// Copyright 2009 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. #include "v8.h" #include "codegen-inl.h" #include "compiler.h" #include "fast-codegen.h" #include "parser.h" #include "debug.h" namespace v8 { namespace internal { #define __ ACCESS_MASM(masm_) // Generate code for a JS function. On entry to the function the receiver // and arguments have been pushed on the stack left to right, with the // return address on top of them. The actual argument count matches the // formal parameter count expected by the function. // // The live registers are: // o edi: the JS function object being called (ie, ourselves) // o esi: our context // o ebp: our caller's frame pointer // o esp: stack pointer (pointing to return address) // // The function builds a JS frame. Please see JavaScriptFrameConstants in // frames-ia32.h for its layout. void FastCodeGenerator::Generate(FunctionLiteral* fun) { function_ = fun; SetFunctionPosition(fun); __ push(ebp); // Caller's frame pointer. __ mov(ebp, esp); __ push(esi); // Callee's context. __ push(edi); // Callee's JS Function. { Comment cmnt(masm_, "[ Allocate locals"); int locals_count = fun->scope()->num_stack_slots(); if (locals_count == 1) { __ push(Immediate(Factory::undefined_value())); } else if (locals_count > 1) { __ mov(eax, Immediate(Factory::undefined_value())); for (int i = 0; i < locals_count; i++) { __ push(eax); } } } bool function_in_register = true; // Possibly allocate a local context. if (fun->scope()->num_heap_slots() > 0) { Comment cmnt(masm_, "[ Allocate local context"); // Argument to NewContext is the function, which is still in edi. __ push(edi); __ CallRuntime(Runtime::kNewContext, 1); function_in_register = false; // Context is returned in both eax and esi. It replaces the context // passed to us. It's saved in the stack and kept live in esi. __ mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi); // Copy parameters into context if necessary. int num_parameters = fun->scope()->num_parameters(); for (int i = 0; i < num_parameters; i++) { Slot* slot = fun->scope()->parameter(i)->slot(); if (slot != NULL && slot->type() == Slot::CONTEXT) { int parameter_offset = StandardFrameConstants::kCallerSPOffset + (num_parameters - 1 - i) * kPointerSize; // Load parameter from stack. __ mov(eax, Operand(ebp, parameter_offset)); // Store it in the context __ mov(Operand(esi, Context::SlotOffset(slot->index())), eax); } } } Variable* arguments = fun->scope()->arguments()->AsVariable(); if (arguments != NULL) { // Function uses arguments object. Comment cmnt(masm_, "[ Allocate arguments object"); if (function_in_register) { __ push(edi); } else { __ push(Operand(ebp, JavaScriptFrameConstants::kFunctionOffset)); } // Receiver is just before the parameters on the caller's stack. __ lea(edx, Operand(ebp, StandardFrameConstants::kCallerSPOffset + fun->num_parameters() * kPointerSize)); __ push(edx); __ push(Immediate(Smi::FromInt(fun->num_parameters()))); // Arguments to ArgumentsAccessStub: // function, receiver address, parameter count. // The stub will rewrite receiever and parameter count if the previous // stack frame was an arguments adapter frame. ArgumentsAccessStub stub(ArgumentsAccessStub::NEW_OBJECT); __ CallStub(&stub); __ mov(ecx, eax); // Duplicate result. Move(arguments->slot(), eax, ebx, edx); Slot* dot_arguments_slot = fun->scope()->arguments_shadow()->AsVariable()->slot(); Move(dot_arguments_slot, ecx, ebx, edx); } { Comment cmnt(masm_, "[ Declarations"); VisitDeclarations(fun->scope()->declarations()); } { Comment cmnt(masm_, "[ Stack check"); Label ok; ExternalReference stack_limit = ExternalReference::address_of_stack_limit(); __ cmp(esp, Operand::StaticVariable(stack_limit)); __ j(above_equal, &ok, taken); StackCheckStub stub; __ CallStub(&stub); __ bind(&ok); } if (FLAG_trace) { __ CallRuntime(Runtime::kTraceEnter, 0); } { Comment cmnt(masm_, "[ Body"); ASSERT(loop_depth() == 0); VisitStatements(fun->body()); ASSERT(loop_depth() == 0); } { Comment cmnt(masm_, "[ return ;"); // Emit a 'return undefined' in case control fell off the end of the body. __ mov(eax, Factory::undefined_value()); EmitReturnSequence(function_->end_position()); } } void FastCodeGenerator::EmitReturnSequence(int position) { Comment cmnt(masm_, "[ Return sequence"); if (return_label_.is_bound()) { __ jmp(&return_label_); } else { // Common return label __ bind(&return_label_); if (FLAG_trace) { __ push(eax); __ CallRuntime(Runtime::kTraceExit, 1); } #ifdef DEBUG // Add a label for checking the size of the code used for returning. Label check_exit_codesize; masm_->bind(&check_exit_codesize); #endif CodeGenerator::RecordPositions(masm_, position); __ RecordJSReturn(); // Do not use the leave instruction here because it is too short to // patch with the code required by the debugger. __ mov(esp, ebp); __ pop(ebp); __ ret((function_->scope()->num_parameters() + 1) * kPointerSize); #ifdef ENABLE_DEBUGGER_SUPPORT // Check that the size of the code used for returning matches what is // expected by the debugger. ASSERT_EQ(Assembler::kJSReturnSequenceLength, masm_->SizeOfCodeGeneratedSince(&check_exit_codesize)); #endif } } void FastCodeGenerator::Move(Expression::Context context, Register source) { switch (context) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kEffect: break; case Expression::kValue: __ push(source); break; case Expression::kTest: TestAndBranch(source, true_label_, false_label_); break; case Expression::kValueTest: { Label discard; __ push(source); TestAndBranch(source, true_label_, &discard); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(false_label_); break; } case Expression::kTestValue: { Label discard; __ push(source); TestAndBranch(source, &discard, false_label_); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(true_label_); } } } template <> Operand FastCodeGenerator::CreateSlotOperand(Slot* source, Register scratch) { switch (source->type()) { case Slot::PARAMETER: case Slot::LOCAL: return Operand(ebp, SlotOffset(source)); case Slot::CONTEXT: { int context_chain_length = function_->scope()->ContextChainLength(source->var()->scope()); __ LoadContext(scratch, context_chain_length); return CodeGenerator::ContextOperand(scratch, source->index()); break; } case Slot::LOOKUP: UNIMPLEMENTED(); // Fall-through. default: UNREACHABLE(); return Operand(eax, 0); // Dead code to make the compiler happy. } } void FastCodeGenerator::Move(Register dst, Slot* source) { Operand location = CreateSlotOperand(source, dst); __ mov(dst, location); } void FastCodeGenerator::Move(Expression::Context context, Slot* source, Register scratch) { switch (context) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kEffect: break; case Expression::kValue: { Operand location = CreateSlotOperand(source, scratch); __ push(location); break; } case Expression::kTest: // Fall through. case Expression::kValueTest: // Fall through. case Expression::kTestValue: Move(scratch, source); Move(context, scratch); break; } } void FastCodeGenerator::Move(Expression::Context context, Literal* expr) { switch (context) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kEffect: break; case Expression::kValue: __ push(Immediate(expr->handle())); break; case Expression::kTest: // Fall through. case Expression::kValueTest: // Fall through. case Expression::kTestValue: __ mov(eax, expr->handle()); Move(context, eax); break; } } void FastCodeGenerator::Move(Slot* dst, Register src, Register scratch1, Register scratch2) { switch (dst->type()) { case Slot::PARAMETER: case Slot::LOCAL: __ mov(Operand(ebp, SlotOffset(dst)), src); break; case Slot::CONTEXT: { ASSERT(!src.is(scratch1)); ASSERT(!src.is(scratch2)); ASSERT(!scratch1.is(scratch2)); int context_chain_length = function_->scope()->ContextChainLength(dst->var()->scope()); __ LoadContext(scratch1, context_chain_length); __ mov(Operand(scratch1, Context::SlotOffset(dst->index())), src); int offset = FixedArray::kHeaderSize + dst->index() * kPointerSize; __ RecordWrite(scratch1, offset, src, scratch2); break; } case Slot::LOOKUP: UNIMPLEMENTED(); default: UNREACHABLE(); } } void FastCodeGenerator::DropAndMove(Expression::Context context, Register source, int count) { ASSERT(count > 0); switch (context) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kEffect: __ add(Operand(esp), Immediate(count * kPointerSize)); break; case Expression::kValue: if (count > 1) { __ add(Operand(esp), Immediate((count - 1) * kPointerSize)); } __ mov(Operand(esp, 0), source); break; case Expression::kTest: ASSERT(!source.is(esp)); __ add(Operand(esp), Immediate(count * kPointerSize)); TestAndBranch(source, true_label_, false_label_); break; case Expression::kValueTest: { Label discard; if (count > 1) { __ add(Operand(esp), Immediate((count - 1) * kPointerSize)); } __ mov(Operand(esp, 0), source); TestAndBranch(source, true_label_, &discard); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(false_label_); break; } case Expression::kTestValue: { Label discard; if (count > 1) { __ add(Operand(esp), Immediate((count - 1) * kPointerSize)); } __ mov(Operand(esp, 0), source); TestAndBranch(source, &discard, false_label_); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(true_label_); break; } } } void FastCodeGenerator::TestAndBranch(Register source, Label* true_label, Label* false_label) { ASSERT_NE(NULL, true_label); ASSERT_NE(NULL, false_label); // Use the shared ToBoolean stub to compile the value in the register into // control flow to the code generator's true and false labels. Perform // the fast checks assumed by the stub. __ cmp(source, Factory::undefined_value()); // The undefined value is false. __ j(equal, false_label); __ cmp(source, Factory::true_value()); // True is true. __ j(equal, true_label); __ cmp(source, Factory::false_value()); // False is false. __ j(equal, false_label); ASSERT_EQ(0, kSmiTag); __ test(source, Operand(source)); // The smi zero is false. __ j(zero, false_label); __ test(source, Immediate(kSmiTagMask)); // All other smis are true. __ j(zero, true_label); // Call the stub for all other cases. __ push(source); ToBooleanStub stub; __ CallStub(&stub); __ test(eax, Operand(eax)); // The stub returns nonzero for true. __ j(not_zero, true_label); __ jmp(false_label); } void FastCodeGenerator::VisitDeclaration(Declaration* decl) { Comment cmnt(masm_, "[ Declaration"); Variable* var = decl->proxy()->var(); ASSERT(var != NULL); // Must have been resolved. Slot* slot = var->slot(); Property* prop = var->AsProperty(); if (slot != NULL) { switch (slot->type()) { case Slot::PARAMETER: // Fall through. case Slot::LOCAL: if (decl->mode() == Variable::CONST) { __ mov(Operand(ebp, SlotOffset(var->slot())), Immediate(Factory::the_hole_value())); } else if (decl->fun() != NULL) { Visit(decl->fun()); __ pop(Operand(ebp, SlotOffset(var->slot()))); } break; case Slot::CONTEXT: // The variable in the decl always resides in the current context. ASSERT_EQ(0, function_->scope()->ContextChainLength(var->scope())); if (FLAG_debug_code) { // Check if we have the correct context pointer. __ mov(ebx, CodeGenerator::ContextOperand(esi, Context::FCONTEXT_INDEX)); __ cmp(ebx, Operand(esi)); __ Check(equal, "Unexpected declaration in current context."); } if (decl->mode() == Variable::CONST) { __ mov(eax, Immediate(Factory::the_hole_value())); __ mov(CodeGenerator::ContextOperand(esi, slot->index()), eax); // No write barrier since the hole value is in old space. } else if (decl->fun() != NULL) { Visit(decl->fun()); __ pop(eax); __ mov(CodeGenerator::ContextOperand(esi, slot->index()), eax); int offset = Context::SlotOffset(slot->index()); __ RecordWrite(esi, offset, eax, ecx); } break; case Slot::LOOKUP: { __ push(esi); __ push(Immediate(var->name())); // Declaration nodes are always introduced in one of two modes. ASSERT(decl->mode() == Variable::VAR || decl->mode() == Variable::CONST); PropertyAttributes attr = (decl->mode() == Variable::VAR) ? NONE : READ_ONLY; __ push(Immediate(Smi::FromInt(attr))); // Push initial value, if any. // Note: For variables we must not push an initial value (such as // 'undefined') because we may have a (legal) redeclaration and we // must not destroy the current value. if (decl->mode() == Variable::CONST) { __ push(Immediate(Factory::the_hole_value())); } else if (decl->fun() != NULL) { Visit(decl->fun()); } else { __ push(Immediate(Smi::FromInt(0))); // No initial value! } __ CallRuntime(Runtime::kDeclareContextSlot, 4); break; } } } else if (prop != NULL) { if (decl->fun() != NULL || decl->mode() == Variable::CONST) { // We are declaring a function or constant that rewrites to a // property. Use (keyed) IC to set the initial value. ASSERT_EQ(Expression::kValue, prop->obj()->context()); Visit(prop->obj()); ASSERT_EQ(Expression::kValue, prop->key()->context()); Visit(prop->key()); if (decl->fun() != NULL) { ASSERT_EQ(Expression::kValue, decl->fun()->context()); Visit(decl->fun()); __ pop(eax); } else { __ Set(eax, Immediate(Factory::the_hole_value())); } Handle ic(Builtins::builtin(Builtins::KeyedStoreIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // Absence of a test eax instruction following the call // indicates that none of the load was inlined. // Value in eax is ignored (declarations are statements). Receiver // and key on stack are discarded. __ add(Operand(esp), Immediate(2 * kPointerSize)); } } } void FastCodeGenerator::DeclareGlobals(Handle pairs) { // Call the runtime to declare the globals. __ push(esi); // The context is the first argument. __ push(Immediate(pairs)); __ push(Immediate(Smi::FromInt(is_eval_ ? 1 : 0))); __ CallRuntime(Runtime::kDeclareGlobals, 3); // Return value is ignored. } void FastCodeGenerator::VisitFunctionLiteral(FunctionLiteral* expr) { Comment cmnt(masm_, "[ FunctionLiteral"); // Build the function boilerplate and instantiate it. Handle boilerplate = Compiler::BuildBoilerplate(expr, script_, this); if (HasStackOverflow()) return; ASSERT(boilerplate->IsBoilerplate()); // Create a new closure. __ push(esi); __ push(Immediate(boilerplate)); __ CallRuntime(Runtime::kNewClosure, 2); Move(expr->context(), eax); } void FastCodeGenerator::VisitVariableProxy(VariableProxy* expr) { Comment cmnt(masm_, "[ VariableProxy"); Expression* rewrite = expr->var()->rewrite(); if (rewrite == NULL) { ASSERT(expr->var()->is_global()); Comment cmnt(masm_, "Global variable"); // Use inline caching. Variable name is passed in ecx and the global // object on the stack. __ push(CodeGenerator::GlobalObject()); __ mov(ecx, expr->name()); Handle ic(Builtins::builtin(Builtins::LoadIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET_CONTEXT); // By emitting a nop we make sure that we do not have a test eax // instruction after the call it is treated specially by the LoadIC code // Remember that the assembler may choose to do peephole optimization // (eg, push/pop elimination). __ nop(); DropAndMove(expr->context(), eax); } else if (rewrite->AsSlot() != NULL) { Slot* slot = rewrite->AsSlot(); if (FLAG_debug_code) { switch (slot->type()) { case Slot::LOCAL: case Slot::PARAMETER: { Comment cmnt(masm_, "Stack slot"); break; } case Slot::CONTEXT: { Comment cmnt(masm_, "Context slot"); break; } case Slot::LOOKUP: UNIMPLEMENTED(); break; default: UNREACHABLE(); } } Move(expr->context(), slot, eax); } else { Comment cmnt(masm_, "Variable rewritten to Property"); // A variable has been rewritten into an explicit access to // an object property. Property* property = rewrite->AsProperty(); ASSERT_NOT_NULL(property); // Currently the only parameter expressions that can occur are // on the form "slot[literal]". // Check that the object is in a slot. Variable* object_var = property->obj()->AsVariableProxy()->AsVariable(); ASSERT_NOT_NULL(object_var); Slot* object_slot = object_var->slot(); ASSERT_NOT_NULL(object_slot); // Load the object. Move(Expression::kValue, object_slot, eax); // Check that the key is a smi. Literal* key_literal = property->key()->AsLiteral(); ASSERT_NOT_NULL(key_literal); ASSERT(key_literal->handle()->IsSmi()); // Load the key. Move(Expression::kValue, key_literal); // Do a KEYED property load. Handle ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // Notice: We must not have a "test eax, ..." instruction after // the call. It is treated specially by the LoadIC code. __ nop(); // Drop key and object left on the stack by IC, and push the result. DropAndMove(expr->context(), eax, 2); } } void FastCodeGenerator::VisitRegExpLiteral(RegExpLiteral* expr) { Comment