[wasm] Several unrelated cleanups

Most are minor performance optimizations that aggregated while implementing
other changes. Those fixes will probably not be visible in perf graphs, but
they bothered me anyway.

R=titzer@chromium.org, ahaas@chromium.org

Review-Url: https://codereview.chromium.org/2714373003
Cr-Commit-Position: refs/heads/master@{#43535}

src/compiler/wasm-compiler.cc

@@ -179,7 +179,15 @@ class WasmTrapHelper : public ZoneObject {
   }
 
   Builtins::Name GetBuiltinIdForTrap(wasm::TrapReason reason) {
-    if (builder_->module_ && !builder_->module_->instance->context.is_null()) {
+    bool in_cctest =
+        !builder_->module_ || builder_->module_->instance->context.is_null();
+    if (in_cctest) {
+      // We use Builtins::builtin_count as a marker to tell the code generator
+      // to generate a call to a testing c-function instead of a runtime
+      // function. This code should only be called from a cctest.
+      return Builtins::builtin_count;
+    }
+
     switch (reason) {
 #define TRAPREASON_TO_MESSAGE(name) \
   case wasm::k##name:               \
@@ -190,12 +198,6 @@ class WasmTrapHelper : public ZoneObject {
         UNREACHABLE();
         return Builtins::builtin_count;
     }
-    } else {
-      // We use Runtime::kNumFunctions as a marker to tell the code generator
-      // to generate a call to a testing c-function instead of a runtime
-      // function. This code should only be called from a cctest.
-      return Builtins::builtin_count;
-    }
   }
 
 #if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_ARM ||      \
@@ -372,11 +374,11 @@ WasmGraphBuilder::WasmGraphBuilder(
       trap_(new (zone) WasmTrapHelper(this)),
       sig_(sig),
       source_position_table_(source_position_table) {
-  for (size_t i = 0; i < sig->parameter_count(); i++) {
-    if (sig->GetParam(i) == wasm::kWasmS128) has_simd_ = true;
+  for (size_t i = sig->parameter_count(); i > 0 && !has_simd_; --i) {
+    if (sig->GetParam(i - 1) == wasm::kWasmS128) has_simd_ = true;
   }
-  for (size_t i = 0; i < sig->return_count(); i++) {
-    if (sig->GetReturn(i) == wasm::kWasmS128) has_simd_ = true;
+  for (size_t i = sig->return_count(); i > 0 && !has_simd_; --i) {
+    if (sig->GetReturn(i - 1) == wasm::kWasmS128) has_simd_ = true;
   }
   DCHECK_NOT_NULL(jsgraph_);
 }
@@ -3064,13 +3066,12 @@ Node* WasmGraphBuilder::CurrentMemoryPages() {
   CallDescriptor* desc = Linkage::GetRuntimeCallDescriptor(
       jsgraph()->zone(), function_id, function->nargs, Operator::kNoThrow,
       CallDescriptor::kNoFlags);
-  wasm::ModuleEnv* module = module_;
   Node* inputs[] = {
       jsgraph()->CEntryStubConstant(function->result_size),  // C entry
       jsgraph()->ExternalConstant(
           ExternalReference(function_id, jsgraph()->isolate())),  // ref
       jsgraph()->Int32Constant(function->nargs),                  // arity
-      jsgraph()->HeapConstant(module->instance->context),         // context
+      jsgraph()->HeapConstant(module_->instance->context),        // context
       *effect_,
       *control_};
   Node* call = graph()->NewNode(jsgraph()->common()->Call(desc),

src/frames.h

@@ -1274,7 +1274,7 @@ class BuiltinFrame final : public JavaScriptFrame {
   friend class StackFrameIteratorBase;
 };
 
-class WasmCompiledFrame : public StandardFrame {
+class WasmCompiledFrame final : public StandardFrame {
  public:
   Type type() const override { return WASM_COMPILED; }
 
@@ -1316,7 +1316,7 @@ class WasmCompiledFrame : public StandardFrame {
   friend class StackFrameIteratorBase;
 };
 
