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| 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/base/platform/elapsed-timer.h" |
| 6 #include "src/signature.h" |
| 7 |
| 8 #include "src/flags.h" |
| 9 #include "src/handles.h" |
| 10 #include "src/zone-containers.h" |
| 11 |
| 12 #include "src/wasm/ast-decoder.h" |
| 13 #include "src/wasm/decoder.h" |
| 14 #include "src/wasm/wasm-module.h" |
| 15 #include "src/wasm/wasm-opcodes.h" |
| 16 |
| 17 #include "src/compiler/wasm-compiler.h" |
| 18 |
| 19 namespace v8 { |
| 20 namespace internal { |
| 21 namespace wasm { |
| 22 |
| 23 #if DEBUG |
| 24 #define TRACE(...) \ |
| 25 do { \ |
| 26 if (FLAG_trace_wasm_decoder) PrintF(__VA_ARGS__); \ |
| 27 } while (false) |
| 28 #else |
| 29 #define TRACE(...) |
| 30 #endif |
| 31 |
| 32 // The root of a decoded tree. |
| 33 struct Tree { |
| 34 LocalType type; // tree type. |
| 35 uint32_t count; // number of children. |
| 36 const byte* pc; // start of the syntax tree. |
| 37 TFNode* node; // node in the TurboFan graph. |
| 38 Tree* children[1]; // pointers to children. |
| 39 |
| 40 WasmOpcode opcode() const { return static_cast<WasmOpcode>(*pc); } |
| 41 }; |
| 42 |
| 43 |
| 44 // A production represents an incomplete decoded tree in the LR decoder. |
| 45 struct Production { |
| 46 Tree* tree; // the root of the syntax tree. |
| 47 int index; // the current index into the children of the tree. |
| 48 |
| 49 WasmOpcode opcode() const { return static_cast<WasmOpcode>(*pc()); } |
| 50 const byte* pc() const { return tree->pc; } |
| 51 bool done() const { return index >= tree->count; } |
| 52 Tree* last() const { return index > 0 ? tree->children[index - 1] : nullptr; } |
| 53 }; |
| 54 |
| 55 |
| 56 // An SsaEnv environment carries the current local variable renaming |
| 57 // as well as the current effect and control dependency in the TF graph. |
| 58 // It maintains a control state that tracks whether the environment |
| 59 // is reachable, has reached a control end, or has been merged. |
| 60 struct SsaEnv { |
| 61 enum State { kControlEnd, kUnreachable, kReached, kMerged }; |
| 62 |
| 63 State state; |
| 64 TFNode* control; |
| 65 TFNode* effect; |
| 66 TFNode** locals; |
| 67 |
| 68 bool go() { return state >= kReached; } |
| 69 void Kill(State new_state = kControlEnd) { |
| 70 state = new_state; |
| 71 locals = nullptr; |
| 72 control = nullptr; |
| 73 effect = nullptr; |
| 74 } |
| 75 }; |
| 76 |
| 77 |
| 78 // An entry in the stack of blocks during decoding. |
| 79 struct Block { |
| 80 SsaEnv* ssa_env; // SSA renaming environment. |
| 81 int stack_depth; // production stack depth. |
| 82 }; |
| 83 |
| 84 |
| 85 // An entry in the stack of ifs during decoding. |
| 86 struct IfEnv { |
| 87 SsaEnv* false_env; |
| 88 SsaEnv* merge_env; |
| 89 SsaEnv** case_envs; |
| 90 }; |
| 91 |
| 92 |
| 93 // Macros that build nodes only if there is a graph and the current SSA |
| 94 // environment is reachable from start. This avoids problems with malformed |
| 95 // TF graphs when decoding inputs that have unreachable code. |
| 96 #define BUILD(func, ...) (build() ? builder_->func(__VA_ARGS__) : nullptr) |
| 97 #define BUILD0(func) (build() ? builder_->func() : nullptr) |
| 98 |
| 99 |
| 100 // A shift-reduce-parser strategy for decoding Wasm code that uses an explicit |
| 101 // shift-reduce strategy with multiple internal stacks. |
| 102 class LR_WasmDecoder : public Decoder { |
| 103 public: |
| 104 LR_WasmDecoder(Zone* zone, TFBuilder* builder) |
| 105 : Decoder(nullptr, nullptr), |
| 106 zone_(zone), |
| 107 builder_(builder), |
| 108 trees_(zone), |
| 109 stack_(zone), |
| 110 blocks_(zone), |
| 111 ifs_(zone) {} |
| 112 |
| 113 TreeResult Decode(FunctionEnv* function_env, const byte* base, const byte* pc, |
| 114 const byte* end) { |
| 115 base::ElapsedTimer decode_timer; |
| 116 if (FLAG_trace_wasm_decode_time) { |
| 117 decode_timer.Start(); |
| 118 } |
| 119 trees_.clear(); |
| 120 stack_.clear(); |
| 121 blocks_.clear(); |
| 122 ifs_.clear(); |
| 123 |
| 124 if (end < pc) { |
| 125 error(pc, "function body end < start"); |
| 126 return result_; |
| 127 } |
| 128 |
| 129 base_ = base; |
| 130 Reset(pc, end); |
| 131 function_env_ = function_env; |
| 132 |
| 133 InitSsaEnv(); |
| 134 DecodeFunctionBody(); |
| 135 |
| 136 Tree* tree = nullptr; |
| 137 if (ok()) { |
| 138 if (ssa_env_->go()) { |
| 139 if (stack_.size() > 0) { |
| 140 error(stack_.back().pc(), end, "fell off end of code"); |
| 141 } |
| 142 AddImplicitReturnAtEnd(); |
| 143 } |
| 144 if (trees_.size() == 0) { |
| 145 if (function_env_->sig->return_count() > 0) { |
| 146 error(start_, "no trees created"); |
| 147 } |
| 148 } else { |
| 149 tree = trees_[0]; |
| 150 } |
| 151 } |
| 152 |
| 153 if (ok()) { |
| 154 if (FLAG_trace_wasm_decode_time) { |
| 155 double ms = decode_timer.Elapsed().InMillisecondsF(); |
| 156 PrintF(" - decoding took %0.3f ms\n", ms); |
| 157 } |
| 158 TRACE("wasm-decode ok\n\n"); |
| 159 } else { |
| 160 TRACE("wasm-error module+%-6d func+%d: %s\n\n", baserel(error_pc_), |
| 161 startrel(error_pc_), error_msg_.get()); |
| 162 } |
| 163 return toResult(tree); |
| 164 } |
| 165 |
| 166 private: |
| 167 static const size_t kErrorMsgSize = 128; |
| 168 |
| 169 Zone* zone_; |
| 170 TFBuilder* builder_; |
| 171 const byte* base_; |
| 172 TreeResult result_; |
| 173 |
| 174 SsaEnv* ssa_env_; |
| 175 FunctionEnv* function_env_; |
| 176 |
| 177 ZoneVector<Tree*> trees_; |
| 178 ZoneVector<Production> stack_; |
| 179 ZoneVector<Block> blocks_; |
| 180 ZoneVector<IfEnv> ifs_; |
| 181 |
| 182 inline bool build() { return builder_ && ssa_env_->go(); } |
| 183 |
| 184 void InitSsaEnv() { |
| 185 FunctionSig* sig = function_env_->sig; |
| 186 int param_count = static_cast<int>(sig->parameter_count()); |
| 187 TFNode* start = nullptr; |
| 188 SsaEnv* ssa_env = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| 189 size_t size = sizeof(TFNode*) * EnvironmentCount(); |
| 190 ssa_env->state = SsaEnv::kReached; |
| 191 ssa_env->locals = |
| 192 size > 0 ? reinterpret_cast<TFNode**>(zone_->New(size)) : nullptr; |
| 193 |
| 194 int pos = 0; |
| 195 if (builder_) { |
| 196 start = builder_->Start(param_count + 1); |
| 197 // Initialize parameters. |
| 198 for (int i = 0; i < param_count; i++) { |
| 199 ssa_env->locals[pos++] = builder_->Param(i, sig->GetParam(i)); |
| 200 } |
| 201 // Initialize int32 locals. |
| 202 if (function_env_->local_int32_count > 0) { |
| 203 TFNode* zero = builder_->Int32Constant(0); |
| 204 for (uint32_t i = 0; i < function_env_->local_int32_count; i++) { |
| 205 ssa_env->locals[pos++] = zero; |