cmnt(masm_, "[ RegExpLiteral"); Label done; // Registers will be used as follows: // edi = JS function. // ebx = literals array. // eax = regexp literal. __ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset)); __ mov(ebx, FieldOperand(edi, JSFunction::kLiteralsOffset)); int literal_offset = FixedArray::kHeaderSize + expr->literal_index() * kPointerSize; __ mov(eax, FieldOperand(ebx, literal_offset)); __ cmp(eax, Factory::undefined_value()); __ j(not_equal, &done); // Create regexp literal using runtime function // Result will be in eax. __ push(ebx); __ push(Immediate(Smi::FromInt(expr->literal_index()))); __ push(Immediate(expr->pattern())); __ push(Immediate(expr->flags())); __ CallRuntime(Runtime::kMaterializeRegExpLiteral, 4); // Label done: __ bind(&done); Move(expr->context(), eax); } void FastCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) { Comment cmnt(masm_, "[ ObjectLiteral"); __ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset)); __ push(FieldOperand(edi, JSFunction::kLiteralsOffset)); __ push(Immediate(Smi::FromInt(expr->literal_index()))); __ push(Immediate(expr->constant_properties())); if (expr->depth() > 1) { __ CallRuntime(Runtime::kCreateObjectLiteral, 3); } else { __ CallRuntime(Runtime::kCreateObjectLiteralShallow, 3); } // If result_saved == true: The result is saved on top of the // stack and in eax. // If result_saved == false: The result not on the stack, just in eax. bool result_saved = false; for (int i = 0; i < expr->properties()->length(); i++) { ObjectLiteral::Property* property = expr->properties()->at(i); if (property->IsCompileTimeValue()) continue; Literal* key = property->key(); Expression* value = property->value(); if (!result_saved) { __ push(eax); // Save result on the stack result_saved = true; } switch (property->kind()) { case ObjectLiteral::Property::MATERIALIZED_LITERAL: // fall through ASSERT(!CompileTimeValue::IsCompileTimeValue(value)); case ObjectLiteral::Property::COMPUTED: if (key->handle()->IsSymbol()) { Visit(value); ASSERT_EQ(Expression::kValue, value->context()); __ pop(eax); __ mov(ecx, Immediate(key->handle())); Handle ic(Builtins::builtin(Builtins::StoreIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // StoreIC leaves the receiver on the stack. __ mov(eax, Operand(esp, 0)); // Restore result into eax. break; } // fall through case ObjectLiteral::Property::PROTOTYPE: __ push(eax); Visit(key); ASSERT_EQ(Expression::kValue, key->context()); Visit(value); ASSERT_EQ(Expression::kValue, value->context()); __ CallRuntime(Runtime::kSetProperty, 3); __ mov(eax, Operand(esp, 0)); // Restore result into eax. break; case ObjectLiteral::Property::SETTER: // fall through case ObjectLiteral::Property::GETTER: __ push(eax); Visit(key); ASSERT_EQ(Expression::kValue, key->context()); __ push(Immediate(property->kind() == ObjectLiteral::Property::SETTER ? Smi::FromInt(1) : Smi::FromInt(0))); Visit(value); ASSERT_EQ(Expression::kValue, value->context()); __ CallRuntime(Runtime::kDefineAccessor, 4); __ mov(eax, Operand(esp, 0)); // Restore result into eax. break; default: UNREACHABLE(); } } switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kEffect: if (result_saved) __ add(Operand(esp), Immediate(kPointerSize)); break; case Expression::kValue: if (!result_saved) __ push(eax); break; case Expression::kTest: if (result_saved) __ pop(eax); TestAndBranch(eax, true_label_, false_label_); break; case Expression::kValueTest: { Label discard; if (!result_saved) __ push(eax); TestAndBranch(eax, true_label_, &discard); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(false_label_); break; } case Expression::kTestValue: { Label discard; if (!result_saved) __ push(eax); TestAndBranch(eax, &discard, false_label_); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(true_label_); break; } } } void FastCodeGenerator::VisitArrayLiteral(ArrayLiteral* expr) { Comment cmnt(masm_, "[ ArrayLiteral"); __ mov(ebx, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset)); __ push(FieldOperand(ebx, JSFunction::kLiteralsOffset)); __ push(Immediate(Smi::FromInt(expr->literal_index()))); __ push(Immediate(expr->literals())); if (expr->depth() > 1) { __ CallRuntime(Runtime::kCreateArrayLiteral, 3); } else { __ CallRuntime(Runtime::kCreateArrayLiteralShallow, 3); } bool result_saved = false; // Is the result saved to the stack? // Emit code to evaluate all the non-constant subexpressions and to store // them into the newly cloned array. ZoneList* subexprs = expr->values(); for (int i = 0, len = subexprs->length(); i < len; i++) { Expression* subexpr = subexprs->at(i); // If the subexpression is a literal or a simple materialized literal it // is already set in the cloned array. if (subexpr->AsLiteral() != NULL || CompileTimeValue::IsCompileTimeValue(subexpr)) { continue; } if (!result_saved) { __ push(eax); result_saved = true; } Visit(subexpr); ASSERT_EQ(Expression::kValue, subexpr->context()); // Store the subexpression value in the array's elements. __ pop(eax); // Subexpression value. __ mov(ebx, Operand(esp, 0)); // Copy of array literal. __ mov(ebx, FieldOperand(ebx, JSObject::kElementsOffset)); int offset = FixedArray::kHeaderSize + (i * kPointerSize); __ mov(FieldOperand(ebx, offset), eax); // Update the write barrier for the array store. __ RecordWrite(ebx, offset, eax, ecx); } switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kEffect: if (result_saved) __ add(Operand(esp), Immediate(kPointerSize)); break; case Expression::kValue: if (!result_saved) __ push(eax); break; case Expression::kTest: if (result_saved) __ pop(eax); TestAndBranch(eax, true_label_, false_label_); break; case Expression::kValueTest: { Label discard; if (!result_saved) __ push(eax); TestAndBranch(eax, true_label_, &discard); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(false_label_); break; } case Expression::kTestValue: { Label discard; if (!result_saved) __ push(eax); TestAndBranch(eax, &discard, false_label_); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(true_label_); break; } } } void FastCodeGenerator::EmitVariableAssignment(Assignment* expr) { Variable* var = expr->target()->AsVariableProxy()->AsVariable(); ASSERT(var != NULL); ASSERT(var->is_global() || var->slot() != NULL); if (var->is_global()) { // Assignment to a global variable. Use inline caching for the // assignment. Right-hand-side value is passed in eax, variable name in // ecx, and the global object on the stack. __ pop(eax); __ mov(ecx, var->name()); __ push(CodeGenerator::GlobalObject()); Handle ic(Builtins::builtin(Builtins::StoreIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // Overwrite the receiver on the stack with the result if needed. DropAndMove(expr->context(), eax); } else if (var->slot() != NULL) { Slot* slot = var->slot(); switch (slot->type()) { case Slot::LOCAL: case Slot::PARAMETER: { Operand target = Operand(ebp, SlotOffset(var->slot())); switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kEffect: // Perform assignment and discard value. __ pop(target); break; case Expression::kValue: // Perform assignment and preserve value. __ mov(eax, Operand(esp, 0)); __ mov(target, eax); break; case Expression::kTest: // Perform assignment and test (and discard) value. __ pop(eax); __ mov(target, eax); TestAndBranch(eax, true_label_, false_label_); break; case Expression::kValueTest: { Label discard; __ mov(eax, Operand(esp, 0)); __ mov(target, eax); TestAndBranch(eax, true_label_, &discard); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(false_label_); break; } case Expression::kTestValue: { Label discard; __ mov(eax, Operand(esp, 0)); __ mov(target, eax); TestAndBranch(eax, &discard, false_label_); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(true_label_); break; } } break; } case Slot::CONTEXT: { int chain_length = function_->scope()->ContextChainLength(slot->var()->scope()); if (chain_length > 0) { // Move up the context chain to the context containing the slot. __ mov(eax, Operand(esi, Context::SlotOffset(Context::CLOSURE_INDEX))); // Load the function context (which is the incoming, outer context). __ mov(eax, FieldOperand(eax, JSFunction::kContextOffset)); for (int i = 1; i < chain_length; i++) { __ mov(eax, Operand(eax, Context::SlotOffset(Context::CLOSURE_INDEX))); __ mov(eax, FieldOperand(eax, JSFunction::kContextOffset)); } } else { // Slot is in the current context. Generate optimized code. __ mov(eax, esi); // RecordWrite destroys the object register. } if (FLAG_debug_code) { __ cmp(eax, Operand(eax, Context::SlotOffset(Context::FCONTEXT_INDEX))); __ Check(equal, "Context Slot chain length wrong."); } __ pop(ecx); __ mov(Operand(eax, Context::SlotOffset(slot->index())), ecx); // RecordWrite may destroy all its register arguments. if (expr->context() == Expression::kValue) { __ push(ecx); } else if (expr->context() != Expression::kEffect) { __ mov(edx, ecx); } int offset = FixedArray::kHeaderSize + slot->index() * kPointerSize; __ RecordWrite(eax, offset, ecx, ebx); if (expr->context() != Expression::kEffect && expr->context() != Expression::kValue) { Move(expr->context(), edx); } break; } case Slot::LOOKUP: UNREACHABLE(); break; } } } void FastCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) { // Assignment to a property, using a named store IC. Property* prop = expr->target()->AsProperty(); ASSERT(prop != NULL); ASSERT(prop->key()->AsLiteral() != NULL); // If the assignment starts a block of assignments to the same object, // change to slow case to avoid the quadratic behavior of repeatedly // adding fast properties. if (expr->starts_initialization_block()) { __ push(Operand(esp, kPointerSize)); // Receiver is under value. __ CallRuntime(Runtime::kToSlowProperties, 1); } __ pop(eax); __ mov(ecx, prop->key()->AsLiteral()->handle()); Handle ic(Builtins::builtin(Builtins::StoreIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // If the assignment ends an initialization block, revert to fast case. if (expr->ends_initialization_block()) { __ push(eax); // Result of assignment, saved even if not needed. __ push(Operand(esp, kPointerSize)); // Receiver is under value. __ CallRuntime(Runtime::kToFastProperties, 1); __ pop(eax); } DropAndMove(expr->context(), eax); } void FastCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) { // Assignment to a property, using a keyed store IC. // If the assignment starts a block of assignments to the same object, // change to slow case to avoid the quadratic behavior of repeatedly // adding fast properties. if (expr->starts_initialization_block()) { // Reciever is under the key and value. __ push(Operand(esp, 2 * kPointerSize)); __ CallRuntime(Runtime::kToSlowProperties, 1); } __ pop(eax); Handle ic(Builtins::builtin(Builtins::KeyedStoreIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // This nop signals to the IC that there is no inlined code at the call // site for it to patch. __ nop(); // If the assignment ends an initialization block, revert to fast case. if (expr->ends_initialization_block()) { __ push(eax); // Result of assignment, saved even if not needed. // Reciever is under the key and value. __ push(Operand(esp, 2 * kPointerSize)); __ CallRuntime(Runtime::kToFastProperties, 1); __ pop(eax); } // Receiver and key are still on stack. __ add(Operand(esp), Immediate(2 * kPointerSize)); Move(expr->context(), eax); } void FastCodeGenerator::VisitProperty(Property* expr) { Comment cmnt(masm_, "[ Property"); Expression* key = expr->key(); uint32_t dummy; // Record the source position for the property load. SetSourcePosition(expr->position()); // Evaluate receiver. Visit(expr->obj()); if (key->AsLiteral() != NULL && key->AsLiteral()->handle()->IsSymbol() && !String::cast(*(key->AsLiteral()->handle()))->AsArrayIndex(&dummy)) { // Do a NAMED property load. // The IC expects the property name in ecx and the receiver on the stack. __ mov(ecx, Immediate(key->AsLiteral()->handle())); Handle ic(Builtins::builtin(Builtins::LoadIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // By emitting a nop we make sure that we do not have a test eax // instruction after the call it is treated specially by the LoadIC code. __ nop(); } else { // Do a KEYED property load. Visit(expr->key()); Handle ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // By emitting a nop we make sure that we do not have a "test eax,..." // instruction after the call it is treated specially by the LoadIC code. __ nop(); // Drop key left on the stack by IC. __ add(Operand(esp), Immediate(kPointerSize)); } DropAndMove(expr->context(), eax); } void FastCodeGenerator::EmitCallWithIC(Call* expr, RelocInfo::Mode reloc_info) { // Code common for calls using the IC. ZoneList* args = expr->arguments(); int arg_count = args->length(); for (int i = 0; i < arg_count; i++) { Visit(args->at(i)); ASSERT_EQ(Expression::kValue, args->at(i)->context()); } // Record source position for debugger. SetSourcePosition(expr->position()); // Call the IC initialization code. Handle ic = CodeGenerator::ComputeCallInitialize(arg_count, NOT_IN_LOOP); __ call(ic, reloc_info); // Restore context register. __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset)); // Discard the function left on TOS. DropAndMove(expr->context(), eax); } void FastCodeGenerator::EmitCallWithStub(Call* expr) { // Code common for calls using the call stub. ZoneList* args = expr->arguments(); int arg_count = args->length(); for (int i = 0; i < arg_count; i++) { Visit(args->at(i)); } // Record source position for debugger. SetSourcePosition(expr->position()); CallFunctionStub stub(arg_count, NOT_IN_LOOP); __ CallStub(&stub); // Restore context register. __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset)); // Discard the function left on TOS. DropAndMove(expr->context(), eax); } void FastCodeGenerator::VisitCall(Call* expr) { Comment cmnt(masm_, "[ Call"); Expression* fun = expr->expression(); Variable* var = fun->AsVariableProxy()->AsVariable(); if (var != NULL && var->is_possibly_eval()) { // Call to the identifier 'eval'. UNREACHABLE(); } else if (var != NULL && !var->is_this() && var->is_global()) { // Call to a global variable. __ push(Immediate(var->name())); // Push global object as receiver for the call IC lookup. __ push(CodeGenerator::GlobalObject()); EmitCallWithIC(expr, RelocInfo::CODE_TARGET_CONTEXT); } else if (var != NULL && var->slot() != NULL && var->slot()->type() == Slot::LOOKUP) { // Call to a lookup slot. UNREACHABLE(); } else if (fun->AsProperty() != NULL) { // Call to an object property. Property* prop = fun->AsProperty(); Literal* key = prop->key()->AsLiteral(); if (key != NULL && key->handle()->IsSymbol()) { // Call to a named property, use call IC. __ push(Immediate(key->handle())); Visit(prop->obj()); EmitCallWithIC(expr, RelocInfo::CODE_TARGET); } else { // Call to a keyed property, use keyed load IC followed by function // call. Visit(prop->obj()); Visit(prop->key()); // Record source code position for IC call. SetSourcePosition(prop->position()); Handle ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // By emitting a nop we make sure that we do not have a "test eax,..." // instruction after the call it is treated specially by the LoadIC code. __ nop(); // Drop key left on the stack by IC. __ add(Operand(esp), Immediate(kPointerSize)); // Pop receiver. __ pop(ebx); // Push result (function). __ push(eax); // Push receiver object on stack. if (prop->is_synthetic()) { __ push(CodeGenerator::GlobalObject()); } else { __ push(ebx); } EmitCallWithStub(expr); } } else { // Call to some other expression. If the expression is an anonymous // function literal not called in a loop, mark it as one that should // also use the fast code generator. FunctionLiteral* lit = fun->AsFunctionLiteral(); if (lit != NULL && lit->name()->Equals(Heap::empty_string()) && loop_depth() == 0) { lit->set_try_fast_codegen(true); } Visit(fun); // Load global receiver object. __ mov(ebx, CodeGenerator::GlobalObject()); __ push(FieldOperand(ebx, GlobalObject::kGlobalReceiverOffset)); // Emit function call. EmitCallWithStub(expr); } } void FastCodeGenerator::VisitCallNew(CallNew* expr) { Comment cmnt(masm_, "[ CallNew"); // According to ECMA-262, section 11.2.2, page 44, the function // expression in new calls must be evaluated before the // arguments. // Push function on the stack. Visit(expr->expression()); ASSERT_EQ(Expression::kValue, expr->expression()->context()); // Push global object (receiver). __ push(CodeGenerator::GlobalObject()); // Push the