Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 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/common-operator.h" |
| 6 | #include "src/compiler/dead-code-elimination.h" |
| 7 | #include "test/unittests/compiler/graph-reducer-unittest.h" |
| 8 | #include "test/unittests/compiler/graph-unittest.h" |
| 9 | #include "test/unittests/compiler/node-test-utils.h" |
| 10 | #include "testing/gmock-support.h" |
| 11 | |
| 12 | using testing::StrictMock; |
| 13 | |
| 14 | namespace v8 { |
| 15 | namespace internal { |
| 16 | namespace compiler { |
| 17 | |
| 18 | class DeadCodeEliminationTest : public GraphTest { |
| 19 | public: |
| 20 | explicit DeadCodeEliminationTest(int num_parameters = 4) |
| 21 | : GraphTest(num_parameters) {} |
| 22 | ~DeadCodeEliminationTest() override {} |
| 23 | |
| 24 | protected: |
| 25 | Reduction Reduce(AdvancedReducer::Editor* editor, Node* node) { |
| 26 | DeadCodeElimination reducer(editor, graph(), common()); |
| 27 | return reducer.Reduce(node); |
| 28 | } |
| 29 | |
| 30 | Reduction Reduce(Node* node) { |
| 31 | StrictMock<MockAdvancedReducerEditor> editor; |
| 32 | return Reduce(&editor, node); |
| 33 | } |
| 34 | }; |
| 35 | |
| 36 | |
| 37 | namespace { |
| 38 | |
| 39 | const MachineRepresentation kMachineRepresentations[] = { |
| 40 | MachineRepresentation::kBit, MachineRepresentation::kWord8, |
| 41 | MachineRepresentation::kWord16, MachineRepresentation::kWord32, |
| 42 | MachineRepresentation::kWord64, MachineRepresentation::kFloat32, |
| 43 | MachineRepresentation::kFloat64, MachineRepresentation::kTagged}; |
| 44 | |
| 45 | |
| 46 | const int kMaxInputs = 16; |
| 47 | |
| 48 | |
| 49 | const Operator kOp0(0, Operator::kNoProperties, "Op0", 1, 1, 1, 1, 1, 1); |
| 50 | |
| 51 | } // namespace |
| 52 | |
| 53 | |
| 54 | // ----------------------------------------------------------------------------- |
| 55 | // General dead propagation |
| 56 | |
| 57 | |
| 58 | TEST_F(DeadCodeEliminationTest, GeneralDeadPropagation) { |
| 59 | Node* const value = Parameter(0); |
| 60 | Node* const effect = graph()->start(); |
| 61 | Node* const dead = graph()->NewNode(common()->Dead()); |
| 62 | Node* const node = graph()->NewNode(&kOp0, value, effect, dead); |
| 63 | Reduction const r = Reduce(node); |
| 64 | ASSERT_TRUE(r.Changed()); |
| 65 | EXPECT_THAT(r.replacement(), IsDead()); |
| 66 | } |
| 67 | |
| 68 | |
| 69 | // ----------------------------------------------------------------------------- |
| 70 | // Branch |
| 71 | |
| 72 | |
| 73 | TEST_F(DeadCodeEliminationTest, BranchWithDeadControlInput) { |
| 74 | BranchHint const kHints[] = {BranchHint::kNone, BranchHint::kTrue, |
| 75 | BranchHint::kFalse}; |
| 76 | TRACED_FOREACH(BranchHint, hint, kHints) { |
| 77 | Reduction const r = |
| 78 | Reduce(graph()->NewNode(common()->Branch(hint), Parameter(0), |
| 79 | graph()->NewNode(common()->Dead()))); |
| 80 | ASSERT_TRUE(r.Changed()); |
| 81 | EXPECT_THAT(r.replacement(), IsDead()); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | |
| 86 | // ----------------------------------------------------------------------------- |
| 87 | // IfTrue |
