| /* |
| * Copyright 2015 WebAssembly Community Group participants |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| // |
| // WebAssembly-to-JS code translator. Converts wasm functions into |
| // valid JavaScript (with a somewhat asm.js-ish flavor). |
| // |
| |
| #ifndef wasm_wasm2js_h |
| #define wasm_wasm2js_h |
| |
| #include <cmath> |
| #include <numeric> |
| |
| #include "abi/js.h" |
| #include "asm_v_wasm.h" |
| #include "asmjs/asmangle.h" |
| #include "asmjs/shared-constants.h" |
| #include "emscripten-optimizer/optimizer.h" |
| #include "ir/branch-utils.h" |
| #include "ir/effects.h" |
| #include "ir/element-utils.h" |
| #include "ir/find_all.h" |
| #include "ir/import-utils.h" |
| #include "ir/load-utils.h" |
| #include "ir/module-utils.h" |
| #include "ir/names.h" |
| #include "ir/table-utils.h" |
| #include "ir/utils.h" |
| #include "mixed_arena.h" |
| #include "passes/passes.h" |
| #include "support/base64.h" |
| #include "support/file.h" |
| #include "wasm-builder.h" |
| #include "wasm-io.h" |
| #include "wasm-validator.h" |
| #include "wasm.h" |
| |
| namespace wasm { |
| |
| using namespace cashew; |
| |
| // Appends extra to block, flattening out if extra is a block as well |
| void flattenAppend(Ref ast, Ref extra) { |
| int index; |
| if (ast[0] == BLOCK || ast[0] == TOPLEVEL) { |
| index = 1; |
| } else if (ast[0] == DEFUN) { |
| index = 3; |
| } else { |
| abort(); |
| } |
| if (extra->isArray() && extra[0] == BLOCK) { |
| for (size_t i = 0; i < extra[1]->size(); i++) { |
| ast[index]->push_back(extra[1][i]); |
| } |
| } else { |
| ast[index]->push_back(extra); |
| } |
| } |
| |
| // Appends extra to a chain of sequence elements |
| void sequenceAppend(Ref& ast, Ref extra) { |
| if (!ast.get()) { |
| ast = extra; |
| return; |
| } |
| ast = ValueBuilder::makeSeq(ast, extra); |
| } |
| |
| bool isTableExported(Module& wasm) { |
| if (wasm.tables.empty() || wasm.tables[0]->imported()) { |
| return false; |
| } |
| for (auto& ex : wasm.exports) { |
| if (ex->kind == ExternalKind::Table && ex->value == wasm.tables[0]->name) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| bool hasActiveSegments(Module& wasm) { |
| for (Index i = 0; i < wasm.memory.segments.size(); i++) { |
| if (!wasm.memory.segments[i].isPassive) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| bool needsBufferView(Module& wasm) { |
| if (!wasm.memory.exists) { |
| return false; |
| } |
| |
| // If there are any active segments, initActiveSegments needs access |
| // to bufferView. |
| if (hasActiveSegments(wasm)) { |
| return true; |
| } |
| |
| // The special support functions are emitted as part of the JS glue, if we |
| // need them. |
| bool need = false; |
| ModuleUtils::iterImportedFunctions(wasm, [&](Function* import) { |
| if (ABI::wasm2js::isHelper(import->base)) { |
| need = true; |
| } |
| }); |
| return need; |
| } |
| |
| IString stringToIString(std::string str) { return IString(str.c_str(), false); } |
| |
| // Used when taking a wasm name and generating a JS identifier. Each scope here |
| // is used to ensure that all names have a unique name but the same wasm name |
| // within a scope always resolves to the same symbol. |
| // |
| // Export: Export names |
| // Top: The main scope which contains functions and globals |
| // Local: Local variables in a function. |
| // Label: Label identifiers in a function |
| enum class NameScope { |
| Export, |
| Top, |
| Local, |
| Label, |
| Max, |
| }; |
| |
| // |
| // Wasm2JSBuilder - converts a WebAssembly module's functions into JS |
| // |
| // Wasm-to-JS is tricky because wasm doesn't distinguish |
| // statements and expressions, or in other words, things like `break` and `if` |
| // can show up in places where JS can't handle them, like inside an a loop's |
| // condition check. For that reason we use flat IR here. |
| // We do optimize it later, to allow some nesting, but we avoid |
| // non-JS-compatible nesting like block return values control flow in an if |
| // condition, etc. |
| // |
| |
| class Wasm2JSBuilder { |
| public: |
| struct Flags { |
| // see wasm2js.cpp for details |
| bool debug = false; |
| bool pedantic = false; |
| bool allowAsserts = false; |
| bool emscripten = false; |
| bool deterministic = false; |
| std::string symbolsFile; |
| }; |
| |
| Wasm2JSBuilder(Flags f, PassOptions options_) : flags(f), options(options_) { |
| // We don't try to model wasm's trapping precisely - if we did, each load |
| // and store would need to do a check. Given that, we can just ignore |
| // implicit traps like those when optimizing. (When not optimizing, it's |
| // nice to see codegen that matches wasm more precisely.) |
| if (options.optimizeLevel > 0) { |
| options.ignoreImplicitTraps = true; |
| } |
| } |
| |
| Ref processWasm(Module* wasm, Name funcName = ASM_FUNC); |
| Ref processFunction(Module* wasm, Function* func, bool standalone = false); |
| Ref processStandaloneFunction(Module* wasm, Function* func) { |
| return processFunction(wasm, func, true); |
| } |
| |
| // The second pass on an expression: process it fully, generating |
| // JS |
| Ref processFunctionBody(Module* m, Function* func, bool standalone); |
| |
| // Get a temp var. |
| IString getTemp(Type type, Function* func) { |
| IString ret; |
| TODO_SINGLE_COMPOUND(type); |
| if (frees[type.getBasic()].size() > 0) { |
| ret = frees[type.getBasic()].back(); |
| frees[type.getBasic()].pop_back(); |
| } else { |
| size_t index = temps[type.getBasic()]++; |
| ret = IString((std::string("wasm2js_") + type.toString() + "$" + |
| std::to_string(index)) |
| .c_str(), |
| false); |
| } |
| if (func->localIndices.find(ret) == func->localIndices.end()) { |
| Builder::addVar(func, ret, type); |
| } |
| return ret; |
| } |
| |
| // Free a temp var. |
| void freeTemp(Type type, IString temp) { |
| TODO_SINGLE_COMPOUND(type); |
| frees[type.getBasic()].push_back(temp); |
| } |
| |
| // Generates a mangled name from `name` within the specified scope. |
| // |
| // The goal of this function is to ensure that all identifiers in JS ar |
| // unique. Otherwise there can be clashes with locals and functions and cause |
| // unwanted name shadowing. |
| // |
| // The returned string from this function is constant for a particular `name` |
| // within a `scope`. Or in other words, the same `name` and `scope` pair will |
| // always return the same result. If `scope` changes, however, the return |
| // value may differ even if the same `name` is passed in. |
| IString fromName(Name name, NameScope scope) { |
| // TODO: checking names do not collide after mangling |
| |
| // First up check our cached of mangled names to avoid doing extra work |
| // below |
| auto& map = wasmNameToMangledName[(int)scope]; |
| auto it = map.find(name.c_str()); |
| if (it != map.end()) { |
| return it->second; |
| } |
| // The mangled names in our scope. |
| auto& scopeMangledNames = mangledNames[(int)scope]; |
| // In some cases (see below) we need to also check the Top scope. |
| auto& topMangledNames = mangledNames[int(NameScope::Top)]; |
| |
| // This is the first time we've seen the `name` and `scope` pair. Generate a |
| // globally unique name based on `name` and then register that in our cache |
| // and return it. |
| // |
| // Identifiers here generated are of the form `${name}_${n}` where `_${n}` |
| // is omitted if `n==0` and otherwise `n` is just looped over to find the |
| // next unused identifier. |
| IString ret; |
| for (int i = 0;; i++) { |
| std::ostringstream out; |
| out << name.c_str(); |
| if (i > 0) { |
| out << "_" << i; |
| } |
| auto mangled = asmangle(out.str()); |
| ret = stringToIString(mangled); |
| if (scopeMangledNames.count(ret)) { |
| // When export names collide things may be confusing, as this is |
| // observable externally by the person using the JS. Report a warning. |
| if (scope == NameScope::Export) { |
| std::cerr << "wasm2js: warning: export names colliding: " << mangled |
| << '\n'; |
| } |
| continue; |
| } |
| // The Local scope is special: a Local name must not collide with a Top |
| // name, as they are in a single namespace in JS and can conflict: |
| // |
| // function foo(bar) { |
| // var bar = 0; |
| // } |
| // function bar() { .. |
| if (scope == NameScope::Local && topMangledNames.count(ret)) { |
| continue; |
| } |
| // We found a good name, use it. |
| scopeMangledNames.insert(ret); |
| map[name.c_str()] = ret; |
| return ret; |
| } |
| } |
| |
| private: |
| Flags flags; |
| PassOptions options; |
| |
| // How many temp vars we need |
| std::vector<size_t> temps; // type => num temps |
| // Which are currently free to use |
| std::vector<std::vector<IString>> frees; // type => list of free names |
| |
| // Mangled names cache by interned names. |
| // Utilizes the usually reused underlying cstring's pointer as the key. |
| std::unordered_map<const void*, IString> |
| wasmNameToMangledName[(int)NameScope::Max]; |
| // Set of all mangled names in each scope. |
| std::unordered_set<IString> mangledNames[(int)NameScope::Max]; |
| |
| // If a function is callable from outside, we'll need to cast the inputs |
| // and our return value. Otherwise, internally, casts are only needed |
| // on operations. |
| std::unordered_set<Name> functionsCallableFromOutside; |
| |
| void addBasics(Ref ast, Module* wasm); |
| void addFunctionImport(Ref ast, Function* import); |
| void addGlobalImport(Ref ast, Global* import); |
| void addTable(Ref ast, Module* wasm); |
| void addStart(Ref ast, Module* wasm); |
| void addExports(Ref ast, Module* wasm); |
| void addGlobal(Ref ast, Global* global); |
| void addMemoryFuncs(Ref ast, Module* wasm); |
| void addMemoryGrowFunc(Ref ast, Module* wasm); |
| |
| Wasm2JSBuilder() = delete; |
| Wasm2JSBuilder(const Wasm2JSBuilder&) = delete; |
| Wasm2JSBuilder& operator=(const Wasm2JSBuilder&) = delete; |
| }; |
| |
| Ref Wasm2JSBuilder::processWasm(Module* wasm, Name funcName) { |
| // Scan the wasm for important things. |
| for (auto& exp : wasm->exports) { |
| if (exp->kind == ExternalKind::Function) { |
| functionsCallableFromOutside.insert(exp->value); |
| } |
| } |
| ElementUtils::iterAllElementFunctionNames( |
| wasm, [&](Name name) { functionsCallableFromOutside.insert(name); }); |
| |
| // Ensure the scratch memory helpers. |
| // If later on they aren't needed, we'll clean them up. |
| ABI::wasm2js::ensureHelpers(wasm); |
| |
| // Process the code, and optimize if relevant. |
| // First, do the lowering to a JS-friendly subset. |
| { |
| PassRunner runner(wasm, options); |
| runner.add(make_unique<AutoDrop>()); |
| // TODO: only legalize if necessary - emscripten would already do so, and |
| // likely other toolchains. but spec test suite needs that. |
| runner.add("legalize-js-interface"); |
| // Before lowering non-JS operations we can optimize some instructions which |
| // may simplify next passes |
| if (options.optimizeLevel > 0) { |
| runner.add("optimize-for-js"); |
| } |
| // First up remove as many non-JS operations we can, including things like |
| // 64-bit integer multiplication/division, `f32.nearest` instructions, etc. |
| // This may inject intrinsics which use i64 so it needs to be run before the |
| // i64-to-i32 lowering pass. |
| runner.add("remove-non-js-ops"); |
| // Currently the i64-to-32 lowering pass requires that `flatten` be run |
| // before it to produce correct code. For some more details about this see |
| // #1480 |
| runner.add("flatten"); |
| runner.add("i64-to-i32-lowering"); |
| runner.add("alignment-lowering"); |
| // Next, optimize that as best we can. This should not generate |
| // non-JS-friendly things. |
| if (options.optimizeLevel > 0) { |
| // It is especially import to propagate constants after the lowering. |
| // However, this can be a slow operation, especially after flattening; |
| // some local simplification helps. |
| if (options.optimizeLevel >= 3 || options.shrinkLevel >= 1) { |