arguments ("left-to-right") on the stack. ZoneList* args = expr->arguments(); int arg_count = args->length(); for (int i = 0; i < arg_count; i++) { Visit(args->at(i)); ASSERT_EQ(Expression::kValue, args->at(i)->context()); // If location is value, it is already on the stack, // so nothing to do here. } // Call the construct call builtin that handles allocation and // constructor invocation. SetSourcePosition(expr->position()); // Load function, arg_count into edi and eax. __ Set(eax, Immediate(arg_count)); // Function is in esp[arg_count + 1]. __ mov(edi, Operand(esp, eax, times_pointer_size, kPointerSize)); Handle construct_builtin(Builtins::builtin(Builtins::JSConstructCall)); __ call(construct_builtin, RelocInfo::CONSTRUCT_CALL); // Replace function on TOS with result in eax, or pop it. DropAndMove(expr->context(), eax); } void FastCodeGenerator::VisitCallRuntime(CallRuntime* expr) { Comment cmnt(masm_, "[ CallRuntime"); ZoneList* args = expr->arguments(); if (expr->is_jsruntime()) { // Prepare for calling JS runtime function. __ push(Immediate(expr->name())); __ mov(eax, CodeGenerator::GlobalObject()); __ push(FieldOperand(eax, GlobalObject::kBuiltinsOffset)); } // Push the arguments ("left-to-right"). int arg_count = args->length(); for (int i = 0; i < arg_count; i++) { Visit(args->at(i)); ASSERT_EQ(Expression::kValue, args->at(i)->context()); } if (expr->is_jsruntime()) { // Call the JS runtime function. Handle ic = CodeGenerator::ComputeCallInitialize(arg_count, NOT_IN_LOOP); __ call(ic, RelocInfo::CODE_TARGET); // Restore context register. __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset)); // Discard the function left on TOS. DropAndMove(expr->context(), eax); } else { // Call the C runtime function. __ CallRuntime(expr->function(), arg_count); Move(expr->context(), eax); } } void FastCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) { switch (expr->op()) { case Token::VOID: { Comment cmnt(masm_, "[ UnaryOperation (VOID)"); Visit(expr->expression()); ASSERT_EQ(Expression::kEffect, expr->expression()->context()); switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); break; case Expression::kEffect: break; case Expression::kValue: __ push(Immediate(Factory::undefined_value())); break; case Expression::kTestValue: // Value is false so it's needed. __ push(Immediate(Factory::undefined_value())); // Fall through. case Expression::kTest: // Fall through. case Expression::kValueTest: __ jmp(false_label_); break; } break; } case Token::NOT: { Comment cmnt(masm_, "[ UnaryOperation (NOT)"); ASSERT_EQ(Expression::kTest, expr->expression()->context()); Label push_true; Label push_false; Label done; Label* saved_true = true_label_; Label* saved_false = false_label_; switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); break; case Expression::kValue: true_label_ = &push_false; false_label_ = &push_true; Visit(expr->expression()); __ bind(&push_true); __ push(Immediate(Factory::true_value())); __ jmp(&done); __ bind(&push_false); __ push(Immediate(Factory::false_value())); __ bind(&done); break; case Expression::kEffect: true_label_ = &done; false_label_ = &done; Visit(expr->expression()); __ bind(&done); break; case Expression::kTest: true_label_ = saved_false; false_label_ = saved_true; Visit(expr->expression()); break; case Expression::kValueTest: true_label_ = saved_false; false_label_ = &push_true; Visit(expr->expression()); __ bind(&push_true); __ push(Immediate(Factory::true_value())); __ jmp(saved_true); break; case Expression::kTestValue: true_label_ = &push_false; false_label_ = saved_true; Visit(expr->expression()); __ bind(&push_false); __ push(Immediate(Factory::false_value())); __ jmp(saved_false); break; } true_label_ = saved_true; false_label_ = saved_false; break; } case Token::TYPEOF: { Comment cmnt(masm_, "[ UnaryOperation (TYPEOF)"); ASSERT_EQ(Expression::kValue, expr->expression()->context()); VariableProxy* proxy = expr->expression()->AsVariableProxy(); if (proxy != NULL && !proxy->var()->is_this() && proxy->var()->is_global()) { Comment cmnt(masm_, "Global variable"); __ push(CodeGenerator::GlobalObject()); __ mov(ecx, Immediate(proxy->name())); Handle ic(Builtins::builtin(Builtins::LoadIC_Initialize)); // Use a regular load, not a contextual load, to avoid a reference // error. __ call(ic, RelocInfo::CODE_TARGET); __ mov(Operand(esp, 0), eax); } else if (proxy != NULL && proxy->var()->slot() != NULL && proxy->var()->slot()->type() == Slot::LOOKUP) { __ push(esi); __ push(Immediate(proxy->name())); __ CallRuntime(Runtime::kLoadContextSlotNoReferenceError, 2); __ push(eax); } else { // This expression cannot throw a reference error at the top level. Visit(expr->expression()); } __ CallRuntime(Runtime::kTypeof, 1); Move(expr->context(), eax); break; } default: UNREACHABLE(); } } void FastCodeGenerator::VisitCountOperation(CountOperation* expr) { Comment cmnt(masm_, "[ CountOperation"); VariableProxy* proxy = expr->expression()->AsVariableProxy(); ASSERT(proxy->AsVariable() != NULL); ASSERT(proxy->AsVariable()->is_global()); Visit(proxy); __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_FUNCTION); switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kValue: // Fall through case Expression::kTest: // Fall through case Expression::kTestValue: // Fall through case Expression::kValueTest: // Duplicate the result on the stack. __ push(eax); break; case Expression::kEffect: // Do not save result. break; } // Call runtime for +1/-1. __ push(eax); __ push(Immediate(Smi::FromInt(1))); if (expr->op() == Token::INC) { __ CallRuntime(Runtime::kNumberAdd, 2); } else { __ CallRuntime(Runtime::kNumberSub, 2); } // Call Store IC. __ mov(ecx, proxy->AsVariable()->name()); __ push(CodeGenerator::GlobalObject()); Handle ic(Builtins::builtin(Builtins::StoreIC_Initialize)); __ call(ic, RelocInfo::CODE_TARGET); // Restore up stack after store IC. __ add(Operand(esp), Immediate(kPointerSize)); switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); case Expression::kEffect: // Fall through case Expression::kValue: // Do nothing. Result in either on the stack for value context // or discarded for effect context. break; case Expression::kTest: __ pop(eax); TestAndBranch(eax, true_label_, false_label_); break; case Expression::kValueTest: { Label discard; __ mov(eax, Operand(esp, 0)); TestAndBranch(eax, true_label_, &discard); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(false_label_); break; } case Expression::kTestValue: { Label discard; __ mov(eax, Operand(esp, 0)); TestAndBranch(eax, &discard, false_label_); __ bind(&discard); __ add(Operand(esp), Immediate(kPointerSize)); __ jmp(true_label_); break; } } } void FastCodeGenerator::VisitBinaryOperation(BinaryOperation* expr) { Comment cmnt(masm_, "[ BinaryOperation"); switch (expr->op()) { case Token::COMMA: ASSERT_EQ(Expression::kEffect, expr->left()->context()); ASSERT_EQ(expr->context(), expr->right()->context()); Visit(expr->left()); Visit(expr->right()); break; case Token::OR: case Token::AND: EmitLogicalOperation(expr); break; case Token::ADD: case Token::SUB: case Token::DIV: case Token::MOD: case Token::MUL: case Token::BIT_OR: case Token::BIT_AND: case Token::BIT_XOR: case Token::SHL: case Token::SHR: case Token::SAR: { ASSERT_EQ(Expression::kValue, expr->left()->context()); ASSERT_EQ(Expression::kValue, expr->right()->context()); Visit(expr->left()); Visit(expr->right()); GenericBinaryOpStub stub(expr->op(), NO_OVERWRITE, NO_GENERIC_BINARY_FLAGS); __ CallStub(&stub); Move(expr->context(), eax); break; } default: UNREACHABLE(); } } void FastCodeGenerator::VisitCompareOperation(CompareOperation* expr) { Comment cmnt(masm_, "[ CompareOperation"); ASSERT_EQ(Expression::kValue, expr->left()->context()); ASSERT_EQ(Expression::kValue, expr->right()->context()); Visit(expr->left()); Visit(expr->right()); // Convert current context to test context: Pre-test code. Label push_true; Label push_false; Label done; Label* saved_true = true_label_; Label* saved_false = false_label_; switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); break; case Expression::kValue: true_label_ = &push_true; false_label_ = &push_false; break; case Expression::kEffect: true_label_ = &done; false_label_ = &done; break; case Expression::kTest: break; case Expression::kValueTest: true_label_ = &push_true; break; case Expression::kTestValue: false_label_ = &push_false; break; } // Convert current context to test context: End pre-test code. switch (expr->op()) { case Token::IN: { __ InvokeBuiltin(Builtins::IN, CALL_FUNCTION); __ cmp(eax, Factory::true_value()); __ j(equal, true_label_); __ jmp(false_label_); break; } case Token::INSTANCEOF: { InstanceofStub stub; __ CallStub(&stub); __ test(eax, Operand(eax)); __ j(zero, true_label_); // The stub returns 0 for true. __ jmp(false_label_); break; } default: { Condition cc = no_condition; bool strict = false; switch (expr->op()) { case Token::EQ_STRICT: strict = true; // Fall through case Token::EQ: cc = equal; __ pop(eax); __ pop(edx); break; case Token::LT: cc = less; __ pop(eax); __ pop(edx); break; case Token::GT: // Reverse left and right sizes to obtain ECMA-262 conversion order. cc = less; __ pop(edx); __ pop(eax); break; case Token::LTE: // Reverse left and right sizes to obtain ECMA-262 conversion order. cc = greater_equal; __ pop(edx); __ pop(eax); break; case Token::GTE: cc = greater_equal; __ pop(eax); __ pop(edx); break; case Token::IN: case Token::INSTANCEOF: default: UNREACHABLE(); } // The comparison stub expects the smi vs. smi case to be handled // before it is called. Label slow_case; __ mov(ecx, Operand(edx)); __ or_(ecx, Operand(eax)); __ test(ecx, Immediate(kSmiTagMask)); __ j(not_zero, &slow_case, not_taken); __ cmp(edx, Operand(eax)); __ j(cc, true_label_); __ jmp(false_label_); __ bind(&slow_case); CompareStub stub(cc, strict); __ CallStub(&stub); __ test(eax, Operand(eax)); __ j(cc, true_label_); __ jmp(false_label_); } } // Convert current context to test context: Post-test code. switch (expr->context()) { case Expression::kUninitialized: UNREACHABLE(); break; case Expression::kValue: __ bind(&push_true); __ push(Immediate(Factory::true_value())); __ jmp(&done); __ bind(&push_false); __ push(Immediate(Factory::false_value())); __ bind(&done); break; case Expression::kEffect: __ bind(&done); break; case Expression::kTest: break; case Expression::kValueTest: __ bind(&push_true); __ push(Immediate(Factory::true_value())); __ jmp(saved_true); break; case Expression::kTestValue: __ bind(&push_false); __ push(Immediate(Factory::false_value())); __ jmp(saved_false); break; } true_label_ = saved_true; false_label_ = saved_false; // Convert current context to test context: End post-test code. } Register FastCodeGenerator::result_register() { return eax; } void FastCodeGenerator::VisitThisFunction(ThisFunction* expr) { __ mov(eax, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset)); Move(expr->context(), eax); } #undef __ } } // namespace v8::internal