| 88 | |
| 89 | |
| 90 | TEST_F(DeadCodeEliminationTest, IfTrueWithDeadInput) { |
| 91 | Reduction const r = Reduce( |
| 92 | graph()->NewNode(common()->IfTrue(), graph()->NewNode(common()->Dead()))); |
| 93 | ASSERT_TRUE(r.Changed()); |
| 94 | EXPECT_THAT(r.replacement(), IsDead()); |
| 95 | } |
| 96 | |
| 97 | |
| 98 | // ----------------------------------------------------------------------------- |
| 99 | // IfFalse |
| 100 | |
| 101 | |
| 102 | TEST_F(DeadCodeEliminationTest, IfFalseWithDeadInput) { |
| 103 | Reduction const r = Reduce(graph()->NewNode( |
| 104 | common()->IfFalse(), graph()->NewNode(common()->Dead()))); |
| 105 | ASSERT_TRUE(r.Changed()); |
| 106 | EXPECT_THAT(r.replacement(), IsDead()); |
| 107 | } |
| 108 | |
| 109 | |
| 110 | // ----------------------------------------------------------------------------- |
| 111 | // IfSuccess |
| 112 | |
| 113 | |
| 114 | TEST_F(DeadCodeEliminationTest, IfSuccessWithDeadInput) { |
| 115 | Reduction const r = Reduce(graph()->NewNode( |
| 116 | common()->IfSuccess(), graph()->NewNode(common()->Dead()))); |
| 117 | ASSERT_TRUE(r.Changed()); |
| 118 | EXPECT_THAT(r.replacement(), IsDead()); |
| 119 | } |
| 120 | |
| 121 | |
| 122 | // ----------------------------------------------------------------------------- |
| 123 | // IfException |
| 124 | |
| 125 | |
| 126 | TEST_F(DeadCodeEliminationTest, IfExceptionWithDeadControlInput) { |
| 127 | IfExceptionHint const kHints[] = {IfExceptionHint::kLocallyCaught, |
| 128 | IfExceptionHint::kLocallyUncaught}; |
| 129 | TRACED_FOREACH(IfExceptionHint, hint, kHints) { |
| 130 | Reduction const r = |
| 131 | Reduce(graph()->NewNode(common()->IfException(hint), graph()->start(), |
| 132 | graph()->NewNode(common()->Dead()))); |
| 133 | ASSERT_TRUE(r.Changed()); |
| 134 | EXPECT_THAT(r.replacement(), IsDead()); |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | |
| 139 | // ----------------------------------------------------------------------------- |
| 140 | // End |
| 141 | |
| 142 | |
| 143 | TEST_F(DeadCodeEliminationTest, EndWithDeadAndStart) { |
| 144 | Node* const dead = graph()->NewNode(common()->Dead()); |
| 145 | Node* const start = graph()->start(); |
| 146 | Reduction const r = Reduce(graph()->NewNode(common()->End(2), dead, start)); |
| 147 | ASSERT_TRUE(r.Changed()); |
| 148 | EXPECT_THAT(r.replacement(), IsEnd(start)); |
| 149 | } |
| 150 | |
| 151 | |
| 152 | TEST_F(DeadCodeEliminationTest, EndWithOnlyDeadInputs) { |
| 153 | Node* inputs[kMaxInputs]; |
| 154 | TRACED_FORRANGE(int, input_count, 1, kMaxInputs - 1) { |
| 155 | for (int i = 0; i < input_count; ++i) { |
| 156 | inputs[i] = graph()->NewNode(common()->Dead()); |
| 157 | } |
| 158 | Reduction const r = Reduce( |
| 159 | graph()->NewNode(common()->End(input_count), input_count, inputs)); |
| 160 | ASSERT_TRUE(r.Changed()); |
| 161 | EXPECT_THAT(r.replacement(), IsDead()); |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | |
| 166 | // ----------------------------------------------------------------------------- |
| 167 | // Merge |
| 168 | |
| 169 | |
| 170 | TEST_F(DeadCodeEliminationTest, MergeWithOnlyDeadInputs) { |
