Implement fast literal support in Crankshaft.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index f845f4709ac726b9d3a4fa4fc8ba5523482563a2..0137ac4b3298778eeec69c2f99b512f9a763e379 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -4380,26 +4380,36 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
   ASSERT(!source.is(r2));
   ASSERT(!result.is(r2));
 
+  // Only elements backing stores for non-cow arrays need to be copied.
+  Handle<FixedArrayBase> elements(object->elements());
+  bool has_elements = elements->length() > 0 &&

[danno, 2012/02/16 16:09:37]

The empty fixed array should always be used when the length is zero, and it's
also COW. You could optionally add some asserts.

[Michael Starzinger, 2012/02/16 17:34:37]

Actually adding an assertion that all non-COW arrays have length > 0 fails all
over the place. As discussed offline I will leave the current check in. I'll
investigate where those "empty non-COW arrays" come from.

+      elements->map() != isolate()->heap()->fixed_cow_array_map();
+
   // Increase the offset so that subsequent objects end up right after
-  // this one.
-  int current_offset = *offset;
-  int size = object->map()->instance_size();
-  *offset += size;
+  // this object and its backing store.
+  int object_offset = *offset;
+  int object_size = object->map()->instance_size();
+  int elements_offset = *offset + object_size;
+  int elements_size = has_elements ? elements->Size() : 0;
+  *offset += object_size + elements_size;
 
   // Copy object header.
   ASSERT(object->properties()->length() == 0);
-  ASSERT(object->elements()->length() == 0 ||
-         object->elements()->map() == isolate()->heap()->fixed_cow_array_map());
   int inobject_properties = object->map()->inobject_properties();
-  int header_size = size - inobject_properties * kPointerSize;
+  int header_size = object_size - inobject_properties * kPointerSize;
   for (int i = 0; i < header_size; i += kPointerSize) {
-    __ ldr(r2, FieldMemOperand(source, i));
-    __ str(r2, FieldMemOperand(result, current_offset + i));
+    if (has_elements && i == JSObject::kElementsOffset) {
+      __ add(r2, result, Operand(elements_offset));
+      __ str(r2, FieldMemOperand(result, object_offset + i));

[danno, 2012/02/16 16:09:37]

The store is the same and can be moved out of the if.

[Michael Starzinger, 2012/02/16 17:34:37]

Done.

+    } else {
+      __ ldr(r2, FieldMemOperand(source, i));
+      __ str(r2, FieldMemOperand(result, object_offset + i));
+    }
   }
 
   // Copy in-object properties.
   for (int i = 0; i < inobject_properties; i++) {
-    int total_offset = current_offset + object->GetInObjectPropertyOffset(i);
+    int total_offset = object_offset + object->GetInObjectPropertyOffset(i);
     Handle<Object> value = Handle<Object>(object->InObjectPropertyAt(i));
     if (value->IsJSObject()) {
       Handle<JSObject> value_object = Handle<JSObject>::cast(value);
@@ -4415,10 +4425,41 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
       __ str(r2, FieldMemOperand(result, total_offset));
     }
   }
+
+  // Copy elements backing store header.
+  ASSERT(!has_elements || elements->IsFixedArray());
+  if (has_elements) {
+    __ LoadHeapObject(source, elements);
+    for (int i = 0; i < FixedArray::kHeaderSize; i += kPointerSize) {
+      __ ldr(r2, FieldMemOperand(source, i));
+      __ str(r2, FieldMemOperand(result, elements_offset + i));
+    }
+  }
+
+  // Copy elements backing store content.
+  ASSERT(!has_elements || elements->IsFixedArray());
+  int elements_length = has_elements ? elements->length() : 0;
+  for (int i = 0; i < elements_length; i++) {
+    int total_offset = elements_offset + FixedArray::OffsetOfElementAt(i);
+    Handle<Object> value = JSObject::GetElement(object, i);
+    if (value->IsJSObject()) {
+      Handle<JSObject> value_object = Handle<JSObject>::cast(value);
+      __ add(r2, result, Operand(*offset));
+      __ str(r2, FieldMemOperand(result, total_offset));
+      __ LoadHeapObject(source, value_object);
+      EmitDeepCopy(value_object, result, source, offset);
+    } else if (value->IsHeapObject()) {
+      __ LoadHeapObject(r2, Handle<HeapObject>::cast(value));
+      __ str(r2, FieldMemOperand(result, total_offset));
+    } else {
+      __ mov(r2, Operand(value));
+      __ str(r2, FieldMemOperand(result, total_offset));
+    }
+  }
 }
 
 
-void LCodeGen::DoObjectLiteralFast(LObjectLiteralFast* instr) {
+void LCodeGen::DoFastLiteral(LFastLiteral* instr) {
   int size = instr->hydrogen()->total_size();
 
   // Allocate all objects that are part of the literal in one big
@@ -4440,7 +4481,7 @@ void LCodeGen::DoObjectLiteralFast(LObjectLiteralFast* instr) {
 }
 
 
-void LCodeGen::DoObjectLiteralGeneric(LObjectLiteralGeneric* instr) {
+void LCodeGen::DoObjectLiteral(LObjectLiteral* instr) {
   Handle<FixedArray> literals(instr->environment()->closure()->literals());
   Handle<FixedArray> constant_properties =
       instr->hydrogen()->constant_properties();