Revert of [wasm] Implement parallel compilation. (patchset #6 id:100001 of...

Revert of [wasm] Implement parallel compilation. (patchset #6 id:100001 of https://codereview.chromium.org/1961973002/ )

Reason for revert:
The ThreadSanitizer finds data races.

Original issue's description:
> [wasm] Implement parallel compilation.
>
> With this CL it is possible to compile a wasm module with multiple
> threads in parallel. Parallel compilation works as follows:
>
> 1)   The main thread allocates a compilation unit for each wasm function.
> 2)   The main thread spawns WasmCompilationTasks which run on the
>      background threads.
> 3.a) The background threads and the main thread pick one compilation unit
>      at a time and execute the parallel phase of the compilation unit.
>      After finishing the execution of the parallel phase, the compilation
>      unit is stored in a result queue.
> 3.b) If the result queue contains a compilation unit, the main thread
>      dequeues it and finishes its compilation.
> 4)   After the execution of the parallel phase of all compilation units has
>      started, the main thread waits for all WasmCompilationTasks to finish.
> 5)   The main thread finalizes the compilation of the module.
>
> I'm going to add some additional tests before committing this CL.
>
> R=titzer@chromium.org, bmeurer@chromium.org, mlippautz@chromium.org, mstarzinger@chromium.org
>
> Committed: https://crrev.com/17215438659d8ff2d7d55f95226bf8a1477ccd79
> Cr-Commit-Position: refs/heads/master@{#36178}

TBR=bmeurer@chromium.org,mlippautz@chromium.org,mstarzinger@chromium.org,titzer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/1965243003
Cr-Commit-Position: refs/heads/master@{#36182}

src/compiler/wasm-compiler.cc

@@ -232,17 +232,14 @@ class WasmTrapHelper : public ZoneObject {
       CallDescriptor* desc = Linkage::GetRuntimeCallDescriptor(
           jsgraph()->zone(), f, fun->nargs, Operator::kNoProperties,
           CallDescriptor::kNoFlags);
-      // CEntryStubConstant nodes have to be created and cached in the main
-      // thread. At the moment this is only done for CEntryStubConstant(1).
-      DCHECK_EQ(1, fun->result_size);
       Node* inputs[] = {
           jsgraph()->CEntryStubConstant(fun->result_size),  // C entry
           trap_reason_smi,                                  // message id
           trap_position_smi,                                // byte position
           jsgraph()->ExternalConstant(
-              ExternalReference(f, jsgraph()->isolate())),    // ref
-          jsgraph()->Int32Constant(fun->nargs),               // arity
-          builder_->HeapConstant(module->instance->context),  // context
+              ExternalReference(f, jsgraph()->isolate())),  // ref
+          jsgraph()->Int32Constant(fun->nargs),             // arity
+          jsgraph()->Constant(module->instance->context),   // context
           *effect_ptr,
           *control_ptr};
 
@@ -893,8 +890,8 @@ Node* WasmGraphBuilder::Float64Constant(double value) {
   return jsgraph()->Float64Constant(value);
 }
 
-Node* WasmGraphBuilder::HeapConstant(Handle<HeapObject> value) {
-  return jsgraph()->HeapConstant(value);
+Node* WasmGraphBuilder::Constant(Handle<Object> value) {
+  return jsgraph()->Constant(value);
 }
 
 Node* WasmGraphBuilder::Branch(Node* cond, Node** true_node,
@@ -1896,7 +1893,7 @@ Node* WasmGraphBuilder::CallDirect(uint32_t index, Node** args,
   DCHECK_NULL(args[0]);
 
   // Add code object as constant.
-  args[0] = HeapConstant(module_->GetFunctionCode(index));
+  args[0] = Constant(module_->GetFunctionCode(index));
   wasm::FunctionSig* sig = module_->GetFunctionSignature(index);
 
   return BuildWasmCall(sig, args, position);
@@ -1907,7 +1904,7 @@ Node* WasmGraphBuilder::CallImport(uint32_t index, Node** args,
   DCHECK_NULL(args[0]);
 
   // Add code object as constant.
-  args[0] = HeapConstant(module_->GetImportCode(index));
+  args[0] = Constant(module_->GetImportCode(index));
   wasm::FunctionSig* sig = module_->GetImportSignature(index);
 
   return BuildWasmCall(sig, args, position);
@@ -2385,7 +2382,7 @@ void WasmGraphBuilder::BuildJSToWasmWrapper(Handle<Code> wasm_code,
       graph()->start());
 
   int pos = 0;
-  args[pos++] = HeapConstant(wasm_code);
+  args[pos++] = Constant(wasm_code);
 