| 171 | Node* inputs[kMaxInputs + 1]; |
| 172 | TRACED_FORRANGE(int, input_count, 1, kMaxInputs - 1) { |
| 173 | for (int i = 0; i < input_count; ++i) { |
| 174 | inputs[i] = graph()->NewNode(common()->Dead()); |
| 175 | } |
| 176 | Reduction const r = Reduce( |
| 177 | graph()->NewNode(common()->Merge(input_count), input_count, inputs)); |
| 178 | ASSERT_TRUE(r.Changed()); |
| 179 | EXPECT_THAT(r.replacement(), IsDead()); |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | |
| 184 | TEST_F(DeadCodeEliminationTest, MergeWithOneLiveAndOneDeadInput) { |
| 185 | Node* const v0 = Parameter(0); |
| 186 | Node* const v1 = Parameter(1); |
| 187 | Node* const c0 = |
| 188 | graph()->NewNode(&kOp0, v0, graph()->start(), graph()->start()); |
| 189 | Node* const c1 = graph()->NewNode(common()->Dead()); |
| 190 | Node* const e0 = graph()->NewNode(&kOp0, v0, graph()->start(), c0); |
| 191 | Node* const e1 = graph()->NewNode(&kOp0, v1, graph()->start(), c1); |
| 192 | Node* const merge = graph()->NewNode(common()->Merge(2), c0, c1); |
| 193 | Node* const phi = graph()->NewNode( |
| 194 | common()->Phi(MachineRepresentation::kTagged, 2), v0, v1, merge); |
| 195 | Node* const ephi = graph()->NewNode(common()->EffectPhi(2), e0, e1, merge); |
| 196 | StrictMock<MockAdvancedReducerEditor> editor; |
| 197 | EXPECT_CALL(editor, Replace(phi, v0)); |
| 198 | EXPECT_CALL(editor, Replace(ephi, e0)); |
| 199 | Reduction const r = Reduce(&editor, merge); |
| 200 | ASSERT_TRUE(r.Changed()); |
| 201 | EXPECT_EQ(c0, r.replacement()); |
| 202 | } |
| 203 | |
| 204 | |
| 205 | TEST_F(DeadCodeEliminationTest, MergeWithTwoLiveAndTwoDeadInputs) { |
| 206 | Node* const v0 = Parameter(0); |
| 207 | Node* const v1 = Parameter(1); |
| 208 | Node* const v2 = Parameter(2); |
| 209 | Node* const v3 = Parameter(3); |
| 210 | Node* const c0 = |
| 211 | graph()->NewNode(&kOp0, v0, graph()->start(), graph()->start()); |
| 212 | Node* const c1 = graph()->NewNode(common()->Dead()); |
| 213 | Node* const c2 = graph()->NewNode(common()->Dead()); |
| 214 | Node* const c3 = graph()->NewNode(&kOp0, v3, graph()->start(), c0); |
| 215 | Node* const e0 = graph()->start(); |
| 216 | Node* const e1 = graph()->NewNode(&kOp0, v1, e0, c0); |
| 217 | Node* const e2 = graph()->NewNode(&kOp0, v2, e1, c0); |
| 218 | Node* const e3 = graph()->NewNode(&kOp0, v3, graph()->start(), c3); |
| 219 | Node* const merge = graph()->NewNode(common()->Merge(4), c0, c1, c2, c3); |
| 220 | Node* const phi = graph()->NewNode( |
| 221 | common()->Phi(MachineRepresentation::kTagged, 4), v0, v1, v2, v3, merge); |
| 222 | Node* const ephi = |
| 223 | graph()->NewNode(common()->EffectPhi(4), e0, e1, e2, e3, merge); |
| 224 | StrictMock<MockAdvancedReducerEditor> editor; |
| 225 | EXPECT_CALL(editor, Revisit(phi)); |
| 226 | EXPECT_CALL(editor, Revisit(ephi)); |
| 227 | Reduction const r = Reduce(&editor, merge); |
| 228 | ASSERT_TRUE(r.Changed()); |
| 229 | EXPECT_THAT(r.replacement(), IsMerge(c0, c3)); |
| 230 | EXPECT_THAT(phi, |
| 231 | IsPhi(MachineRepresentation::kTagged, v0, v3, r.replacement())); |
| 232 | EXPECT_THAT(ephi, IsEffectPhi(e0, e3, r.replacement())); |
