1 // Copyright 2014 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/simplified-operator-reducer.h"
6
7 #include "src/compiler/js-graph.h"
8 #include "src/compiler/machine-operator.h"
9 #include "src/compiler/node-matchers.h"
10 #include "src/compiler/operator-properties.h"
11 #include "src/compiler/simplified-operator.h"
12 #include "src/compiler/type-cache.h"
13 #include "src/numbers/conversions-inl.h"
14
15 namespace v8 {
16 namespace internal {
17 namespace compiler {
18
19 namespace {
20
DecideObjectIsSmi(Node * const input)21 Decision DecideObjectIsSmi(Node* const input) {
22 NumberMatcher m(input);
23 if (m.HasResolvedValue()) {
24 return IsSmiDouble(m.ResolvedValue()) ? Decision::kTrue : Decision::kFalse;
25 }
26 if (m.IsAllocate()) return Decision::kFalse;
27 if (m.IsChangeBitToTagged()) return Decision::kFalse;
28 if (m.IsChangeInt31ToTaggedSigned()) return Decision::kTrue;
29 if (m.IsHeapConstant()) return Decision::kFalse;
30 return Decision::kUnknown;
31 }
32
33 } // namespace
34
SimplifiedOperatorReducer(Editor * editor,JSGraph * jsgraph,JSHeapBroker * broker)35 SimplifiedOperatorReducer::SimplifiedOperatorReducer(Editor* editor,
36 JSGraph* jsgraph,
37 JSHeapBroker* broker)
38 : AdvancedReducer(editor), jsgraph_(jsgraph), broker_(broker) {}
39
40 SimplifiedOperatorReducer::~SimplifiedOperatorReducer() = default;
41
42
Reduce(Node * node)43 Reduction SimplifiedOperatorReducer::Reduce(Node* node) {
44 DisallowHeapAccess no_heap_access;
45 switch (node->opcode()) {
46 case IrOpcode::kBooleanNot: {
47 HeapObjectMatcher m(node->InputAt(0));
48 if (m.Is(factory()->true_value())) return ReplaceBoolean(false);
49 if (m.Is(factory()->false_value())) return ReplaceBoolean(true);
50 if (m.IsBooleanNot()) return Replace(m.InputAt(0));
51 break;
52 }
53 case IrOpcode::kChangeBitToTagged: {
54 Int32Matcher m(node->InputAt(0));
55 if (m.Is(0)) return Replace(jsgraph()->FalseConstant());
56 if (m.Is(1)) return Replace(jsgraph()->TrueConstant());
57 if (m.IsChangeTaggedToBit()) return Replace(m.InputAt(0));
58 break;
59 }
60 case IrOpcode::kChangeTaggedToBit: {
61 HeapObjectMatcher m(node->InputAt(0));
62 if (m.HasResolvedValue()) {
63 return ReplaceInt32(m.Ref(broker()).BooleanValue());
64 }
65 if (m.IsChangeBitToTagged()) return Replace(m.InputAt(0));
66 break;
67 }
68 case IrOpcode::kChangeFloat64ToTagged: {
69 Float64Matcher m(node->InputAt(0));
70 if (m.HasResolvedValue()) return ReplaceNumber(m.ResolvedValue());
71 if (m.IsChangeTaggedToFloat64()) return Replace(m.node()->InputAt(0));
72 break;
73 }
74 case IrOpcode::kChangeInt31ToTaggedSigned:
75 case IrOpcode::kChangeInt32ToTagged: {
76 Int32Matcher m(node->InputAt(0));
77 if (m.HasResolvedValue()) return ReplaceNumber(m.ResolvedValue());
78 if (m.IsChangeTaggedToInt32() || m.IsChangeTaggedSignedToInt32()) {
79 return Replace(m.InputAt(0));
80 }
81 break;
82 }
83 case IrOpcode::kChangeTaggedToFloat64:
84 case IrOpcode::kTruncateTaggedToFloat64: {
85 NumberMatcher m(node->InputAt(0));
86 if (m.HasResolvedValue()) return ReplaceFloat64(m.ResolvedValue());
87 if (m.IsChangeFloat64ToTagged() || m.IsChangeFloat64ToTaggedPointer()) {
88 return Replace(m.node()->InputAt(0));
89 }
90 if (m.IsChangeInt31ToTaggedSigned() || m.IsChangeInt32ToTagged()) {
91 return Change(node, machine()->ChangeInt32ToFloat64(), m.InputAt(0));
92 }
93 if (m.IsChangeUint32ToTagged()) {
94 return Change(node, machine()->ChangeUint32ToFloat64(), m.InputAt(0));
95 }
96 break;
97 }
98 case IrOpcode::kChangeTaggedSignedToInt32:
99 case IrOpcode::kChangeTaggedToInt32: {
100 NumberMatcher m(node->InputAt(0));
101 if (m.HasResolvedValue())
102 return ReplaceInt32(DoubleToInt32(m.ResolvedValue()));
103 if (m.IsChangeFloat64ToTagged() || m.IsChangeFloat64ToTaggedPointer()) {
104 return Change(node, machine()->ChangeFloat64ToInt32(), m.InputAt(0));
105 }