| 206 } |
| 207 } |
| 208 // Initialize int64 locals. |
| 209 if (function_env_->local_int64_count > 0) { |
| 210 TFNode* zero = builder_->Int64Constant(0); |
| 211 for (uint32_t i = 0; i < function_env_->local_int64_count; i++) { |
| 212 ssa_env->locals[pos++] = zero; |
| 213 } |
| 214 } |
| 215 // Initialize float32 locals. |
| 216 if (function_env_->local_float32_count > 0) { |
| 217 TFNode* zero = builder_->Float32Constant(0); |
| 218 for (uint32_t i = 0; i < function_env_->local_float32_count; i++) { |
| 219 ssa_env->locals[pos++] = zero; |
| 220 } |
| 221 } |
| 222 // Initialize float64 locals. |
| 223 if (function_env_->local_float64_count > 0) { |
| 224 TFNode* zero = builder_->Float64Constant(0); |
| 225 for (uint32_t i = 0; i < function_env_->local_float64_count; i++) { |
| 226 ssa_env->locals[pos++] = zero; |
| 227 } |
| 228 } |
| 229 DCHECK_EQ(function_env_->total_locals, pos); |
| 230 DCHECK_EQ(EnvironmentCount(), pos); |
| 231 builder_->set_module(function_env_->module); |
| 232 } |
| 233 ssa_env->control = start; |
| 234 ssa_env->effect = start; |
| 235 SetEnv("initial", ssa_env); |
| 236 } |
| 237 |
| 238 void Leaf(LocalType type, TFNode* node = nullptr) { |
| 239 size_t size = sizeof(Tree); |
| 240 Tree* tree = reinterpret_cast<Tree*>(zone_->New(size)); |
| 241 tree->type = type; |
| 242 tree->count = 0; |
| 243 tree->pc = pc_; |
| 244 tree->node = node; |
| 245 tree->children[0] = nullptr; |
| 246 Reduce(tree); |
| 247 } |
| 248 |
| 249 void Shift(LocalType type, uint32_t count) { |
| 250 size_t size = |
| 251 sizeof(Tree) + (count == 0 ? 0 : ((count - 1) * sizeof(Tree*))); |
| 252 Tree* tree = reinterpret_cast<Tree*>(zone_->New(size)); |
| 253 tree->type = type; |
| 254 tree->count = count; |
| 255 tree->pc = pc_; |
| 256 tree->node = nullptr; |
| 257 for (uint32_t i = 0; i < count; i++) tree->children[i] = nullptr; |
| 258 if (count == 0) { |
| 259 Production p = {tree, 0}; |
| 260 Reduce(&p); |
| 261 Reduce(tree); |
| 262 } else { |
| 263 stack_.push_back({tree, 0}); |
| 264 } |
| 265 } |
| 266 |
| 267 void Reduce(Tree* tree) { |
| 268 while (true) { |
| 269 if (stack_.size() == 0) { |
| 270 trees_.push_back(tree); |
| 271 break; |
| 272 } |
| 273 Production* p = &stack_.back(); |
| 274 p->tree->children[p->index++] = tree; |
| 275 Reduce(p); |
| 276 if (p->done()) { |
| 277 tree = p->tree; |
| 278 stack_.pop_back(); |
| 279 } else { |
| 280 break; |
| 281 } |
| 282 } |
| 283 } |
| 284 |
| 285 char* indentation() { |
| 286 static const int kMaxIndent = 64; |
| 287 static char bytes[kMaxIndent + 1]; |
| 288 for (int i = 0; i < kMaxIndent; i++) bytes[i] = ' '; |
| 289 bytes[kMaxIndent] = 0; |
| 290 if (stack_.size() < kMaxIndent / 2) { |
| 291 bytes[stack_.size() * 2] = 0; |
| 292 } |
| 293 return bytes; |
| 294 } |
| 295 |
| 296 // Decodes the body of a function, producing reduced trees into {result}. |
| 297 void DecodeFunctionBody() { |
| 298 TRACE("wasm-decode %p...%p (%d bytes) %s\n", |
| 299 reinterpret_cast<const void*>(start_), |
| 300 reinterpret_cast<const void*>(limit_), |
| 301 static_cast<int>(limit_ - start_), builder_ ? "graph building" : ""); |
| 302 |
| 303 if (pc_ >= limit_) return; // Nothing to do. |
| 304 |
| 305 while (true) { // decoding loop. |
| 306 int len = 1; |
| 307 WasmOpcode opcode = static_cast<WasmOpcode>(*pc_); |
| 308 TRACE("wasm-decode module+%-6d %s func+%d: 0x%02x %s\n", baserel(pc_), |
| 309 indentation(), startrel(pc_), opcode, |
| 310 WasmOpcodes::OpcodeName(opcode)); |
| 311 |
| 312 FunctionSig* sig = WasmOpcodes::Signature(opcode); |
| 313 if (sig) { |
| 314 // A simple expression with a fixed signature. |
| 315 Shift(sig->GetReturn(), static_cast<uint32_t>(sig->parameter_count())); |
| 316 pc_ += len; |
| 317 if (pc_ >= limit_) { |
| 318 // End of code reached or exceeded. |
| 319 if (pc_ > limit_ && ok()) { |
| 320 error("Beyond end of code"); |
| 321 } |
| 322 return; |
| 323 } |
| 324 continue; // back to decoding loop. |
| 325 } |
| 326 |
| 327 switch (opcode) { |
| 328 case kExprNop: |
| 329 Leaf(kAstStmt); |
| 330 break; |
| 331 case kExprBlock: { |
| 332 int length = Operand<uint8_t>(pc_); |
| 333 if (length < 1) { |
| 334 Leaf(kAstStmt); |
| 335 } else { |
| 336 Shift(kAstEnd, length); |
| 337 // The break environment is the outer environment. |
| 338 SsaEnv* break_env = ssa_env_; |
| 339 PushBlock(break_env); |
| 340 SetEnv("block:start", Steal(break_env)); |
| 341 } |
| 342 len = 2; |
| 343 break; |
| 344 } |
| 345 case kExprLoop: { |
| 346 int length = Operand<uint8_t>(pc_); |
| 347 if (length < 1) { |
| 348 Leaf(kAstStmt); |
| 349 } else { |
| 350 Shift(kAstEnd, length); |
| 351 // The break environment is the outer environment. |
| 352 SsaEnv* break_env = ssa_env_; |
| 353 PushBlock(break_env); |
| 354 SsaEnv* cont_env = Steal(break_env); |
| 355 // The continue environment is the inner environment. |
| 356 PrepareForLoop(cont_env); |
| 357 SetEnv("loop:start", Split(cont_env)); |
| 358 if (ssa_env_->go()) ssa_env_->state = SsaEnv::kReached; |
| 359 PushBlock(cont_env); |
| 360 blocks_.back().stack_depth = -1; // no production for inner block. |
| 361 } |
| 362 len = 2; |
| 363 break; |
| 364 } |
| 365 case kExprIf: |
| 366 Shift(kAstStmt, 2); |
| 367 break; |
| 368 case kExprIfElse: |
| 369 Shift(kAstEnd, 3); // Result type is typeof(x) in {c ? x : y}. |
| 370 break; |
| 371 case kExprSelect: |
| 372 Shift(kAstStmt, 3); // Result type is typeof(x) in {c ? x : y}. |
| 373 break; |
| 374 case kExprBr: { |
| 375 uint32_t depth = Operand<uint8_t>(pc_); |
| 376 Shift(kAstEnd, 1); |
| 377 if (depth >= blocks_.size()) { |
| 378 error("improperly nested branch"); |
| 379 } |
| 380 len = 2; |
| 381 break; |
| 382 } |
| 383 case kExprBrIf: { |
| 384 uint32_t depth = Operand<uint8_t>(pc_); |
| 385 Shift(kAstStmt, 2); |
| 386 if (depth >= blocks_.size()) { |
| 387 error("improperly nested conditional branch"); |
| 388 } |
| 389 len = 2; |
| 390 break; |
| 391 } |
| 392 case kExprTableSwitch: { |
| 393 if (!checkAvailable(5)) { |
| 394 error("expected #tableswitch <cases> <table>, fell off end"); |
| 395 break; |
| 396 } |
| 397 uint16_t case_count = *reinterpret_cast<const uint16_t*>(pc_ + 1); |
| 398 uint16_t table_count = *reinterpret_cast<const uint16_t*>(pc_ + 3); |
| 399 len = 5 + table_count * 2; |
| 400 |
| 401 if (table_count == 0) { |
| 402 error("tableswitch with 0 entries"); |
| 403 break; |
| 404 } |
| 405 |
| 406 if (!checkAvailable(len)) { |
| 407 error("expected #tableswitch <cases> <table>, fell off end"); |
| 408 break; |
| 409 } |
| 410 |
| 411 Shift(kAstEnd, 1 + case_count); |
| 412 |
