Supporting AllocationSiteInfo for Nested arrays

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 3d167ef8fe2557e17e21b56374c46333f481a045..cb18c28e9610d7171089ce494472d2fe4470a749 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -5175,6 +5175,10 @@ void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
     DeoptimizeIf(not_equal, instr->environment());
   }
 
+  int flags = allocation_site_mode == TRACK_ALLOCATION_SITE
+      ? ArrayLiteral::kCreateAllocationSiteInfos
+      : ArrayLiteral::kNoFlags;
+
   // Set up the parameters to the stub/runtime call.
   __ PushHeapObject(literals);
   __ Push(Smi::FromInt(instr->hydrogen()->literal_index()));
@@ -5191,9 +5195,11 @@ void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
     FastCloneShallowArrayStub stub(mode, DONT_TRACK_ALLOCATION_SITE, length);
     CallCode(stub.GetCode(isolate()), RelocInfo::CODE_TARGET, instr);
   } else if (instr->hydrogen()->depth() > 1) {
-    CallRuntime(Runtime::kCreateArrayLiteral, 3, instr);
+    __ Push(Smi::FromInt(flags));
+    CallRuntime(Runtime::kCreateArrayLiteral, 4, instr);
   } else if (length > FastCloneShallowArrayStub::kMaximumClonedLength) {
-    CallRuntime(Runtime::kCreateArrayLiteralShallow, 3, instr);
+    __ Push(Smi::FromInt(flags));
+    CallRuntime(Runtime::kCreateArrayLiteralShallow, 4, instr);
   } else {
     FastCloneShallowArrayStub::Mode mode =
         boilerplate_elements_kind == FAST_DOUBLE_ELEMENTS
@@ -5206,6 +5212,7 @@ void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
 
 
 void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
+                            Handle<JSObject> original_object,
                             Register result,
                             Register source,
                             int* offset,
@@ -5213,11 +5220,13 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
   ASSERT(!source.is(rcx));
   ASSERT(!result.is(rcx));
 
+  // Should we track allocation info for *this* object in the tree?
   bool create_allocation_site_info = mode == TRACK_ALLOCATION_SITE &&
-      object->map()->CanTrackAllocationSite();
+      object->ShouldTrackAllocationInfo();
 
   // Only elements backing stores for non-COW arrays need to be copied.
   Handle<FixedArrayBase> elements(object->elements());
+  Handle<FixedArrayBase> original_elements(original_object->elements());
   bool has_elements = elements->length() > 0 &&
       elements->map() != isolate()->heap()->fixed_cow_array_map();
 
@@ -5254,11 +5263,14 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
                                           isolate());
     if (value->IsJSObject()) {
       Handle<JSObject> value_object = Handle<JSObject>::cast(value);
+      Handle<JSObject> original_value_object = Handle<JSObject>::cast(
+          Handle<Object>(original_object->InObjectPropertyAt(i), isolate()));
+
       __ lea(rcx, Operand(result, *offset));
       __ movq(FieldOperand(result, total_offset), rcx);
       __ LoadHeapObject(source, value_object);
-      EmitDeepCopy(value_object, result, source, offset,
-                   DONT_TRACK_ALLOCATION_SITE);
+      EmitDeepCopy(value_object, original_value_object, result, source,
+                   offset, mode);
     } else if (value->IsHeapObject()) {
       __ LoadHeapObject(rcx, Handle<HeapObject>::cast(value));
       __ movq(FieldOperand(result, total_offset), rcx);
@@ -5271,8 +5283,11 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
   // Build Allocation Site Info if desired
   if (create_allocation_site_info) {
     __ LoadRoot(kScratchRegister, Heap::kAllocationSiteInfoMapRootIndex);
-    __ movq(FieldOperand(result, object_size), kScratchRegister);
-    __ movq(FieldOperand(result, object_size + kPointerSize), source);
+    __ movq(FieldOperand(result, object_size + object_offset),
+            kScratchRegister);
+    __ LoadHeapObject(rcx, original_object);
+    __ movq(FieldOperand(result, object_size + object_offset + kPointerSize),
+            rcx);
   }
 
