
372 // +----+ | |
373 // | | | |
374 // | StateValues | |
375 // | ^ | |
376 // +----+ | | |
377 // | | | | |
378 // | FrameState | |
379 // | ^ | |
380 // | | | +---+
381 // | | | | |
382 // +----+ Checkpoint(checkpoint) |
383 // | | ^ |
384 // | StateValues | +-------------+
385 // | | | |
386 // +-----+ | | |
387 // | | | | |
388 // | FrameState | |
389 // | ^ | |
390 // +-----------+ | | |
391 // Call(node)
392 // |
393 // |
394 // .
395 //
396 // The {callee} here is a phi that merges the possible call targets, {node}
397 // is the actual call that we will try to duplicate and connect to the
398 // control that comes into {merge}. There can be a {checkpoint} between
399 // the call and the calle phi.
400 //
401 // The idea is to get rid of the merge, effect phi and phi, then duplicate
402 // the call (with all the frame states and such), and connect the duplicated
403 // calls and states directly to the inputs of the ex-phi, ex-effect-phi and
404 // ex-merge. The tricky part is to make sure that there is no interference
405 // from the outside. In particular, there should not be any unaccounted uses
406 // of the phi, effect-phi and merge because we will remove them from
407 // the graph.
408 //
409 // V1 E1 C1 V2 E2 C2
410 // . . . . . .
411 // | | | | | |
412 // +----+ | | +----+ |
413 // | | | | | | |
414 // | StateValues | | | StateValues |
415 // | ^ | | | ^ |
416 // +----+ | | | +----+ | |
417 // | | | | | | | | |
418 // | FrameState | | | FrameState |
419 // | ^ | | | ^ |
420 // | | | | | | |
421 // | | | | | | |
422 // +----+ Checkpoint | +----+ Checkpoint |
423 // | | ^ | | | ^ |
424 // | StateValues | | | StateValues | |
425 // | | | | | | | |
426 // +-----+ | | | +-----+ | | |
427 // | | | | | | | | | |
428 // | FrameState | | | FrameState | |
429 // | ^ | | | ^ | |
430 // +-------------+| | | +-------------+| | |
431 // Call----+ Call----+
432 // | |
433 // +-------+ +------------+
434 // | |
435 // Merge
436 // EffectPhi
437 // Phi
438 // |
439 // ...
440
441 // If there is a control node between the callee computation
442 // and the call, bail out.
443 Node* merge = NodeProperties::GetControlInput(callee);
444 if (NodeProperties::GetControlInput(node) != merge) return false;
445
446 // If there is a non-checkpoint effect node between the callee computation
447 // and the call, bail out. We will drop any checkpoint between the call and
448 // the callee phi because the callee computation should have its own
449 // checkpoint that the call can fall back to.
450 Node* checkpoint = nullptr;
451 Node* effect = NodeProperties::GetEffectInput(node);
452 if (effect->opcode() == IrOpcode::kCheckpoint) {
453 checkpoint = effect;
454 if (NodeProperties::GetControlInput(checkpoint) != merge) return false;
455 effect = NodeProperties::GetEffectInput(effect);
456 }
457 if (effect->opcode() != IrOpcode::kEffectPhi) return false;
458 if (NodeProperties::GetControlInput(effect) != merge) return false;
459 Node* effect_phi = effect;
460
461 // The effect phi, the callee, the call and the checkpoint must be the only
462 // users of the merge.
463 for (Node* merge_use : merge->uses()) {
464 if (merge_use != effect_phi && merge_use != callee && merge_use != node &&
465 merge_use != checkpoint) {
466 return false;
467 }
468 }
469
470 // The effect phi must be only used by the checkpoint or the call.
471 for (Node* effect_phi_use : effect_phi->uses()) {
472 if (effect_phi_use != node && effect_phi_use != checkpoint) return false;
473 }
474
475 // We must replace the callee phi with the appropriate constant in
476 // the entire subgraph reachable by inputs from the call (terminating
477 // at phis and merges). Since we do not want to walk (and later duplicate)
478 // the subgraph here, we limit the possible uses to this set:
479 //
480 // 1. In the call (as a target).
