[wasm] Implement parallel compilation.

src/compiler/wasm-compiler.cc

Index: src/compiler/wasm-compiler.cc
diff --git a/src/compiler/wasm-compiler.cc b/src/compiler/wasm-compiler.cc
index b543c80e5722fc7828a65e019371359e0d8a1f01..286c238af817cfe080a5ab9b5402ad54b1eaf657 100644
--- a/src/compiler/wasm-compiler.cc
+++ b/src/compiler/wasm-compiler.cc
@@ -233,16 +233,19 @@ 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
-          jsgraph()->Constant(module->instance->context),   // context
-          *effect_ptr,
-          *control_ptr};
+          jsgraph()->ExternalConstant(                      // ref
+              ExternalReference(f, jsgraph()->isolate())),
+          jsgraph()->Int32Constant(fun->nargs),                // arity
+          graph()->NewNode(jsgraph()->common()->HeapConstant(  // context
+              module->instance->context)),
+          *effect_ptr, *control_ptr};
 
       Node* node = graph()->NewNode(
           common()->Call(desc), static_cast<int>(arraysize(inputs)), inputs);
@@ -1878,7 +1881,8 @@ Node* WasmGraphBuilder::CallDirect(uint32_t index, Node** args,
   DCHECK_NULL(args[0]);
 
   // Add code object as constant.
-  args[0] = Constant(module_->GetFunctionCode(index));
+  args[0] = graph()->NewNode(

[titzer, 2016/05/10 12:32:10]

Can you extract a helper function for this sequence?

[ahaas, 2016/05/11 09:52:21]

Done. PTAL

+      jsgraph()->common()->HeapConstant(module_->GetFunctionCode(index)));
   wasm::FunctionSig* sig = module_->GetFunctionSignature(index);
 
   return BuildWasmCall(sig, args, position);
@@ -1889,7 +1893,8 @@ Node* WasmGraphBuilder::CallImport(uint32_t index, Node** args,
   DCHECK_NULL(args[0]);
 
   // Add code object as constant.
-  args[0] = Constant(module_->GetImportCode(index));
+  args[0] = graph()->NewNode(
+      jsgraph()->common()->HeapConstant(module_->GetImportCode(index)));
   wasm::FunctionSig* sig = module_->GetImportSignature(index);
 
   return BuildWasmCall(sig, args, position);
@@ -2534,7 +2539,8 @@ Node* WasmGraphBuilder::FunctionTable() {
   DCHECK(module_ && module_->instance &&
          !module_->instance->function_table.is_null());
   if (!function_table_) {
-    function_table_ = jsgraph()->Constant(module_->instance->function_table);
+    function_table_ = graph()->NewNode(
+        jsgraph()->common()->HeapConstant(module_->instance->function_table));
   }
   return function_table_;
 }
@@ -2876,7 +2882,7 @@ Handle<Code> CompileWasmToJSWrapper(Isolate* isolate, wasm::ModuleEnv* module,
 }
 
 std::pair<JSGraph*, SourcePositionTable*> BuildGraphForWasmFunction(
-    Zone* zone, wasm::ErrorThrower* thrower, Isolate* isolate,
+    JSGraph* jsgraph, wasm::ErrorThrower* thrower, Isolate* isolate,
     wasm::ModuleEnv*& module_env, const wasm::WasmFunction* function,
     double* decode_ms) {
   base::ElapsedTimer decode_timer;
@@ -2884,16 +2890,13 @@ std::pair<JSGraph*, SourcePositionTable*> BuildGraphForWasmFunction(
     decode_timer.Start();
   }
   // Create a TF graph during decoding.
-  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);
+  Graph* graph = jsgraph->graph();
+  CommonOperatorBuilder* common = jsgraph->common();
+  MachineOperatorBuilder* machine = jsgraph->machine();
   SourcePositionTable* source_position_table =
-      new (zone) SourcePositionTable(graph);
-  WasmGraphBuilder builder(zone, jsgraph, function->sig, source_position_table);
+      new (jsgraph->zone()) SourcePositionTable(graph);
+  WasmGraphBuilder builder(jsgraph->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,
@@ -2902,7 +2905,7 @@ std::pair<JSGraph*, SourcePositionTable*> BuildGraphForWasmFunction(
       wasm::BuildTFGraph(isolate->allocator(), &builder, body);
 
   if (machine->Is32()) {
-    Int64Lowering r(graph, machine, common, zone, function->sig);
+    Int64Lowering r(graph, machine, common, jsgraph->zone(), function->sig);
     r.LowerGraph();
   }
 
@@ -2939,6 +2942,14 @@ class WasmCompilationUnit {
         isolate_(isolate),
         module_env_(module_env),
         function_(function),
+        graph_zone_(new Zone(isolate->allocator())),
+        jsgraph_(new (graph_zone()) JSGraph(

[Michael Starzinger, 2016/05/10 10:29:59]

Comment just for posterity (not actionable): IMHO the wasm-compiler shouldn't
use the JSGraph class. It doesn't need a JSOperatorBuilder or a
SimplifiedOperatorBuilder. In the long run we might consider switching
wasm-compiler to use the underlying Graph class directly (or alternatively a
dedicated container).

[ahaas, 2016/05/11 09:52:21]

I plan to remove the JSGraph in a separate CL.

+            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,
@@ -2948,7 +2959,12 @@ class WasmCompilationUnit {
               Code::ComputeFlags(Code::WASM_FUNCTION)),
         job_(),
         index_(index),
-        ok_(true) {}
+        ok_(true) {
+    // Create and cache this node in the main thread.
+    jsgraph_->CEntryStubConstant(1);
+  }
+
+  Zone* graph_zone() { return graph_zone_.get(); }
 
   void ExecuteCompilation() {
     HistogramTimerScope wasm_compile_function_time_scope(
@@ -2963,9 +2979,9 @@ class WasmCompilationUnit {
     double decode_ms = 0;
     size_t node_count = 0;
 
-    Zone zone(isolate_->allocator());
+    base::SmartPointer<Zone> graph_zone(graph_zone_.Detach());
     std::pair<JSGraph*, SourcePositionTable*> graph_result =
-        BuildGraphForWasmFunction(&zone, thrower_, isolate_, module_env_,
+        BuildGraphForWasmFunction(jsgraph_, thrower_, isolate_, module_env_,
                                   function_, &decode_ms);
     JSGraph* jsgraph = graph_result.first;
     SourcePositionTable* source_positions = graph_result.second;
@@ -3050,6 +3066,9 @@ 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_;