| 413 // Verify table. |
| 414 for (int i = 0; i < table_count; i++) { |
| 415 uint16_t target = |
| 416 *reinterpret_cast<const uint16_t*>(pc_ + 5 + i * 2); |
| 417 if (target >= 0x8000) { |
| 418 size_t depth = target - 0x8000; |
| 419 if (depth > blocks_.size()) { |
| 420 error(pc_ + 5 + i * 2, "improper branch in tableswitch"); |
| 421 } |
| 422 } else { |
| 423 if (target >= case_count) { |
| 424 error(pc_ + 5 + i * 2, "invalid case target in tableswitch"); |
| 425 } |
| 426 } |
| 427 } |
| 428 break; |
| 429 } |
| 430 case kExprReturn: { |
| 431 int count = static_cast<int>(function_env_->sig->return_count()); |
| 432 if (count == 0) { |
| 433 BUILD(Return, 0, builder_->Buffer(0)); |
| 434 ssa_env_->Kill(); |
| 435 Leaf(kAstEnd); |
| 436 } else { |
| 437 Shift(kAstEnd, count); |
| 438 } |
| 439 break; |
| 440 } |
| 441 case kExprUnreachable: { |
| 442 BUILD0(Unreachable); |
| 443 ssa_env_->Kill(SsaEnv::kControlEnd); |
| 444 Leaf(kAstEnd, nullptr); |
| 445 break; |
| 446 } |
| 447 case kExprI8Const: { |
| 448 int32_t value = Operand<int8_t>(pc_); |
| 449 Leaf(kAstI32, BUILD(Int32Constant, value)); |
| 450 len = 2; |
| 451 break; |
| 452 } |
| 453 case kExprI32Const: { |
| 454 int32_t value = Operand<int32_t>(pc_); |
| 455 Leaf(kAstI32, BUILD(Int32Constant, value)); |
| 456 len = 5; |
| 457 break; |
| 458 } |
| 459 case kExprI64Const: { |
| 460 int64_t value = Operand<int64_t>(pc_); |
| 461 Leaf(kAstI64, BUILD(Int64Constant, value)); |
| 462 len = 9; |
| 463 break; |
| 464 } |
| 465 case kExprF32Const: { |
| 466 float value = Operand<float>(pc_); |
| 467 Leaf(kAstF32, BUILD(Float32Constant, value)); |
| 468 len = 5; |
| 469 break; |
| 470 } |
| 471 case kExprF64Const: { |
| 472 double value = Operand<double>(pc_); |
| 473 Leaf(kAstF64, BUILD(Float64Constant, value)); |
| 474 len = 9; |
| 475 break; |
| 476 } |
| 477 case kExprGetLocal: { |
| 478 uint32_t index; |
| 479 LocalType type = LocalOperand(pc_, &index, &len); |
| 480 TFNode* val = |
| 481 build() && type != kAstStmt ? ssa_env_->locals[index] : nullptr; |
| 482 Leaf(type, val); |
| 483 break; |
| 484 } |
| 485 case kExprSetLocal: { |
| 486 uint32_t index; |
| 487 LocalType type = LocalOperand(pc_, &index, &len); |
| 488 Shift(type, 1); |
| 489 break; |
| 490 } |
| 491 case kExprLoadGlobal: { |
| 492 uint32_t index; |
| 493 LocalType type = GlobalOperand(pc_, &index, &len); |
| 494 Leaf(type, BUILD(LoadGlobal, index)); |
| 495 break; |
| 496 } |
| 497 case kExprStoreGlobal: { |
| 498 uint32_t index; |
| 499 LocalType type = GlobalOperand(pc_, &index, &len); |
| 500 Shift(type, 1); |
| 501 break; |
| 502 } |
| 503 case kExprI32LoadMem8S: |
| 504 case kExprI32LoadMem8U: |
| 505 case kExprI32LoadMem16S: |
| 506 case kExprI32LoadMem16U: |
| 507 case kExprI32LoadMem: |
| 508 len = DecodeLoadMem(pc_, kAstI32); |
| 509 break; |
| 510 case kExprI64LoadMem8S: |
| 511 case kExprI64LoadMem8U: |
| 512 case kExprI64LoadMem16S: |
| 513 case kExprI64LoadMem16U: |
| 514 case kExprI64LoadMem32S: |
| 515 case kExprI64LoadMem32U: |
| 516 case kExprI64LoadMem: |
| 517 len = DecodeLoadMem(pc_, kAstI64); |
| 518 break; |
| 519 case kExprF32LoadMem: |
| 520 len = DecodeLoadMem(pc_, kAstF32); |
| 521 break; |
| 522 case kExprF64LoadMem: |
| 523 len = DecodeLoadMem(pc_, kAstF64); |
| 524 break; |
| 525 case kExprI32StoreMem8: |
| 526 case kExprI32StoreMem16: |
| 527 case kExprI32StoreMem: |
| 528 len = DecodeStoreMem(pc_, kAstI32); |
| 529 break; |
| 530 case kExprI64StoreMem8: |
| 531 case kExprI64StoreMem16: |
| 532 case kExprI64StoreMem32: |
| 533 case kExprI64StoreMem: |
| 534 len = DecodeStoreMem(pc_, kAstI64); |
| 535 break; |
| 536 case kExprF32StoreMem: |
| 537 len = DecodeStoreMem(pc_, kAstF32); |
| 538 break; |
| 539 case kExprF64StoreMem: |
| 540 len = DecodeStoreMem(pc_, kAstF64); |
| 541 break; |
| 542 case kExprMemorySize: |
| 543 Leaf(kAstI32, BUILD(MemSize, 0)); |
| 544 break; |
| 545 case kExprGrowMemory: |
| 546 Shift(kAstI32, 1); |
| 547 break; |
| 548 case kExprCallFunction: { |
| 549 uint32_t unused; |
| 550 FunctionSig* sig = FunctionSigOperand(pc_, &unused, &len); |
| 551 if (sig) { |
| 552 LocalType type = |
| 553 sig->return_count() == 0 ? kAstStmt : sig->GetReturn(); |
| 554 Shift(type, static_cast<int>(sig->parameter_count())); |
| 555 } else { |
| 556 Leaf(kAstI32); // error |
| 557 } |
| 558 break; |
| 559 } |
| 560 case kExprCallIndirect: { |
| 561 uint32_t unused; |
| 562 FunctionSig* sig = SigOperand(pc_, &unused, &len); |
| 563 if (sig) { |
| 564 LocalType type = |
| 565 sig->return_count() == 0 ? kAstStmt : sig->GetReturn(); |
| 566 Shift(type, static_cast<int>(1 + sig->parameter_count())); |
| 567 } else { |
| 568 Leaf(kAstI32); // error |
| 569 } |
| 570 break; |
| 571 } |
| 572 default: |
| 573 error("Invalid opcode"); |
| 574 return; |
| 575 } |
| 576 pc_ += len; |
| 577 if (pc_ >= limit_) { |
| 578 // End of code reached or exceeded. |
| 579 if (pc_ > limit_ && ok()) { |
| 580 error("Beyond end of code"); |
| 581 } |
| 582 return; |
| 583 } |
| 584 } |
| 585 } |
| 586 |
| 587 void PushBlock(SsaEnv* ssa_env) { |
| 588 blocks_.push_back({ssa_env, static_cast<int>(stack_.size() - 1)}); |
| 589 } |
| 590 |
| 591 int DecodeLoadMem(const byte* pc, LocalType type) { |
| 592 int length = 2; |
| 593 uint32_t offset; |
| 594 MemoryAccessOperand(pc, &length, &offset); |
| 595 Shift(type, 1); |
| 596 return length; |
| 597 } |
| 598 |
| 599 int DecodeStoreMem(const byte* pc, LocalType type) { |
| 600 int length = 2; |
| 601 uint32_t offset; |
| 602 MemoryAccessOperand(pc, &length, &offset); |
| 603 Shift(type, 2); |
| 604 return length; |
| 605 } |
| 606 |
| 607 void AddImplicitReturnAtEnd() { |
| 608 int retcount = static_cast<int>(function_env_->sig->return_count()); |
| 609 if (retcount == 0) { |
| 610 BUILD0(ReturnVoid); |
| 611 return; |
| 612 } |
| 613 |
| 614 if (trees_.size() < retcount) { |
| 615 error(limit_, nullptr, |
| 616 "ImplicitReturn expects %d arguments, only %d remain", retcount, |
| 617 static_cast<int>(trees_.size())); |
| 618 return; |
| 619 } |
| 620 |
| 621 TRACE("wasm-decode implicit return of %d args\n", retcount); |
| 622 |
| 623 TFNode** buffer = BUILD(Buffer, retcount); |
| 624 for (int index = 0; index < retcount; index++) { |
| 625 Tree* tree = trees_[trees_.size() - 1 - index]; |
| 626 if (buffer) buffer[index] = tree->node; |
| 627 LocalType expected = function_env_->sig->GetReturn(index); |
| 628 if (tree->type != expected) { |
| 629 error(limit_, tree->pc, |
| 630 "ImplicitReturn[%d] expected type %s, found %s of type %s", index, |
| 631 WasmOpcodes::TypeName(expected), |