481 // 2. The checkpoint between the call and the callee computation merge.
482 // 3. The lazy deoptimization frame state.
483 //
484 // This corresponds to the most common pattern, where the function is
485 // called with only local variables or constants as arguments.
486 //
487 // To check the uses, we first collect all the occurrences of callee in 1, 2
488 // and 3, and then we check that all uses of callee are in the collected
489 // occurrences. If there is an unaccounted use, we do not try to rewire
490 // the control flow.
491 //
492 // Note: With CFG, this would be much easier and more robust - we would just
493 // duplicate all the nodes between the merge and the call, replacing all
494 // occurrences of the {callee} phi with the appropriate constant.
495
496 // First compute the set of uses that are only reachable from 2 and 3.
497 const size_t kMaxUses = 8;
498 NodeAndIndex replaceable_uses[kMaxUses];
499 size_t replaceable_uses_count = 0;
500
501 // Collect the uses to check case 2.
502 Node* checkpoint_state = nullptr;
503 if (checkpoint) {
504 checkpoint_state = checkpoint->InputAt(0);
505 if (!CollectFrameStateUniqueUses(callee, checkpoint_state, replaceable_uses,
506 &replaceable_uses_count, kMaxUses)) {
507 return false;
508 }
509 }
510
511 // Collect the uses to check case 3.
512 Node* frame_state = NodeProperties::GetFrameStateInput(node);
513 if (!CollectFrameStateUniqueUses(callee, frame_state, replaceable_uses,
514 &replaceable_uses_count, kMaxUses)) {
515 return false;
516 }
517
518 // Bail out if there is a use of {callee} that is not reachable from 1, 2
519 // and 3.
520 for (Edge edge : callee->use_edges()) {
521 // Case 1 (use by the call as a target).
522 if (edge.from() == node && edge.index() == 0) continue;
523 // Case 2 and 3 - used in checkpoint and/or lazy deopt frame states.
524 bool found = false;
525 for (size_t i = 0; i < replaceable_uses_count; i++) {
526 if (replaceable_uses[i].node == edge.from() &&
527 replaceable_uses[i].index == edge.index()) {
528 found = true;
529 break;
530 }
531 }
532 if (!found) return false;
533 }
534
535 // Clone the call and the framestate, including the uniquely reachable
536 // state values, making sure that we replace the phi with the constant.
537 for (int i = 0; i < num_calls; ++i) {
538 // Clone the calls for each branch.
539 // We need to specialize the calls to the correct target, effect, and
540 // control. We also need to duplicate the checkpoint and the lazy
541 // frame state, and change all the uses of the callee to the constant
542 // callee.
543 Node* target = callee->InputAt(i);
544 Node* effect = effect_phi->InputAt(i);
545 Node* control = merge->InputAt(i);
546
547 if (checkpoint) {
548 // Duplicate the checkpoint.
549 Node* new_checkpoint_state = DuplicateFrameStateAndRename(
550 checkpoint_state, callee, target,
551 (i == num_calls - 1) ? kChangeInPlace : kCloneState);
552 effect = graph()->NewNode(checkpoint->op(), new_checkpoint_state, effect,
553 control);
554 }
555
556 // Duplicate the call.
557 Node* new_lazy_frame_state = DuplicateFrameStateAndRename(
558 frame_state, callee, target,
559 (i == num_calls - 1) ? kChangeInPlace : kCloneState);
560 inputs[0] = target;
561 inputs[input_count - 3] = new_lazy_frame_state;
562 inputs[input_count - 2] = effect;
563 inputs[input_count - 1] = control;
564 calls[i] = if_successes[i] =
565 graph()->NewNode(node->op(), input_count, inputs);
566 }
567
568 // Mark the control inputs dead, so that we can kill the merge.
