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/crankshaft/hydrogen-mark-deoptimize.h"
6
7namespace v8 {
8namespace internal {
9
10void 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
22void 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
44void 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 internal
62}  // namespace v8
63