| runner.add("simplify-locals-nonesting"); |
| runner.add("precompute-propagate"); |
| // Avoiding reinterpretation is helped by propagation. We also run |
| // it later down as default optimizations help as well. |
| runner.add("avoid-reinterprets"); |
| } |
| runner.addDefaultOptimizationPasses(); |
| runner.add("avoid-reinterprets"); |
| } |
| // Finally, get the code into the flat form we need for wasm2js itself, and |
| // optimize that a little in a way that keeps that property. |
| runner.add("flatten"); |
| // Regardless of optimization level, run some simple optimizations to undo |
| // some of the effects of flattening. |
| runner.add("simplify-locals-notee-nostructure"); |
| // Some operations can be very slow if we didn't run full optimizations |
| // earlier, so don't run them automatically. |
| if (options.optimizeLevel > 0) { |
| runner.add("remove-unused-names"); |
| runner.add("merge-blocks"); |
| runner.add("reorder-locals"); |
| runner.add("coalesce-locals"); |
| } |
| runner.add("reorder-locals"); |
| runner.add("vacuum"); |
| runner.add("remove-unused-module-elements"); |
| // DCE at the end to make sure all IR nodes have valid types for conversion |
| // to JS, and not unreachable. |
| runner.add("dce"); |
| runner.setDebug(flags.debug); |
| runner.run(); |
| } |
| |
| if (flags.symbolsFile.size() > 0) { |
| Output out(flags.symbolsFile, wasm::Flags::Text); |
| Index i = 0; |
| for (auto& func : wasm->functions) { |
| out.getStream() << i++ << ':' << func->name.str << '\n'; |
| } |
| } |
| |
| #ifndef NDEBUG |
| if (!WasmValidator().validate(*wasm)) { |
| std::cout << *wasm << '\n'; |
| Fatal() << "error in validating wasm2js output"; |
| } |
| #endif |
| |
| Ref ret = ValueBuilder::makeToplevel(); |
| Ref asmFunc = ValueBuilder::makeFunction(funcName); |
| ret[1]->push_back(asmFunc); |
| ValueBuilder::appendArgumentToFunction(asmFunc, ENV); |
| |
| // add memory import |
| if (wasm->memory.exists) { |
| if (wasm->memory.imported()) { |
| // find memory and buffer in imports |
| Ref theVar = ValueBuilder::makeVar(); |
| asmFunc[3]->push_back(theVar); |
| ValueBuilder::appendToVar( |
| theVar, |
| "memory", |
| ValueBuilder::makeDot(ValueBuilder::makeName(ENV), |
| ValueBuilder::makeName(wasm->memory.base))); |
| |
| // Assign `buffer = memory.buffer` |
| Ref buf = ValueBuilder::makeVar(); |
| asmFunc[3]->push_back(buf); |
| ValueBuilder::appendToVar( |
| buf, |
| BUFFER, |
| ValueBuilder::makeDot(ValueBuilder::makeName("memory"), |
| ValueBuilder::makeName("buffer"))); |
| |
| // If memory is growable, override the imported memory's grow method to |
| // ensure so that when grow is called from the output it works as expected |
| if (wasm->memory.max > wasm->memory.initial) { |
| asmFunc[3]->push_back( |
| ValueBuilder::makeStatement(ValueBuilder::makeBinary( |
| ValueBuilder::makeDot(ValueBuilder::makeName("memory"), |
| ValueBuilder::makeName("grow")), |
| SET, |
| ValueBuilder::makeName(WASM_MEMORY_GROW)))); |
| } |
| } else { |
| Ref theVar = ValueBuilder::makeVar(); |
| asmFunc[3]->push_back(theVar); |
| ValueBuilder::appendToVar( |
| theVar, |
| BUFFER, |
| ValueBuilder::makeNew(ValueBuilder::makeCall( |
| ValueBuilder::makeName("ArrayBuffer"), |
| ValueBuilder::makeInt(Address::address32_t(wasm->memory.initial.addr * |
| Memory::kPageSize))))); |
| } |
| } |
| |
| // add imported tables |
| ModuleUtils::iterImportedTables(*wasm, [&](Table* table) { |
| Ref theVar = ValueBuilder::makeVar(); |
| asmFunc[3]->push_back(theVar); |
| ValueBuilder::appendToVar( |
| theVar, |
| FUNCTION_TABLE, |
| ValueBuilder::makeDot(ValueBuilder::makeName(ENV), table->base)); |
| }); |
| |
| // create heaps, etc |
| addBasics(asmFunc[3], wasm); |
| ModuleUtils::iterImportedFunctions( |
| *wasm, [&](Function* import) { addFunctionImport(asmFunc[3], import); }); |
| ModuleUtils::iterImportedGlobals( |
| *wasm, [&](Global* import) { addGlobalImport(asmFunc[3], import); }); |
| |
| // Note the names of functions. We need to do this here as when generating |
| // mangled local names we need them not to conflict with these (see fromName) |
| // so we can't wait until we parse each function to note its name. |
| for (auto& f : wasm->functions) { |
| fromName(f->name, NameScope::Top); |
| } |
| |
| // globals |
| bool generateFetchHighBits = false; |
| ModuleUtils::iterDefinedGlobals(*wasm, [&](Global* global) { |
| addGlobal(asmFunc[3], global); |
| if (flags.allowAsserts && global->name == INT64_TO_32_HIGH_BITS) { |
| generateFetchHighBits = true; |
| } |
| }); |
| if (flags.emscripten) { |
| asmFunc[3]->push_back( |
| ValueBuilder::makeName("// EMSCRIPTEN_START_FUNCS\n")); |
| } |
| // functions |
| ModuleUtils::iterDefinedFunctions(*wasm, [&](Function* func) { |
| asmFunc[3]->push_back(processFunction(wasm, func)); |
| }); |
| if (generateFetchHighBits) { |
| Builder builder(*wasm); |
| asmFunc[3]->push_back( |
| processFunction(wasm, |
| wasm->addFunction(builder.makeFunction( |
| WASM_FETCH_HIGH_BITS, |
| Signature(Type::none, Type::i32), |
| {}, |
| builder.makeReturn(builder.makeGlobalGet( |
| INT64_TO_32_HIGH_BITS, Type::i32)))))); |
| auto e = new Export(); |
| e->name = WASM_FETCH_HIGH_BITS; |
| e->value = WASM_FETCH_HIGH_BITS; |
| e->kind = ExternalKind::Function; |
| wasm->addExport(e); |
| } |
| if (flags.emscripten) { |
| asmFunc[3]->push_back(ValueBuilder::makeName("// EMSCRIPTEN_END_FUNCS\n")); |
| } |
| |
| if (needsBufferView(*wasm)) { |
| asmFunc[3]->push_back( |
| ValueBuilder::makeBinary(ValueBuilder::makeName("bufferView"), |
| SET, |
| ValueBuilder::makeName(HEAPU8))); |
| } |
| if (hasActiveSegments(*wasm)) { |
| asmFunc[3]->push_back( |
| ValueBuilder::makeCall(ValueBuilder::makeName("initActiveSegments"), |
| ValueBuilder::makeName(ENV))); |
| } |
| |
| addTable(asmFunc[3], wasm); |
| addStart(asmFunc[3], wasm); |
| addExports(asmFunc[3], wasm); |
| return ret; |
| } |
| |
| void Wasm2JSBuilder::addBasics(Ref ast, Module* wasm) { |
| if (wasm->memory.exists) { |
| // heaps, var HEAP8 = new global.Int8Array(buffer); etc |
| auto addHeap = [&](IString name, IString view) { |
| Ref theVar = ValueBuilder::makeVar(); |
| ast->push_back(theVar); |
| ValueBuilder::appendToVar(theVar, |
| name, |
| ValueBuilder::makeNew(ValueBuilder::makeCall( |
| view, ValueBuilder::makeName(BUFFER)))); |
| }; |
| addHeap(HEAP8, INT8ARRAY); |
| addHeap(HEAP16, INT16ARRAY); |
| addHeap(HEAP32, INT32ARRAY); |
| addHeap(HEAPU8, UINT8ARRAY); |
| addHeap(HEAPU16, UINT16ARRAY); |
| addHeap(HEAPU32, UINT32ARRAY); |
| addHeap(HEAPF32, FLOAT32ARRAY); |
| addHeap(HEAPF64, FLOAT64ARRAY); |
| } |
| // core asm.js imports |
| auto addMath = [&](IString name, IString base) { |
| Ref theVar = ValueBuilder::makeVar(); |
| ast->push_back(theVar); |
| ValueBuilder::appendToVar( |
| theVar, name, ValueBuilder::makeDot(ValueBuilder::makeName(MATH), base)); |
| }; |
| addMath(MATH_IMUL, IMUL); |
| addMath(MATH_FROUND, FROUND); |
| addMath(MATH_ABS, ABS); |
| addMath(MATH_CLZ32, CLZ32); |
| addMath(MATH_MIN, MIN); |
| addMath(MATH_MAX, MAX); |
| addMath(MATH_FLOOR, FLOOR); |
| addMath(MATH_CEIL, CEIL); |
| addMath(MATH_TRUNC, TRUNC); |
| addMath(MATH_SQRT, SQRT); |
| // abort function |
| Ref abortVar = ValueBuilder::makeVar(); |
| ast->push_back(abortVar); |
| ValueBuilder::appendToVar( |
| abortVar, |
| "abort", |
| ValueBuilder::makeDot(ValueBuilder::makeName(ENV), ABORT_FUNC)); |
| // TODO: this shouldn't be needed once we stop generating literal asm.js code |
| // NaN and Infinity variables |
| Ref nanVar = ValueBuilder::makeVar(); |
| ast->push_back(nanVar); |
| ValueBuilder::appendToVar(nanVar, "nan", ValueBuilder::makeName("NaN")); |
| Ref infinityVar = ValueBuilder::makeVar(); |
| ast->push_back(infinityVar); |
| ValueBuilder::appendToVar( |
| infinityVar, "infinity", ValueBuilder::makeName("Infinity")); |
| } |
| |
| void Wasm2JSBuilder::addFunctionImport(Ref ast, Function* import) { |
| // The scratch memory helpers are emitted in the glue, see code and comments |
| // below. |
| if (ABI::wasm2js::isHelper(import->base)) { |
| return; |
| } |
| Ref theVar = ValueBuilder::makeVar(); |
| ast->push_back(theVar); |
| // TODO: handle nested module imports |
| Ref module = ValueBuilder::makeName(ENV); |
| ValueBuilder::appendToVar( |
| theVar, |
| fromName(import->name, NameScope::Top), |
| ValueBuilder::makeDot(module, fromName(import->base, NameScope::Top))); |
| } |
| |
| void Wasm2JSBuilder::addGlobalImport(Ref ast, Global* import) { |
| Ref theVar = ValueBuilder::makeVar(); |
| ast->push_back(theVar); |
| // TODO: handle nested module imports |
| Ref module = ValueBuilder::makeName(ENV); |
| Ref value = |
| ValueBuilder::makeDot(module, fromName(import->base, NameScope::Top)); |
| if (import->type == Type::i32) { |
| value = makeJsCoercion(value, JS_INT); |
| } |
| ValueBuilder::appendToVar( |
| theVar, fromName(import->name, NameScope::Top), value); |
| } |
| |
| void Wasm2JSBuilder::addTable(Ref ast, Module* wasm) { |
| if (wasm->tables.size() == 0) { |
| return; |
| } |
| |
| bool perElementInit = false; |
| |
| // Emit a simple flat table as a JS array literal. Otherwise, |
| // emit assignments separately for each index. |
| Ref theArray = ValueBuilder::makeArray(); |
| for (auto& table : wasm->tables) { |
| if (!table->type.isFunction()) { |
| Fatal() << "wasm2js doesn't support non-function tables\n"; |
| } |
| |
| if (!table->imported()) { |
| TableUtils::FlatTable flat(*wasm, *table); |
| if (flat.valid) { |
| Name null("null"); |
| for (auto& name : flat.names) { |
| if (name.is()) { |
| name = fromName(name, NameScope::Top); |
| } else { |
| name = null; |
| } |
| ValueBuilder::appendToArray(theArray, ValueBuilder::makeName(name)); |
| } |
| } else { |
| perElementInit = true; |
| Ref initial = |
| ValueBuilder::makeInt(Address::address32_t(table->initial.addr)); |
| theArray = ValueBuilder::makeNew( |
| ValueBuilder::makeCall(IString("Array"), initial)); |
| } |
| } else { |
| perElementInit = true; |
| } |
| |
| if (isTableExported(*wasm)) { |
| // If the table is exported use a fake WebAssembly.Table object |
| // We don't handle the case where a table is both imported and exported. |
| if (table->imported()) { |
| Fatal() << "wasm2js doesn't support a table that is both imported and " |
| "exported\n"; |
| } |
| Ref theVar = ValueBuilder::makeVar(); |
| ast->push_back(theVar); |
| |
| Ref table = ValueBuilder::makeCall(IString("Table"), theArray); |
| ValueBuilder::appendToVar(theVar, FUNCTION_TABLE, table); |
| } else if (!table->imported()) { |
| // Otherwise if the table is internal (neither imported not exported). |
| // Just use a plain array in this case, avoiding the Table. |
| Ref theVar = ValueBuilder::makeVar(); |
| ast->push_back(theVar); |
| ValueBuilder::appendToVar(theVar, FUNCTION_TABLE, theArray); |
| } |
| |
| if (perElementInit) { |
| // TODO: optimize for size |
| ModuleUtils::iterTableSegments( |
| *wasm, table->name, [&](ElementSegment* segment) { |
| auto offset = segment->offset; |
| ElementUtils::iterElementSegmentFunctionNames( |
| segment, [&](Name entry, Index i) { |
| Ref index; |
| if (auto* c = offset->dynCast<Const>()) { |
| index = ValueBuilder::makeInt(c->value.geti32() + i); |
| } else if (auto* get = offset->dynCast<GlobalGet>()) { |
| index = ValueBuilder::makeBinary( |
| ValueBuilder::makeName( |
| stringToIString(asmangle(get->name.str))), |
| PLUS, |
| ValueBuilder::makeNum(i)); |
| } else { |
| WASM_UNREACHABLE("unexpected expr type"); |
| } |
| ast->push_back( |
| ValueBuilder::makeStatement(ValueBuilder::makeBinary( |
| ValueBuilder::makeSub(ValueBuilder::makeName(FUNCTION_TABLE), |
| index), |
| SET, |
| ValueBuilder::makeName(fromName(entry, NameScope::Top))))); |
| }); |
| }); |
| } |
| } |
| } |
| |
| void Wasm2JSBuilder::addStart(Ref ast, Module* wasm) { |
| if (wasm->start.is()) { |
| ast->push_back( |