569 node->ReplaceInput(input_count - 1, jsgraph()->Dead());
570 callee->ReplaceInput(num_calls, jsgraph()->Dead());
571 effect_phi->ReplaceInput(num_calls, jsgraph()->Dead());
572 if (checkpoint) {
573 checkpoint->ReplaceInput(2, jsgraph()->Dead());
574 }
575
576 merge->Kill();
577 return true;
578}
579
580void JSInliningHeuristic::CreateOrReuseDispatch(Node* node, Node* callee,
581 Candidate const& candidate,
582 Node** if_successes,
583 Node** calls, Node** inputs,
584 int input_count) {
585 SourcePositionTable::Scope position(
586 source_positions_, source_positions_->GetSourcePosition(node));
587 if (TryReuseDispatch(node, callee, candidate, if_successes, calls, inputs,
588 input_count)) {
589 return;
590 }
591
592 Node* fallthrough_control = NodeProperties::GetControlInput(node);
593 int const num_calls = candidate.num_functions;
594
595 // Create the appropriate control flow to dispatch to the cloned calls.
596 for (int i = 0; i < num_calls; ++i) {
597 // TODO(2206): Make comparison be based on underlying SharedFunctionInfo
598 // instead of the target JSFunction reference directly.
599 Node* target = jsgraph()->Constant(candidate.functions[i].value());
600 if (i != (num_calls - 1)) {
601 Node* check =
602 graph()->NewNode(simplified()->ReferenceEqual(), callee, target);
603 Node* branch =
604 graph()->NewNode(common()->Branch(), check, fallthrough_control);
605 fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
606 if_successes[i] = graph()->NewNode(common()->IfTrue(), branch);
607 } else {
608 if_successes[i] = fallthrough_control;
609 }
610
611 // Clone the calls for each branch.
612 // The first input to the call is the actual target (which we specialize
613 // to the known {target}); the last input is the control dependency.
614 // We also specialize the new.target of JSConstruct {node}s if it refers
615 // to the same node as the {node}'s target input, so that we can later
616 // properly inline the JSCreate operations.
617 if (node->opcode() == IrOpcode::kJSConstruct && inputs[0] == inputs[1]) {
618 inputs[1] = target;
619 }
620 inputs[0] = target;
621 inputs[input_count - 1] = if_successes[i];
622 calls[i] = if_successes[i] =
623 graph()->NewNode(node->op(), input_count, inputs);
624 }
625}
626
627Reduction JSInliningHeuristic::InlineCandidate(Candidate const& candidate,
628 bool small_function) {
629 int const num_calls = candidate.num_functions;
630 Node* const node = candidate.node;
631 if (num_calls == 1) {
632 Reduction const reduction = inliner_.ReduceJSCall(node);
633 if (reduction.Changed()) {
634 cumulative_count_ += candidate.bytecode[0].value().length();
635 }
636 return reduction;
637 }
638
639 // Expand the JSCall/JSConstruct node to a subgraph first if
640 // we have multiple known target functions.
641 DCHECK_LT(1, num_calls);
642 Node* calls[kMaxCallPolymorphism + 1];
643 Node* if_successes[kMaxCallPolymorphism];
644 Node* callee = NodeProperties::GetValueInput(node, 0);
645
646 // Setup the inputs for the cloned call nodes.
647 int const input_count = node->InputCount();
648 Node** inputs = graph()->zone()->NewArray<Node*>(input_count);
649 for (int i = 0; i < input_count; ++i) {
650 inputs[i] = node->InputAt(i);
651 }
652
653 // Create the appropriate control flow to dispatch to the cloned calls.
654 CreateOrReuseDispatch(node, callee, candidate, if_successes, calls, inputs,
655 input_count);
656
657 // Check if we have an exception projection for the call {node}.
658 Node* if_exception = nullptr;
659 if (NodeProperties::IsExceptionalCall(node, &if_exception)) {
660 Node* if_exceptions[kMaxCallPolymorphism + 1];
661 for (int i = 0; i < num_calls; ++i) {
662 if_successes[i] = graph()->NewNode(common()->IfSuccess(), calls[i]);
663 if_exceptions[i] =
664 graph()->NewNode(common()->IfException(), calls[i], calls[i]);
665 }
666
667 // Morph the {if_exception} projection into a join.