106 if (m.IsChangeInt31ToTaggedSigned() || m.IsChangeInt32ToTagged()) {
107 return Replace(m.InputAt(0));
108 }
109 break;
110 }
111 case IrOpcode::kChangeTaggedToUint32: {
112 NumberMatcher m(node->InputAt(0));
113 if (m.HasResolvedValue())
114 return ReplaceUint32(DoubleToUint32(m.ResolvedValue()));
115 if (m.IsChangeFloat64ToTagged() || m.IsChangeFloat64ToTaggedPointer()) {
116 return Change(node, machine()->ChangeFloat64ToUint32(), m.InputAt(0));
117 }
118 if (m.IsChangeUint32ToTagged()) return Replace(m.InputAt(0));
119 break;
120 }
121 case IrOpcode::kChangeUint32ToTagged: {
122 Uint32Matcher m(node->InputAt(0));
123 if (m.HasResolvedValue())
124 return ReplaceNumber(FastUI2D(m.ResolvedValue()));
125 break;
126 }
127 case IrOpcode::kTruncateTaggedToWord32: {
128 NumberMatcher m(node->InputAt(0));
129 if (m.HasResolvedValue())
130 return ReplaceInt32(DoubleToInt32(m.ResolvedValue()));
131 if (m.IsChangeInt31ToTaggedSigned() || m.IsChangeInt32ToTagged() ||
132 m.IsChangeUint32ToTagged()) {
133 return Replace(m.InputAt(0));
134 }
135 if (m.IsChangeFloat64ToTagged() || m.IsChangeFloat64ToTaggedPointer()) {
136 return Change(node, machine()->TruncateFloat64ToWord32(), m.InputAt(0));
137 }
138 break;
139 }
140 case IrOpcode::kCheckedFloat64ToInt32: {
141 Float64Matcher m(node->InputAt(0));
142 if (m.HasResolvedValue() && IsInt32Double(m.ResolvedValue())) {
143 Node* value =
144 jsgraph()->Int32Constant(static_cast<int32_t>(m.ResolvedValue()));
145 ReplaceWithValue(node, value);
146 return Replace(value);
147 }
148 break;
149 }
150 case IrOpcode::kCheckedTaggedToArrayIndex:
151 case IrOpcode::kCheckedTaggedToInt32:
152 case IrOpcode::kCheckedTaggedSignedToInt32: {
153 NodeMatcher m(node->InputAt(0));
154 if (m.IsConvertTaggedHoleToUndefined()) {
155 node->ReplaceInput(0, m.InputAt(0));
156 return Changed(node);
157 }
158 break;
159 }
160 case IrOpcode::kCheckIf: {
161 HeapObjectMatcher m(node->InputAt(0));
162 if (m.Is(factory()->true_value())) {
163 Node* const effect = NodeProperties::GetEffectInput(node);
164 return Replace(effect);
165 }
166 break;
167 }
168 case IrOpcode::kCheckNumber: {
169 NodeMatcher m(node->InputAt(0));
170 if (m.IsConvertTaggedHoleToUndefined()) {
171 node->ReplaceInput(0, m.InputAt(0));
172 return Changed(node);
173 }
174 break;
175 }
176 case IrOpcode::kCheckHeapObject: {
177 Node* const input = node->InputAt(0);
178 if (DecideObjectIsSmi(input) == Decision::kFalse) {
179 ReplaceWithValue(node, input);
180 return Replace(input);
181 }
182 NodeMatcher m(input);
183 if (m.IsCheckHeapObject()) {
184 ReplaceWithValue(node, input);
185 return Replace(input);
186 }
187 break;
188 }
189 case IrOpcode::kCheckSmi: {
190 Node* const input = node->InputAt(0);
191 if (DecideObjectIsSmi(input) == Decision::kTrue) {
192 ReplaceWithValue(node, input);
193 return Replace(input);
194 }
195 NodeMatcher m(input);
196 if (m.IsCheckSmi()) {
197 ReplaceWithValue(node, input);
198 return Replace(input);
199 } else if (m.IsConvertTaggedHoleToUndefined()) {
200 node->ReplaceInput(0, m.InputAt(0));
201 return Changed(node);
202 }
203 break;
204 }
205 case IrOpcode::kObjectIsSmi: {
206 Node* const input = node->InputAt(0);
207 switch (DecideObjectIsSmi(input)) {
208 case Decision::kTrue:
209 return ReplaceBoolean(true);
210 case Decision::kFalse:
211 return ReplaceBoolean(false);
212 case Decision::kUnknown:
213 break;
214 }
215 break;
216 }
217 case IrOpcode::kNumberAbs: {
218 NumberMatcher m(node->InputAt(0));
219 if (m.HasResolvedValue())
220 return ReplaceNumber(std::fabs(m.ResolvedValue()));
221 break;
222 }
223 case IrOpcode::kReferenceEqual: {
224 HeapObjectBinopMatcher m(node);
225 if (m.left().node() == m.right().node()) return ReplaceBoolean(true);
226 break;
227 }
228 case IrOpcode::kCheckedInt32Add: {
229 // (x + a) + b => x + (a + b) where a and b are constants and have the
230 // same sign.