-class WasmInterpreterEntryFrame : public StandardFrame {
+class WasmInterpreterEntryFrame final : public StandardFrame {
  public:
   Type type() const override { return WASM_INTERPRETER_ENTRY; }
 

src/wasm/module-decoder.cc

@@ -575,9 +575,9 @@ class ModuleDecoder : public Decoder {
         WasmIndirectFunctionTable* table = nullptr;
         if (table_index >= module->function_tables.size()) {
           error(pos, pos, "out of bounds table index %u", table_index);
-        } else {
-          table = &module->function_tables[table_index];
+          break;
         }
+        table = &module->function_tables[table_index];
         WasmInitExpr offset = consume_init_expr(module, kWasmI32);
         uint32_t num_elem =
             consume_count("number of elements", kV8MaxWasmTableEntries);
@@ -587,11 +587,12 @@ class ModuleDecoder : public Decoder {
         for (uint32_t j = 0; ok() && j < num_elem; j++) {
           WasmFunction* func = nullptr;
           uint32_t index = consume_func_index(module, &func);
+          DCHECK_EQ(func != nullptr, ok());
+          if (!func) break;
+          DCHECK_EQ(index, func->func_index);
           init->entries.push_back(index);
-          if (table && index < module->functions.size()) {
           // Canonicalize signature indices during decoding.
-            table->map.FindOrInsert(module->functions[index].sig);
-          }
+          table->map.FindOrInsert(func->sig);
         }
       }
 

src/wasm/wasm-module.cc

@@ -828,7 +828,6 @@ WasmInstanceObject* wasm::GetOwningWasmInstance(Code* code) {
   DCHECK(code->kind() == Code::WASM_FUNCTION ||
          code->kind() == Code::WASM_INTERPRETER_ENTRY);
   FixedArray* deopt_data = code->deoptimization_data();
-  DCHECK_NOT_NULL(deopt_data);
   DCHECK_EQ(code->kind() == Code::WASM_INTERPRETER_ENTRY ? 1 : 2,
             deopt_data->length());
   Object* weak_link = deopt_data->get(0);
@@ -846,7 +845,9 @@ int wasm::GetFunctionCodeOffset(Handle<WasmCompiledModule> compiled_module,
 WasmModule::WasmModule(Zone* owned)
     : owned_zone(owned), pending_tasks(new base::Semaphore(0)) {}
 
-static WasmFunction* GetWasmFunctionForImportWrapper(Isolate* isolate,
+namespace {
+
+WasmFunction* GetWasmFunctionForImportWrapper(Isolate* isolate,
                                               Handle<Object> target) {
   if (target->IsJSFunction()) {
     Handle<JSFunction> func = Handle<JSFunction>::cast(target);
@@ -884,8 +885,7 @@ static Handle<Code> UnwrapImportWrapper(Handle<Object> import_wrapper) {
   return Handle<Code>::null();
 }
 
-static Handle<Code> CompileImportWrapper(Isolate* isolate, int index,
-                                         FunctionSig* sig,
+Handle<Code> CompileImportWrapper(Isolate* isolate, int index, FunctionSig* sig,
                                   Handle<JSReceiver> target,
                                   Handle<String> module_name,
                                   MaybeHandle<String> import_name,
@@ -906,10 +906,9 @@ static Handle<Code> CompileImportWrapper(Isolate* isolate, int index,
   }
 }
 
