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/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 >= static_cast<int>(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 (static_cast<int>(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 (build()) 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 (uint32_t 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 (uint32_t 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 (uint32_t j = 0; j < count - 1; j++) { |
| 1173 | effects[j] = to->effect; |
| 1174 | } |
| 1175 | effects[count - 1] = from->effect; |
| 1176 | to->effect = builder_->EffectPhi(count, effects, merge); |
| 1177 | } |
| 1178 | // Merge locals. |
| 1179 | for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| 1180 | TFNode* tnode = to->locals[i]; |
| 1181 | TFNode* fnode = from->locals[i]; |
| 1182 | if (builder_->IsPhiWithMerge(tnode, merge)) { |
| 1183 | builder_->AppendToPhi(merge, tnode, fnode); |
| 1184 | } else if (tnode != fnode) { |
| 1185 | uint32_t count = builder_->InputCount(merge); |
| 1186 | TFNode** vals = builder_->Buffer(count); |
| 1187 | for (uint32_t j = 0; j < count - 1; j++) { |
| 1188 | vals[j] = tnode; |
| 1189 | } |
| 1190 | vals[count - 1] = fnode; |
| 1191 | to->locals[i] = builder_->Phi(function_env_->GetLocalType(i), count, |
| 1192 | vals, merge); |
| 1193 | } |
| 1194 | } |
| 1195 | break; |
| 1196 | } |
| 1197 | default: |
| 1198 | UNREACHABLE(); |
| 1199 | } |
| 1200 | return from->Kill(); |
| 1201 | } |
| 1202 | |
| 1203 | TFNode* CreateOrMergeIntoPhi(LocalType type, TFNode* merge, TFNode* tnode, |
| 1204 | TFNode* fnode) { |
| 1205 | if (builder_->IsPhiWithMerge(tnode, merge)) { |
| 1206 | builder_->AppendToPhi(merge, tnode, fnode); |
| 1207 | } else if (tnode != fnode) { |
| 1208 | uint32_t count = builder_->InputCount(merge); |
| 1209 | TFNode** vals = builder_->Buffer(count); |
| 1210 | for (uint32_t j = 0; j < count - 1; j++) vals[j] = tnode; |
| 1211 | vals[count - 1] = fnode; |
| 1212 | return builder_->Phi(type, count, vals, merge); |
| 1213 | } |
| 1214 | return tnode; |
| 1215 | } |
| 1216 | |
| 1217 | void BuildInfiniteLoop() { |
| 1218 | if (ssa_env_->go()) { |
| 1219 | PrepareForLoop(ssa_env_); |
| 1220 | SsaEnv* cont_env = ssa_env_; |
| 1221 | ssa_env_ = Split(ssa_env_); |
| 1222 | ssa_env_->state = SsaEnv::kReached; |
| 1223 | Goto(ssa_env_, cont_env); |
| 1224 | } |
| 1225 | } |
| 1226 | |
| 1227 | void PrepareForLoop(SsaEnv* env) { |
| 1228 | if (env->go()) { |
| 1229 | env->state = SsaEnv::kMerged; |
| 1230 | if (builder_) { |
| 1231 | env->control = builder_->Loop(env->control); |
| 1232 | env->effect = builder_->EffectPhi(1, &env->effect, env->control); |
| 1233 | builder_->Terminate(env->effect, env->control); |
| 1234 | for (int i = EnvironmentCount() - 1; i >= 0; i--) { |
| 1235 | env->locals[i] = builder_->Phi(function_env_->GetLocalType(i), 1, |
| 1236 | &env->locals[i], env->control); |
| 1237 | } |
| 1238 | } |
| 1239 | } |
| 1240 | } |
| 1241 | |
| 1242 | // Create a complete copy of the {from}. |