| ValueBuilder::makeCall(fromName(wasm->start, NameScope::Top))); |
| } |
| } |
| |
| void Wasm2JSBuilder::addExports(Ref ast, Module* wasm) { |
| Ref exports = ValueBuilder::makeObject(); |
| for (auto& export_ : wasm->exports) { |
| switch (export_->kind) { |
| case ExternalKind::Function: { |
| ValueBuilder::appendToObjectWithQuotes( |
| exports, |
| fromName(export_->name, NameScope::Export), |
| ValueBuilder::makeName(fromName(export_->value, NameScope::Top))); |
| break; |
| } |
| case ExternalKind::Memory: { |
| Ref descs = ValueBuilder::makeObject(); |
| Ref growDesc = ValueBuilder::makeObject(); |
| ValueBuilder::appendToObjectWithQuotes( |
| descs, IString("grow"), growDesc); |
| if (wasm->memory.max > wasm->memory.initial) { |
| ValueBuilder::appendToObjectWithQuotes( |
| growDesc, |
| IString("value"), |
| ValueBuilder::makeName(WASM_MEMORY_GROW)); |
| } |
| Ref bufferDesc = ValueBuilder::makeObject(); |
| Ref bufferGetter = ValueBuilder::makeFunction(IString("")); |
| bufferGetter[3]->push_back( |
| ValueBuilder::makeReturn(ValueBuilder::makeName(BUFFER))); |
| ValueBuilder::appendToObjectWithQuotes( |
| bufferDesc, IString("get"), bufferGetter); |
| ValueBuilder::appendToObjectWithQuotes( |
| descs, IString("buffer"), bufferDesc); |
| Ref memory = ValueBuilder::makeCall( |
| ValueBuilder::makeDot(ValueBuilder::makeName(IString("Object")), |
| IString("create")), |
| ValueBuilder::makeDot(ValueBuilder::makeName(IString("Object")), |
| IString("prototype"))); |
| ValueBuilder::appendToCall(memory, descs); |
| ValueBuilder::appendToObjectWithQuotes( |
| exports, fromName(export_->name, NameScope::Export), memory); |
| break; |
| } |
| case ExternalKind::Table: { |
| ValueBuilder::appendToObjectWithQuotes( |
| exports, |
| fromName(export_->name, NameScope::Export), |
| ValueBuilder::makeName(FUNCTION_TABLE)); |
| break; |
| } |
| case ExternalKind::Global: { |
| Ref object = ValueBuilder::makeObject(); |
| |
| IString identName = fromName(export_->value, NameScope::Top); |
| |
| // getter |
| { |
| Ref block = ValueBuilder::makeBlock(); |
| |
| block[1]->push_back( |
| ValueBuilder::makeReturn(ValueBuilder::makeName(identName))); |
| |
| ValueBuilder::appendToObjectAsGetter(object, IString("value"), block); |
| } |
| |
| // setter |
| { |
| std::ostringstream buffer; |
| buffer << '_' << identName.c_str(); |
| auto setterParam = stringToIString(buffer.str()); |
| |
| auto block = ValueBuilder::makeBlock(); |
| |
| block[1]->push_back( |
| ValueBuilder::makeBinary(ValueBuilder::makeName(identName), |
| SET, |
| ValueBuilder::makeName(setterParam))); |
| |
| ValueBuilder::appendToObjectAsSetter( |
| object, IString("value"), setterParam, block); |
| } |
| |
| ValueBuilder::appendToObjectWithQuotes( |
| exports, fromName(export_->name, NameScope::Export), object); |
| |
| break; |
| } |
| case ExternalKind::Tag: |
| case ExternalKind::Invalid: |
| Fatal() << "unsupported export type: " << export_->name << "\n"; |
| } |
| } |
| if (wasm->memory.exists) { |
| addMemoryFuncs(ast, wasm); |
| } |
| ast->push_back( |
| ValueBuilder::makeStatement(ValueBuilder::makeReturn(exports))); |
| } |
| |
| void Wasm2JSBuilder::addGlobal(Ref ast, Global* global) { |
| if (auto* const_ = global->init->dynCast<Const>()) { |
| Ref theValue; |
| TODO_SINGLE_COMPOUND(const_->type); |
| switch (const_->type.getBasic()) { |
| case Type::i32: { |
| theValue = ValueBuilder::makeInt(const_->value.geti32()); |
| break; |
| } |
| case Type::f32: { |
| theValue = ValueBuilder::makeCall( |
| MATH_FROUND, |
| makeJsCoercion(ValueBuilder::makeDouble(const_->value.getf32()), |
| JS_DOUBLE)); |
| break; |
| } |
| case Type::f64: { |
| theValue = makeJsCoercion( |
| ValueBuilder::makeDouble(const_->value.getf64()), JS_DOUBLE); |
| break; |
| } |
| default: { |
| assert(false && "Top const type not supported"); |
| } |
| } |
| Ref theVar = ValueBuilder::makeVar(); |
| ast->push_back(theVar); |
| ValueBuilder::appendToVar( |
| theVar, fromName(global->name, NameScope::Top), theValue); |
| } else if (auto* get = global->init->dynCast<GlobalGet>()) { |
| Ref theVar = ValueBuilder::makeVar(); |
| ast->push_back(theVar); |
| ValueBuilder::appendToVar( |
| theVar, |
| fromName(global->name, NameScope::Top), |
| ValueBuilder::makeName(fromName(get->name, NameScope::Top))); |
| } else { |
| assert(false && "Top init type not supported"); |
| } |
| } |
| |
| Ref Wasm2JSBuilder::processFunction(Module* m, |
| Function* func, |
| bool standaloneFunction) { |
| if (standaloneFunction) { |
| // We are only printing a function, not a whole module. Prepare it for |
| // translation now (if there were a module, we'd have done this for all |
| // functions in parallel, earlier). |
| PassRunner runner(m); |
| // We only run a subset of all passes here. TODO: create a full valid module |
| // for each assertion body. |
| runner.add("flatten"); |
| runner.add("simplify-locals-notee-nostructure"); |
| runner.add("reorder-locals"); |
| runner.add("remove-unused-names"); |
| runner.add("vacuum"); |
| runner.runOnFunction(func); |
| } |
| |
| // We will be symbolically referring to all variables in the function, so make |
| // sure that everything has a name and it's unique. |
| Names::ensureNames(func); |
| Ref ret = ValueBuilder::makeFunction(fromName(func->name, NameScope::Top)); |
| frees.clear(); |
| frees.resize(std::max(Type::i32, std::max(Type::f32, Type::f64)) + 1); |
| temps.clear(); |
| temps.resize(std::max(Type::i32, std::max(Type::f32, Type::f64)) + 1); |
| temps[Type::i32] = temps[Type::f32] = temps[Type::f64] = 0; |
| // arguments |
| bool needCoercions = options.optimizeLevel == 0 || standaloneFunction || |
| functionsCallableFromOutside.count(func->name); |
| for (Index i = 0; i < func->getNumParams(); i++) { |
| IString name = fromName(func->getLocalNameOrGeneric(i), NameScope::Local); |
| ValueBuilder::appendArgumentToFunction(ret, name); |
| if (needCoercions) { |
| ret[3]->push_back(ValueBuilder::makeStatement(ValueBuilder::makeBinary( |
| ValueBuilder::makeName(name), |
| SET, |
| makeJsCoercion(ValueBuilder::makeName(name), |
| wasmToJsType(func->getLocalType(i)))))); |
| } |
| } |
| Ref theVar = ValueBuilder::makeVar(); |
| size_t theVarIndex = ret[3]->size(); |
| ret[3]->push_back(theVar); |
| // body |
| flattenAppend(ret, processFunctionBody(m, func, standaloneFunction)); |
| // vars, including new temp vars |
| for (Index i = func->getVarIndexBase(); i < func->getNumLocals(); i++) { |
| ValueBuilder::appendToVar( |
| theVar, |
| fromName(func->getLocalNameOrGeneric(i), NameScope::Local), |
| makeJsCoercedZero(wasmToJsType(func->getLocalType(i)))); |
| } |
| if (theVar[1]->size() == 0) { |
| ret[3]->splice(theVarIndex, 1); |
| } |
| // checks: all temp vars should be free at the end |
| assert(frees[Type::i32].size() == temps[Type::i32]); |
| assert(frees[Type::f32].size() == temps[Type::f32]); |
| assert(frees[Type::f64].size() == temps[Type::f64]); |
| return ret; |
| } |
| |
| Ref Wasm2JSBuilder::processFunctionBody(Module* m, |
| Function* func, |
| bool standaloneFunction) { |
| // Switches are tricky to handle - in wasm they often come with |
| // massively-nested "towers" of blocks, which if naively translated |
| // to JS may exceed parse recursion limits of VMs. Therefore even when |
| // not optimizing we work hard to emit minimal and minimally-nested |
| // switches. |
| // We do so by pre-scanning for br_tables and noting which of their |
| // targets can be hoisted up into them, e.g. |
| // |
| // (block $a |
| // (block $b |
| // (block $c |
| // (block $d |
| // (block $e |
| // (br_table $a $b $c $d $e (..)) |
| // ) |
| // ;; code X (for block $e) |
| // ;; implicit fallthrough - can be done in the switch too |
| // ) |
| // ;; code Y |
| // (br $c) ;; branch which is identical to a fallthrough |
| // ) |
| // ;; code Z |
| // (br $a) ;; skip some blocks - can't do this in a switch! |
| // ) |
| // ;; code W |
| // ) |
| // |
| // Every branch we see is a potential hazard - all targets must not |
| // be optimized into the switch, since they must be reached normally, |
| // unless they happen to be right after us, in which case it's just |
| // a fallthrough anyhow. |
| struct SwitchProcessor : public ExpressionStackWalker<SwitchProcessor> { |
| // A list of expressions we don't need to emit, as we are handling them |
| // in another way. |
| std::set<Expression*> unneededExpressions; |
| |
| struct SwitchCase { |
| Name target; |
| std::vector<Expression*> code; |
| SwitchCase(Name target) : target(target) {} |
| }; |
| |
| // The switch cases we found that we can hoist up. |
| std::map<Switch*, std::vector<SwitchCase>> hoistedSwitchCases; |
| |
| void visitSwitch(Switch* brTable) { |
| Index i = expressionStack.size() - 1; |
| assert(expressionStack[i] == brTable); |
| // A set of names we must stop at, since we've seen branches to them. |
| std::set<Name> namesBranchedTo; |
| while (1) { |
| // Stop if we are at the top level. |
| if (i == 0) { |
| break; |
| } |
| i--; |
| auto* child = expressionStack[i + 1]; |
| auto* curr = expressionStack[i]; |
| // Stop if the current node is not a block with the child in the |
| // first position, i.e., the classic switch pattern. |
| auto* block = curr->dynCast<Block>(); |
| if (!block || block->list[0] != child) { |
| break; |
| } |
| // Ignore the case of a name-less block for simplicity (merge-blocks |
| // would have removed it). |
| if (!block->name.is()) { |
| break; |
| } |
| // If we have already seen this block, stop here. |
| if (unneededExpressions.count(block)) { |
| // XXX FIXME we should probably abort the entire optimization |
| break; |
| } |
| auto& list = block->list; |
| if (child == brTable) { |
| // Nothing more to do here (we can in fact skip any code til |
| // the parent block). |
| continue; |
| } |
| // Ok, we are a block and our child in the first position is a |
| // block, and the neither is branched to - unless maybe the child |
| // branches to the parent, check that. Note how we treat the |
| // final element which may be a break that is a fallthrough. |
| Expression* unneededBr = nullptr; |
| for (Index j = 1; j < list.size(); j++) { |
| auto* item = list[j]; |
| auto newBranches = BranchUtils::getExitingBranches(item); |
| if (auto* br = item->dynCast<Break>()) { |
| if (j == list.size() - 1) { |
| if (!br->condition && br->name == block->name) { |
| // This is a natural, unnecessary-to-emit fallthrough. |
| unneededBr = br; |
| break; |
| } |
| } |
| } |
| namesBranchedTo.insert(newBranches.begin(), newBranches.end()); |
| } |
| if (namesBranchedTo.count(block->name)) { |
| break; |
| } |
| // We can move code after the child (reached by branching on the |
| // child) into the switch. |
| auto* childBlock = child->cast<Block>(); |
| hoistedSwitchCases[brTable].emplace_back(childBlock->name); |
| SwitchCase& case_ = hoistedSwitchCases[brTable].back(); |
| for (Index j = 1; j < list.size(); j++) { |
| auto* item = list[j]; |
| if (item != unneededBr) { |
| case_.code.push_back(item); |
| } |
| } |
| list.resize(1); |
| // Finally, mark the block as unneeded outside the switch. |
| unneededExpressions.insert(childBlock); |
| } |
| } |
| }; |
| |
| struct ExpressionProcessor |
| : public OverriddenVisitor<ExpressionProcessor, Ref> { |
| Wasm2JSBuilder* parent; |
| IString result; // TODO: remove |
| Function* func; |
| Module* module; |
| bool standaloneFunction; |
| |
| SwitchProcessor switchProcessor; |
| |
| ExpressionProcessor(Wasm2JSBuilder* parent, |
| Module* m, |
| Function* func, |
| bool standaloneFunction) |
| : parent(parent), func(func), module(m), |
| standaloneFunction(standaloneFunction) {} |
| |
| Ref process() { |
| switchProcessor.walk(func->body); |
| return visit(func->body, NO_RESULT); |
| } |
| |
| // A scoped temporary variable. |
| struct ScopedTemp { |
| Wasm2JSBuilder* parent; |
| Type type; |
| IString temp; // TODO: switch to indexes; avoid names |