| 632 WasmOpcodes::OpcodeName(tree->opcode()), |
| 633 WasmOpcodes::TypeName(tree->type)); |
| 634 return; |
| 635 } |
| 636 } |
| 637 |
| 638 BUILD(Return, retcount, buffer); |
| 639 } |
| 640 |
| 641 int baserel(const byte* ptr) { |
| 642 return base_ ? static_cast<int>(ptr - base_) : 0; |
| 643 } |
| 644 |
| 645 int startrel(const byte* ptr) { return static_cast<int>(ptr - start_); } |
| 646 |
| 647 void Reduce(Production* p) { |
| 648 WasmOpcode opcode = p->opcode(); |
| 649 TRACE("-----reduce module+%-6d %s func+%d: 0x%02x %s\n", baserel(p->pc()), |
| 650 indentation(), startrel(p->pc()), opcode, |
| 651 WasmOpcodes::OpcodeName(opcode)); |
| 652 FunctionSig* sig = WasmOpcodes::Signature(opcode); |
| 653 if (sig) { |
| 654 // A simple expression with a fixed signature. |
| 655 TypeCheckLast(p, sig->GetParam(p->index - 1)); |
| 656 if (p->done() && build()) { |
| 657 if (sig->parameter_count() == 2) { |
| 658 p->tree->node = builder_->Binop(opcode, p->tree->children[0]->node, |
| 659 p->tree->children[1]->node); |
| 660 } else if (sig->parameter_count() == 1) { |
| 661 p->tree->node = builder_->Unop(opcode, p->tree->children[0]->node); |
| 662 } else { |
| 663 UNREACHABLE(); |
| 664 } |
| 665 } |
| 666 return; |
| 667 } |
| 668 |
| 669 switch (opcode) { |
| 670 case kExprBlock: { |
| 671 if (p->done()) { |
| 672 Block* last = &blocks_.back(); |
| 673 DCHECK_EQ(stack_.size() - 1, last->stack_depth); |
| 674 // fallthrough with the last expression. |
| 675 ReduceBreakToExprBlock(p, last); |
| 676 SetEnv("block:end", last->ssa_env); |
| 677 blocks_.pop_back(); |
| 678 } |
| 679 break; |
| 680 } |
| 681 case kExprLoop: { |
| 682 if (p->done()) { |
| 683 // Pop the continue environment. |
| 684 blocks_.pop_back(); |
| 685 // Get the break environment. |
| 686 Block* last = &blocks_.back(); |
| 687 DCHECK_EQ(stack_.size() - 1, last->stack_depth); |
| 688 // fallthrough with the last expression. |
| 689 ReduceBreakToExprBlock(p, last); |
| 690 SetEnv("loop:end", last->ssa_env); |
| 691 blocks_.pop_back(); |
| 692 } |
| 693 break; |
| 694 } |
| 695 case kExprIf: { |
| 696 if (p->index == 1) { |
| 697 // Condition done. Split environment for true branch. |
| 698 TypeCheckLast(p, kAstI32); |
| 699 SsaEnv* false_env = ssa_env_; |
| 700 SsaEnv* true_env = Split(ssa_env_); |
| 701 ifs_.push_back({nullptr, false_env, nullptr}); |
| 702 BUILD(Branch, p->last()->node, &true_env->control, |
| 703 &false_env->control); |
| 704 SetEnv("if:true", true_env); |
| 705 } else if (p->index == 2) { |
| 706 // True block done. Merge true and false environments. |
| 707 IfEnv* env = &ifs_.back(); |
| 708 SsaEnv* merge = env->merge_env; |
| 709 if (merge->go()) { |
| 710 merge->state = SsaEnv::kReached; |
| 711 Goto(ssa_env_, merge); |
| 712 } |
| 713 SetEnv("if:merge", merge); |
| 714 ifs_.pop_back(); |
| 715 } |
| 716 break; |
| 717 } |
| 718 case kExprIfElse: { |
| 719 if (p->index == 1) { |
| 720 // Condition done. Split environment for true and false branches. |
| 721 TypeCheckLast(p, kAstI32); |
| 722 SsaEnv* merge_env = ssa_env_; |
| 723 TFNode* if_true = nullptr; |
| 724 TFNode* if_false = nullptr; |
| 725 BUILD(Branch, p->last()->node, &if_true, &if_false); |
| 726 SsaEnv* false_env = Split(ssa_env_); |
| 727 SsaEnv* true_env = Steal(ssa_env_); |
| 728 false_env->control = if_false; |
| 729 true_env->control = if_true; |
| 730 ifs_.push_back({false_env, merge_env, nullptr}); |
| 731 SetEnv("if_else:true", true_env); |
| 732 } else if (p->index == 2) { |
| 733 // True expr done. |
| 734 IfEnv* env = &ifs_.back(); |
| 735 MergeIntoProduction(p, env->merge_env, p->last()); |
| 736 // Switch to environment for false branch. |
| 737 SsaEnv* false_env = ifs_.back().false_env; |
| 738 SetEnv("if_else:false", false_env); |
| 739 } else if (p->index == 3) { |
| 740 // False expr done. |
| 741 IfEnv* env = &ifs_.back(); |
| 742 MergeIntoProduction(p, env->merge_env, p->last()); |
| 743 SetEnv("if_else:merge", env->merge_env); |
| 744 ifs_.pop_back(); |
| 745 } |
| 746 break; |
| 747 } |
| 748 case kExprSelect: { |
| 749 if (p->index == 1) { |
| 750 // Condition done. |
| 751 TypeCheckLast(p, kAstI32); |
| 752 } else if (p->index == 2) { |
| 753 // True expression done. |
| 754 p->tree->type = p->last()->type; |
| 755 if (p->tree->type == kAstStmt) { |
| 756 error(p->pc(), p->tree->children[1]->pc, |
| 757 "select operand should be expression"); |
| 758 } |
| 759 } else { |
| 760 // False expression done. |
| 761 DCHECK(p->done()); |
| 762 TypeCheckLast(p, p->tree->type); |
| 763 if (build()) { |
| 764 TFNode* controls[2]; |
| 765 builder_->Branch(p->tree->children[0]->node, &controls[0], |
| 766 &controls[1]); |
| 767 TFNode* merge = builder_->Merge(2, controls); |
| 768 TFNode* vals[2] = {p->tree->children[1]->node, |
| 769 p->tree->children[2]->node}; |
| 770 TFNode* phi = builder_->Phi(p->tree->type, 2, vals, merge); |
| 771 p->tree->node = phi; |
| 772 ssa_env_->control = merge; |
| 773 } |
| 774 } |
| 775 break; |
| 776 } |
| 777 case kExprBr: { |
| 778 uint32_t depth = Operand<uint8_t>(p->pc()); |
| 779 if (depth >= blocks_.size()) { |
| 780 error("improperly nested branch"); |
| 781 break; |
| 782 } |
| 783 Block* block = &blocks_[blocks_.size() - depth - 1]; |
| 784 ReduceBreakToExprBlock(p, block); |
| 785 break; |
| 786 } |
| 787 case kExprBrIf: { |
| 788 if (p->index == 1) { |
| 789 TypeCheckLast(p, kAstI32); |
| 790 } else if (p->done()) { |
| 791 uint32_t depth = Operand<uint8_t>(p->pc()); |
| 792 if (depth >= blocks_.size()) { |
| 793 error("improperly nested branch"); |
| 794 break; |
| 795 } |
| 796 Block* block = &blocks_[blocks_.size() - depth - 1]; |
| 797 SsaEnv* fenv = ssa_env_; |
| 798 SsaEnv* tenv = Split(fenv); |
| 799 BUILD(Branch, p->tree->children[0]->node, &tenv->control, |
| 800 &fenv->control); |
| 801 ssa_env_ = tenv; |
| 802 ReduceBreakToExprBlock(p, block); |
| 803 ssa_env_ = fenv; |
| 804 } |
| 805 break; |
| 806 } |
| 807 case kExprTableSwitch: { |
| 808 uint16_t table_count = *reinterpret_cast<const uint16_t*>(p->pc() + 3); |
| 809 if (table_count == 1) { |
| 810 // Degenerate switch with only a default target. |
| 811 if (p->index == 1) { |
| 812 SsaEnv* break_env = ssa_env_; |
| 813 PushBlock(break_env); |
| 814 SetEnv("switch:default", Steal(break_env)); |
| 815 } |
| 816 if (p->done()) { |
| 817 Block* block = &blocks_.back(); |
| 818 // fall through to the end. |
| 819 ReduceBreakToExprBlock(p, block); |
| 820 SetEnv("switch:end", block->ssa_env); |
| 821 blocks_.pop_back(); |
| 822 } |
| 823 break; |
| 824 } |
| 825 |
| 826 if (p->index == 1) { |
| 827 // Switch key finished. |
