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1 // Copyright 2013 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/hydrogen-mark-deoptimize.h"
6 
7 namespace v8 {
8 namespace internal {
9 
Run()10 void HMarkDeoptimizeOnUndefinedPhase::Run() {
11   const ZoneList<HPhi*>* phi_list = graph()->phi_list();
12   for (int i = 0; i < phi_list->length(); i++) {
13     HPhi* phi = phi_list->at(i);
14     if (phi->CheckFlag(HValue::kAllowUndefinedAsNaN) &&
15         !phi->CheckUsesForFlag(HValue::kAllowUndefinedAsNaN)) {
16       ProcessPhi(phi);
17     }
18   }
19 }
20 
21 
ProcessPhi(HPhi * phi)22 void HMarkDeoptimizeOnUndefinedPhase::ProcessPhi(HPhi* phi) {
23   DCHECK(phi->CheckFlag(HValue::kAllowUndefinedAsNaN));
24   DCHECK(worklist_.is_empty());
25 
26   // Push the phi onto the worklist
27   phi->ClearFlag(HValue::kAllowUndefinedAsNaN);
28   worklist_.Add(phi, zone());
29 
30   // Process all phis that can reach this phi
31   while (!worklist_.is_empty()) {
32     phi = worklist_.RemoveLast();
33     for (int i = phi->OperandCount() - 1; i >= 0; --i) {
34       HValue* input = phi->OperandAt(i);
35       if (input->IsPhi() && input->CheckFlag(HValue::kAllowUndefinedAsNaN)) {
36         input->ClearFlag(HValue::kAllowUndefinedAsNaN);
37         worklist_.Add(HPhi::cast(input), zone());
38       }
39     }
40   }
41 }
42 
43 
Run()44 void HComputeChangeUndefinedToNaN::Run() {
45   const ZoneList<HBasicBlock*>* blocks(graph()->blocks());
46   for (int i = 0; i < blocks->length(); ++i) {
47     const HBasicBlock* block(blocks->at(i));
48     for (HInstruction* current = block->first(); current != NULL; ) {
49       HInstruction* next = current->next();
50       if (current->IsChange()) {
51         if (HChange::cast(current)->can_convert_undefined_to_nan()) {
52           current->SetFlag(HValue::kAllowUndefinedAsNaN);
53         }
54       }
55       current = next;
56     }
57   }
58 }
59 
60 
61 } }  // namespace v8::internal
62