| bool needFree; |
| // @param possible if provided, this is a variable we can use as our temp. |
| // it has already been allocated in a higher scope, and we |
| // can just assign to it as our result is going there |
| // anyhow. |
| ScopedTemp(Type type, |
| Wasm2JSBuilder* parent, |
| Function* func, |
| IString possible = NO_RESULT) |
| : parent(parent), type(type) { |
| assert(possible != EXPRESSION_RESULT); |
| if (possible == NO_RESULT) { |
| temp = parent->getTemp(type, func); |
| needFree = true; |
| } else { |
| temp = possible; |
| needFree = false; |
| } |
| } |
| ~ScopedTemp() { |
| if (needFree) { |
| parent->freeTemp(type, temp); |
| } |
| } |
| |
| IString getName() { return temp; } |
| Ref getAstName() { return ValueBuilder::makeName(temp); } |
| }; |
| |
| Ref visit(Expression* curr, IString nextResult) { |
| IString old = result; |
| result = nextResult; |
| Ref ret = OverriddenVisitor::visit(curr); |
| // keep it consistent for the rest of this frame, which may call visit on |
| // multiple children |
| result = old; |
| return ret; |
| } |
| |
| Ref visit(Expression* curr, ScopedTemp& temp) { |
| return visit(curr, temp.temp); |
| } |
| |
| Ref visitAndAssign(Expression* curr, IString result) { |
| assert(result != NO_RESULT); |
| Ref ret = visit(curr, result); |
| return ValueBuilder::makeStatement( |
| ValueBuilder::makeBinary(ValueBuilder::makeName(result), SET, ret)); |
| } |
| |
| Ref visitAndAssign(Expression* curr, ScopedTemp& temp) { |
| return visitAndAssign(curr, temp.getName()); |
| } |
| |
| // Expressions with control flow turn into a block, which we must |
| // then handle, even if we are an expression. |
| bool isBlock(Ref ast) { return !!ast && ast->isArray() && ast[0] == BLOCK; } |
| |
| Ref blockify(Ref ast) { |
| if (isBlock(ast)) { |
| return ast; |
| } |
| Ref ret = ValueBuilder::makeBlock(); |
| ret[1]->push_back(ValueBuilder::makeStatement(ast)); |
| return ret; |
| } |
| |
| // Breaks to the top of a loop should be emitted as continues, to that |
| // loop's main label |
| std::unordered_set<Name> continueLabels; |
| |
| IString fromName(Name name, NameScope scope) { |
| return parent->fromName(name, scope); |
| } |
| |
| // Visitors |
| |
| Ref visitBlock(Block* curr) { |
| if (switchProcessor.unneededExpressions.count(curr)) { |
| // We have had our tail hoisted into a switch that is nested in our |
| // first position, so we don't need to emit that code again, or |
| // ourselves in fact. |
| return visit(curr->list[0], NO_RESULT); |
| } |
| Ref ret = ValueBuilder::makeBlock(); |
| size_t size = curr->list.size(); |
| for (size_t i = 0; i < size; i++) { |
| flattenAppend( |
| ret, ValueBuilder::makeStatement(visit(curr->list[i], NO_RESULT))); |
| } |
| if (curr->name.is()) { |
| ret = |
| ValueBuilder::makeLabel(fromName(curr->name, NameScope::Label), ret); |
| } |
| return ret; |
| } |
| |
| Ref visitIf(If* curr) { |
| Ref condition = visit(curr->condition, EXPRESSION_RESULT); |
| Ref ifTrue = visit(curr->ifTrue, NO_RESULT); |
| Ref ifFalse; |
| if (curr->ifFalse) { |
| ifFalse = visit(curr->ifFalse, NO_RESULT); |
| } |
| return ValueBuilder::makeIf(condition, ifTrue, ifFalse); // simple if |
| } |
| |
| Ref visitLoop(Loop* curr) { |
| Name asmLabel = curr->name; |
| continueLabels.insert(asmLabel); |
| Ref body = visit(curr->body, result); |
| // if we can reach the end of the block, we must leave the while (1) loop |
| if (curr->body->type != Type::unreachable) { |
| assert(curr->body->type == Type::none); // flat IR |
| body = blockify(body); |
| flattenAppend( |
| body, ValueBuilder::makeBreak(fromName(asmLabel, NameScope::Label))); |
| } |
| Ref ret = ValueBuilder::makeWhile(ValueBuilder::makeInt(1), body); |
| return ValueBuilder::makeLabel(fromName(asmLabel, NameScope::Label), ret); |
| } |
| |
| Ref makeBreakOrContinue(Name name) { |
| if (continueLabels.count(name)) { |
| return ValueBuilder::makeContinue(fromName(name, NameScope::Label)); |
| } else { |
| return ValueBuilder::makeBreak(fromName(name, NameScope::Label)); |
| } |
| } |
| |
| Ref visitBreak(Break* curr) { |
| if (curr->condition) { |
| // we need an equivalent to an if here, so use that code |
| Break fakeBreak = *curr; |
| fakeBreak.condition = nullptr; |
| If fakeIf; |
| fakeIf.condition = curr->condition; |
| fakeIf.ifTrue = &fakeBreak; |
| return visit(&fakeIf, result); |
| } |
| return makeBreakOrContinue(curr->name); |
| } |
| |
| Expression* defaultBody = nullptr; // default must be last in asm.js |
| |
| Ref visitSwitch(Switch* curr) { |
| // Even without optimizations, we work hard here to emit minimal and |
| // especially minimally-nested code, since otherwise we may get block |
| // nesting of a size that JS engines can't handle. |
| Ref condition = visit(curr->condition, EXPRESSION_RESULT); |
| Ref theSwitch = |
| ValueBuilder::makeSwitch(makeJsCoercion(condition, JS_INT)); |
| // First, group the switch targets. |
| std::map<Name, std::vector<Index>> targetIndexes; |
| for (size_t i = 0; i < curr->targets.size(); i++) { |
| targetIndexes[curr->targets[i]].push_back(i); |
| } |
| // Emit first any hoisted groups. |
| auto& hoistedCases = switchProcessor.hoistedSwitchCases[curr]; |
| std::set<Name> emittedTargets; |
| bool hoistedEndsWithUnreachable = false; |
| for (auto& case_ : hoistedCases) { |
| auto target = case_.target; |
| auto& code = case_.code; |
| emittedTargets.insert(target); |
| if (target != curr->default_) { |
| auto& indexes = targetIndexes[target]; |
| for (auto i : indexes) { |
| ValueBuilder::appendCaseToSwitch(theSwitch, |
| ValueBuilder::makeNum(i)); |
| } |
| } else { |
| ValueBuilder::appendDefaultToSwitch(theSwitch); |
| } |
| for (auto* c : code) { |
| ValueBuilder::appendCodeToSwitch( |
| theSwitch, blockify(visit(c, NO_RESULT)), false); |
| hoistedEndsWithUnreachable = c->type == Type::unreachable; |
| } |
| } |
| // After the hoisted cases, if any remain we must make sure not to |
| // fall through into them. If no code was hoisted, this is unnecessary, |
| // and if the hoisted code ended with an unreachable it also is not |
| // necessary. |
| bool stoppedFurtherFallthrough = false; |
| auto stopFurtherFallthrough = [&]() { |
| if (!stoppedFurtherFallthrough && !hoistedCases.empty() && |
| !hoistedEndsWithUnreachable) { |
| stoppedFurtherFallthrough = true; |
| ValueBuilder::appendCodeToSwitch( |
| theSwitch, blockify(ValueBuilder::makeBreak(IString())), false); |
| } |
| }; |
| |
| // Emit any remaining groups by just emitting branches to their code, |
| // which will appear outside the switch. |
| for (auto& [target, indexes] : targetIndexes) { |
| if (emittedTargets.count(target)) { |
| continue; |
| } |
| stopFurtherFallthrough(); |
| if (target != curr->default_) { |
| for (auto i : indexes) { |
| ValueBuilder::appendCaseToSwitch(theSwitch, |
| ValueBuilder::makeNum(i)); |
| } |
| ValueBuilder::appendCodeToSwitch( |
| theSwitch, blockify(makeBreakOrContinue(target)), false); |
| } else { |
| // For the group going to the same place as the default, we can just |
| // emit the default itself, which we do at the end. |
| } |
| } |
| // TODO: if the group the default is in is not the largest, we can turn |
| // the largest into |
| // the default by using a local and a check on the range |
| if (!emittedTargets.count(curr->default_)) { |
| stopFurtherFallthrough(); |
| ValueBuilder::appendDefaultToSwitch(theSwitch); |
| ValueBuilder::appendCodeToSwitch( |
| theSwitch, blockify(makeBreakOrContinue(curr->default_)), false); |
| } |
| return theSwitch; |
| } |
| |
| Ref visitCall(Call* curr) { |
| if (curr->isReturn) { |
| Fatal() << "tail calls not yet supported in wasm2js"; |
| } |
| Ref theCall = |
| ValueBuilder::makeCall(fromName(curr->target, NameScope::Top)); |
| // For wasm => wasm calls, we don't need coercions. TODO: even imports |
| // might be safe? |
| bool needCoercions = parent->options.optimizeLevel == 0 || |
| standaloneFunction || |
| module->getFunction(curr->target)->imported(); |
| for (auto operand : curr->operands) { |
| auto value = visit(operand, EXPRESSION_RESULT); |
| if (needCoercions) { |
| value = makeJsCoercion(value, wasmToJsType(operand->type)); |
| } |
| theCall[2]->push_back(value); |
| } |
| if (needCoercions) { |
| theCall = makeJsCoercion(theCall, wasmToJsType(curr->type)); |
| } |
| return theCall; |
| } |
| |
| Ref visitCallIndirect(CallIndirect* curr) { |
| if (curr->isReturn) { |
| Fatal() << "tail calls not yet supported in wasm2js"; |
| } |
| // If the target has effects that interact with the operands, we must |
| // reorder it to the start. |
| bool mustReorder = false; |
| EffectAnalyzer targetEffects(parent->options, *module, curr->target); |
| if (targetEffects.hasAnything()) { |
| for (auto* operand : curr->operands) { |
| if (targetEffects.invalidates( |
| EffectAnalyzer(parent->options, *module, operand))) { |
| mustReorder = true; |
| break; |
| } |
| } |
| } |
| // Ensure the function pointer is a number. In general in wasm2js we are |
| // ok with true/false being present, as they are immediately cast to a |
| // number anyhow on their use. However, FUNCTION_TABLE[true] is *not* the |
| // same as FUNCTION_TABLE[1], so we must cast. This is a rare exception |
| // because FUNCTION_TABLE is just a normal JS object, not a typed array |
| // or a mathematical operation (all of which coerce to a number for us). |
| auto target = visit(curr->target, EXPRESSION_RESULT); |
| target = makeJsCoercion(target, JS_INT); |
| if (mustReorder) { |
| Ref ret; |
| ScopedTemp idx(Type::i32, parent, func); |
| std::vector<ScopedTemp*> temps; // TODO: utility class, with destructor? |
| for (auto* operand : curr->operands) { |
| temps.push_back(new ScopedTemp(operand->type, parent, func)); |
| IString temp = temps.back()->temp; |
| sequenceAppend(ret, visitAndAssign(operand, temp)); |
| } |
| sequenceAppend(ret, |
| ValueBuilder::makeBinary( |
| ValueBuilder::makeName(idx.getName()), SET, target)); |
| Ref theCall = ValueBuilder::makeCall(ValueBuilder::makeSub( |
| ValueBuilder::makeName(FUNCTION_TABLE), idx.getAstName())); |
| for (size_t i = 0; i < temps.size(); i++) { |
| IString temp = temps[i]->temp; |
| auto& operand = curr->operands[i]; |
| theCall[2]->push_back(makeJsCoercion(ValueBuilder::makeName(temp), |
| wasmToJsType(operand->type))); |
| } |
| theCall = makeJsCoercion(theCall, wasmToJsType(curr->type)); |
| sequenceAppend(ret, theCall); |
| for (auto temp : temps) { |
| delete temp; |
| } |
| return ret; |
| } else { |
| // Target has no side effects, emit simple code |
| Ref theCall = ValueBuilder::makeCall(ValueBuilder::makeSub( |
| ValueBuilder::makeName(FUNCTION_TABLE), target)); |
| for (auto* operand : curr->operands) { |
| theCall[2]->push_back(visit(operand, EXPRESSION_RESULT)); |
| } |
| theCall = makeJsCoercion(theCall, wasmToJsType(curr->type)); |
| return theCall; |
| } |
| } |
| |
| // TODO: remove |
| Ref makeSetVar(Expression* curr, |
| Expression* value, |
| Name name, |
| NameScope scope) { |
| return ValueBuilder::makeBinary( |
| ValueBuilder::makeName(fromName(name, scope)), |
| SET, |
| visit(value, EXPRESSION_RESULT)); |
| } |
| |
| Ref visitLocalGet(LocalGet* curr) { |
| return ValueBuilder::makeName( |
| fromName(func->getLocalNameOrGeneric(curr->index), NameScope::Local)); |
| } |
| |
| Ref visitLocalSet(LocalSet* curr) { |
| return makeSetVar(curr, |
| curr->value, |
| func->getLocalNameOrGeneric(curr->index), |
| NameScope::Local); |
| } |
| |
| Ref visitGlobalGet(GlobalGet* curr) { |
| return ValueBuilder::makeName(fromName(curr->name, NameScope::Top)); |
| } |
| |
| Ref visitGlobalSet(GlobalSet* curr) { |
| return makeSetVar(curr, curr->value, curr->name, NameScope::Top); |
| } |
| |
| Ref visitLoad(Load* curr) { |
| // Unaligned loads and stores must have been fixed up already. |
| assert(curr->align == 0 || curr->align == curr->bytes); |