| 828 TypeCheckLast(p, kAstI32); |
| 829 |
| 830 TFNode* sw = BUILD(Switch, table_count, p->last()->node); |
| 831 |
| 832 // Allocate environments for each case. |
| 833 uint16_t case_count = *reinterpret_cast<const uint16_t*>(p->pc() + 1); |
| 834 SsaEnv** case_envs = zone_->NewArray<SsaEnv*>(case_count); |
| 835 for (int i = 0; i < case_count; i++) { |
| 836 case_envs[i] = UnreachableEnv(); |
| 837 } |
| 838 |
| 839 ifs_.push_back({nullptr, nullptr, case_envs}); |
| 840 SsaEnv* break_env = ssa_env_; |
| 841 PushBlock(break_env); |
| 842 SsaEnv* copy = Steal(break_env); |
| 843 ssa_env_ = copy; |
| 844 |
| 845 // Build the environments for each case based on the table. |
| 846 const uint16_t* table = |
| 847 reinterpret_cast<const uint16_t*>(p->pc() + 5); |
| 848 for (int i = 0; i < table_count; i++) { |
| 849 uint16_t target = table[i]; |
| 850 SsaEnv* env = Split(copy); |
| 851 env->control = (i == table_count - 1) ? BUILD(IfDefault, sw) |
| 852 : BUILD(IfValue, i, sw); |
| 853 if (target >= 0x8000) { |
| 854 // Targets an outer block. |
| 855 int depth = target - 0x8000; |
| 856 SsaEnv* tenv = blocks_[blocks_.size() - depth - 1].ssa_env; |
| 857 Goto(env, tenv); |
| 858 } else { |
| 859 // Targets a case. |
| 860 Goto(env, case_envs[target]); |
| 861 } |
| 862 } |
| 863 |
| 864 // Switch to the environment for the first case. |
| 865 SetEnv("switch:case", case_envs[0]); |
| 866 } else { |
| 867 // Switch case finished. |
| 868 if (p->done()) { |
| 869 // Last case. Fall through to the end. |
| 870 Block* block = &blocks_.back(); |
| 871 ReduceBreakToExprBlock(p, block); |
| 872 SsaEnv* next = block->ssa_env; |
| 873 blocks_.pop_back(); |
| 874 ifs_.pop_back(); |
| 875 SetEnv("switch:end", next); |
| 876 } else { |
| 877 // Interior case. Maybe fall through to the next case. |
| 878 SsaEnv* next = ifs_.back().case_envs[p->index - 1]; |
| 879 if (ssa_env_->go()) Goto(ssa_env_, next); |
| 880 SetEnv("switch:case", next); |
| 881 } |
| 882 } |
| 883 break; |
| 884 } |
| 885 case kExprReturn: { |
| 886 TypeCheckLast(p, function_env_->sig->GetReturn(p->index - 1)); |
| 887 if (p->done()) { |
| 888 if (build()) { |
| 889 int count = p->tree->count; |
| 890 TFNode** buffer = builder_->Buffer(count); |
| 891 for (int i = 0; i < count; i++) { |
| 892 buffer[i] = p->tree->children[i]->node; |
| 893 } |
| 894 BUILD(Return, count, buffer); |
| 895 } |
| 896 ssa_env_->Kill(SsaEnv::kControlEnd); |
| 897 } |
| 898 break; |
| 899 } |
| 900 case kExprSetLocal: { |
| 901 int unused = 0; |
| 902 uint32_t index; |
| 903 LocalType type = LocalOperand(p->pc(), &index, &unused); |
| 904 Tree* val = p->last(); |
| 905 if (type == val->type) { |
| 906 if (builder_) ssa_env_->locals[index] = val->node; |
| 907 p->tree->node = val->node; |
| 908 } else { |
| 909 error(p->pc(), val->pc, "Typecheck failed in SetLocal"); |
| 910 } |
| 911 break; |
| 912 } |
| 913 case kExprStoreGlobal: { |
| 914 int unused = 0; |
| 915 uint32_t index; |
| 916 LocalType type = GlobalOperand(p->pc(), &index, &unused); |
| 917 Tree* val = p->last(); |
| 918 if (type == val->type) { |
| 919 BUILD(StoreGlobal, index, val->node); |
| 920 p->tree->node = val->node; |
| 921 } else { |
| 922 error(p->pc(), val->pc, "Typecheck failed in StoreGlobal"); |
| 923 } |
| 924 break; |
| 925 } |
| 926 |
| 927 case kExprI32LoadMem8S: |
| 928 return ReduceLoadMem(p, kAstI32, MachineType::Int8()); |
| 929 case kExprI32LoadMem8U: |
| 930 return ReduceLoadMem(p, kAstI32, MachineType::Uint8()); |
| 931 case kExprI32LoadMem16S: |
| 932 return ReduceLoadMem(p, kAstI32, MachineType::Int16()); |
| 933 case kExprI32LoadMem16U: |
| 934 return ReduceLoadMem(p, kAstI32, MachineType::Uint16()); |
| 935 case kExprI32LoadMem: |
| 936 return ReduceLoadMem(p, kAstI32, MachineType::Int32()); |
| 937 |
| 938 case kExprI64LoadMem8S: |
| 939 return ReduceLoadMem(p, kAstI64, MachineType::Int8()); |
| 940 case kExprI64LoadMem8U: |
| 941 return ReduceLoadMem(p, kAstI64, MachineType::Uint8()); |
| 942 case kExprI64LoadMem16S: |
| 943 return ReduceLoadMem(p, kAstI64, MachineType::Int16()); |
| 944 case kExprI64LoadMem16U: |
| 945 return ReduceLoadMem(p, kAstI64, MachineType::Uint16()); |
| 946 case kExprI64LoadMem32S: |
| 947 return ReduceLoadMem(p, kAstI64, MachineType::Int32()); |
| 948 case kExprI64LoadMem32U: |
| 949 return ReduceLoadMem(p, kAstI64, MachineType::Uint32()); |
| 950 case kExprI64LoadMem: |
| 951 return ReduceLoadMem(p, kAstI64, MachineType::Int64()); |
| 952 |
| 953 case kExprF32LoadMem: |
| 954 return ReduceLoadMem(p, kAstF32, MachineType::Float32()); |
| 955 |
| 956 case kExprF64LoadMem: |
| 957 return ReduceLoadMem(p, kAstF64, MachineType::Float64()); |
| 958 |
| 959 case kExprI32StoreMem8: |
| 960 return ReduceStoreMem(p, kAstI32, MachineType::Int8()); |
| 961 case kExprI32StoreMem16: |
| 962 return ReduceStoreMem(p, kAstI32, MachineType::Int16()); |
| 963 case kExprI32StoreMem: |
| 964 return ReduceStoreMem(p, kAstI32, MachineType::Int32()); |
| 965 |
| 966 case kExprI64StoreMem8: |
| 967 return ReduceStoreMem(p, kAstI64, MachineType::Int8()); |
| 968 case kExprI64StoreMem16: |
| 969 return ReduceStoreMem(p, kAstI64, MachineType::Int16()); |
| 970 case kExprI64StoreMem32: |
| 971 return ReduceStoreMem(p, kAstI64, MachineType::Int32()); |
| 972 case kExprI64StoreMem: |
| 973 return ReduceStoreMem(p, kAstI64, MachineType::Int64()); |
| 974 |
| 975 case kExprF32StoreMem: |
| 976 return ReduceStoreMem(p, kAstF32, MachineType::Float32()); |
| 977 |
| 978 case kExprF64StoreMem: |
| 979 return ReduceStoreMem(p, kAstF64, MachineType::Float64()); |
| 980 |
| 981 case kExprGrowMemory: |
| 982 TypeCheckLast(p, kAstI32); |
| 983 // TODO(titzer): build node for GrowMemory |
| 984 p->tree->node = BUILD(Int32Constant, 0); |
| 985 return; |
| 986 |
| 987 case kExprCallFunction: { |
| 988 int len; |
| 989 uint32_t index; |
| 990 FunctionSig* sig = FunctionSigOperand(p->pc(), &index, &len); |
| 991 if (!sig) break; |
| 992 if (p->index > 0) { |
| 993 TypeCheckLast(p, sig->GetParam(p->index - 1)); |
| 994 } |
| 995 if (p->done() && build()) { |
| 996 uint32_t count = p->tree->count + 1; |
| 997 TFNode** buffer = builder_->Buffer(count); |
| 998 FunctionSig* sig = FunctionSigOperand(p->pc(), &index, &len); |
| 999 USE(sig); |
| 1000 buffer[0] = nullptr; // reserved for code object. |
| 1001 for (int i = 1; i < count; i++) { |
| 1002 buffer[i] = p->tree->children[i - 1]->node; |
| 1003 } |
| 1004 p->tree->node = builder_->CallDirect(index, buffer); |
| 1005 } |
| 1006 break; |
| 1007 } |
| 1008 case kExprCallIndirect: { |
| 1009 int len; |
| 1010 uint32_t index; |
