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-frame-specialization.h"
6
7 #include "src/compiler/js-graph.h"
8 #include "src/compiler/linkage.h"
9 #include "src/frames-inl.h"
10
11 namespace v8 {
12 namespace internal {
13 namespace compiler {
14
Reduce(Node * node)15 Reduction JSFrameSpecialization::Reduce(Node* node) {
16 switch (node->opcode()) {
17 case IrOpcode::kOsrValue:
18 return ReduceOsrValue(node);
19 case IrOpcode::kOsrGuard:
20 return ReduceOsrGuard(node);
21 case IrOpcode::kParameter:
22 return ReduceParameter(node);
23 default:
24 break;
25 }
26 return NoChange();
27 }
28
ReduceOsrValue(Node * node)29 Reduction JSFrameSpecialization::ReduceOsrValue(Node* node) {
30 // JSFrameSpecialization should never run on interpreted frames, since the
31 // code below assumes standard stack frame layouts.
32 DCHECK(!frame()->is_interpreted());
33 DCHECK_EQ(IrOpcode::kOsrValue, node->opcode());
34 Handle<Object> value;
35 int index = OsrValueIndexOf(node->op());
36 int const parameters_count = frame()->ComputeParametersCount() + 1;
37 if (index == Linkage::kOsrContextSpillSlotIndex) {
38 value = handle(frame()->context(), isolate());
39 } else if (index >= parameters_count) {
40 value = handle(frame()->GetExpression(index - parameters_count), isolate());
41 } else {
42 // The OsrValue index 0 is the receiver.
43 value =
44 handle(index ? frame()->GetParameter(index - 1) : frame()->receiver(),
45 isolate());
46 }
47 return Replace(jsgraph()->Constant(value));
48 }
49
ReduceOsrGuard(Node * node)50 Reduction JSFrameSpecialization::ReduceOsrGuard(Node* node) {
51 DCHECK_EQ(IrOpcode::kOsrGuard, node->opcode());
52 ReplaceWithValue(node, node->InputAt(0),
53 NodeProperties::GetEffectInput(node));
54 return Changed(node);
55 }
56
ReduceParameter(Node * node)57 Reduction JSFrameSpecialization::ReduceParameter(Node* node) {
58 DCHECK_EQ(IrOpcode::kParameter, node->opcode());
59 Handle<Object> value;
60 int const index = ParameterIndexOf(node->op());
61 int const parameters_count = frame()->ComputeParametersCount() + 1;
62 if (index == Linkage::kJSCallClosureParamIndex) {
63 // The Parameter index references the closure.
64 value = handle(frame()->function(), isolate());
65 } else if (index == Linkage::GetJSCallArgCountParamIndex(parameters_count)) {
66 // The Parameter index references the parameter count.
67 value = handle(Smi::FromInt(parameters_count - 1), isolate());
68 } else if (index == Linkage::GetJSCallContextParamIndex(parameters_count)) {
69 // The Parameter index references the context.
70 value = handle(frame()->context(), isolate());
71 } else {
72 // The Parameter index 0 is the receiver.
73 value =
74 handle(index ? frame()->GetParameter(index - 1) : frame()->receiver(),
75 isolate());
76 }
77 return Replace(jsgraph()->Constant(value));
78 }
79
80
isolate() const81 Isolate* JSFrameSpecialization::isolate() const { return jsgraph()->isolate(); }
82
83 } // namespace compiler
84 } // namespace internal
85 } // namespace v8
86