1 // Copyright 2018 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/type-narrowing-reducer.h"
6
7 #include "src/compiler/js-graph.h"
8
9 namespace v8 {
10 namespace internal {
11 namespace compiler {
12
TypeNarrowingReducer(Editor * editor,JSGraph * jsgraph,JSHeapBroker * broker)13 TypeNarrowingReducer::TypeNarrowingReducer(Editor* editor, JSGraph* jsgraph,
14 JSHeapBroker* broker)
15 : AdvancedReducer(editor), jsgraph_(jsgraph), op_typer_(broker, zone()) {}
16
17 TypeNarrowingReducer::~TypeNarrowingReducer() = default;
18
Reduce(Node * node)19 Reduction TypeNarrowingReducer::Reduce(Node* node) {
20 DisallowHeapAccess no_heap_access;
21
22 Type new_type = Type::Any();
23
24 switch (node->opcode()) {
25 case IrOpcode::kNumberLessThan: {
26 // TODO(turbofan) Reuse the logic from typer.cc (by integrating relational
27 // comparisons with the operation typer).
28 Type left_type = NodeProperties::GetType(node->InputAt(0));
29 Type right_type = NodeProperties::GetType(node->InputAt(1));
30 if (left_type.Is(Type::PlainNumber()) &&
31 right_type.Is(Type::PlainNumber())) {
32 if (left_type.Max() < right_type.Min()) {
33 new_type = op_typer_.singleton_true();
34 } else if (left_type.Min() >= right_type.Max()) {
35 new_type = op_typer_.singleton_false();
36 }
37 }
38 break;
39 }
40
41 case IrOpcode::kTypeGuard: {
42 new_type = op_typer_.TypeTypeGuard(
43 node->op(), NodeProperties::GetType(node->InputAt(0)));
44 break;
45 }
46
47 #define DECLARE_CASE(Name) \
48 case IrOpcode::k##Name: { \
49 new_type = op_typer_.Name(NodeProperties::GetType(node->InputAt(0)), \
50 NodeProperties::GetType(node->InputAt(1))); \
51 break; \
52 }
53 SIMPLIFIED_NUMBER_BINOP_LIST(DECLARE_CASE)
54 DECLARE_CASE(SameValue)
55 #undef DECLARE_CASE
56
57 #define DECLARE_CASE(Name) \
58 case IrOpcode::k##Name: { \
59 new_type = op_typer_.Name(NodeProperties::GetType(node->InputAt(0))); \
60 break; \
61 }
62 SIMPLIFIED_NUMBER_UNOP_LIST(DECLARE_CASE)
63 DECLARE_CASE(ToBoolean)
64 #undef DECLARE_CASE
65
66 default:
67 return NoChange();
68 }
69
70 Type original_type = NodeProperties::GetType(node);
71 Type restricted = Type::Intersect(new_type, original_type, zone());
72 if (!original_type.Is(restricted)) {
73 NodeProperties::SetType(node, restricted);
74 return Changed(node);
75 }
76 return NoChange();
77 }
78
graph() const79 Graph* TypeNarrowingReducer::graph() const { return jsgraph()->graph(); }
80
zone() const81 Zone* TypeNarrowingReducer::zone() const { return graph()->zone(); }
82
83 } // namespace compiler
84 } // namespace internal
85 } // namespace v8
86