| 1011 FunctionSig* sig = SigOperand(p->pc(), &index, &len); |
| 1012 if (p->index == 1) { |
| 1013 TypeCheckLast(p, kAstI32); |
| 1014 } else { |
| 1015 TypeCheckLast(p, sig->GetParam(p->index - 2)); |
| 1016 } |
| 1017 if (p->done() && build()) { |
| 1018 uint32_t count = p->tree->count; |
| 1019 TFNode** buffer = builder_->Buffer(count); |
| 1020 for (int i = 0; i < count; i++) { |
| 1021 buffer[i] = p->tree->children[i]->node; |
| 1022 } |
| 1023 p->tree->node = builder_->CallIndirect(index, buffer); |
| 1024 } |
| 1025 break; |
| 1026 } |
| 1027 default: |
| 1028 break; |
| 1029 } |
| 1030 } |
| 1031 |
| 1032 void ReduceBreakToExprBlock(Production* p, Block* block) { |
| 1033 if (block->stack_depth < 0) { |
| 1034 // This is the inner loop block, which does not have a value. |
| 1035 Goto(ssa_env_, block->ssa_env); |
| 1036 } else { |
| 1037 // Merge the value into the production for the block. |
| 1038 Production* bp = &stack_[block->stack_depth]; |
| 1039 MergeIntoProduction(bp, block->ssa_env, p->last()); |
| 1040 } |
| 1041 } |
| 1042 |
| 1043 void MergeIntoProduction(Production* p, SsaEnv* target, Tree* expr) { |
| 1044 if (!ssa_env_->go()) return; |
| 1045 |
| 1046 bool first = target->state == SsaEnv::kUnreachable; |
| 1047 Goto(ssa_env_, target); |
| 1048 if (expr->type == kAstEnd) return; |
| 1049 |
| 1050 if (first) { |
| 1051 // first merge to this environment; set the type and the node. |
| 1052 p->tree->type = expr->type; |
| 1053 p->tree->node = expr->node; |
| 1054 } else { |
| 1055 // merge with the existing value for this block. |
| 1056 LocalType type = p->tree->type; |
| 1057 if (expr->type != type) { |
| 1058 type = kAstStmt; |
| 1059 p->tree->type = kAstStmt; |
| 1060 p->tree->node = nullptr; |
| 1061 } else if (type != kAstStmt) { |
| 1062 p->tree->node = CreateOrMergeIntoPhi(type, target->control, |
| 1063 p->tree->node, expr->node); |
| 1064 } |
| 1065 } |
| 1066 } |
| 1067 |
| 1068 void ReduceLoadMem(Production* p, LocalType type, MachineType mem_type) { |
| 1069 DCHECK_EQ(1, p->index); |
| 1070 TypeCheckLast(p, kAstI32); // index |
| 1071 if (build()) { |
| 1072 int length = 0; |
| 1073 uint32_t offset = 0; |
| 1074 MemoryAccessOperand(p->pc(), &length, &offset); |
| 1075 p->tree->node = |
| 1076 builder_->LoadMem(type, mem_type, p->last()->node, offset); |
| 1077 } |
| 1078 } |
| 1079 |
| 1080 void ReduceStoreMem(Production* p, LocalType type, MachineType mem_type) { |
| 1081 if (p->index == 1) { |
| 1082 TypeCheckLast(p, kAstI32); // index |
| 1083 } else { |
| 1084 DCHECK_EQ(2, p->index); |
| 1085 TypeCheckLast(p, type); |
| 1086 if (build()) { |
| 1087 int length = 0; |
| 1088 uint32_t offset = 0; |
| 1089 MemoryAccessOperand(p->pc(), &length, &offset); |
| 1090 TFNode* val = p->tree->children[1]->node; |
| 1091 builder_->StoreMem(mem_type, p->tree->children[0]->node, offset, val); |
| 1092 p->tree->node = val; |
| 1093 } |
| 1094 } |
| 1095 } |
| 1096 |
| 1097 void TypeCheckLast(Production* p, LocalType expected) { |
| 1098 LocalType result = p->last()->type; |
| 1099 if (result == expected) return; |
| 1100 if (result == kAstEnd) return; |
| 1101 if (expected != kAstStmt) { |
| 1102 error(p->pc(), p->last()->pc, |
| 1103 "%s[%d] expected type %s, found %s of type %s", |
| 1104 WasmOpcodes::OpcodeName(p->opcode()), p->index - 1, |
| 1105 WasmOpcodes::TypeName(expected), |
| 1106 WasmOpcodes::OpcodeName(p->last()->opcode()), |
| 1107 WasmOpcodes::TypeName(p->last()->type)); |
| 1108 } |
| 1109 } |
| 1110 |
| 1111 void SetEnv(const char* reason, SsaEnv* env) { |
| 1112 TRACE(" env = %p, block depth = %d, reason = %s", static_cast<void*>(env), |
| 1113 static_cast<int>(blocks_.size()), reason); |
| 1114 if (env->control != nullptr && FLAG_trace_wasm_decoder) { |
| 1115 TRACE(", control = "); |
| 1116 compiler::WasmGraphBuilder::PrintDebugName(env->control); |
| 1117 } |
| 1118 TRACE("\n"); |
| 1119 ssa_env_ = env; |
| 1120 if (builder_) { |
| 1121 builder_->set_control_ptr(&env->control); |
| 1122 builder_->set_effect_ptr(&env->effect); |
| 1123 } |
| 1124 } |
| 1125 |
| 1126 void Goto(SsaEnv* from, SsaEnv* to) { |
| 1127 DCHECK_NOT_NULL(to); |
| 1128 if (!from->go()) return; |
| 1129 switch (to->state) { |
| 1130 case SsaEnv::kUnreachable: { // Overwrite destination. |
| 1131 to->state = SsaEnv::kReached; |
| 1132 to->locals = from->locals; |
| 1133 to->control = from->control; |
| 1134 to->effect = from->effect; |
| 1135 break; |
| 1136 } |
| 1137 case SsaEnv::kReached: { // Create a new merge. |
| 1138 to->state = SsaEnv::kMerged; |
| 1139 if (!builder_) break; |
| 1140 // Merge control. |
| 1141 TFNode* controls[] = {to->control, from->control}; |
| 1142 TFNode* merge = builder_->Merge(2, controls); |
| 1143 to->control = merge; |
| 1144 // Merge effects. |
| 1145 if (from->effect != to->effect) { |
| 1146 TFNode* effects[] = {to->effect, from->effect, merge}; |
| 1147 to->effect = builder_->EffectPhi(2, effects, merge); |
| 1148 } |
| 1149 // Merge SSA values. |
| 1150 for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| 1151 TFNode* a = to->locals[i]; |
| 1152 TFNode* b = from->locals[i]; |
| 1153 if (a != b) { |
| 1154 TFNode* vals[] = {a, b}; |
| 1155 to->locals[i] = |
| 1156 builder_->Phi(function_env_->GetLocalType(i), 2, vals, merge); |
| 1157 } |
| 1158 } |
| 1159 break; |
| 1160 } |
| 1161 case SsaEnv::kMerged: { |
| 1162 if (!builder_) break; |
| 1163 TFNode* merge = to->control; |
| 1164 // Extend the existing merge. |
| 1165 builder_->AppendToMerge(merge, from->control); |
| 1166 // Merge effects. |
| 1167 if (builder_->IsPhiWithMerge(to->effect, merge)) { |
| 1168 builder_->AppendToPhi(merge, to->effect, from->effect); |
| 1169 } else if (to->effect != from->effect) { |
| 1170 uint32_t count = builder_->InputCount(merge); |
| 1171 TFNode** effects = builder_->Buffer(count); |
| 1172 for (int j = 0; j < count - 1; j++) effects[j] = to->effect; |
| 1173 effects[count - 1] = from->effect; |
| 1174 to->effect = builder_->EffectPhi(count, effects, merge); |
| 1175 } |
| 1176 // Merge locals. |
| 1177 for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| 1178 TFNode* tnode = to->locals[i]; |
| 1179 TFNode* fnode = from->locals[i]; |
| 1180 if (builder_->IsPhiWithMerge(tnode, merge)) { |
| 1181 builder_->AppendToPhi(merge, tnode, fnode); |
| 1182 } else if (tnode != fnode) { |
| 1183 uint32_t count = builder_->InputCount(merge); |
| 1184 TFNode** vals = builder_->Buffer(count); |
| 1185 for (int j = 0; j < count - 1; j++) vals[j] = tnode; |
| 1186 vals[count - 1] = fnode; |
| 1187 to->locals[i] = builder_->Phi(function_env_->GetLocalType(i), count, |