| 233 | } |
| 234 | |
| 235 | |
| 236 | // ----------------------------------------------------------------------------- |
| 237 | // Loop |
| 238 | |
| 239 | |
| 240 | TEST_F(DeadCodeEliminationTest, LoopWithDeadFirstInput) { |
| 241 | Node* inputs[kMaxInputs + 1]; |
| 242 | TRACED_FORRANGE(int, input_count, 1, kMaxInputs - 1) { |
| 243 | inputs[0] = graph()->NewNode(common()->Dead()); |
| 244 | for (int i = 1; i < input_count; ++i) { |
| 245 | inputs[i] = graph()->start(); |
| 246 | } |
| 247 | Reduction const r = Reduce( |
| 248 | graph()->NewNode(common()->Loop(input_count), input_count, inputs)); |
| 249 | ASSERT_TRUE(r.Changed()); |
| 250 | EXPECT_THAT(r.replacement(), IsDead()); |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | |
| 255 | TEST_F(DeadCodeEliminationTest, LoopWithOnlyDeadInputs) { |
| 256 | Node* inputs[kMaxInputs + 1]; |
| 257 | TRACED_FORRANGE(int, input_count, 1, kMaxInputs - 1) { |
| 258 | for (int i = 0; i < input_count; ++i) { |
| 259 | inputs[i] = graph()->NewNode(common()->Dead()); |
| 260 | } |
| 261 | Reduction const r = Reduce( |
| 262 | graph()->NewNode(common()->Loop(input_count), input_count, inputs)); |
| 263 | ASSERT_TRUE(r.Changed()); |
| 264 | EXPECT_THAT(r.replacement(), IsDead()); |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | |
| 269 | TEST_F(DeadCodeEliminationTest, LoopWithOneLiveAndOneDeadInput) { |
| 270 | Node* const v0 = Parameter(0); |
| 271 | Node* const v1 = Parameter(1); |
| 272 | Node* const c0 = |
| 273 | graph()->NewNode(&kOp0, v0, graph()->start(), graph()->start()); |
| 274 | Node* const c1 = graph()->NewNode(common()->Dead()); |
| 275 | Node* const e0 = graph()->NewNode(&kOp0, v0, graph()->start(), c0); |
| 276 | Node* const e1 = graph()->NewNode(&kOp0, v1, graph()->start(), c1); |
| 277 | Node* const loop = graph()->NewNode(common()->Loop(2), c0, c1); |
| 278 | Node* const phi = graph()->NewNode( |
| 279 | common()->Phi(MachineRepresentation::kTagged, 2), v0, v1, loop); |
| 280 | Node* const ephi = graph()->NewNode(common()->EffectPhi(2), e0, e1, loop); |
| 281 | Node* const terminate = graph()->NewNode(common()->Terminate(), ephi, loop); |
| 282 | StrictMock<MockAdvancedReducerEditor> editor; |
| 283 | EXPECT_CALL(editor, Replace(phi, v0)); |
| 284 | EXPECT_CALL(editor, Replace(ephi, e0)); |
| 285 | EXPECT_CALL(editor, Replace(terminate, IsDead())); |
| 286 | Reduction const r = Reduce(&editor, loop); |
| 287 | ASSERT_TRUE(r.Changed()); |
| 288 | EXPECT_EQ(c0, r.replacement()); |
| 289 | } |
| 290 | |
| 291 | |
| 292 | TEST_F(DeadCodeEliminationTest, LoopWithTwoLiveAndTwoDeadInputs) { |
| 293 | Node* const v0 = Parameter(0); |
| 294 | Node* const v1 = Parameter(1); |
| 295 | Node* const v2 = Parameter(2); |
| 296 | Node* const v3 = Parameter(3); |
| 297 | Node* const c0 = |
| 298 | graph()->NewNode(&kOp0, v0, graph()->start(), graph()->start()); |
| 299 | Node* const c1 = graph()->NewNode(common()->Dead()); |
| 300 | Node* const c2 = graph()->NewNode(common()->Dead()); |
| 301 | Node* const c3 = graph()->NewNode(&kOp0, v3, graph()->start(), c0); |
| 302 | Node* const e0 = graph()->start(); |