| 1243 | SsaEnv* Split(SsaEnv* from) { |
| 1244 | DCHECK_NOT_NULL(from); |
| 1245 | SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| 1246 | size_t size = sizeof(TFNode*) * EnvironmentCount(); |
| 1247 | result->control = from->control; |
| 1248 | result->effect = from->effect; |
| 1249 | result->state = from->state == SsaEnv::kUnreachable ? SsaEnv::kUnreachable |
| 1250 | : SsaEnv::kReached; |
| 1251 | |
| 1252 | if (from->go()) { |
| 1253 | result->state = SsaEnv::kReached; |
| 1254 | result->locals = |
| 1255 | size > 0 ? reinterpret_cast<TFNode**>(zone_->New(size)) : nullptr; |
| 1256 | memcpy(result->locals, from->locals, size); |
| 1257 | } else { |
| 1258 | result->state = SsaEnv::kUnreachable; |
| 1259 | result->locals = nullptr; |
| 1260 | } |
| 1261 | |
| 1262 | return result; |
| 1263 | } |
| 1264 | |
| 1265 | // Create a copy of {from} that steals its state and leaves {from} |
| 1266 | // unreachable. |
| 1267 | SsaEnv* Steal(SsaEnv* from) { |
| 1268 | DCHECK_NOT_NULL(from); |
| 1269 | if (!from->go()) return UnreachableEnv(); |
| 1270 | SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| 1271 | result->state = SsaEnv::kReached; |
| 1272 | result->locals = from->locals; |
| 1273 | result->control = from->control; |
| 1274 | result->effect = from->effect; |
| 1275 | from->Kill(SsaEnv::kUnreachable); |
| 1276 | return result; |
| 1277 | } |
| 1278 | |
| 1279 | // Create an unreachable environment. |
| 1280 | SsaEnv* UnreachableEnv() { |
| 1281 | SsaEnv* result = reinterpret_cast<SsaEnv*>(zone_->New(sizeof(SsaEnv))); |
| 1282 | result->state = SsaEnv::kUnreachable; |
| 1283 | result->control = nullptr; |
| 1284 | result->effect = nullptr; |
| 1285 | result->locals = nullptr; |
| 1286 | return result; |
| 1287 | } |
| 1288 | |
| 1289 | // Load an operand at [pc + 1]. |
| 1290 | template <typename V> |
| 1291 | V Operand(const byte* pc) { |
| 1292 | if ((limit_ - pc) < static_cast<int>(1 + sizeof(V))) { |
| 1293 | const char* msg = "Expected operand following opcode"; |
| 1294 | switch (sizeof(V)) { |
| 1295 | case 1: |
| 1296 | msg = "Expected 1-byte operand following opcode"; |
| 1297 | break; |
| 1298 | case 2: |
| 1299 | msg = "Expected 2-byte operand following opcode"; |
| 1300 | break; |
| 1301 | case 4: |
| 1302 | msg = "Expected 4-byte operand following opcode"; |
| 1303 | break; |
| 1304 | default: |
| 1305 | break; |
| 1306 | } |
| 1307 | error(pc, msg); |
| 1308 | return -1; |
| 1309 | } |
| 1310 | return *reinterpret_cast<const V*>(pc + 1); |
| 1311 | } |
| 1312 | |
| 1313 | int EnvironmentCount() { |
| 1314 | if (builder_) return static_cast<int>(function_env_->GetLocalCount()); |
| 1315 | return 0; // if we aren't building a graph, don't bother with SSA renaming. |
| 1316 | } |
| 1317 | |
| 1318 | LocalType LocalOperand(const byte* pc, uint32_t* index, int* length) { |
| 1319 | *index = UnsignedLEB128Operand(pc, length); |
| 1320 | if (function_env_->IsValidLocal(*index)) { |
| 1321 | return function_env_->GetLocalType(*index); |
| 1322 | } |
| 1323 | error(pc, "invalid local variable index"); |