| 1188 vals, merge); |
| 1189 } |
| 1190 } |
| 1191 break; |
| 1192 } |
| 1193 default: |
| 1194 UNREACHABLE(); |
| 1195 } |
| 1196 return from->Kill(); |
| 1197 } |
| 1198 |
| 1199 TFNode* CreateOrMergeIntoPhi(LocalType type, TFNode* merge, TFNode* tnode, |
| 1200 TFNode* fnode) { |
| 1201 if (builder_->IsPhiWithMerge(tnode, merge)) { |
| 1202 builder_->AppendToPhi(merge, tnode, fnode); |
| 1203 } else if (tnode != fnode) { |
| 1204 uint32_t count = builder_->InputCount(merge); |
| 1205 TFNode** vals = builder_->Buffer(count); |
| 1206 for (int j = 0; j < count - 1; j++) vals[j] = tnode; |
| 1207 vals[count - 1] = fnode; |
| 1208 return builder_->Phi(type, count, vals, merge); |
| 1209 } |
| 1210 return tnode; |
| 1211 } |
| 1212 |
| 1213 void BuildInfiniteLoop() { |
| 1214 if (ssa_env_->go()) { |
| 1215 PrepareForLoop(ssa_env_); |
| 1216 SsaEnv* cont_env = ssa_env_; |
| 1217 ssa_env_ = Split(ssa_env_); |
| 1218 ssa_env_->state = SsaEnv::kReached; |
| 1219 Goto(ssa_env_, cont_env); |
| 1220 } |
| 1221 } |
| 1222 |
| 1223 void PrepareForLoop(SsaEnv* env) { |
| 1224 if (env->go()) { |
| 1225 env->state = SsaEnv::kMerged; |
| 1226 if (builder_) { |
| 1227 env->control = builder_->Loop(env->control); |
| 1228 env->effect = builder_->EffectPhi(1, &env->effect, env->control); |
| 1229 builder_->Terminate(env->effect, env->control); |
| 1230 for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| 1231 env->locals[i] = builder_->Phi(function_env_->GetLocalType(i), 1, |
| 1232 &env->locals[i], env->control); |
| 1233 } |
| 1234 } |
| 1235 } |
| 1236 } |
| 1237 |
| 1238 // Create a complete copy of the {from}. |
| 1239 SsaEnv* Split(SsaEnv* from) { |
| 1240 DCHECK_NOT_NULL(from); |
| 1241 SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| 1242 size_t size = sizeof(TFNode*) * EnvironmentCount(); |
| 1243 result->control = from->control; |
| 1244 result->effect = from->effect; |
| 1245 result->state = from->state == SsaEnv::kUnreachable ? SsaEnv::kUnreachable |
| 1246 : SsaEnv::kReached; |
| 1247 |
| 1248 if (from->go()) { |
| 1249 result->state = SsaEnv::kReached; |
| 1250 result->locals = |
| 1251 size > 0 ? reinterpret_cast<TFNode**>(zone_->New(size)) : nullptr; |
| 1252 memcpy(result->locals, from->locals, size); |
| 1253 } else { |
| 1254 result->state = SsaEnv::kUnreachable; |
| 1255 result->locals = nullptr; |
| 1256 } |
| 1257 |
| 1258 return result; |
| 1259 } |
| 1260 |
| 1261 // Create a copy of {from} that steals its state and leaves {from} |
| 1262 // unreachable. |
| 1263 SsaEnv* Steal(SsaEnv* from) { |
| 1264 DCHECK_NOT_NULL(from); |
| 1265 if (!from->go()) return UnreachableEnv(); |
| 1266 SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| 1267 result->state = SsaEnv::kReached; |
| 1268 result->locals = from->locals; |
| 1269 result->control = from->control; |
| 1270 result->effect = from->effect; |
| 1271 from->Kill(SsaEnv::kUnreachable); |
| 1272 return result; |
| 1273 } |
| 1274 |
| 1275 // Create an unreachable environment. |
| 1276 SsaEnv* UnreachableEnv() { |
| 1277 SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| 1278 result->state = SsaEnv::kUnreachable; |
| 1279 result->control = nullptr; |
| 1280 result->effect = nullptr; |
| 1281 result->locals = nullptr; |
| 1282 return result; |
| 1283 } |
| 1284 |
| 1285 // Load an operand at [pc + 1]. |
| 1286 template <typename V> |
| 1287 V Operand(const byte* pc) { |
| 1288 if ((limit_ - pc) < static_cast<int>(1 + sizeof(V))) { |
| 1289 const char* msg = "Expected operand following opcode"; |
| 1290 switch (sizeof(V)) { |
| 1291 case 1: |
| 1292 msg = "Expected 1-byte operand following opcode"; |
| 1293 break; |
| 1294 case 2: |
| 1295 msg = "Expected 2-byte operand following opcode"; |
| 1296 break; |
| 1297 case 4: |
| 1298 msg = "Expected 4-byte operand following opcode"; |
| 1299 break; |
| 1300 default: |
| 1301 break; |
| 1302 } |
| 1303 error(pc, msg); |
| 1304 return -1; |
| 1305 } |
| 1306 return *reinterpret_cast<const V*>(pc + 1); |
| 1307 } |
| 1308 |
| 1309 int EnvironmentCount() { |
| 1310 if (builder_) return static_cast<int>(function_env_->GetLocalCount()); |
| 1311 return 0; // if we aren't building a graph, don't bother with SSA renaming. |
| 1312 } |
| 1313 |
| 1314 LocalType LocalOperand(const byte* pc, uint32_t* index, int* length) { |
| 1315 *index = UnsignedLEB128Operand(pc, length); |
| 1316 if (function_env_->IsValidLocal(*index)) { |
| 1317 return function_env_->GetLocalType(*index); |
| 1318 } |
| 1319 error(pc, "invalid local variable index"); |
| 1320 return kAstStmt; |
| 1321 } |
| 1322 |
| 1323 LocalType GlobalOperand(const byte* pc, uint32_t* index, int* length) { |
| 1324 *index = UnsignedLEB128Operand(pc, length); |
| 1325 if (function_env_->module->IsValidGlobal(*index)) { |
| 1326 return WasmOpcodes::LocalTypeFor( |
| 1327 function_env_->module->GetGlobalType(*index)); |
| 1328 } |
| 1329 error(pc, "invalid global variable index"); |
| 1330 return kAstStmt; |
| 1331 } |
| 1332 |
| 1333 FunctionSig* FunctionSigOperand(const byte* pc, uint32_t* index, |
| 1334 int* length) { |
| 1335 *index = UnsignedLEB128Operand(pc, length); |
| 1336 if (function_env_->module->IsValidFunction(*index)) { |
| 1337 return function_env_->module->GetFunctionSignature(*index); |
| 1338 } |
| 1339 error(pc, "invalid function index"); |
| 1340 return nullptr; |
| 1341 } |
| 1342 |
| 1343 FunctionSig* SigOperand(const byte* pc, uint32_t* index, int* length) { |
| 1344 *index = UnsignedLEB128Operand(pc, length); |
| 1345 if (function_env_->module->IsValidSignature(*index)) { |
| 1346 return function_env_->module->GetSignature(*index); |
| 1347 } |
| 1348 error(pc, "invalid signature index"); |
| 1349 return nullptr; |
| 1350 } |
| 1351 |
| 1352 uint32_t UnsignedLEB128Operand(const byte* pc, int* length) { |
| 1353 uint32_t result = 0; |
| 1354 ReadUnsignedLEB128ErrorCode error_code = |
| 1355 ReadUnsignedLEB128Operand(pc + 1, limit_, length, &result); |
| 1356 if (error_code == kInvalidLEB128) error(pc, "invalid LEB128 varint"); |
| 1357 if (error_code == kMissingLEB128) error(pc, "expected LEB128 varint"); |
| 1358 (*length)++; |
| 1359 return result; |
| 1360 } |
| 1361 |
| 1362 void MemoryAccessOperand(const byte* pc, int* length, uint32_t* offset) { |
| 1363 byte bitfield = Operand<uint8_t>(pc); |
| 1364 if (MemoryAccess::OffsetField::decode(bitfield)) { |
| 1365 *offset = UnsignedLEB128Operand(pc + 1, length); |
| 1366 (*length)++; // to account for the memory access byte |
| 1367 } else { |
| 1368 *offset = 0; |
| 1369 *length = 2; |
| 1370 } |
| 1371 } |
| 1372 |
| 1373 virtual void onFirstError() { |