668 Node* exception_control =
669 graph()->NewNode(common()->Merge(num_calls), num_calls, if_exceptions);
670 if_exceptions[num_calls] = exception_control;
671 Node* exception_effect = graph()->NewNode(common()->EffectPhi(num_calls),
672 num_calls + 1, if_exceptions);
673 Node* exception_value = graph()->NewNode(
674 common()->Phi(MachineRepresentation::kTagged, num_calls), num_calls + 1,
675 if_exceptions);
676 ReplaceWithValue(if_exception, exception_value, exception_effect,
677 exception_control);
678 }
679
680 // Morph the original call site into a join of the dispatched call sites.
681 Node* control =
682 graph()->NewNode(common()->Merge(num_calls), num_calls, if_successes);
683 calls[num_calls] = control;
684 Node* effect =
685 graph()->NewNode(common()->EffectPhi(num_calls), num_calls + 1, calls);
686 Node* value =
687 graph()->NewNode(common()->Phi(MachineRepresentation::kTagged, num_calls),
688 num_calls + 1, calls);
689 ReplaceWithValue(node, value, effect, control);
690
691 // Inline the individual, cloned call sites.
692 for (int i = 0; i < num_calls; ++i) {
693 Node* node = calls[i];
694 if (candidate.can_inline_function[i] &&
695 (small_function ||
696 cumulative_count_ < FLAG_max_inlined_bytecode_size_cumulative)) {
697 Reduction const reduction = inliner_.ReduceJSCall(node);
698 if (reduction.Changed()) {
699 // Killing the call node is not strictly necessary, but it is safer to
700 // make sure we do not resurrect the node.
701 node->Kill();
702 // Small functions don't count towards the budget.
703 if (!small_function) {
704 cumulative_count_ += candidate.bytecode[i]->length();
705 }
706 }
707 }
708 }
709
710 return Replace(value);
711}
712
713bool JSInliningHeuristic::CandidateCompare::operator()(
714 const Candidate& left, const Candidate& right) const {
715 if (right.frequency.IsUnknown()) {
716 if (left.frequency.IsUnknown()) {
717 // If left and right are both unknown then the ordering is indeterminate,
718 // which breaks strict weak ordering requirements, so we fall back to the
719 // node id as a tie breaker.
720 return left.node->id() > right.node->id();
721 }
722 return true;
723 } else if (left.frequency.IsUnknown()) {
724 return false;
725 } else if (left.frequency.value() > right.frequency.value()) {
726 return true;
727 } else if (left.frequency.value() < right.frequency.value()) {
728 return false;
729 } else {
730 return left.node->id() > right.node->id();
731 }
732}
733
734void JSInliningHeuristic::PrintCandidates() {
735 StdoutStream os;
736 os << "Candidates for inlining (size=" << candidates_.size() << "):\n";
737 for (const Candidate& candidate : candidates_) {
738 os << " #" << candidate.node->id() << ":"
739 << candidate.node->op()->mnemonic()
740 << ", frequency: " << candidate.frequency << std::endl;
741 for (int i = 0; i < candidate.num_functions; ++i) {
742 SharedFunctionInfoRef shared =
743 candidate.functions[i].has_value()
744 ? candidate.functions[i].value().shared()
745 : candidate.shared_info.value();
746 PrintF(" - size:%d, name: %s\n", candidate.bytecode[i].value().length(),
747 shared.object()->DebugName()->ToCString().get());
748 }
749 }
750}
751
752Graph* JSInliningHeuristic::graph() const { return jsgraph()->graph(); }
753
754CommonOperatorBuilder* JSInliningHeuristic::common() const {
755 return jsgraph()->common();
756}
757
758SimplifiedOperatorBuilder* JSInliningHeuristic::simplified() const {
759 return jsgraph()->simplified();
760}
761
762#undef TRACE
763
764} // namespace compiler
765} // namespace internal
766} // namespace v8
767