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 #include "src/objects-inl.h"
9
10 namespace v8 {
11 namespace internal {
12 namespace compiler {
13
TypeNarrowingReducer(Editor * editor,JSGraph * jsgraph,JSHeapBroker * js_heap_broker)14 TypeNarrowingReducer::TypeNarrowingReducer(Editor* editor, JSGraph* jsgraph,
15 JSHeapBroker* js_heap_broker)
16 : AdvancedReducer(editor),
17 jsgraph_(jsgraph),
18 op_typer_(jsgraph->isolate(), js_heap_broker, zone()) {}
19
~TypeNarrowingReducer()20 TypeNarrowingReducer::~TypeNarrowingReducer() {}
21
Reduce(Node * node)22 Reduction TypeNarrowingReducer::Reduce(Node* node) {
23 DisallowHeapAccess no_heap_access;
24
25 Type new_type = Type::Any();
26
27 switch (node->opcode()) {
28 case IrOpcode::kNumberLessThan: {
29 // TODO(turbofan) Reuse the logic from typer.cc (by integrating relational
30 // comparisons with the operation typer).
31 Type left_type = NodeProperties::GetType(node->InputAt(0));
32 Type right_type = NodeProperties::GetType(node->InputAt(1));
33 if (left_type.Is(Type::PlainNumber()) &&
34 right_type.Is(Type::PlainNumber())) {
35 if (left_type.Max() < right_type.Min()) {
36 new_type = op_typer_.singleton_true();
37 } else if (left_type.Min() >= right_type.Max()) {
38 new_type = op_typer_.singleton_false();
39 }
40 }
41 break;
42 }
43
44 case IrOpcode::kTypeGuard: {
45 new_type = op_typer_.TypeTypeGuard(
46 node->op(), NodeProperties::GetType(node->InputAt(0)));
47 break;
48 }
49
50 #define DECLARE_CASE(Name) \
51 case IrOpcode::k##Name: { \
52 new_type = op_typer_.Name(NodeProperties::GetType(node->InputAt(0)), \
53 NodeProperties::GetType(node->InputAt(1))); \
54 break; \
55 }
56 SIMPLIFIED_NUMBER_BINOP_LIST(DECLARE_CASE)
57 DECLARE_CASE(SameValue)
58 #undef DECLARE_CASE
59
60 #define DECLARE_CASE(Name) \
61 case IrOpcode::k##Name: { \
62 new_type = op_typer_.Name(NodeProperties::GetType(node->InputAt(0))); \
63 break; \
64 }
65 SIMPLIFIED_NUMBER_UNOP_LIST(DECLARE_CASE)
66 DECLARE_CASE(ToBoolean)
67 #undef DECLARE_CASE
68
69 default:
70 return NoChange();
71 }
72
73 Type original_type = NodeProperties::GetType(node);
74 Type restricted = Type::Intersect(new_type, original_type, zone());
75 if (!original_type.Is(restricted)) {
76 NodeProperties::SetType(node, restricted);
77 return Changed(node);
78 }
79 return NoChange();
80 }
81
graph() const82 Graph* TypeNarrowingReducer::graph() const { return jsgraph()->graph(); }
83
zone() const84 Zone* TypeNarrowingReducer::zone() const { return graph()->zone(); }
85
86 } // namespace compiler
87 } // namespace internal
88 } // namespace v8
89