| 1374 limit_ = start_; // Terminate decoding loop. |
| 1375 builder_ = nullptr; // Don't build any more nodes. |
| 1376 #if DEBUG |
| 1377 PrintStackForDebugging(); |
| 1378 #endif |
| 1379 } |
| 1380 |
| 1381 #if DEBUG |
| 1382 void PrintStackForDebugging() { PrintProduction(0); } |
| 1383 |
| 1384 void PrintProduction(size_t depth) { |
| 1385 if (depth >= stack_.size()) return; |
| 1386 Production* p = &stack_[depth]; |
| 1387 for (size_t d = 0; d < depth; d++) PrintF(" "); |
| 1388 |
| 1389 PrintF("@%d %s [%d]\n", static_cast<int>(p->tree->pc - start_), |
| 1390 WasmOpcodes::OpcodeName(p->opcode()), p->tree->count); |
| 1391 for (int i = 0; i < p->index; i++) { |
| 1392 Tree* child = p->tree->children[i]; |
| 1393 for (size_t d = 0; d <= depth; d++) PrintF(" "); |
| 1394 PrintF("@%d %s [%d]", static_cast<int>(child->pc - start_), |
| 1395 WasmOpcodes::OpcodeName(child->opcode()), child->count); |
| 1396 if (child->node) { |
| 1397 PrintF(" => TF"); |
| 1398 compiler::WasmGraphBuilder::PrintDebugName(child->node); |
| 1399 } |
| 1400 PrintF("\n"); |
| 1401 } |
| 1402 PrintProduction(depth + 1); |
| 1403 } |
| 1404 #endif |
| 1405 }; |
| 1406 |
| 1407 |
| 1408 TreeResult VerifyWasmCode(FunctionEnv* env, const byte* base, const byte* start, |
| 1409 const byte* end) { |
| 1410 Zone zone; |
| 1411 LR_WasmDecoder decoder(&zone, nullptr); |
| 1412 TreeResult result = decoder.Decode(env, base, start, end); |
| 1413 return result; |
| 1414 } |
| 1415 |
| 1416 |
| 1417 TreeResult BuildTFGraph(TFBuilder* builder, FunctionEnv* env, const byte* base, |
| 1418 const byte* start, const byte* end) { |
| 1419 Zone zone; |
| 1420 LR_WasmDecoder decoder(&zone, builder); |
| 1421 TreeResult result = decoder.Decode(env, base, start, end); |
| 1422 return result; |
| 1423 } |
| 1424 |
| 1425 |
| 1426 std::ostream& operator<<(std::ostream& os, const Tree& tree) { |
| 1427 if (tree.pc == nullptr) { |
| 1428 os << "null"; |
| 1429 return os; |
| 1430 } |
| 1431 PrintF("%s", WasmOpcodes::OpcodeName(tree.opcode())); |
| 1432 if (tree.count > 0) os << "("; |
| 1433 for (int i = 0; i < tree.count; i++) { |
| 1434 if (i > 0) os << ", "; |
| 1435 os << *tree.children[i]; |
| 1436 } |
| 1437 if (tree.count > 0) os << ")"; |
| 1438 return os; |
| 1439 } |
| 1440 |
| 1441 |
| 1442 ReadUnsignedLEB128ErrorCode ReadUnsignedLEB128Operand(const byte* pc, |
| 1443 const byte* limit, |
| 1444 int* length, |
| 1445 uint32_t* result) { |
| 1446 *result = 0; |
| 1447 const byte* ptr = pc; |
| 1448 const byte* end = pc + 5; // maximum 5 bytes. |
| 1449 if (end > limit) end = limit; |
| 1450 int shift = 0; |
| 1451 byte b = 0; |
| 1452 while (ptr < end) { |
| 1453 b = *ptr++; |
| 1454 *result = *result | ((b & 0x7F) << shift); |
| 1455 if ((b & 0x80) == 0) break; |
| 1456 shift += 7; |
| 1457 } |
| 1458 DCHECK_LE(ptr - pc, 5); |
| 1459 *length = static_cast<int>(ptr - pc); |
| 1460 if (ptr == end && (b & 0x80)) { |
| 1461 return kInvalidLEB128; |
| 1462 } else if (*length == 0) { |
| 1463 return kMissingLEB128; |
| 1464 } else { |
| 1465 return kNoError; |
| 1466 } |
| 1467 } |
| 1468 |
| 1469 |
| 1470 int OpcodeLength(const byte* pc) { |
| 1471 switch (static_cast<WasmOpcode>(*pc)) { |
| 1472 #define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name: |
| 1473 FOREACH_LOAD_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1474 FOREACH_STORE_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1475 #undef DECLARE_OPCODE_CASE |
| 1476 |
| 1477 case kExprI8Const: |
| 1478 case kExprBlock: |
| 1479 case kExprLoop: |
| 1480 case kExprBr: |
| 1481 case kExprBrIf: |
| 1482 return 2; |
| 1483 case kExprI32Const: |
| 1484 case kExprF32Const: |
| 1485 return 5; |
| 1486 case kExprI64Const: |
| 1487 case kExprF64Const: |
| 1488 return 9; |
| 1489 case kExprStoreGlobal: |
| 1490 case kExprSetLocal: |
| 1491 case kExprLoadGlobal: |
| 1492 case kExprCallFunction: |
| 1493 case kExprCallIndirect: |
| 1494 case kExprGetLocal: { |
| 1495 int length; |
| 1496 uint32_t result = 0; |
| 1497 ReadUnsignedLEB128Operand(pc + 1, pc + 6, &length, &result); |
| 1498 return 1 + length; |
| 1499 } |
| 1500 case kExprTableSwitch: { |
| 1501 uint16_t table_count = *reinterpret_cast<const uint16_t*>(pc + 3); |
| 1502 return 5 + table_count * 2; |
| 1503 } |
| 1504 |
| 1505 default: |
| 1506 return 1; |
| 1507 } |
| 1508 } |
| 1509 |
| 1510 |
| 1511 int OpcodeArity(FunctionEnv* env, const byte* pc) { |
| 1512 #define DECLARE_ARITY(name, ...) \ |
| 1513 static const LocalType kTypes_##name[] = {__VA_ARGS__}; \ |
| 1514 static const int kArity_##name = \ |
| 1515 static_cast<int>(arraysize(kTypes_##name) - 1); |
| 1516 |
| 1517 FOREACH_SIGNATURE(DECLARE_ARITY); |
| 1518 #undef DECLARE_ARITY |
| 1519 |
| 1520 switch (static_cast<WasmOpcode>(*pc)) { |
| 1521 case kExprI8Const: |
| 1522 case kExprI32Const: |
| 1523 case kExprI64Const: |
| 1524 case kExprF64Const: |
| 1525 case kExprF32Const: |
| 1526 case kExprGetLocal: |
| 1527 case kExprLoadGlobal: |
| 1528 case kExprNop: |
| 1529 case kExprUnreachable: |
| 1530 return 0; |
| 1531 |
| 1532 case kExprBr: |
| 1533 case kExprStoreGlobal: |
| 1534 case kExprSetLocal: |
| 1535 return 1; |
| 1536 |
| 1537 case kExprIf: |
| 1538 case kExprBrIf: |
| 1539 return 2; |
| 1540 case kExprIfElse: |
| 1541 case kExprSelect: |
| 1542 return 3; |
| 1543 case kExprBlock: |
| 1544 case kExprLoop: |
| 1545 return *(pc + 1); |
| 1546 |
| 1547 case kExprCallFunction: { |
| 1548 int index = *(pc + 1); |
| 1549 return static_cast<int>( |
| 1550 env->module->GetFunctionSignature(index)->parameter_count()); |
| 1551 } |
| 1552 case kExprCallIndirect: { |
| 1553 int index = *(pc + 1); |
| 1554 return 1 + static_cast<int>( |
| 1555 env->module->GetSignature(index)->parameter_count()); |
| 1556 } |
| 1557 case kExprReturn: |
| 1558 return static_cast<int>(env->sig->return_count()); |
| 1559 case kExprTableSwitch: { |
| 1560 uint16_t case_count = *reinterpret_cast<const uint16_t*>(pc + 1); |
| 1561 return 1 + case_count; |
| 1562 } |
| 1563 |
| 1564 #define DECLARE_OPCODE_CASE(name, opcode, sig) \ |
| 1565 case kExpr##name: \ |
| 1566 return kArity_##sig; |
| 1567 |
| 1568 FOREACH_LOAD_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1569 FOREACH_STORE_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1570 FOREACH_MISC_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1571 FOREACH_SIMPLE_OPCODE(DECLARE_OPCODE_CASE) |
| 1572 #undef DECLARE_OPCODE_CASE |
| 1573 } |
| 1574 } |
| 1575 } // namespace wasm |
| 1576 } // namespace internal |
| 1577 } // namespace v8 |
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