| // normal load |
| Ref ptr = makePointer(curr->ptr, curr->offset); |
| Ref ret; |
| switch (curr->type.getBasic()) { |
| case Type::i32: { |
| switch (curr->bytes) { |
| case 1: |
| ret = ValueBuilder::makeSub( |
| ValueBuilder::makeName( |
| LoadUtils::isSignRelevant(curr) && curr->signed_ ? HEAP8 |
| : HEAPU8), |
| ValueBuilder::makePtrShift(ptr, 0)); |
| break; |
| case 2: |
| ret = ValueBuilder::makeSub( |
| ValueBuilder::makeName( |
| LoadUtils::isSignRelevant(curr) && curr->signed_ ? HEAP16 |
| : HEAPU16), |
| ValueBuilder::makePtrShift(ptr, 1)); |
| break; |
| case 4: |
| ret = ValueBuilder::makeSub(ValueBuilder::makeName(HEAP32), |
| ValueBuilder::makePtrShift(ptr, 2)); |
| break; |
| default: { |
| Fatal() << "Unhandled number of bytes in i32 load: " |
| << curr->bytes; |
| } |
| } |
| break; |
| } |
| case Type::f32: |
| ret = ValueBuilder::makeSub(ValueBuilder::makeName(HEAPF32), |
| ValueBuilder::makePtrShift(ptr, 2)); |
| break; |
| case Type::f64: |
| ret = ValueBuilder::makeSub(ValueBuilder::makeName(HEAPF64), |
| ValueBuilder::makePtrShift(ptr, 3)); |
| break; |
| default: { |
| Fatal() << "Unhandled type in load: " << curr->type; |
| } |
| } |
| if (curr->isAtomic) { |
| Ref call = ValueBuilder::makeCall( |
| ValueBuilder::makeDot(ValueBuilder::makeName(ATOMICS), LOAD)); |
| ValueBuilder::appendToCall(call, ret[1]); |
| ValueBuilder::appendToCall(call, ret[2]); |
| ret = call; |
| } |
| // Coercions are not actually needed, as if the user reads beyond valid |
| // memory, it's undefined behavior anyhow, and so we don't care much about |
| // slowness of undefined values etc. |
| bool needCoercions = |
| parent->options.optimizeLevel == 0 || standaloneFunction; |
| if (needCoercions) { |
| ret = makeJsCoercion(ret, wasmToJsType(curr->type)); |
| } |
| return ret; |
| } |
| |
| Ref visitStore(Store* curr) { |
| if (module->memory.initial < module->memory.max && |
| curr->type != Type::unreachable) { |
| // In JS, if memory grows then it is dangerous to write |
| // HEAP[f()] = .. |
| // or |
| // HEAP[..] = f() |
| // since if the call swaps HEAP (in a growth operation) then |
| // we will not actually write to the new version (since the |
| // semantics of JS mean we already looked at HEAP and have |
| // decided where to assign to). |
| if (!FindAll<Call>(curr->ptr).list.empty() || |
| !FindAll<Call>(curr->value).list.empty() || |
| !FindAll<CallIndirect>(curr->ptr).list.empty() || |
| !FindAll<CallIndirect>(curr->value).list.empty() || |
| !FindAll<MemoryGrow>(curr->ptr).list.empty() || |
| !FindAll<MemoryGrow>(curr->value).list.empty()) { |
| Ref ret; |
| ScopedTemp ptr(Type::i32, parent, func); |
| sequenceAppend(ret, visitAndAssign(curr->ptr, ptr)); |
| ScopedTemp value(curr->value->type, parent, func); |
| sequenceAppend(ret, visitAndAssign(curr->value, value)); |
| LocalGet getPtr; |
| getPtr.index = func->getLocalIndex(ptr.getName()); |
| getPtr.type = Type::i32; |
| LocalGet getValue; |
| getValue.index = func->getLocalIndex(value.getName()); |
| getValue.type = curr->value->type; |
| Store fakeStore = *curr; |
| fakeStore.ptr = &getPtr; |
| fakeStore.value = &getValue; |
| sequenceAppend(ret, visitStore(&fakeStore)); |
| return ret; |
| } |
| } |
| // FIXME if memory growth, store ptr cannot contain a function call |
| // also other stores to memory, check them, all makeSub's |
| // Unaligned loads and stores must have been fixed up already. |
| assert(curr->align == 0 || curr->align == curr->bytes); |
| // normal store |
| Ref ptr = makePointer(curr->ptr, curr->offset); |
| Ref value = visit(curr->value, EXPRESSION_RESULT); |
| Ref ret; |
| switch (curr->valueType.getBasic()) { |
| case Type::i32: { |
| switch (curr->bytes) { |
| case 1: |
| ret = ValueBuilder::makeSub(ValueBuilder::makeName(HEAP8), |
| ValueBuilder::makePtrShift(ptr, 0)); |
| break; |
| case 2: |
| ret = ValueBuilder::makeSub(ValueBuilder::makeName(HEAP16), |
| ValueBuilder::makePtrShift(ptr, 1)); |
| break; |
| case 4: |
| ret = ValueBuilder::makeSub(ValueBuilder::makeName(HEAP32), |
| ValueBuilder::makePtrShift(ptr, 2)); |
| break; |
| default: |
| abort(); |
| } |
| break; |
| } |
| case Type::f32: |
| ret = ValueBuilder::makeSub(ValueBuilder::makeName(HEAPF32), |
| ValueBuilder::makePtrShift(ptr, 2)); |
| break; |
| case Type::f64: |
| ret = ValueBuilder::makeSub(ValueBuilder::makeName(HEAPF64), |
| ValueBuilder::makePtrShift(ptr, 3)); |
| break; |
| default: { |
| Fatal() << "Unhandled type in store: " << curr->valueType; |
| } |
| } |
| if (curr->isAtomic) { |
| Ref call = ValueBuilder::makeCall( |
| ValueBuilder::makeDot(ValueBuilder::makeName(ATOMICS), STORE)); |
| ValueBuilder::appendToCall(call, ret[1]); |
| ValueBuilder::appendToCall(call, ret[2]); |
| ValueBuilder::appendToCall(call, value); |
| return call; |
| } |
| return ValueBuilder::makeBinary(ret, SET, value); |
| } |
| |
| Ref visitDrop(Drop* curr) { return visit(curr->value, NO_RESULT); } |
| |
| Ref visitConst(Const* curr) { |
| switch (curr->type.getBasic()) { |
| case Type::i32: |
| return ValueBuilder::makeInt(curr->value.geti32()); |
| // An i64 argument translates to two actual arguments to asm.js |
| // functions, so we do a bit of a hack here to get our one `Ref` to look |
| // like two function arguments. |
| case Type::i64: { |
| auto lo = (unsigned)curr->value.geti64(); |
| auto hi = (unsigned)(curr->value.geti64() >> 32); |
| std::ostringstream out; |
| out << lo << "," << hi; |
| std::string os = out.str(); |
| IString name(os.c_str(), false); |
| return ValueBuilder::makeName(name); |
| } |
| case Type::f32: { |
| Ref ret = ValueBuilder::makeCall(MATH_FROUND); |
| Const fake; |
| fake.value = Literal(double(curr->value.getf32())); |
| fake.type = Type::f64; |
| ret[2]->push_back(visitConst(&fake)); |
| return ret; |
| } |
| case Type::f64: { |
| double d = curr->value.getf64(); |
| if (d == 0 && std::signbit(d)) { // negative zero |
| return ValueBuilder::makeUnary( |
| PLUS, |
| ValueBuilder::makeUnary(MINUS, ValueBuilder::makeDouble(0))); |
| } |
| return ValueBuilder::makeUnary( |
| PLUS, ValueBuilder::makeDouble(curr->value.getf64())); |
| } |
| default: |
| Fatal() << "unknown const type"; |
| } |
| } |
| |
| Ref visitUnary(Unary* curr) { |
| // normal unary |
| switch (curr->type.getBasic()) { |
| case Type::i32: { |
| switch (curr->op) { |
| case ClzInt32: { |
| return ValueBuilder::makeCall( |
| MATH_CLZ32, visit(curr->value, EXPRESSION_RESULT)); |
| } |
| case CtzInt32: |
| case PopcntInt32: { |
| WASM_UNREACHABLE("i32 unary should have been removed"); |
| } |
| case EqZInt32: { |
| // XXX !x does change the type to bool, which is correct, but may |
| // be slower? |
| return ValueBuilder::makeUnary( |
| L_NOT, visit(curr->value, EXPRESSION_RESULT)); |
| } |
| case ReinterpretFloat32: { |
| ABI::wasm2js::ensureHelpers(module, |
| ABI::wasm2js::SCRATCH_STORE_F32); |
| ABI::wasm2js::ensureHelpers(module, |
| ABI::wasm2js::SCRATCH_LOAD_I32); |
| |
| Ref store = |
| ValueBuilder::makeCall(ABI::wasm2js::SCRATCH_STORE_F32, |
| visit(curr->value, EXPRESSION_RESULT)); |
| // 32-bit scratch memory uses index 2, so that it does not |
| // conflict with indexes 0, 1 which are used for 64-bit, see |
| // comment where |scratchBuffer| is defined. |
| Ref load = ValueBuilder::makeCall(ABI::wasm2js::SCRATCH_LOAD_I32, |
| ValueBuilder::makeInt(2)); |
| return ValueBuilder::makeSeq(store, load); |
| } |
| // generate (~~expr), what Emscripten does |
| case TruncSFloat32ToInt32: |
| case TruncSFloat64ToInt32: |
| case TruncSatSFloat32ToInt32: |
| case TruncSatSFloat64ToInt32: { |
| return ValueBuilder::makeUnary( |
| B_NOT, |
| ValueBuilder::makeUnary(B_NOT, |
| visit(curr->value, EXPRESSION_RESULT))); |
| } |
| // generate (~~expr >>> 0), what Emscripten does |
| case TruncUFloat32ToInt32: |
| case TruncUFloat64ToInt32: |
| case TruncSatUFloat32ToInt32: |
| case TruncSatUFloat64ToInt32: { |
| return ValueBuilder::makeBinary( |
| ValueBuilder::makeUnary( |
| B_NOT, |
| ValueBuilder::makeUnary( |
| B_NOT, visit(curr->value, EXPRESSION_RESULT))), |
| TRSHIFT, |
| ValueBuilder::makeNum(0)); |
| } |
| case ExtendS8Int32: { |
| return ValueBuilder::makeBinary( |
| ValueBuilder::makeBinary(visit(curr->value, EXPRESSION_RESULT), |
| LSHIFT, |
| ValueBuilder::makeNum(24)), |
| RSHIFT, |
| ValueBuilder::makeNum(24)); |
| } |
| case ExtendS16Int32: { |
| return ValueBuilder::makeBinary( |
| ValueBuilder::makeBinary(visit(curr->value, EXPRESSION_RESULT), |
| LSHIFT, |
| ValueBuilder::makeNum(16)), |
| RSHIFT, |
| ValueBuilder::makeNum(16)); |
| } |
| default: |
| WASM_UNREACHABLE("unhandled unary"); |
| } |
| } |
| case Type::f32: |
| case Type::f64: { |
| Ref ret; |
| switch (curr->op) { |
| case NegFloat32: |
| case NegFloat64: |
| ret = ValueBuilder::makeUnary( |
| MINUS, visit(curr->value, EXPRESSION_RESULT)); |
| break; |
| case AbsFloat32: |
| case AbsFloat64: |
| ret = ValueBuilder::makeCall( |
| MATH_ABS, visit(curr->value, EXPRESSION_RESULT)); |
| break; |
| case CeilFloat32: |
| case CeilFloat64: |
| ret = ValueBuilder::makeCall( |
| MATH_CEIL, visit(curr->value, EXPRESSION_RESULT)); |
| break; |
| case FloorFloat32: |
| case FloorFloat64: |
| ret = ValueBuilder::makeCall( |
| MATH_FLOOR, visit(curr->value, EXPRESSION_RESULT)); |
| break; |
| case TruncFloat32: |
| case TruncFloat64: |
| ret = ValueBuilder::makeCall( |
| MATH_TRUNC, visit(curr->value, EXPRESSION_RESULT)); |
| break; |
| case SqrtFloat32: |
| case SqrtFloat64: |
| ret = ValueBuilder::makeCall( |
| MATH_SQRT, visit(curr->value, EXPRESSION_RESULT)); |
| break; |
| case PromoteFloat32: |
| return makeJsCoercion(visit(curr->value, EXPRESSION_RESULT), |
| JS_DOUBLE); |
| case DemoteFloat64: |
| return makeJsCoercion(visit(curr->value, EXPRESSION_RESULT), |
| JS_FLOAT); |
| case ReinterpretInt32: { |
| ABI::wasm2js::ensureHelpers(module, |
| ABI::wasm2js::SCRATCH_STORE_I32); |
| ABI::wasm2js::ensureHelpers(module, |
| ABI::wasm2js::SCRATCH_LOAD_F32); |
| |
| // 32-bit scratch memory uses index 2, so that it does not |
| // conflict with indexes 0, 1 which are used for 64-bit, see |
| // comment where |scratchBuffer| is defined. |
| Ref store = |
| ValueBuilder::makeCall(ABI::wasm2js::SCRATCH_STORE_I32, |
| ValueBuilder::makeNum(2), |
| visit(curr->value, EXPRESSION_RESULT)); |
| Ref load = ValueBuilder::makeCall(ABI::wasm2js::SCRATCH_LOAD_F32); |
| return ValueBuilder::makeSeq(store, load); |
| } |
| // Coerce the integer to a float as emscripten does |
| case ConvertSInt32ToFloat32: |
| return makeJsCoercion( |
| makeJsCoercion(visit(curr->value, EXPRESSION_RESULT), JS_INT), |
| JS_FLOAT); |
| case ConvertSInt32ToFloat64: |
| return makeJsCoercion( |
| makeJsCoercion(visit(curr->value, EXPRESSION_RESULT), JS_INT), |
| JS_DOUBLE); |
| |
| // Generate (expr >>> 0), followed by a coercion |
| case ConvertUInt32ToFloat32: |
| return makeJsCoercion( |
| ValueBuilder::makeBinary(visit(curr->value, EXPRESSION_RESULT), |
| TRSHIFT, |
| ValueBuilder::makeInt(0)), |
| JS_FLOAT); |
| case ConvertUInt32ToFloat64: |
| return makeJsCoercion( |
| ValueBuilder::makeBinary(visit(curr->value, EXPRESSION_RESULT), |
| TRSHIFT, |
| ValueBuilder::makeInt(0)), |
| JS_DOUBLE); |
| // TODO: more complex unary conversions |
| case NearestFloat32: |
| case NearestFloat64: |
| WASM_UNREACHABLE( |
| "operation should have been removed in previous passes"); |
| |
| default: |
| WASM_UNREACHABLE("unhandled unary float operator"); |
| } |
| if (curr->type == Type::f32) { // doubles need much less coercing |
| return makeJsCoercion(ret, JS_FLOAT); |
| } |
| return ret; |
| } |
| default: { |
| Fatal() << "Unhandled type in unary: " << curr; |
| } |
| } |
| } |
| |
| Ref visitBinary(Binary* curr) { |
| // normal binary |
| Ref left = visit(curr->left, EXPRESSION_RESULT); |
| Ref right = visit(curr->right, EXPRESSION_RESULT); |
| Ref ret; |
| switch (curr->type.getBasic()) { |
| case Type::i32: { |