| 1324 | return kAstStmt; |
| 1325 | } |
| 1326 | |
| 1327 | LocalType GlobalOperand(const byte* pc, uint32_t* index, int* length) { |
| 1328 | *index = UnsignedLEB128Operand(pc, length); |
| 1329 | if (function_env_->module->IsValidGlobal(*index)) { |
| 1330 | return WasmOpcodes::LocalTypeFor( |
| 1331 | function_env_->module->GetGlobalType(*index)); |
| 1332 | } |
| 1333 | error(pc, "invalid global variable index"); |
| 1334 | return kAstStmt; |
| 1335 | } |
| 1336 | |
| 1337 | FunctionSig* FunctionSigOperand(const byte* pc, uint32_t* index, |
| 1338 | int* length) { |
| 1339 | *index = UnsignedLEB128Operand(pc, length); |
| 1340 | if (function_env_->module->IsValidFunction(*index)) { |
| 1341 | return function_env_->module->GetFunctionSignature(*index); |
| 1342 | } |
| 1343 | error(pc, "invalid function index"); |
| 1344 | return nullptr; |
| 1345 | } |
| 1346 | |
| 1347 | FunctionSig* SigOperand(const byte* pc, uint32_t* index, int* length) { |
| 1348 | *index = UnsignedLEB128Operand(pc, length); |
| 1349 | if (function_env_->module->IsValidSignature(*index)) { |
| 1350 | return function_env_->module->GetSignature(*index); |
| 1351 | } |
| 1352 | error(pc, "invalid signature index"); |
| 1353 | return nullptr; |
| 1354 | } |
| 1355 | |
| 1356 | uint32_t UnsignedLEB128Operand(const byte* pc, int* length) { |
| 1357 | uint32_t result = 0; |
| 1358 | ReadUnsignedLEB128ErrorCode error_code = |
| 1359 | ReadUnsignedLEB128Operand(pc + 1, limit_, length, &result); |
| 1360 | if (error_code == kInvalidLEB128) error(pc, "invalid LEB128 varint"); |
| 1361 | if (error_code == kMissingLEB128) error(pc, "expected LEB128 varint"); |
| 1362 | (*length)++; |
| 1363 | return result; |
| 1364 | } |
| 1365 | |
| 1366 | void MemoryAccessOperand(const byte* pc, int* length, uint32_t* offset) { |
| 1367 | byte bitfield = Operand<uint8_t>(pc); |
| 1368 | if (MemoryAccess::OffsetField::decode(bitfield)) { |
| 1369 | *offset = UnsignedLEB128Operand(pc + 1, length); |
| 1370 | (*length)++; // to account for the memory access byte |
| 1371 | } else { |
| 1372 | *offset = 0; |
| 1373 | *length = 2; |
| 1374 | } |
| 1375 | } |
| 1376 | |
| 1377 | virtual void onFirstError() { |
| 1378 | limit_ = start_; // Terminate decoding loop. |
| 1379 | builder_ = nullptr; // Don't build any more nodes. |
| 1380 | #if DEBUG |
| 1381 | PrintStackForDebugging(); |
| 1382 | #endif |
| 1383 | } |
| 1384 | |
| 1385 | #if DEBUG |
| 1386 | void PrintStackForDebugging() { PrintProduction(0); } |
| 1387 | |
| 1388 | void PrintProduction(size_t depth) { |
| 1389 | if (depth >= stack_.size()) return; |
| 1390 | Production* p = &stack_[depth]; |
| 1391 | for (size_t d = 0; d < depth; d++) PrintF(" "); |
| 1392 | |
| 1393 | PrintF("@%d %s [%d]\n", static_cast<int>(p->tree->pc - start_), |
| 1394 | WasmOpcodes::OpcodeName(p->opcode()), p->tree->count); |
| 1395 | for (int i = 0; i < p->index; i++) { |
| 1396 | Tree* child = p->tree->children[i]; |
| 1397 | for (size_t d = 0; d <= depth; d++) PrintF(" "); |
| 1398 | PrintF("@%d %s [%d]", static_cast<int>(child->pc - start_), |
