Make the ResolvePossiblyDirectEval faster by avoiding the

stack traversal code.
Review URL: http://codereview.chromium.org/523051

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3533 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/codegen-arm.cc

@@ -2892,13 +2892,15 @@ void CodeGenerator::VisitCall(Call* node) {
       frame_->EmitPush(r2);
     }
 
+    // Push the receiver.
+    __ ldr(r1, frame_->Receiver());
+    frame_->EmitPush(r1);
+
     // Resolve the call.
-    frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 2);
+    frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 3);
 
     // Touch up stack with the right values for the function and the receiver.
-    __ ldr(r1, FieldMemOperand(r0, FixedArray::kHeaderSize));
-    __ str(r1, MemOperand(sp, (arg_count + 1) * kPointerSize));
-    __ ldr(r1, FieldMemOperand(r0, FixedArray::kHeaderSize + kPointerSize));
+    __ str(r0, MemOperand(sp, (arg_count + 1) * kPointerSize));
     __ str(r1, MemOperand(sp, arg_count * kPointerSize));
 
     // Call the function.

src/bootstrapper.cc

@@ -992,6 +992,7 @@ void Genesis::InstallNativeFunctions() {
   INSTALL_NATIVE(JSFunction, "ToUint32", to_uint32_fun);
   INSTALL_NATIVE(JSFunction, "ToInt32", to_int32_fun);
   INSTALL_NATIVE(JSFunction, "ToBoolean", to_boolean_fun);
+  INSTALL_NATIVE(JSFunction, "GlobalEval", global_eval_fun);
   INSTALL_NATIVE(JSFunction, "Instantiate", instantiate_fun);
   INSTALL_NATIVE(JSFunction, "ConfigureTemplateInstance",
                  configure_instance_fun);

src/contexts.h

@@ -77,6 +77,7 @@ enum ContextLookupFlags {
   V(TO_UINT32_FUN_INDEX, JSFunction, to_uint32_fun) \
   V(TO_INT32_FUN_INDEX, JSFunction, to_int32_fun) \
   V(TO_BOOLEAN_FUN_INDEX, JSFunction, to_boolean_fun) \
+  V(GLOBAL_EVAL_FUN_INDEX, JSFunction, global_eval_fun) \
   V(INSTANTIATE_FUN_INDEX, JSFunction, instantiate_fun) \
   V(CONFIGURE_INSTANCE_FUN_INDEX, JSFunction, configure_instance_fun) \
   V(FUNCTION_MAP_INDEX, Map, function_map) \
@@ -202,6 +203,7 @@ class Context: public FixedArray {
     TO_UINT32_FUN_INDEX,
     TO_INT32_FUN_INDEX,
     TO_BOOLEAN_FUN_INDEX,
+    GLOBAL_EVAL_FUN_INDEX,
     INSTANTIATE_FUN_INDEX,
     CONFIGURE_INSTANCE_FUN_INDEX,
     SPECIAL_FUNCTION_TABLE_INDEX,

src/ia32/codegen-ia32.cc

@@ -4580,22 +4580,19 @@ void CodeGenerator::VisitCall(Call* node) {
       frame_->Push(Factory::undefined_value());
     }
 
+    // Push the receiver.
+    frame_->PushParameterAt(-1);
+
     // Resolve the call.
     Result result =
-        frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 2);
+        frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 3);
 
-    // Touch up the stack with the right values for the function and the
-    // receiver.  Use a scratch register to avoid destroying the result.
-    Result scratch = allocator_->Allocate();
-    ASSERT(scratch.is_valid());
-    __ mov(scratch.reg(), FieldOperand(result.reg(), FixedArray::kHeaderSize));
-    frame_->SetElementAt(arg_count + 1, &scratch);
-
-    // We can reuse the result register now.
-    frame_->Spill(result.reg());
-    __ mov(result.reg(),
-           FieldOperand(result.reg(), FixedArray::kHeaderSize + kPointerSize));
-    frame_->SetElementAt(arg_count, &result);
+    // The runtime call returns a pair of values in eax (function) and
+    // edx (receiver). Touch up the stack with the right values.
+    Result receiver = allocator_->Allocate(edx);
+    frame_->SetElementAt(arg_count + 1, &result);
+    frame_->SetElementAt(arg_count, &receiver);
+    receiver.Unuse();
 
     // Call the function.
     CodeForSourcePosition(node->position());

src/runtime.cc

@@ -5233,51 +5233,31 @@ static Object* Runtime_CompileString(Arguments args) {
 }
 
 
-static Handle<JSFunction> GetBuiltinFunction(String* name) {
-  LookupResult result;
-  Top::global_context()->builtins()->LocalLookup(name, &result);
-  return Handle<JSFunction>(JSFunction::cast(result.GetValue()));
-}
+static ObjectPair Runtime_ResolvePossiblyDirectEval(Arguments args) {
+  ASSERT(args.length() == 3);
+  if (!args[0]->IsJSFunction()) {
+    return MakePair(Top::ThrowIllegalOperation(), NULL);
+  }
 