   // Convert JS parameters to WASM numbers.
   for (int i = 0; i < wasm_count; i++) {
@@ -2443,7 +2440,7 @@ void WasmGraphBuilder::BuildWasmToJSWrapper(Handle<JSFunction> function,
   *effect_ = start;
   *control_ = start;
   // JS context is the last parameter.
-  Node* context = HeapConstant(Handle<Context>(function->context(), isolate));
+  Node* context = Constant(Handle<Context>(function->context(), isolate));
   Node** args = Buffer(wasm_count + 7);
 
   bool arg_count_before_args = false;
@@ -2548,7 +2545,7 @@ Node* WasmGraphBuilder::FunctionTable() {
   DCHECK(module_ && module_->instance &&
          !module_->instance->function_table.is_null());
   if (!function_table_) {
-    function_table_ = HeapConstant(module_->instance->function_table);
+    function_table_ = jsgraph()->Constant(module_->instance->function_table);
   }
   return function_table_;
 }
@@ -2888,7 +2885,7 @@ Handle<Code> CompileWasmToJSWrapper(Isolate* isolate, wasm::ModuleEnv* module,
 }
 
 std::pair<JSGraph*, SourcePositionTable*> BuildGraphForWasmFunction(
-    JSGraph* jsgraph, wasm::ErrorThrower* thrower, Isolate* isolate,
+    Zone* zone, wasm::ErrorThrower* thrower, Isolate* isolate,
     wasm::ModuleEnv*& module_env, const wasm::WasmFunction* function,
     double* decode_ms) {
   base::ElapsedTimer decode_timer;
@@ -2896,13 +2893,16 @@ std::pair<JSGraph*, SourcePositionTable*> BuildGraphForWasmFunction(
     decode_timer.Start();
   }
   // Create a TF graph during decoding.
-  Graph* graph = jsgraph->graph();
-  CommonOperatorBuilder* common = jsgraph->common();
-  MachineOperatorBuilder* machine = jsgraph->machine();
+  Graph* graph = new (zone) Graph(zone);
+  CommonOperatorBuilder* common = new (zone) CommonOperatorBuilder(zone);
+  MachineOperatorBuilder* machine = new (zone) MachineOperatorBuilder(
+      zone, MachineType::PointerRepresentation(),
+      InstructionSelector::SupportedMachineOperatorFlags());
+  JSGraph* jsgraph =
+      new (zone) JSGraph(isolate, graph, common, nullptr, nullptr, machine);
   SourcePositionTable* source_position_table =
-      new (jsgraph->zone()) SourcePositionTable(graph);
-  WasmGraphBuilder builder(jsgraph->zone(), jsgraph, function->sig,
-                           source_position_table);
+      new (zone) SourcePositionTable(graph);
+  WasmGraphBuilder builder(zone, jsgraph, function->sig, source_position_table);
   wasm::FunctionBody body = {
       module_env, function->sig, module_env->module->module_start,
       module_env->module->module_start + function->code_start_offset,
@@ -2911,7 +2911,7 @@ std::pair<JSGraph*, SourcePositionTable*> BuildGraphForWasmFunction(
       wasm::BuildTFGraph(isolate->allocator(), &builder, body);
 
   if (machine->Is32()) {
-    Int64Lowering r(graph, machine, common, jsgraph->zone(), function->sig);
+    Int64Lowering r(graph, machine, common, zone, function->sig);
     r.LowerGraph();
   }
 
@@ -2948,14 +2948,6 @@ class WasmCompilationUnit {
         isolate_(isolate),
         module_env_(module_env),
         function_(function),
-        graph_zone_(new Zone(isolate->allocator())),
-        jsgraph_(new (graph_zone()) JSGraph(
-            isolate, new (graph_zone()) Graph(graph_zone()),
-            new (graph_zone()) CommonOperatorBuilder(graph_zone()), nullptr,
-            nullptr,
-            new (graph_zone()) MachineOperatorBuilder(
-                graph_zone(), MachineType::PointerRepresentation(),
-                InstructionSelector::SupportedMachineOperatorFlags()))),
         compilation_zone_(isolate->allocator()),
         info_(function->name_length != 0
                   ? module_env->module->GetNameOrNull(function->name_offset,
@@ -2965,12 +2957,7 @@ class WasmCompilationUnit {
               Code::ComputeFlags(Code::WASM_FUNCTION)),
         job_(),
         index_(index),
-        ok_(true) {
-    // Create and cache this node in the main thread.
-    jsgraph_->CEntryStubConstant(1);
-  }
-
-  Zone* graph_zone() { return graph_zone_.get(); }
+        ok_(true) {}
 
   void ExecuteCompilation() {
     HistogramTimerScope wasm_compile_function_time_scope(
@@ -2985,9 +2972,9 @@ class WasmCompilationUnit {
     double decode_ms = 0;
     size_t node_count = 0;
 