| 1399 | WasmOpcodes::OpcodeName(child->opcode()), child->count); |
| 1400 | if (child->node) { |
| 1401 | PrintF(" => TF"); |
| 1402 | compiler::WasmGraphBuilder::PrintDebugName(child->node); |
| 1403 | } |
| 1404 | PrintF("\n"); |
| 1405 | } |
| 1406 | PrintProduction(depth + 1); |
| 1407 | } |
| 1408 | #endif |
| 1409 | }; |
| 1410 | |
| 1411 | |
| 1412 | TreeResult VerifyWasmCode(FunctionEnv* env, const byte* base, const byte* start, |
| 1413 | const byte* end) { |
| 1414 | Zone zone; |
| 1415 | LR_WasmDecoder decoder(&zone, nullptr); |
| 1416 | TreeResult result = decoder.Decode(env, base, start, end); |
| 1417 | return result; |
| 1418 | } |
| 1419 | |
| 1420 | |
| 1421 | TreeResult BuildTFGraph(TFBuilder* builder, FunctionEnv* env, const byte* base, |
| 1422 | const byte* start, const byte* end) { |
| 1423 | Zone zone; |
| 1424 | LR_WasmDecoder decoder(&zone, builder); |
| 1425 | TreeResult result = decoder.Decode(env, base, start, end); |
| 1426 | return result; |
| 1427 | } |
| 1428 | |
| 1429 | |
| 1430 | std::ostream& operator<<(std::ostream& os, const Tree& tree) { |
| 1431 | if (tree.pc == nullptr) { |
| 1432 | os << "null"; |
| 1433 | return os; |
| 1434 | } |
| 1435 | PrintF("%s", WasmOpcodes::OpcodeName(tree.opcode())); |
| 1436 | if (tree.count > 0) os << "("; |
| 1437 | for (uint32_t i = 0; i < tree.count; i++) { |
| 1438 | if (i > 0) os << ", "; |
| 1439 | os << *tree.children[i]; |
| 1440 | } |
| 1441 | if (tree.count > 0) os << ")"; |
| 1442 | return os; |
| 1443 | } |
| 1444 | |
| 1445 | |
| 1446 | ReadUnsignedLEB128ErrorCode ReadUnsignedLEB128Operand(const byte* pc, |
| 1447 | const byte* limit, |
| 1448 | int* length, |
| 1449 | uint32_t* result) { |
| 1450 | *result = 0; |
| 1451 | const byte* ptr = pc; |
| 1452 | const byte* end = pc + 5; // maximum 5 bytes. |
| 1453 | if (end > limit) end = limit; |
| 1454 | int shift = 0; |
| 1455 | byte b = 0; |
| 1456 | while (ptr < end) { |
| 1457 | b = *ptr++; |
| 1458 | *result = *result | ((b & 0x7F) << shift); |
| 1459 | if ((b & 0x80) == 0) break; |
| 1460 | shift += 7; |
| 1461 | } |
| 1462 | DCHECK_LE(ptr - pc, 5); |
| 1463 | *length = static_cast<int>(ptr - pc); |
| 1464 | if (ptr == end && (b & 0x80)) { |
| 1465 | return kInvalidLEB128; |
| 1466 | } else if (*length == 0) { |
| 1467 | return kMissingLEB128; |
| 1468 | } else { |
| 1469 | return kNoError; |
| 1470 | } |
| 1471 | } |
| 1472 | |
| 1473 | |
| 1474 | int OpcodeLength(const byte* pc) { |
| 1475 | switch (static_cast<WasmOpcode>(*pc)) { |
| 1476 | #define DECLARE_OPCODE_CASE(name, opcode, sig) case kExpr##name: |
| 1477 | FOREACH_LOAD_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1478 | FOREACH_STORE_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1479 | #undef DECLARE_OPCODE_CASE |
| 1480 | |
| 1481 | case kExprI8Const: |
| 1482 | case kExprBlock: |
| 1483 | case kExprLoop: |
| 1484 | case kExprBr: |
| 1485 | case kExprBrIf: |
| 1486 | return 2; |
| 1487 | case kExprI32Const: |
| 1488 | case kExprF32Const: |
| 1489 | return 5; |