| switch (curr->op) { |
| case AddInt32: |
| ret = ValueBuilder::makeBinary(left, PLUS, right); |
| break; |
| case SubInt32: |
| ret = ValueBuilder::makeBinary(left, MINUS, right); |
| break; |
| case MulInt32: { |
| if (curr->type == Type::i32) { |
| // TODO: when one operand is a small int, emit a multiply |
| return ValueBuilder::makeCall(MATH_IMUL, left, right); |
| } else { |
| return ValueBuilder::makeBinary(left, MUL, right); |
| } |
| } |
| case DivSInt32: |
| ret = ValueBuilder::makeBinary(makeSigning(left, JS_SIGNED), |
| DIV, |
| makeSigning(right, JS_SIGNED)); |
| break; |
| case DivUInt32: |
| ret = ValueBuilder::makeBinary(makeSigning(left, JS_UNSIGNED), |
| DIV, |
| makeSigning(right, JS_UNSIGNED)); |
| break; |
| case RemSInt32: |
| ret = ValueBuilder::makeBinary(makeSigning(left, JS_SIGNED), |
| MOD, |
| makeSigning(right, JS_SIGNED)); |
| break; |
| case RemUInt32: |
| ret = ValueBuilder::makeBinary(makeSigning(left, JS_UNSIGNED), |
| MOD, |
| makeSigning(right, JS_UNSIGNED)); |
| break; |
| case AndInt32: |
| ret = ValueBuilder::makeBinary(left, AND, right); |
| break; |
| case OrInt32: |
| ret = ValueBuilder::makeBinary(left, OR, right); |
| break; |
| case XorInt32: |
| ret = ValueBuilder::makeBinary(left, XOR, right); |
| break; |
| case ShlInt32: |
| ret = ValueBuilder::makeBinary(left, LSHIFT, right); |
| break; |
| case ShrUInt32: |
| ret = ValueBuilder::makeBinary(left, TRSHIFT, right); |
| break; |
| case ShrSInt32: |
| ret = ValueBuilder::makeBinary(left, RSHIFT, right); |
| break; |
| case EqInt32: { |
| return ValueBuilder::makeBinary(makeSigning(left, JS_SIGNED), |
| EQ, |
| makeSigning(right, JS_SIGNED)); |
| } |
| case NeInt32: { |
| return ValueBuilder::makeBinary(makeSigning(left, JS_SIGNED), |
| NE, |
| makeSigning(right, JS_SIGNED)); |
| } |
| case LtSInt32: |
| return ValueBuilder::makeBinary(makeSigning(left, JS_SIGNED), |
| LT, |
| makeSigning(right, JS_SIGNED)); |
| case LtUInt32: |
| return ValueBuilder::makeBinary(makeSigning(left, JS_UNSIGNED), |
| LT, |
| makeSigning(right, JS_UNSIGNED)); |
| case LeSInt32: |
| return ValueBuilder::makeBinary(makeSigning(left, JS_SIGNED), |
| LE, |
| makeSigning(right, JS_SIGNED)); |
| case LeUInt32: |
| return ValueBuilder::makeBinary(makeSigning(left, JS_UNSIGNED), |
| LE, |
| makeSigning(right, JS_UNSIGNED)); |
| case GtSInt32: |
| return ValueBuilder::makeBinary(makeSigning(left, JS_SIGNED), |
| GT, |
| makeSigning(right, JS_SIGNED)); |
| case GtUInt32: |
| return ValueBuilder::makeBinary(makeSigning(left, JS_UNSIGNED), |
| GT, |
| makeSigning(right, JS_UNSIGNED)); |
| case GeSInt32: |
| return ValueBuilder::makeBinary(makeSigning(left, JS_SIGNED), |
| GE, |
| makeSigning(right, JS_SIGNED)); |
| case GeUInt32: |
| return ValueBuilder::makeBinary(makeSigning(left, JS_UNSIGNED), |
| GE, |
| makeSigning(right, JS_UNSIGNED)); |
| case EqFloat32: |
| case EqFloat64: |
| return ValueBuilder::makeBinary(left, EQ, right); |
| case NeFloat32: |
| case NeFloat64: |
| return ValueBuilder::makeBinary(left, NE, right); |
| case GeFloat32: |
| case GeFloat64: |
| return ValueBuilder::makeBinary(left, GE, right); |
| case GtFloat32: |
| case GtFloat64: |
| return ValueBuilder::makeBinary(left, GT, right); |
| case LeFloat32: |
| case LeFloat64: |
| return ValueBuilder::makeBinary(left, LE, right); |
| case LtFloat32: |
| case LtFloat64: |
| return ValueBuilder::makeBinary(left, LT, right); |
| case RotLInt32: |
| case RotRInt32: |
| WASM_UNREACHABLE("should be removed already"); |
| default: |
| WASM_UNREACHABLE("unhandled i32 binary operator"); |
| } |
| break; |
| } |
| case Type::f32: |
| case Type::f64: |
| switch (curr->op) { |
| case AddFloat32: |
| case AddFloat64: |
| ret = ValueBuilder::makeBinary(left, PLUS, right); |
| break; |
| case SubFloat32: |
| case SubFloat64: |
| ret = ValueBuilder::makeBinary(left, MINUS, right); |
| break; |
| case MulFloat32: |
| case MulFloat64: |
| ret = ValueBuilder::makeBinary(left, MUL, right); |
| break; |
| case DivFloat32: |
| case DivFloat64: |
| ret = ValueBuilder::makeBinary(left, DIV, right); |
| break; |
| case MinFloat32: |
| case MinFloat64: |
| ret = ValueBuilder::makeCall(MATH_MIN, left, right); |
| break; |
| case MaxFloat32: |
| case MaxFloat64: |
| ret = ValueBuilder::makeCall(MATH_MAX, left, right); |
| break; |
| case CopySignFloat32: |
| case CopySignFloat64: |
| default: |
| Fatal() << "Unhandled binary float operator: "; |
| } |
| if (curr->type == Type::f32) { |
| return makeJsCoercion(ret, JS_FLOAT); |
| } |
| return ret; |
| default: |
| Fatal() << "Unhandled type in binary: " << curr; |
| } |
| return makeJsCoercion(ret, wasmToJsType(curr->type)); |
| } |
| |
| Ref visitSelect(Select* curr) { |
| // If the condition has effects that interact with the operands, we must |
| // reorder it to the start. We must also use locals if the values have |
| // side effects, as a JS conditional does not visit both sides. |
| bool useLocals = false; |
| EffectAnalyzer conditionEffects( |
| parent->options, *module, curr->condition); |
| EffectAnalyzer ifTrueEffects(parent->options, *module, curr->ifTrue); |
| EffectAnalyzer ifFalseEffects(parent->options, *module, curr->ifFalse); |
| if (conditionEffects.invalidates(ifTrueEffects) || |
| conditionEffects.invalidates(ifFalseEffects) || |
| ifTrueEffects.hasSideEffects() || ifFalseEffects.hasSideEffects()) { |
| useLocals = true; |
| } |
| if (useLocals) { |
| ScopedTemp tempIfTrue(curr->type, parent, func), |
| tempIfFalse(curr->type, parent, func), |
| tempCondition(Type::i32, parent, func); |
| Ref ifTrue = visit(curr->ifTrue, EXPRESSION_RESULT); |
| Ref ifFalse = visit(curr->ifFalse, EXPRESSION_RESULT); |
| Ref condition = visit(curr->condition, EXPRESSION_RESULT); |
| return ValueBuilder::makeSeq( |
| ValueBuilder::makeBinary(tempIfTrue.getAstName(), SET, ifTrue), |
| ValueBuilder::makeSeq( |
| ValueBuilder::makeBinary(tempIfFalse.getAstName(), SET, ifFalse), |
| ValueBuilder::makeSeq( |
| ValueBuilder::makeBinary( |
| tempCondition.getAstName(), SET, condition), |
| ValueBuilder::makeConditional(tempCondition.getAstName(), |
| tempIfTrue.getAstName(), |
| tempIfFalse.getAstName())))); |
| } else { |
| // Simple case without reordering. |
| return ValueBuilder::makeConditional( |
| visit(curr->condition, EXPRESSION_RESULT), |
| visit(curr->ifTrue, EXPRESSION_RESULT), |
| visit(curr->ifFalse, EXPRESSION_RESULT)); |
| } |
| } |
| |
| Ref visitReturn(Return* curr) { |
| if (!curr->value) { |
| return ValueBuilder::makeReturn(Ref()); |
| } |
| Ref val = visit(curr->value, EXPRESSION_RESULT); |
| bool needCoercion = |
| parent->options.optimizeLevel == 0 || standaloneFunction || |
| parent->functionsCallableFromOutside.count(func->name); |
| if (needCoercion) { |
| val = makeJsCoercion(val, wasmToJsType(curr->value->type)); |
| } |
| return ValueBuilder::makeReturn(val); |
| } |
| |
| Ref visitMemorySize(MemorySize* curr) { |
| return ValueBuilder::makeCall(WASM_MEMORY_SIZE); |
| } |
| |
| Ref visitMemoryGrow(MemoryGrow* curr) { |
| if (module->memory.exists && |
| module->memory.max > module->memory.initial) { |
| return ValueBuilder::makeCall( |
| WASM_MEMORY_GROW, |
| makeJsCoercion(visit(curr->delta, EXPRESSION_RESULT), |
| wasmToJsType(curr->delta->type))); |
| } else { |
| return ValueBuilder::makeCall(ABORT_FUNC); |
| } |
| } |
| |
| Ref visitNop(Nop* curr) { return ValueBuilder::makeToplevel(); } |
| Ref visitUnreachable(Unreachable* curr) { |
| return ValueBuilder::makeCall(ABORT_FUNC); |
| } |
| |
| // Atomics |
| |
| struct HeapAndPointer { |
| Ref heap; |
| Ref ptr; |
| }; |
| |
| HeapAndPointer |
| getHeapAndAdjustedPointer(Index bytes, Expression* ptr, Index offset) { |
| IString heap; |
| Ref adjustedPtr = makePointer(ptr, offset); |
| switch (bytes) { |
| case 1: |
| heap = HEAP8; |
| break; |
| case 2: |
| heap = HEAP16; |
| adjustedPtr = ValueBuilder::makePtrShift(adjustedPtr, 1); |
| break; |
| case 4: |
| heap = HEAP32; |
| adjustedPtr = ValueBuilder::makePtrShift(adjustedPtr, 2); |
| break; |
| default: { |
| WASM_UNREACHABLE("unimp"); |
| } |
| } |
| return {ValueBuilder::makeName(heap), adjustedPtr}; |
| } |
| |
| Ref visitAtomicRMW(AtomicRMW* curr) { |
| auto hap = |
| getHeapAndAdjustedPointer(curr->bytes, curr->ptr, curr->offset); |
| IString target; |
| switch (curr->op) { |
| case RMWAdd: |
| target = IString("add"); |
| break; |
| case RMWSub: |
| target = IString("sub"); |
| break; |
| case RMWAnd: |
| target = IString("and"); |
| break; |
| case RMWOr: |
| target = IString("or"); |
| break; |
| case RMWXor: |
| target = IString("xor"); |
| break; |
| case RMWXchg: |
| target = IString("exchange"); |
| break; |
| default: |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref call = ValueBuilder::makeCall( |
| ValueBuilder::makeDot(ValueBuilder::makeName(ATOMICS), target)); |
| ValueBuilder::appendToCall(call, hap.heap); |
| ValueBuilder::appendToCall(call, hap.ptr); |
| ValueBuilder::appendToCall(call, visit(curr->value, EXPRESSION_RESULT)); |
| return call; |
| } |
| |
| Ref visitAtomicCmpxchg(AtomicCmpxchg* curr) { |
| auto hap = |
| getHeapAndAdjustedPointer(curr->bytes, curr->ptr, curr->offset); |
| Ref expected = visit(curr->expected, EXPRESSION_RESULT); |
| Ref replacement = visit(curr->replacement, EXPRESSION_RESULT); |
| Ref call = ValueBuilder::makeCall(ValueBuilder::makeDot( |
| ValueBuilder::makeName(ATOMICS), COMPARE_EXCHANGE)); |
| ValueBuilder::appendToCall(call, hap.heap); |
| ValueBuilder::appendToCall(call, hap.ptr); |
| ValueBuilder::appendToCall(call, expected); |
| ValueBuilder::appendToCall(call, replacement); |
| return makeJsCoercion(call, wasmToJsType(curr->type)); |
| } |
| |
| Ref visitAtomicWait(AtomicWait* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| |
| Ref visitAtomicNotify(AtomicNotify* curr) { |
| Ref call = ValueBuilder::makeCall(ValueBuilder::makeDot( |
| ValueBuilder::makeName(ATOMICS), IString("notify"))); |
| ValueBuilder::appendToCall(call, ValueBuilder::makeName(HEAP32)); |
| ValueBuilder::appendToCall( |
| call, |
| ValueBuilder::makePtrShift(makePointer(curr->ptr, curr->offset), 2)); |
| ValueBuilder::appendToCall(call, |
| visit(curr->notifyCount, EXPRESSION_RESULT)); |
| return call; |
| } |
| |
| Ref visitAtomicFence(AtomicFence* curr) { |
| // Sequentially consistent fences can be lowered to no operation |
| return ValueBuilder::makeToplevel(); |
| } |
| |
| // TODOs |
| |
| Ref visitSIMDExtract(SIMDExtract* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitSIMDReplace(SIMDReplace* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitSIMDShuffle(SIMDShuffle* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitSIMDTernary(SIMDTernary* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitSIMDShift(SIMDShift* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitSIMDLoad(SIMDLoad* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitSIMDLoadStoreLane(SIMDLoadStoreLane* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitMemoryInit(MemoryInit* curr) { |
| ABI::wasm2js::ensureHelpers(module, ABI::wasm2js::MEMORY_INIT); |
| return ValueBuilder::makeCall(ABI::wasm2js::MEMORY_INIT, |
| ValueBuilder::makeNum(curr->segment), |
| visit(curr->dest, EXPRESSION_RESULT), |
| visit(curr->offset, EXPRESSION_RESULT), |
| visit(curr->size, EXPRESSION_RESULT)); |
| } |
| Ref visitDataDrop(DataDrop* curr) { |
| ABI::wasm2js::ensureHelpers(module, ABI::wasm2js::DATA_DROP); |
| return ValueBuilder::makeCall(ABI::wasm2js::DATA_DROP, |
| ValueBuilder::makeNum(curr->segment)); |
| } |
| Ref visitMemoryCopy(MemoryCopy* curr) { |
| ABI::wasm2js::ensureHelpers(module, ABI::wasm2js::MEMORY_COPY); |
| return ValueBuilder::makeCall(ABI::wasm2js::MEMORY_COPY, |
| visit(curr->dest, EXPRESSION_RESULT), |
| visit(curr->source, EXPRESSION_RESULT), |
| visit(curr->size, EXPRESSION_RESULT)); |
| } |
| Ref visitMemoryFill(MemoryFill* curr) { |
| ABI::wasm2js::ensureHelpers(module, ABI::wasm2js::MEMORY_FILL); |