-
-static Object* CompileDirectEval(Handle<String> source) {
-  // Compute the eval context.
   HandleScope scope;
+  Handle<JSFunction> callee = args.at<JSFunction>(0);
+  Handle<Object> receiver;  // Will be overwritten.
+
+  // Compute the calling context.
+  Handle<Context> context = Handle<Context>(Top::context());
+#ifdef DEBUG
+  // Make sure Top::context() agrees with the old code that traversed
+  // the stack frames to compute the context.
   StackFrameLocator locator;
   JavaScriptFrame* frame = locator.FindJavaScriptFrame(0);
-  Handle<Context> context(Context::cast(frame->context()));
-  bool is_global = context->IsGlobalContext();
-
-  // Compile source string in the current context.
-  Handle<JSFunction> boilerplate = Compiler::CompileEval(
-      source,
-      context,
-      is_global,
-      Compiler::DONT_VALIDATE_JSON);
-  if (boilerplate.is_null()) return Failure::Exception();
-  Handle<JSFunction> fun =
-      Factory::NewFunctionFromBoilerplate(boilerplate, context, NOT_TENURED);
-  return *fun;
-}
-
-
-static Object* Runtime_ResolvePossiblyDirectEval(Arguments args) {
-  ASSERT(args.length() == 2);
-
-  HandleScope scope;
-
-  CONVERT_ARG_CHECKED(JSFunction, callee, 0);
-
-  Handle<Object> receiver;
+  ASSERT(Context::cast(frame->context()) == *context);
+#endif
 
   // Find where the 'eval' symbol is bound. It is unaliased only if
   // it is bound in the global context.
-  StackFrameLocator locator;
-  JavaScriptFrame* frame = locator.FindJavaScriptFrame(0);
-  Handle<Context> context(Context::cast(frame->context()));
-  int index;
-  PropertyAttributes attributes;
-  while (!context.is_null()) {
+  int index = -1;
+  PropertyAttributes attributes = ABSENT;
+  while (true) {
     receiver = context->Lookup(Factory::eval_symbol(), FOLLOW_PROTOTYPE_CHAIN,
                                &index, &attributes);
     // Stop search when eval is found or when the global context is
@@ -5296,46 +5276,42 @@ static Object* Runtime_ResolvePossiblyDirectEval(Arguments args) {
     Handle<Object> name = Factory::eval_symbol();
     Handle<Object> reference_error =
         Factory::NewReferenceError("not_defined", HandleVector(&name, 1));
-    return Top::Throw(*reference_error);
+    return MakePair(Top::Throw(*reference_error), NULL);
   }
 
-  if (context->IsGlobalContext()) {
-    // 'eval' is bound in the global context, but it may have been overwritten.
-    // Compare it to the builtin 'GlobalEval' function to make sure.
-    Handle<JSFunction> global_eval =
-      GetBuiltinFunction(Heap::global_eval_symbol());
-    if (global_eval.is_identical_to(callee)) {
-      // A direct eval call.
-      if (args[1]->IsString()) {
-        CONVERT_ARG_CHECKED(String, source, 1);
-        // A normal eval call on a string. Compile it and return the
-        // compiled function bound in the local context.
-        Object* compiled_source = CompileDirectEval(source);
-        if (compiled_source->IsFailure()) return compiled_source;
-        receiver = Handle<Object>(frame->receiver());
-        callee = Handle<JSFunction>(JSFunction::cast(compiled_source));
-      } else {
-        // An eval call that is not called on a string. Global eval
-        // deals better with this.
-        receiver = Handle<Object>(Top::global_context()->global());
-      }
-    } else {
-      // 'eval' is overwritten. Just call the function with the given arguments.
-      receiver = Handle<Object>(Top::global_context()->global());
-    }
-  } else {
+  if (!context->IsGlobalContext()) {
     // 'eval' is not bound in the global context. Just call the function
     // with the given arguments. This is not necessarily the global eval.
     if (receiver->IsContext()) {
       context = Handle<Context>::cast(receiver);
       receiver = Handle<Object>(context->get(index));
+    } else if (receiver->IsJSContextExtensionObject()) {
+      receiver = Handle<JSObject>(Top::context()->global()->global_receiver());
     }
+    return MakePair(*callee, *receiver);
   }
 
-  Handle<FixedArray> call = Factory::NewFixedArray(2);
-  call->set(0, *callee);
-  call->set(1, *receiver);
-  return *call;
+  // 'eval' is bound in the global context, but it may have been overwritten.
+  // Compare it to the builtin 'GlobalEval' function to make sure.
+  if (*callee != Top::global_context()->global_eval_fun() ||
+      !args[1]->IsString()) {
+    return MakePair(*callee, Top::context()->global()->global_receiver());
+  }
+
+  // Deal with a normal eval call with a string argument. Compile it
+  // and return the compiled function bound in the local context.
+  Handle<String> source = args.at<String>(1);
+  Handle<JSFunction> boilerplate = Compiler::CompileEval(
+      source,
+      Handle<Context>(Top::context()),
+      Top::context()->IsGlobalContext(),
+      Compiler::DONT_VALIDATE_JSON);
+  if (boilerplate.is_null()) return MakePair(Failure::Exception(), NULL);
+  callee = Factory::NewFunctionFromBoilerplate(
+      boilerplate,
+      Handle<Context>(Top::context()),
+      NOT_TENURED);
+  return MakePair(*callee, args[2]);
 }
 