| 1490 | case kExprI64Const: |
| 1491 | case kExprF64Const: |
| 1492 | return 9; |
| 1493 | case kExprStoreGlobal: |
| 1494 | case kExprSetLocal: |
| 1495 | case kExprLoadGlobal: |
| 1496 | case kExprCallFunction: |
| 1497 | case kExprCallIndirect: |
| 1498 | case kExprGetLocal: { |
| 1499 | int length; |
| 1500 | uint32_t result = 0; |
| 1501 | ReadUnsignedLEB128Operand(pc + 1, pc + 6, &length, &result); |
| 1502 | return 1 + length; |
| 1503 | } |
| 1504 | case kExprTableSwitch: { |
| 1505 | uint16_t table_count = *reinterpret_cast<const uint16_t*>(pc + 3); |
| 1506 | return 5 + table_count * 2; |
| 1507 | } |
| 1508 | |
| 1509 | default: |
| 1510 | return 1; |
| 1511 | } |
| 1512 | } |
| 1513 | |
| 1514 | |
| 1515 | int OpcodeArity(FunctionEnv* env, const byte* pc) { |
| 1516 | #define DECLARE_ARITY(name, ...) \ |
| 1517 | static const LocalType kTypes_##name[] = {__VA_ARGS__}; \ |
| 1518 | static const int kArity_##name = \ |
| 1519 | static_cast<int>(arraysize(kTypes_##name) - 1); |
| 1520 | |
| 1521 | FOREACH_SIGNATURE(DECLARE_ARITY); |
| 1522 | #undef DECLARE_ARITY |
| 1523 | |
| 1524 | switch (static_cast<WasmOpcode>(*pc)) { |
| 1525 | case kExprI8Const: |
| 1526 | case kExprI32Const: |
| 1527 | case kExprI64Const: |
| 1528 | case kExprF64Const: |
| 1529 | case kExprF32Const: |
| 1530 | case kExprGetLocal: |
| 1531 | case kExprLoadGlobal: |
| 1532 | case kExprNop: |
| 1533 | case kExprUnreachable: |
| 1534 | return 0; |
| 1535 | |
| 1536 | case kExprBr: |
| 1537 | case kExprStoreGlobal: |
| 1538 | case kExprSetLocal: |
| 1539 | return 1; |
| 1540 | |
| 1541 | case kExprIf: |
| 1542 | case kExprBrIf: |
| 1543 | return 2; |
| 1544 | case kExprIfElse: |
| 1545 | case kExprSelect: |
| 1546 | return 3; |
| 1547 | case kExprBlock: |
| 1548 | case kExprLoop: |
| 1549 | return *(pc + 1); |
| 1550 | |
| 1551 | case kExprCallFunction: { |
| 1552 | int index = *(pc + 1); |
| 1553 | return static_cast<int>( |
| 1554 | env->module->GetFunctionSignature(index)->parameter_count()); |
| 1555 | } |
| 1556 | case kExprCallIndirect: { |
| 1557 | int index = *(pc + 1); |
| 1558 | return 1 + static_cast<int>( |
| 1559 | env->module->GetSignature(index)->parameter_count()); |
| 1560 | } |
| 1561 | case kExprReturn: |
| 1562 | return static_cast<int>(env->sig->return_count()); |
| 1563 | case kExprTableSwitch: { |
| 1564 | uint16_t case_count = *reinterpret_cast<const uint16_t*>(pc + 1); |
| 1565 | return 1 + case_count; |
| 1566 | } |
| 1567 | |
| 1568 | #define DECLARE_OPCODE_CASE(name, opcode, sig) \ |
| 1569 | case kExpr##name: \ |
| 1570 | return kArity_##sig; |
| 1571 | |
| 1572 | FOREACH_LOAD_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1573 | FOREACH_STORE_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1574 | FOREACH_MISC_MEM_OPCODE(DECLARE_OPCODE_CASE) |
| 1575 | FOREACH_SIMPLE_OPCODE(DECLARE_OPCODE_CASE) |
| 1576 | #undef DECLARE_OPCODE_CASE |
| 1577 | } |
| 1578 | UNREACHABLE(); |
| 1579 | return 0; |
| 1580 | } |
| 1581 | } // namespace wasm |
| 1582 | } // namespace internal |
| 1583 | } // namespace v8 |