| return ValueBuilder::makeCall(ABI::wasm2js::MEMORY_FILL, |
| visit(curr->dest, EXPRESSION_RESULT), |
| visit(curr->value, EXPRESSION_RESULT), |
| visit(curr->size, EXPRESSION_RESULT)); |
| } |
| Ref visitRefNull(RefNull* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRefIs(RefIs* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRefFunc(RefFunc* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRefEq(RefEq* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitTableGet(TableGet* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitTableSet(TableSet* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitTableSize(TableSize* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitTableGrow(TableGrow* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitTry(Try* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitThrow(Throw* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRethrow(Rethrow* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitPop(Pop* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitTupleMake(TupleMake* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitTupleExtract(TupleExtract* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitI31New(I31New* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitI31Get(I31Get* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitCallRef(CallRef* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRefTest(RefTest* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRefCast(RefCast* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitBrOn(BrOn* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRttCanon(RttCanon* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRttSub(RttSub* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitStructNew(StructNew* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitStructGet(StructGet* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitStructSet(StructSet* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitArrayNew(ArrayNew* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitArrayInit(ArrayInit* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitArrayGet(ArrayGet* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitArraySet(ArraySet* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitArrayLen(ArrayLen* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitArrayCopy(ArrayCopy* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| Ref visitRefAs(RefAs* curr) { |
| unimplemented(curr); |
| WASM_UNREACHABLE("unimp"); |
| } |
| |
| private: |
| Ref makePointer(Expression* ptr, Address offset) { |
| auto ret = visit(ptr, EXPRESSION_RESULT); |
| if (offset) { |
| ret = makeJsCoercion( |
| ValueBuilder::makeBinary(ret, PLUS, ValueBuilder::makeNum(offset)), |
| JS_INT); |
| } |
| return ret; |
| } |
| |
| void unimplemented(Expression* curr) { |
| Fatal() << "wasm2js cannot convert " << *curr; |
| } |
| }; |
| |
| return ExpressionProcessor(this, m, func, standaloneFunction).process(); |
| } |
| |
| void Wasm2JSBuilder::addMemoryFuncs(Ref ast, Module* wasm) { |
| Ref memorySizeFunc = ValueBuilder::makeFunction(WASM_MEMORY_SIZE); |
| memorySizeFunc[3]->push_back(ValueBuilder::makeReturn( |
| makeJsCoercion(ValueBuilder::makeBinary( |
| ValueBuilder::makeDot(ValueBuilder::makeName(BUFFER), |
| IString("byteLength")), |
| DIV, |
| ValueBuilder::makeInt(Memory::kPageSize)), |
| JsType::JS_INT))); |
| ast->push_back(memorySizeFunc); |
| |
| if (wasm->memory.max > wasm->memory.initial) { |
| addMemoryGrowFunc(ast, wasm); |
| } |
| } |
| |
| void Wasm2JSBuilder::addMemoryGrowFunc(Ref ast, Module* wasm) { |
| Ref memoryGrowFunc = ValueBuilder::makeFunction(WASM_MEMORY_GROW); |
| ValueBuilder::appendArgumentToFunction(memoryGrowFunc, IString("pagesToAdd")); |
| |
| memoryGrowFunc[3]->push_back( |
| ValueBuilder::makeStatement(ValueBuilder::makeBinary( |
| ValueBuilder::makeName(IString("pagesToAdd")), |
| SET, |
| makeJsCoercion(ValueBuilder::makeName(IString("pagesToAdd")), |
| JsType::JS_INT)))); |
| |
| Ref oldPages = ValueBuilder::makeVar(); |
| memoryGrowFunc[3]->push_back(oldPages); |
| ValueBuilder::appendToVar( |
| oldPages, |
| IString("oldPages"), |
| makeJsCoercion(ValueBuilder::makeCall(WASM_MEMORY_SIZE), JsType::JS_INT)); |
| |
| Ref newPages = ValueBuilder::makeVar(); |
| memoryGrowFunc[3]->push_back(newPages); |
| ValueBuilder::appendToVar( |
| newPages, |
| IString("newPages"), |
| makeJsCoercion( |
| ValueBuilder::makeBinary(ValueBuilder::makeName(IString("oldPages")), |
| PLUS, |
| ValueBuilder::makeName(IString("pagesToAdd"))), |
| JsType::JS_INT)); |
| |
| Ref block = ValueBuilder::makeBlock(); |
| memoryGrowFunc[3]->push_back(ValueBuilder::makeIf( |
| ValueBuilder::makeBinary( |
| ValueBuilder::makeBinary(ValueBuilder::makeName(IString("oldPages")), |
| LT, |
| ValueBuilder::makeName(IString("newPages"))), |
| IString("&&"), |
| ValueBuilder::makeBinary(ValueBuilder::makeName(IString("newPages")), |
| LT, |
| ValueBuilder::makeInt(Memory::kMaxSize32))), |
| block, |
| NULL)); |
| |
| Ref newBuffer = ValueBuilder::makeVar(); |
| ValueBuilder::appendToBlock(block, newBuffer); |
| ValueBuilder::appendToVar( |
| newBuffer, |
| IString("newBuffer"), |
| ValueBuilder::makeNew(ValueBuilder::makeCall( |
| ARRAY_BUFFER, |
| ValueBuilder::makeCall(MATH_IMUL, |
| ValueBuilder::makeName(IString("newPages")), |
| ValueBuilder::makeInt(Memory::kPageSize))))); |
| |
| Ref newHEAP8 = ValueBuilder::makeVar(); |
| ValueBuilder::appendToBlock(block, newHEAP8); |
| ValueBuilder::appendToVar(newHEAP8, |
| IString("newHEAP8"), |
| ValueBuilder::makeNew(ValueBuilder::makeCall( |
| ValueBuilder::makeName(INT8ARRAY), |
| ValueBuilder::makeName(IString("newBuffer"))))); |
| |
| ValueBuilder::appendToBlock( |
| block, |
| ValueBuilder::makeCall( |
| ValueBuilder::makeDot(ValueBuilder::makeName(IString("newHEAP8")), |
| IString("set")), |
| ValueBuilder::makeName(HEAP8))); |
| |
| auto setHeap = [&](IString name, IString view) { |
| ValueBuilder::appendToBlock( |
| block, |
| ValueBuilder::makeBinary( |
| ValueBuilder::makeName(name), |
| SET, |
| ValueBuilder::makeNew(ValueBuilder::makeCall( |
| ValueBuilder::makeName(view), |
| ValueBuilder::makeName(IString("newBuffer")))))); |
| }; |
| |
| setHeap(HEAP8, INT8ARRAY); |
| setHeap(HEAP16, INT16ARRAY); |
| setHeap(HEAP32, INT32ARRAY); |
| setHeap(HEAPU8, UINT8ARRAY); |
| setHeap(HEAPU16, UINT16ARRAY); |
| setHeap(HEAPU32, UINT32ARRAY); |
| setHeap(HEAPF32, FLOAT32ARRAY); |
| setHeap(HEAPF64, FLOAT64ARRAY); |
| |
| ValueBuilder::appendToBlock( |
| block, |
| ValueBuilder::makeBinary(ValueBuilder::makeName(BUFFER), |
| SET, |
| ValueBuilder::makeName(IString("newBuffer")))); |
| |
| // apply the changes to the memory import |
| if (wasm->memory.imported()) { |
| ValueBuilder::appendToBlock( |
| block, |
| ValueBuilder::makeBinary( |
| ValueBuilder::makeDot(ValueBuilder::makeName("memory"), |
| ValueBuilder::makeName(BUFFER)), |
| SET, |
| ValueBuilder::makeName(BUFFER))); |
| } |
| |
| if (needsBufferView(*wasm)) { |
| ValueBuilder::appendToBlock( |
| block, |
| ValueBuilder::makeBinary(ValueBuilder::makeName("bufferView"), |
| SET, |
| ValueBuilder::makeName(HEAPU8))); |
| } |
| |
| memoryGrowFunc[3]->push_back( |
| ValueBuilder::makeReturn(ValueBuilder::makeName(IString("oldPages")))); |
| |
| ast->push_back(memoryGrowFunc); |
| } |
| |
| // Wasm2JSGlue emits the core of the module - the functions etc. that would |
| // be the asm.js function in an asm.js world. This class emits the rest of the |
| // "glue" around that. |
| class Wasm2JSGlue { |
| public: |
| Wasm2JSGlue(Module& wasm, |
| Output& out, |
| Wasm2JSBuilder::Flags flags, |
| Name moduleName) |
| : wasm(wasm), out(out), flags(flags), moduleName(moduleName) {} |
| |
| void emitPre(); |
| void emitPost(); |
| |
| private: |
| Module& wasm; |
| Output& out; |
| Wasm2JSBuilder::Flags flags; |
| Name moduleName; |
| |
| void emitPreEmscripten(); |
| void emitPreES6(); |
| void emitPostEmscripten(); |
| void emitPostES6(); |
| |
| void emitMemory(); |
| void emitSpecialSupport(); |
| }; |
| |
| void Wasm2JSGlue::emitPre() { |
| if (flags.emscripten) { |
| emitPreEmscripten(); |
| } else { |
| emitPreES6(); |
| } |
| |
| if (isTableExported(wasm)) { |
| out << "function Table(ret) {\n"; |
| if (wasm.tables[0]->initial == wasm.tables[0]->max) { |
| out << " // grow method not included; table is not growable\n"; |
| } else { |
| out << " ret.grow = function(by) {\n" |
| << " var old = this.length;\n" |
| << " this.length = this.length + by;\n" |
| << " return old;\n" |
| << " };\n"; |
| } |
| out << " ret.set = function(i, func) {\n" |
| << " this[i] = func;\n" |
| << " };\n" |
| << " ret.get = function(i) {\n" |
| << " return this[i];\n" |
| << " };\n" |
| << " return ret;\n" |
| << "}\n\n"; |
| } |
| |
| emitMemory(); |
| emitSpecialSupport(); |
| } |
| |
| void Wasm2JSGlue::emitPreEmscripten() { |
| out << "function instantiate(asmLibraryArg) {\n"; |
| } |
| |
| void Wasm2JSGlue::emitPreES6() { |
| std::unordered_map<Name, Name> baseModuleMap; |
| |
| auto noteImport = [&](Name module, Name base) { |
| // Right now codegen requires a flat namespace going into the module, |
| // meaning we don't support importing the same name from multiple namespaces |
| // yet. |
| if (baseModuleMap.count(base) && baseModuleMap[base] != module) { |
| Fatal() << "the name " << base << " cannot be imported from " |
| << "two different modules yet"; |
| } |
| baseModuleMap[base] = module; |
| |
| out << "import { " << asmangle(base.str) << " } from '" << module.str |
| << "';\n"; |
| }; |
| |
| ImportInfo imports(wasm); |
| |
| ModuleUtils::iterImportedGlobals( |
| wasm, [&](Global* import) { noteImport(import->module, import->base); }); |
| ModuleUtils::iterImportedTables( |
| wasm, [&](Table* import) { noteImport(import->module, import->base); }); |
| ModuleUtils::iterImportedFunctions(wasm, [&](Function* import) { |
| // The special helpers are emitted in the glue, see code and comments |
| // below. |
| if (ABI::wasm2js::isHelper(import->base)) { |
| return; |
| } |
| noteImport(import->module, import->base); |
| }); |
| |
| out << '\n'; |
| } |
| |
| void Wasm2JSGlue::emitPost() { |
| if (flags.emscripten) { |
| emitPostEmscripten(); |
| } else { |
| emitPostES6(); |
| } |
| } |
| |
| void Wasm2JSGlue::emitPostEmscripten() { |
| out << " return asmFunc(asmLibraryArg);\n}\n"; |
| } |
| |
| void Wasm2JSGlue::emitPostES6() { |
| // Create an initial `ArrayBuffer` and populate it with static data. |
| // Currently we use base64 encoding to encode static data and we decode it at |
| // instantiation time. |
| // |
| // Note that the translation here expects that the lower values of this memory |
| // can be used for conversions, so make sure there's at least one page. |
| if (wasm.memory.exists && wasm.memory.imported()) { |
| out << "var mem" << moduleName.str << " = new ArrayBuffer(" |
| << wasm.memory.initial.addr * Memory::kPageSize << ");\n"; |
| } |
| |
| // Actually invoke the `asmFunc` generated function, passing in all global |
| // values followed by all imports |
| out << "var ret" << moduleName.str << " = " << moduleName.str << "("; |
| out << " { abort: function() { throw new Error('abort'); }"; |
| |
| ModuleUtils::iterImportedFunctions(wasm, [&](Function* import) { |
| // The special helpers are emitted in the glue, see code and comments |
| // below. |
| if (ABI::wasm2js::isHelper(import->base)) { |
| return; |
| } |
| out << ",\n " << asmangle(import->base.str); |
| }); |
| |
| ModuleUtils::iterImportedMemories(wasm, [&](Memory* import) { |
| // The special helpers are emitted in the glue, see code and comments |
| // below. |
| if (ABI::wasm2js::isHelper(import->base)) { |
| return; |
| } |
| out << ",\n " << asmangle(import->base.str) << ": { buffer : mem" |
| << moduleName.str << " }"; |
| }); |
| |
| ModuleUtils::iterImportedTables(wasm, [&](Table* import) { |
