Implement code stub for object literal creation.

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 27b127d904b362a198fc6573fce2ddd96274735d..c6c1009c8cf7d28e2d8bf6ea12259783b5424a64 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -368,6 +368,52 @@ void FastCloneShallowArrayStub::Generate(MacroAssembler* masm) {
 }
 
 
+void FastCloneShallowObjectStub::Generate(MacroAssembler* masm) {
+  // Stack layout on entry:
+  //
+  // [esp + kPointerSize]: object literal flags.
+  // [esp + (2 * kPointerSize)]: constant properties.
+  // [esp + (3 * kPointerSize)]: literal index.
+  // [esp + (4 * kPointerSize)]: literals array.
+
+  // Load boilerplate object into ecx and check if we need to create a
+  // boilerplate.
+  Label slow_case;
+  __ mov(ecx, Operand(esp, 4 * kPointerSize));
+  __ mov(eax, Operand(esp, 3 * kPointerSize));
+  STATIC_ASSERT(kPointerSize == 4);
+  STATIC_ASSERT(kSmiTagSize == 1);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ mov(ecx, FieldOperand(ecx, eax, times_half_pointer_size,
+                           FixedArray::kHeaderSize));
+  Factory* factory = masm->isolate()->factory();
+  __ cmp(ecx, factory->undefined_value());
+  __ j(equal, &slow_case);
+
+  // Check that the boilerplate contains only fast properties and we can
+  // statically determine the instance size.
+  int size = JSObject::kHeaderSize + length_ * kPointerSize;
+  __ mov(eax, FieldOperand(ecx, HeapObject::kMapOffset));
+  __ movzx_b(eax, FieldOperand(eax, Map::kInstanceSizeOffset));
+  __ cmp(eax, Immediate(size >> kPointerSizeLog2));
+  __ j(not_equal, &slow_case);
+
+  // Allocate the JS object and copy header together with all in-object
+  // properties from the boilerplate.
+  __ AllocateInNewSpace(size, eax, ebx, edx, &slow_case, TAG_OBJECT);
+  for (int i = 0; i < size; i += kPointerSize) {
+    __ mov(ebx, FieldOperand(ecx, i));
+    __ mov(FieldOperand(eax, i), ebx);
+  }
+
+  // Return and remove the on-stack parameters.
+  __ ret(4 * kPointerSize);
+
+  __ bind(&slow_case);
+  __ TailCallRuntime(Runtime::kCreateObjectLiteralShallow, 4, 1);
+}
+
+
 // The stub expects its argument on the stack and returns its result in tos_:
 // zero for false, and a non-zero value for true.
 void ToBooleanStub::Generate(MacroAssembler* masm) {