231 Int32BinopMatcher m(node);
232 if (m.right().HasResolvedValue()) {
233 Node* checked_int32_add = m.left().node();
234 if (checked_int32_add->opcode() == IrOpcode::kCheckedInt32Add) {
235 Int32BinopMatcher n(checked_int32_add);
236 if (n.right().HasResolvedValue() &&
237 (n.right().ResolvedValue() >= 0) ==
238 (m.right().ResolvedValue() >= 0)) {
239 int32_t val;
240 bool overflow = base::bits::SignedAddOverflow32(
241 n.right().ResolvedValue(), m.right().ResolvedValue(), &val);
242 if (!overflow) {
243 bool has_no_other_uses = true;
244 for (Edge edge : checked_int32_add->use_edges()) {
245 if (!edge.from()->IsDead() && edge.from() != node) {
246 has_no_other_uses = false;
247 break;
248 }
249 }
250 if (has_no_other_uses) {
251 node->ReplaceInput(0, n.left().node());
252 node->ReplaceInput(1, jsgraph()->Int32Constant(val));
253 RelaxEffectsAndControls(checked_int32_add);
254 return Changed(node);
255 }
256 }
257 }
258 }
259 }
260 break;
261 }
262 default:
263 break;
264 }
265 return NoChange();
266 }
267
Change(Node * node,const Operator * op,Node * a)268 Reduction SimplifiedOperatorReducer::Change(Node* node, const Operator* op,
269 Node* a) {
270 DCHECK_EQ(node->InputCount(), OperatorProperties::GetTotalInputCount(op));
271 DCHECK_LE(1, node->InputCount());
272 node->ReplaceInput(0, a);
273 NodeProperties::ChangeOp(node, op);
274 return Changed(node);
275 }
276
ReplaceBoolean(bool value)277 Reduction SimplifiedOperatorReducer::ReplaceBoolean(bool value) {
278 return Replace(jsgraph()->BooleanConstant(value));
279 }
280
ReplaceFloat64(double value)281 Reduction SimplifiedOperatorReducer::ReplaceFloat64(double value) {
282 return Replace(jsgraph()->Float64Constant(value));
283 }
284
285
ReplaceInt32(int32_t value)286 Reduction SimplifiedOperatorReducer::ReplaceInt32(int32_t value) {
287 return Replace(jsgraph()->Int32Constant(value));
288 }
289
290
ReplaceNumber(double value)291 Reduction SimplifiedOperatorReducer::ReplaceNumber(double value) {
292 return Replace(jsgraph()->Constant(value));
293 }
294
295
ReplaceNumber(int32_t value)296 Reduction SimplifiedOperatorReducer::ReplaceNumber(int32_t value) {
297 return Replace(jsgraph()->Constant(value));
298 }
299
factory() const300 Factory* SimplifiedOperatorReducer::factory() const {
301 return jsgraph()->isolate()->factory();
302 }
303
graph() const304 Graph* SimplifiedOperatorReducer::graph() const { return jsgraph()->graph(); }
305
machine() const306 MachineOperatorBuilder* SimplifiedOperatorReducer::machine() const {
307 return jsgraph()->machine();
308 }
309
simplified() const310 SimplifiedOperatorBuilder* SimplifiedOperatorReducer::simplified() const {
311 return jsgraph()->simplified();
312 }
313
314 } // namespace compiler
315 } // namespace internal
316 } // namespace v8
317