-    base::SmartPointer<Zone> graph_zone(graph_zone_.Detach());
+    Zone zone(isolate_->allocator());
     std::pair<JSGraph*, SourcePositionTable*> graph_result =
-        BuildGraphForWasmFunction(jsgraph_, thrower_, isolate_, module_env_,
+        BuildGraphForWasmFunction(&zone, thrower_, isolate_, module_env_,
                                   function_, &decode_ms);
     JSGraph* jsgraph = graph_result.first;
     SourcePositionTable* source_positions = graph_result.second;
@@ -3072,9 +3059,6 @@ class WasmCompilationUnit {
   Isolate* isolate_;
   wasm::ModuleEnv* module_env_;
   const wasm::WasmFunction* function_;
-  // The graph zone is deallocated at the end of ExecuteCompilation.
-  base::SmartPointer<Zone> graph_zone_;
-  JSGraph* jsgraph_;
   Zone compilation_zone_;
   CompilationInfo info_;
   base::SmartPointer<CompilationJob> job_;

src/compiler/wasm-compiler.h

@@ -98,7 +98,7 @@ class WasmGraphBuilder {
   Node* Int64Constant(int64_t value);
   Node* Float32Constant(float value);
   Node* Float64Constant(double value);
-  Node* HeapConstant(Handle<HeapObject> value);
+  Node* Constant(Handle<Object> value);
   Node* Binop(wasm::WasmOpcode opcode, Node* left, Node* right,
               wasm::WasmCodePosition position = wasm::kNoCodePosition);
   Node* Unop(wasm::WasmOpcode opcode, Node* input,

src/flag-definitions.h

@@ -461,8 +461,7 @@ DEFINE_BOOL(turbo_stress_instruction_scheduling, false,
 
 // Flags for native WebAssembly.
 DEFINE_BOOL(expose_wasm, false, "expose WASM interface to JavaScript")
-DEFINE_INT(wasm_num_compilation_tasks, 0,
-           "number of parallel compilation tasks for wasm")
+DEFINE_BOOL(wasm_parallel_compilation, false, "compile WASM code in parallel")
 DEFINE_BOOL(trace_wasm_encoder, false, "trace encoding of wasm code")
 DEFINE_BOOL(trace_wasm_decoder, false, "trace decoding of wasm code")
 DEFINE_BOOL(trace_wasm_decode_time, false, "trace decoding time of wasm code")

test/mjsunit/wasm/parallel_compilation.js

-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --expose-wasm --wasm-num-compilation-tasks=10
-
-load("test/mjsunit/wasm/wasm-constants.js");
-load("test/mjsunit/wasm/wasm-module-builder.js");
-
-function assertModule(module, memsize) {
-  // Check the module exists.
-  assertFalse(module === undefined);
-  assertFalse(module === null);
-  assertFalse(module === 0);
-  assertEquals("object", typeof module);
-
-  // Check the memory is an ArrayBuffer.
-  var mem = module.exports.memory;
-  assertFalse(mem === undefined);
-  assertFalse(mem === null);
-  assertFalse(mem === 0);
-  assertEquals("object", typeof mem);
-  assertTrue(mem instanceof ArrayBuffer);
-  for (var i = 0; i < 4; i++) {
-    module.exports.memory = 0;  // should be ignored
-    assertEquals(mem, module.exports.memory);
-  }
-
-  assertEquals(memsize, module.exports.memory.byteLength);
-}
-
-function assertFunction(module, func) {
-  assertEquals("object", typeof module.exports);
-
-  var exp = module.exports[func];
-  assertFalse(exp === undefined);
-  assertFalse(exp === null);
-  assertFalse(exp === 0);
-  assertEquals("function", typeof exp);
-  return exp;
-}
-
-(function CompileFunctionsTest() {
-
-  var builder = new WasmModuleBuilder();
-
-  builder.addMemory(1, 1, true);
-  for (i = 0; i < 1000; i++) {
-    builder.addFunction("sub" + i, kSig_i_i)
-      .addBody([                // --
-        kExprGetLocal, 0,       // --
-        kExprI32Const, i % 61,  // --
-        kExprI32Sub])           // --
-      .exportFunc()
-  }
-
-  var module = builder.instantiate();
-  assertModule(module, kPageSize);
-
-  // Check the properties of the functions.
-  for (i = 0; i < 1000; i++) {
-    var sub = assertFunction(module, "sub" + i);
-    assertEquals(33 - (i % 61), sub(33));
-  }
-})();
-
-(function CallFunctionsTest() {
-
-  var builder = new WasmModuleBuilder();
-
-  var f = []
-
-  f[0] = builder.addFunction("add0", kSig_i_ii)
-  .addBody([
-            kExprGetLocal, 0,             // --
-            kExprGetLocal, 1,             // --
-            kExprI32Add,                  // --
-          ])
-          .exportFunc()
-
-  builder.addMemory(1, 1, true);
-  for (i = 1; i < 256; i++) {
-    f[i] = builder.addFunction("add" + i, kSig_i_ii)
-      .addBody([                                            // --
-        kExprGetLocal, 0,                                   // --
-        kExprGetLocal, 1,                                   // --
-        kExprCallFunction, kArity2, f[i >>> 1].index])      // --
-      .exportFunc()
-  }
-  var module = builder.instantiate();
-  assertModule(module, kPageSize);
-
-  // Check the properties of the functions.
-  for (i = 0; i < 256; i++) {
-    var add = assertFunction(module, "add" + i);
-    assertEquals(88, add(33, 55));
-    assertEquals(88888, add(33333, 55555));
-    assertEquals(8888888, add(3333333, 5555555));
-  }
-})();