-static void UpdateDispatchTablesInternal(Isolate* isolate,
-                                         Handle<FixedArray> dispatch_tables,
-                                         int index, WasmFunction* function,
-                                         Handle<Code> code) {
+void UpdateDispatchTablesInternal(Isolate* isolate,
+                                  Handle<FixedArray> dispatch_tables, int index,
+                                  WasmFunction* function, Handle<Code> code) {
   DCHECK_EQ(0, dispatch_tables->length() % 4);
   for (int i = 0; i < dispatch_tables->length(); i += 4) {
     int table_index = Smi::cast(dispatch_tables->get(i + 1))->value();
@@ -922,19 +921,19 @@ static void UpdateDispatchTablesInternal(Isolate* isolate,
       // a dangling pointer in the signature map.
       Handle<WasmInstanceObject> instance(
           WasmInstanceObject::cast(dispatch_tables->get(i)), isolate);
-      int sig_index = static_cast<int>(
-          instance->module()->function_tables[table_index].map.FindOrInsert(
-              function->sig));
-      signature_table->set(index, Smi::FromInt(sig_index));
+      auto func_table = instance->module()->function_tables[table_index];
+      uint32_t sig_index = func_table.map.FindOrInsert(function->sig);
+      signature_table->set(index, Smi::FromInt(static_cast<int>(sig_index)));
       function_table->set(index, *code);
     } else {
-      Code* code = nullptr;
       signature_table->set(index, Smi::FromInt(-1));
-      function_table->set(index, code);
+      function_table->set(index, Smi::kZero);
     }
   }
 }
 
+}  // namespace
+
 void wasm::UpdateDispatchTables(Isolate* isolate,
                                 Handle<FixedArray> dispatch_tables, int index,
                                 Handle<JSFunction> function) {
@@ -1024,8 +1023,7 @@ class InstantiationHelper {
 
         // Clone the code for WASM functions and exports.
         for (int i = 0; i < code_table->length(); ++i) {
-          Handle<Code> orig_code =
-              code_table->GetValueChecked<Code>(isolate_, i);
+          Handle<Code> orig_code(Code::cast(code_table->get(i)), isolate_);
           switch (orig_code->kind()) {
             case Code::WASM_TO_JS_FUNCTION:
               // Imports will be overwritten with newly compiled wrappers.
@@ -1187,14 +1185,14 @@ class InstantiationHelper {
     //--------------------------------------------------------------------------
     Handle<WeakCell> weak_link = factory->NewWeakCell(instance);
 
-    for (int i = num_imported_functions + FLAG_skip_compiling_wasm_funcs;
-         i < code_table->length(); ++i) {
-      Handle<Code> code = code_table->GetValueChecked<Code>(isolate_, i);
+    for (int i = num_imported_functions + FLAG_skip_compiling_wasm_funcs,
+             num_functions = code_table->length();
+         i < num_functions; ++i) {
+      Handle<Code> code = handle(Code::cast(code_table->get(i)), isolate_);
       if (code->kind() == Code::WASM_FUNCTION) {
         Handle<FixedArray> deopt_data = factory->NewFixedArray(2, TENURED);
         deopt_data->set(0, *weak_link);
-        deopt_data->set(1, Smi::FromInt(static_cast<int>(i)));
-        deopt_data->set_length(2);
+        deopt_data->set(1, Smi::FromInt(i));
         code->set_deoptimization_data(*deopt_data);
       }
     }
@@ -1303,8 +1301,8 @@ class InstantiationHelper {
     if (module_->start_function_index >= 0) {
       HandleScope scope(isolate_);
       int start_index = module_->start_function_index;
-      Handle<Code> startup_code =
-          code_table->GetValueChecked<Code>(isolate_, start_index);
+      Handle<Code> startup_code(Code::cast(code_table->get(start_index)),
+                                isolate_);
       FunctionSig* sig = module_->functions[start_index].sig;
       Handle<Code> wrapper_code =
           js_to_wasm_cache_.CloneOrCompileJSToWasmWrapper(
@@ -2002,7 +2000,8 @@ class InstantiationHelper {
         uint32_t base = EvalUint32InitExpr(table_init.offset);
         DCHECK(in_bounds(base, static_cast<uint32_t>(table_init.entries.size()),
                          table_instance.function_table->length()));
-        for (int i = 0; i < static_cast<int>(table_init.entries.size()); ++i) {
+        for (int i = 0, e = static_cast<int>(table_init.entries.size()); i < e;
+             ++i) {
           uint32_t func_index = table_init.entries[i];
           WasmFunction* function = &module_->functions[func_index];
           int table_index = static_cast<int>(i + base);
@@ -2642,6 +2641,8 @@ MaybeHandle<WasmInstanceObject> wasm::SyncInstantiate(
   return helper.Build();
 }
 
