Optimizing generation of nested literals for both object and array literals.

src/codegen-ia32.cc

Index: src/codegen-ia32.cc
===================================================================
--- src/codegen-ia32.cc	(revision 1467)
+++ src/codegen-ia32.cc	(working copy)
@@ -32,6 +32,7 @@
 #include "debug.h"
 #include "scopes.h"
 #include "runtime.h"
+#include "parser.h"
 
 namespace v8 { namespace internal {
 
@@ -3488,7 +3489,7 @@
   frame_->Push(&boilerplate);
   // Clone the boilerplate object.
   Result clone =
-      frame_->CallRuntime(Runtime::kCloneObjectLiteralBoilerplate, 1);
+      frame_->CallRuntime(Runtime::kCloneLiteralBoilerplate, 1);
   // Push the newly cloned literal object as the result.
   frame_->Push(&clone);
 
@@ -3497,8 +3498,9 @@
     switch (property->kind()) {
       case ObjectLiteral::Property::CONSTANT:
         break;
-      case ObjectLiteral::Property::OBJECT_LITERAL:
-        if (property->value()->AsObjectLiteral()->is_simple()) break;
+      case ObjectLiteral::Property::MATERIALIZED_LITERAL:
+        if (CompileTimeValue::IsCompileTimeValue(property->value())) break;
+        // else fall through.
       case ObjectLiteral::Property::COMPUTED: {
         Handle<Object> key(property->key()->handle());
         Handle<Code> ic(Builtins::builtin(Builtins::StoreIC_Initialize));
@@ -3556,59 +3558,123 @@
 }
 
 
+// This deferred code stub will be used for creating the boilerplate
+// by calling Runtime_CreateArrayLiteralBoilerplate.
+// Each created boilerplate is stored in the JSFunction and they are
+// therefore context dependent.
+class DeferredArrayLiteral: public DeferredCode {
+ public:
+  DeferredArrayLiteral(CodeGenerator* generator,
+                       ArrayLiteral* node)
+      : DeferredCode(generator), node_(node) {
+    set_comment("[ DeferredArrayLiteral");
+  }
+
+  virtual void Generate();
+
+ private:
+  ArrayLiteral* node_;
+};
+
+
+void DeferredArrayLiteral::Generate() {
+  Result literals(generator());
+  enter()->Bind(&literals);
+  // Since the entry is undefined we call the runtime system to
+  // compute the literal.
+
+  VirtualFrame* frame = generator()->frame();
+  // Literal array (0).
+  frame->Push(&literals);
+  // Literal index (1).
+  frame->Push(Smi::FromInt(node_->literal_index()));
+  // Constant properties (2).
+  frame->Push(node_->literals());
+  Result boilerplate =
+      frame->CallRuntime(Runtime::kCreateArrayLiteralBoilerplate, 3);
+  exit_.Jump(&boilerplate);
+}
+
+
 void CodeGenerator::VisitArrayLiteral(ArrayLiteral* node) {
   Comment cmnt(masm_, "[ ArrayLiteral");
+  DeferredArrayLiteral* deferred = new DeferredArrayLiteral(this, node);
 
-  // Call the runtime to create the array literal.
-  frame_->Push(node->literals());
-  // Load the literals array of the current function.
+  // Retrieve the literals array and check the allocated entry.  Begin
+  // with a writable copy of the function of this activation in a
+  // register.
   frame_->PushFunction();
   Result literals = frame_->Pop();
   literals.ToRegister();
-  frame_->Spill(literals.reg());  // Make it writable.
+  frame_->Spill(literals.reg());
+
+  // Load the literals array of the function.
   __ mov(literals.reg(),
          FieldOperand(literals.reg(), JSFunction::kLiteralsOffset));
-  frame_->Push(&literals);
-  Result array = frame_->CallRuntime(Runtime::kCreateArrayLiteral, 2);
 
+  // Load the literal at the ast saved index.
+  int literal_offset =
+      FixedArray::kHeaderSize + node->literal_index() * kPointerSize;
+  Result boilerplate = allocator_->Allocate();
+  ASSERT(boilerplate.is_valid());
+  __ mov(boilerplate.reg(), FieldOperand(literals.reg(), literal_offset));
+
+  // Check whether we need to materialize the object literal boilerplate.
+  // If so, jump to the deferred code passing the literals array.
+  __ cmp(boilerplate.reg(), Factory::undefined_value());
+  deferred->enter()->Branch(equal, &literals, not_taken);
+
+  literals.Unuse();
+  // The deferred code returns the boilerplate object.
+  deferred->BindExit(&boilerplate);
+
   // Push the resulting array literal on the stack.
-  frame_->Push(&array);
+  frame_->Push(&boilerplate);
 
+  // Clone the boilerplate object.
+  Result clone =
+      frame_->CallRuntime(Runtime::kCloneLiteralBoilerplate, 1);
+  // Push the newly cloned literal object as the result.
+  frame_->Push(&clone);
+
   // Generate code to set the elements in the array that are not
   // literals.
   for (int i = 0; i < node->values()->length(); i++) {
     Expression* value = node->values()->at(i);
 
-    // If value is literal the property value is already set in the
+    // If value is a literal the property value is already set in the
     // boilerplate object.
-    if (value->AsLiteral() == NULL) {
-      // The property must be set by generated code.
-      Load(value);
+    if (value->AsLiteral() != NULL) continue;
+    // If value is a materialized literal the property value is already set
+    // in the boilerplate object if it is simple.
+    if (CompileTimeValue::IsCompileTimeValue(value)) continue;
 
-      // Get the property value off the stack.
-      Result prop_value = frame_->Pop();
-      prop_value.ToRegister();
+    // The property must be set by generated code.
+    Load(value);
 
-      // Fetch the array literal while leaving a copy on the stack and
-      // use it to get the elements array.
-      frame_->Dup();
-      Result elements = frame_->Pop();
-      elements.ToRegister();
-      frame_->Spill(elements.reg());
-      // Get the elements array.
-      __ mov(elements.reg(),
-             FieldOperand(elements.reg(), JSObject::kElementsOffset));
+    // Get the property value off the stack.
+    Result prop_value = frame_->Pop();
+    prop_value.ToRegister();
 
-      // Write to the indexed properties array.
-      int offset = i * kPointerSize + Array::kHeaderSize;
-      __ mov(FieldOperand(elements.reg(), offset), prop_value.reg());
+    // Fetch the array literal while leaving a copy on the stack and
+    // use it to get the elements array.
+    frame_->Dup();
+    Result elements = frame_->Pop();
+    elements.ToRegister();
+    frame_->Spill(elements.reg());
+    // Get the elements array.
+    __ mov(elements.reg(),
+           FieldOperand(elements.reg(), JSObject::kElementsOffset));
 
-      // Update the write barrier for the array address.
-      frame_->Spill(prop_value.reg());  // Overwritten by the write barrier.
-      Result scratch = allocator_->Allocate();
-      ASSERT(scratch.is_valid());
-      __ RecordWrite(elements.reg(), offset, prop_value.reg(), scratch.reg());
-    }
+    // Write to the indexed properties array.
+    int offset = i * kPointerSize + Array::kHeaderSize;
+    __ mov(FieldOperand(elements.reg(), offset), prop_value.reg());
+
+    // Update the write barrier for the array address.
+    frame_->Spill(prop_value.reg());  // Overwritten by the write barrier.
+    Result scratch = allocator_->Allocate();
+    ASSERT(scratch.is_valid());
+    __ RecordWrite(elements.reg(), offset, prop_value.reg(), scratch.reg());
   }
 }