| // The special helpers are emitted in the glue, see code and comments |
| // below. |
| if (ABI::wasm2js::isHelper(import->base)) { |
| return; |
| } |
| out << ",\n " << asmangle(import->base.str); |
| }); |
| |
| out << "\n });\n"; |
| |
| if (flags.allowAsserts) { |
| return; |
| } |
| |
| // And now that we have our returned instance, export all our functions |
| // that are hanging off it. |
| for (auto& exp : wasm.exports) { |
| switch (exp->kind) { |
| case ExternalKind::Function: |
| case ExternalKind::Global: |
| case ExternalKind::Memory: |
| break; |
| |
| // Exported globals and function tables aren't supported yet |
| default: |
| continue; |
| } |
| std::ostringstream export_name; |
| for (auto* ptr = exp->name.str; *ptr; ptr++) { |
| if (*ptr == '-') { |
| export_name << '_'; |
| } else { |
| export_name << *ptr; |
| } |
| } |
| out << "export var " << asmangle(exp->name.str) << " = ret" |
| << moduleName.str << "." << asmangle(exp->name.str) << ";\n"; |
| } |
| } |
| |
| void Wasm2JSGlue::emitMemory() { |
| if (needsBufferView(wasm)) { |
| // Create a helper bufferView to access the buffer if we need one. We use it |
| // for creating memory segments if we have any (we may not if the segments |
| // are shipped in a side .mem file, for example), and also in bulk memory |
| // operations. |
| // This will get assigned during `asmFunc` (and potentially re-assigned |
| // during __wasm_memory_grow). |
| // TODO: We should probably just share a single HEAPU8 var. |
| out << " var bufferView;\n"; |
| } |
| |
| // If there are no memory segments, we don't need to emit any support code for |
| // segment creation. |
| if ((!wasm.memory.exists) || wasm.memory.segments.empty()) { |
| return; |
| } |
| |
| // If we have passive memory segments, we need to store those. |
| for (auto& seg : wasm.memory.segments) { |
| if (seg.isPassive) { |
| out << " var memorySegments = {};\n"; |
| break; |
| } |
| } |
| |
| out << |
| R"( var base64ReverseLookup = new Uint8Array(123/*'z'+1*/); |
| for (var i = 25; i >= 0; --i) { |
| base64ReverseLookup[48+i] = 52+i; // '0-9' |
| base64ReverseLookup[65+i] = i; // 'A-Z' |
| base64ReverseLookup[97+i] = 26+i; // 'a-z' |
| } |
| base64ReverseLookup[43] = 62; // '+' |
| base64ReverseLookup[47] = 63; // '/' |
| /** @noinline Inlining this function would mean expanding the base64 string 4x times in the source code, which Closure seems to be happy to do. */ |
| function base64DecodeToExistingUint8Array(uint8Array, offset, b64) { |
| var b1, b2, i = 0, j = offset, bLength = b64.length, end = offset + (bLength*3>>2) - (b64[bLength-2] == '=') - (b64[bLength-1] == '='); |
| for (; i < bLength; i += 4) { |
| b1 = base64ReverseLookup[b64.charCodeAt(i+1)]; |
| b2 = base64ReverseLookup[b64.charCodeAt(i+2)]; |
| uint8Array[j++] = base64ReverseLookup[b64.charCodeAt(i)] << 2 | b1 >> 4; |
| if (j < end) uint8Array[j++] = b1 << 4 | b2 >> 2; |
| if (j < end) uint8Array[j++] = b2 << 6 | base64ReverseLookup[b64.charCodeAt(i+3)]; |
| })"; |
| if (wasm.features.hasBulkMemory()) { |
| // Passive segments in bulk memory are initialized into new arrays that are |
| // passed into here, and we need to return them. |
| out << R"( |
| return uint8Array;)"; |
| } |
| out << R"( |
| } |
| )"; |
| |
| for (Index i = 0; i < wasm.memory.segments.size(); i++) { |
| auto& seg = wasm.memory.segments[i]; |
| if (seg.isPassive) { |
| // Fancy passive segments are decoded into typed arrays on the side, for |
| // later copying. |
| out << "memorySegments[" << i |
| << "] = base64DecodeToExistingUint8Array(new Uint8Array(" |
| << seg.data.size() << ")" |
| << ", 0, \"" << base64Encode(seg.data) << "\");\n"; |
| } |
| } |
| |
| if (hasActiveSegments(wasm)) { |
| auto globalOffset = [&](const Memory::Segment& segment) { |
| if (auto* c = segment.offset->dynCast<Const>()) { |
| return std::to_string(c->value.getInteger()); |
| } |
| if (auto* get = segment.offset->dynCast<GlobalGet>()) { |
| auto internalName = get->name; |
| auto importedName = wasm.getGlobal(internalName)->base; |
| return std::string("imports[") + asmangle(importedName.str) + "]"; |
| } |
| Fatal() << "non-constant offsets aren't supported yet\n"; |
| }; |
| |
| out << "function initActiveSegments(imports) {\n"; |
| for (Index i = 0; i < wasm.memory.segments.size(); i++) { |
| auto& seg = wasm.memory.segments[i]; |
| if (!seg.isPassive) { |
| // Plain active segments are decoded directly into the main memory. |
| out << " base64DecodeToExistingUint8Array(bufferView, " |
| << globalOffset(seg) << ", \"" << base64Encode(seg.data) |
| << "\");\n"; |
| } |
| } |
| out << "}\n"; |
| } |
| } |
| |
| void Wasm2JSGlue::emitSpecialSupport() { |
| // The special support functions are emitted as part of the JS glue, if we |
| // need them. |
| bool need = false; |
| ModuleUtils::iterImportedFunctions(wasm, [&](Function* import) { |
| if (ABI::wasm2js::isHelper(import->base)) { |
| need = true; |
| } |
| }); |
| if (!need) { |
| return; |
| } |
| |
| // Scratch memory uses 3 indexes, each referring to 4 bytes. Indexes 0, 1 are |
| // used for 64-bit operations, while 2 is for 32-bit. These operations need |
| // separate indexes because we need to handle the case where the optimizer |
| // reorders a 32-bit reinterpret in between a 64-bit's split-out parts. |
| // That situation can occur because the 64-bit reinterpret was split up into |
| // pieces early, in the 64-bit lowering pass, while the 32-bit reinterprets |
| // are lowered only at the very end, and until then the optimizer sees wasm |
| // reinterprets which have no side effects (but they will have the side effect |
| // of altering scratch memory). That is, conceptual code like this: |
| // |
| // a = reinterpret_64(b) |
| // x = reinterpret_32(y) |
| // |
| // turns into |
| // |
| // scratch_write(b) |
| // a_low = scratch_read(0) |
| // a_high = scratch_read(1) |
| // x = reinterpret_32(y) |
| // |
| // (Note how the single wasm instruction for a 64-bit reinterpret turns into |
| // multiple operations. We have to do such splitting, because in JS we will |
| // have to have separate operations to receive each 32-bit chunk anyhow. A |
| // *32*-bit reinterpret *could* be a single function, but given we have the |
| // separate functions anyhow for the 64-bit case, it's more compact to reuse |
| // those.) |
| // At this point, the scratch_* functions look like they have side effects to |
| // the optimizer (which is true, as they modify scratch memory), but the |
| // reinterpret_32 is still a normal wasm instruction without side effects, so |
| // the optimizer might do this: |
| // |
| // scratch_write(b) |
| // a_low = scratch_read(0) |
| // x = reinterpret_32(y) ;; this moved one line up |
| // a_high = scratch_read(1) |
| // |
| // When we do lower the reinterpret_32 into JS, we get: |
| // |
| // scratch_write(b) |
| // a_low = scratch_read(0) |
| // scratch_write(y) |
| // x = scratch_read() |
| // a_high = scratch_read(1) |
| // |
| // The second write occurs before the first's values have been read, so they |
| // interfere. |
| // |
| // There isn't a problem with reordering 32-bit reinterprets with each other |
| // as each is lowered into a pair of write+read in JS (after the wasm |
| // optimizer runs), so they are guaranteed to be adjacent (and a JS optimizer |
| // that runs later will handle that ok since they are calls, which can always |
| // have side effects). |
| out << R"( |
| var scratchBuffer = new ArrayBuffer(16); |
| var i32ScratchView = new Int32Array(scratchBuffer); |
| var f32ScratchView = new Float32Array(scratchBuffer); |
| var f64ScratchView = new Float64Array(scratchBuffer); |
| )"; |
| |
| ModuleUtils::iterImportedFunctions(wasm, [&](Function* import) { |
| if (import->base == ABI::wasm2js::SCRATCH_STORE_I32) { |
| out << R"( |
| function wasm2js_scratch_store_i32(index, value) { |
| i32ScratchView[index] = value; |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::SCRATCH_LOAD_I32) { |
| out << R"( |
| function wasm2js_scratch_load_i32(index) { |
| return i32ScratchView[index]; |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::SCRATCH_STORE_F32) { |
| out << R"( |
| function wasm2js_scratch_store_f32(value) { |
| f32ScratchView[2] = value; |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::SCRATCH_LOAD_F32) { |
| out << R"( |
| function wasm2js_scratch_load_f32() { |
| return f32ScratchView[2]; |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::SCRATCH_STORE_F64) { |
| out << R"( |
| function wasm2js_scratch_store_f64(value) { |
| f64ScratchView[0] = value; |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::SCRATCH_LOAD_F64) { |
| out << R"( |
| function wasm2js_scratch_load_f64() { |
| return f64ScratchView[0]; |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::MEMORY_INIT) { |
| out << R"( |
| function wasm2js_memory_init(segment, dest, offset, size) { |
| // TODO: traps on invalid things |
| bufferView.set(memorySegments[segment].subarray(offset, offset + size), dest); |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::MEMORY_FILL) { |
| out << R"( |
| function wasm2js_memory_fill(dest, value, size) { |
| dest = dest >>> 0; |
| size = size >>> 0; |
| if (dest + size > bufferView.length) throw "trap: invalid memory.fill"; |
| bufferView.fill(value, dest, dest + size); |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::MEMORY_COPY) { |
| out << R"( |
| function wasm2js_memory_copy(dest, source, size) { |
| // TODO: traps on invalid things |
| bufferView.copyWithin(dest, source, source + size); |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::DATA_DROP) { |
| out << R"( |
| function wasm2js_data_drop(segment) { |
| // TODO: traps on invalid things |
| memorySegments[segment] = new Uint8Array(0); |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::ATOMIC_WAIT_I32) { |
| out << R"( |
| function wasm2js_atomic_wait_i32(ptr, expected, timeoutLow, timeoutHigh) { |
| var timeout = Infinity; |
| if (timeoutHigh >= 0) { |
| // Convert from nanoseconds to milliseconds |
| // Taken from convertI32PairToI53 in emscripten's library_int53.js |
| timeout = ((timeoutLow >>> 0) / 1e6) + timeoutHigh * (4294967296 / 1e6); |
| } |
| var view = new Int32Array(bufferView.buffer); // TODO cache |
| var result = Atomics.wait(view, ptr >> 2, expected, timeout); |
| if (result == 'ok') return 0; |
| if (result == 'not-equal') return 1; |
| if (result == 'timed-out') return 2; |
| throw 'bad result ' + result; |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::ATOMIC_RMW_I64) { |
| out << R"( |
| function wasm2js_atomic_rmw_i64(op, bytes, offset, ptr, valueLow, valueHigh) { |
| // TODO: support bytes=1, 2, 4 as well as 8. |
| var view = new BigInt64Array(bufferView.buffer); // TODO cache |
| ptr = (ptr + offset) >> 3; |
| var value = BigInt(valueLow >>> 0) | (BigInt(valueHigh >>> 0) << BigInt(32)); |
| var result; |
| switch (op) { |
| case 0: { // Add |
| result = Atomics.add(view, ptr, value); |
| break; |
| } |
| case 1: { // Sub |
| result = Atomics.sub(view, ptr, value); |
| break; |
| } |
| case 2: { // And |
| result = Atomics.and(view, ptr, value); |
| break; |
| } |
| case 3: { // Or |
| result = Atomics.or(view, ptr, value); |
| break; |
| } |
| case 4: { // Xor |
| result = Atomics.xor(view, ptr, value); |
| break; |
| } |
| case 5: { // Xchg |
| result = Atomics.exchange(view, ptr, value); |
| break; |
| } |
| default: throw 'bad op'; |
| } |
| var low = Number(result & BigInt(0xffffffff)) | 0; |
| var high = Number((result >> BigInt(32)) & BigInt(0xffffffff)) | 0; |
| stashedBits = high; |
| return low; |
| } |
| )"; |
| } else if (import->base == ABI::wasm2js::GET_STASHED_BITS) { |
| out << R"( |
| var stashedBits = 0; |
| |
| function wasm2js_get_stashed_bits() { |
| return stashedBits; |
| } |
| )"; |
| } |
| }); |
| |
| out << '\n'; |
| } |
| |
| } // namespace wasm |
| |
| #endif // wasm_wasm2js_h |