| 303 | Node* const e1 = graph()->NewNode(&kOp0, v1, e0, c0); |
| 304 | Node* const e2 = graph()->NewNode(&kOp0, v2, e1, c0); |
| 305 | Node* const e3 = graph()->NewNode(&kOp0, v3, graph()->start(), c3); |
| 306 | Node* const loop = graph()->NewNode(common()->Loop(4), c0, c1, c2, c3); |
| 307 | Node* const phi = graph()->NewNode( |
| 308 | common()->Phi(MachineRepresentation::kTagged, 4), v0, v1, v2, v3, loop); |
| 309 | Node* const ephi = |
| 310 | graph()->NewNode(common()->EffectPhi(4), e0, e1, e2, e3, loop); |
| 311 | StrictMock<MockAdvancedReducerEditor> editor; |
| 312 | EXPECT_CALL(editor, Revisit(phi)); |
| 313 | EXPECT_CALL(editor, Revisit(ephi)); |
| 314 | Reduction const r = Reduce(&editor, loop); |
| 315 | ASSERT_TRUE(r.Changed()); |
| 316 | EXPECT_THAT(r.replacement(), IsLoop(c0, c3)); |
| 317 | EXPECT_THAT(phi, |
| 318 | IsPhi(MachineRepresentation::kTagged, v0, v3, r.replacement())); |
| 319 | EXPECT_THAT(ephi, IsEffectPhi(e0, e3, r.replacement())); |
| 320 | } |
| 321 | |
| 322 | |
| 323 | // ----------------------------------------------------------------------------- |
| 324 | // Phi |
| 325 | |
| 326 | |
| 327 | TEST_F(DeadCodeEliminationTest, PhiWithDeadControlInput) { |
| 328 | Node* inputs[kMaxInputs + 1]; |
| 329 | TRACED_FOREACH(MachineRepresentation, rep, kMachineRepresentations) { |
| 330 | TRACED_FORRANGE(int, input_count, 1, kMaxInputs) { |
| 331 | for (int i = 0; i < input_count; ++i) { |
| 332 | inputs[i] = Parameter(i); |
| 333 | } |
| 334 | inputs[input_count] = graph()->NewNode(common()->Dead()); |
| 335 | Reduction const r = Reduce(graph()->NewNode( |
| 336 | common()->Phi(rep, input_count), input_count + 1, inputs)); |
| 337 | ASSERT_TRUE(r.Changed()); |
| 338 | EXPECT_THAT(r.replacement(), IsDead()); |
| 339 | } |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | |
| 344 | // ----------------------------------------------------------------------------- |
| 345 | // EffectPhi |
| 346 | |
| 347 | |
| 348 | TEST_F(DeadCodeEliminationTest, EffectPhiWithDeadControlInput) { |
| 349 | Node* inputs[kMaxInputs + 1]; |
| 350 | TRACED_FORRANGE(int, input_count, 1, kMaxInputs) { |
| 351 | for (int i = 0; i < input_count; ++i) { |
| 352 | inputs[i] = graph()->start(); |
| 353 | } |
| 354 | inputs[input_count] = graph()->NewNode(common()->Dead()); |
| 355 | Reduction const r = Reduce(graph()->NewNode( |
| 356 | common()->EffectPhi(input_count), input_count + 1, inputs)); |
| 357 | ASSERT_TRUE(r.Changed()); |
| 358 | EXPECT_THAT(r.replacement(), IsDead()); |
| 359 | } |
| 360 | } |
| 361 | |
| 362 | |
| 363 | // ----------------------------------------------------------------------------- |
| 364 | // Terminate |
| 365 | |
| 366 | |
| 367 | TEST_F(DeadCodeEliminationTest, TerminateWithDeadControlInput) { |
| 368 | Reduction const r = |
| 369 | Reduce(graph()->NewNode(common()->Terminate(), graph()->start(), |
| 370 | graph()->NewNode(common()->Dead()))); |
| 371 | ASSERT_TRUE(r.Changed()); |
| 372 | EXPECT_THAT(r.replacement(), IsDead()); |
| 373 | } |
| 374 | |
| 375 | } // namespace compiler |
| 376 | } // namespace internal |
| 377 | } // namespace v8 |