 

src/runtime.h

@@ -202,7 +202,7 @@ namespace internal {
   \
   /* Eval */ \
   F(GlobalReceiver, 1, 1) \
-  F(ResolvePossiblyDirectEval, 2, 1) \
+  F(ResolvePossiblyDirectEval, 3, 1) \
   \
   F(SetProperty, -1 /* 3 or 4 */, 1) \
   F(IgnoreAttributesAndSetProperty, -1 /* 3 or 4 */, 1) \

src/scopes.cc

@@ -236,7 +236,7 @@ Variable* Scope::DeclareLocal(Handle<String> name, Variable::Mode mode) {
 
 Variable* Scope::DeclareGlobal(Handle<String> name) {
   ASSERT(is_global_scope());
-  return variables_.Declare(this, name, Variable::DYNAMIC, true,
+  return variables_.Declare(this, name, Variable::DYNAMIC_GLOBAL, true,
                             Variable::NORMAL);
 }
 

src/x64/codegen-x64.cc

@@ -2671,23 +2671,19 @@ void CodeGenerator::VisitCall(Call* node) {
       frame_->Push(Factory::undefined_value());
     }
 
+    // Push the receiver.
+    frame_->PushParameterAt(-1);
+
     // Resolve the call.
     Result result =
-        frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 2);
+        frame_->CallRuntime(Runtime::kResolvePossiblyDirectEval, 3);
 
-    // Touch up the stack with the right values for the function and the
-    // receiver.  Use a scratch register to avoid destroying the result.
-    Result scratch = allocator_->Allocate();
-    ASSERT(scratch.is_valid());
-    __ movq(scratch.reg(),
-            FieldOperand(result.reg(), FixedArray::OffsetOfElementAt(0)));
-    frame_->SetElementAt(arg_count + 1, &scratch);
-
-    // We can reuse the result register now.
-    frame_->Spill(result.reg());
-    __ movq(result.reg(),
-            FieldOperand(result.reg(), FixedArray::OffsetOfElementAt(1)));
-    frame_->SetElementAt(arg_count, &result);
+    // The runtime call returns a pair of values in rax (function) and
+    // rdx (receiver). Touch up the stack with the right values.
+    Result receiver = allocator_->Allocate(rdx);
+    frame_->SetElementAt(arg_count + 1, &result);
+    frame_->SetElementAt(arg_count, &receiver);
+    receiver.Unuse();
 
     // Call the function.
     CodeForSourcePosition(node->position());

test/mjsunit/eval.js

@@ -58,16 +58,16 @@ eval = global_eval;
 
 // Test that un-aliased eval reads from local context.
 foo = 0;
-result = 
+result =
   (function() {
     var foo = 2;
     return eval('foo');
   })();
 assertEquals(2, result);
 
-//Test that un-aliased eval writes to local context.
+// Test that un-aliased eval writes to local context.
 foo = 0;
-result = 
+result =
   (function() {
     var foo = 1;
     eval('foo = 2');
@@ -84,7 +84,7 @@ assertTrue(o === o.self);
 // Test that aliased eval reads from global context.
 var e = eval;
 foo = 0;
-result = 
+result =
   (function() {
     var foo = 2;
     return e('foo');
@@ -105,7 +105,7 @@ assertTrue(this === o.self);
 // Try to cheat the 'aliased eval' detection.
 var x = this;
 foo = 0;
-result = 
+result =
   (function() {
     var foo = 2;
     return x.eval('foo');
@@ -113,7 +113,7 @@ result =
 assertEquals(0, result);
 
 foo = 0;
-result = 
+result =
   (function() {
     var eval = function(x) { return x; };
     var foo = eval(2);
@@ -128,8 +128,29 @@ result =
   })();
 assertEquals(4, result);
 
+result =
+  (function() {
+    eval("var eval = function(s) { return this; }");
+    return eval("42");  // Should return the global object
+  })();
+assertEquals(this, result);
+
+result =
+  (function() {
+    var obj = { f: function(eval) { return eval("this"); } };
+    return obj.f(eval);
+  })();
+assertEquals(this, result);
+
+result =
+  (function() {
+    var obj = { f: function(eval) { arguments; return eval("this"); } };
+    return obj.f(eval);
+  })();
+assertEquals(this, result);
+
 eval = function(x) { return 2 * x; };
-result = 
+result =
   (function() {
     return (function() { return eval(2); })();
   })();