+namespace {
+
 void RejectPromise(Isolate* isolate, ErrorThrower* thrower,
                    Handle<JSPromise> promise) {
   v8::Local<v8::Promise::Resolver> resolver =
@@ -2659,6 +2660,8 @@ void ResolvePromise(Isolate* isolate, Handle<JSPromise> promise,
   resolver->Resolve(v8::Utils::ToLocal(context), v8::Utils::ToLocal(result));
 }
 
+}  // namespace
+
 void wasm::AsyncCompile(Isolate* isolate, Handle<JSPromise> promise,
                         const ModuleWireBytes& bytes) {
   ErrorThrower thrower(isolate, nullptr);

src/wasm/wasm-opcodes.h

@@ -33,16 +33,16 @@ static const uint8_t kMultivalBlock = 0x41;
 // We reuse the internal machine type to represent WebAssembly types.
 // A typedef improves readability without adding a whole new type system.
 typedef MachineRepresentation ValueType;
-const ValueType kWasmStmt = MachineRepresentation::kNone;
-const ValueType kWasmI32 = MachineRepresentation::kWord32;
-const ValueType kWasmI64 = MachineRepresentation::kWord64;
-const ValueType kWasmF32 = MachineRepresentation::kFloat32;
-const ValueType kWasmF64 = MachineRepresentation::kFloat64;
-const ValueType kWasmS128 = MachineRepresentation::kSimd128;
-const ValueType kWasmS1x4 = MachineRepresentation::kSimd1x4;
-const ValueType kWasmS1x8 = MachineRepresentation::kSimd1x8;
-const ValueType kWasmS1x16 = MachineRepresentation::kSimd1x16;
-const ValueType kWasmVar = MachineRepresentation::kTagged;
+constexpr ValueType kWasmStmt = MachineRepresentation::kNone;
+constexpr ValueType kWasmI32 = MachineRepresentation::kWord32;
+constexpr ValueType kWasmI64 = MachineRepresentation::kWord64;
+constexpr ValueType kWasmF32 = MachineRepresentation::kFloat32;
+constexpr ValueType kWasmF64 = MachineRepresentation::kFloat64;
+constexpr ValueType kWasmS128 = MachineRepresentation::kSimd128;
+constexpr ValueType kWasmS1x4 = MachineRepresentation::kSimd1x4;
+constexpr ValueType kWasmS1x8 = MachineRepresentation::kSimd1x8;
+constexpr ValueType kWasmS1x16 = MachineRepresentation::kSimd1x16;
+constexpr ValueType kWasmVar = MachineRepresentation::kTagged;
 
 typedef Signature<ValueType> FunctionSig;
 std::ostream& operator<<(std::ostream& os, const FunctionSig& function);
@@ -50,7 +50,7 @@ std::ostream& operator<<(std::ostream& os, const FunctionSig& function);
 typedef Vector<const char> WasmName;
 
 typedef int WasmCodePosition;
-const WasmCodePosition kNoCodePosition = -1;
+constexpr WasmCodePosition kNoCodePosition = -1;
 
 // Control expressions and blocks.
 #define FOREACH_CONTROL_OPCODE(V)      \

test/cctest/wasm/wasm-run-utils.h

@@ -205,7 +205,7 @@ class TestingModule : public ModuleEnv {
     if (interpreter_) {
       const WasmFunction* function = &module->functions.back();
       int interpreter_index = interpreter_->AddFunctionForTesting(function);
-      CHECK_EQ(index, static_cast<uint32_t>(interpreter_index));
+      CHECK_EQ(index, interpreter_index);
     }
     DCHECK_LT(index, kMaxFunctions);  // limited for testing.
     return index;
@@ -628,7 +628,6 @@ class WasmFunctionCompiler : private GraphAndBuilders {
         isolate()->factory()->NewWeakCell(testing_module_->instance_object());
     deopt_data->set(0, *weak_instance);
     deopt_data->set(1, Smi::FromInt(static_cast<int>(function_index())));
-    deopt_data->set_length(2);
     code->set_deoptimization_data(*deopt_data);
 
 #ifdef ENABLE_DISASSEMBLER