   if (has_elements) {
@@ -5297,16 +5312,22 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
       }
     } else if (elements->IsFixedArray()) {
       Handle<FixedArray> fast_elements = Handle<FixedArray>::cast(elements);
+      ASSERT(original_object->HasFastObjectElements());
+      Handle<FixedArray> original_fast_elements =
+          Handle<FixedArray>::cast(original_elements);
       for (int i = 0; i < elements_length; i++) {
         int total_offset = elements_offset + FixedArray::OffsetOfElementAt(i);
         Handle<Object> value(fast_elements->get(i), isolate());
         if (value->IsJSObject()) {
           Handle<JSObject> value_object = Handle<JSObject>::cast(value);
+          Handle<JSObject> original_value_object = Handle<JSObject>::cast(
+              Handle<Object>(original_fast_elements->get(i), isolate()));
           __ lea(rcx, Operand(result, *offset));
           __ movq(FieldOperand(result, total_offset), rcx);
           __ LoadHeapObject(source, value_object);
-          EmitDeepCopy(value_object, result, source, offset,
-                       DONT_TRACK_ALLOCATION_SITE);
+          ASSERT(!value_object.is_identical_to(original_value_object));
+          EmitDeepCopy(value_object, original_value_object, result, source,
+                       offset, mode);
         } else if (value->IsHeapObject()) {
           __ LoadHeapObject(rcx, Handle<HeapObject>::cast(value));
           __ movq(FieldOperand(result, total_offset), rcx);
@@ -5322,26 +5343,10 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
 }
 
 
-void LCodeGen::DoFastLiteral(LFastLiteral* instr) {
-  int size = instr->hydrogen()->total_size();
-  ElementsKind boilerplate_elements_kind =
-      instr->hydrogen()->boilerplate()->GetElementsKind();
-
-  // Deopt if the array literal boilerplate ElementsKind is of a type different
-  // than the expected one. The check isn't necessary if the boilerplate has
-  // already been converted to TERMINAL_FAST_ELEMENTS_KIND.
-  if (CanTransitionToMoreGeneralFastElementsKind(
-          boilerplate_elements_kind, true)) {
-    __ LoadHeapObject(rbx, instr->hydrogen()->boilerplate());
-    __ movq(rcx, FieldOperand(rbx, HeapObject::kMapOffset));
-    // Load the map's "bit field 2".
-    __ movb(rcx, FieldOperand(rcx, Map::kBitField2Offset));
-    // Retrieve elements_kind from bit field 2.
-    __ and_(rcx, Immediate(Map::kElementsKindMask));
-    __ cmpb(rcx, Immediate(boilerplate_elements_kind <<
-                           Map::kElementsKindShift));
-    DeoptimizeIf(not_equal, instr->environment());
-  }
+void LCodeGen::FastLiteralHelper(LFastLiteral* instr, AllocationSiteMode mode) {
+  int size = mode == DONT_TRACK_ALLOCATION_SITE
+      ? instr->hydrogen()->size_without_allocation_sites()
+      : instr->hydrogen()->total_size();
 
   // Allocate all objects that are part of the literal in one big
   // allocation. This avoids multiple limit checks.
@@ -5356,11 +5361,37 @@ void LCodeGen::DoFastLiteral(LFastLiteral* instr) {
   __ bind(&allocated);
   int offset = 0;
   __ LoadHeapObject(rbx, instr->hydrogen()->boilerplate());
-  EmitDeepCopy(instr->hydrogen()->boilerplate(), rax, rbx, &offset,
+  EmitDeepCopy(instr->hydrogen()->boilerplate(),
+               instr->hydrogen()->original_boilerplate(),
+               rax, rbx, &offset,
                instr->hydrogen()->allocation_site_mode());
   ASSERT_EQ(size, offset);
 }
 
+void LCodeGen::DoFastLiteral(LFastLiteral* instr) {
+  // TODO(mvstanton): Revisit this heuristic as site info matures.
+  // If allocation site mode is on, then we need the ability to turn it off
+  // after "awhile." Later, better options should be available, but for
+  // now just allow a certain number of gcs to pass.
+  if (instr->hydrogen()->allocation_site_mode() == TRACK_ALLOCATION_SITE) {
+    // How many gcs have passed?
+    const int maxCount = 3;
+    ExternalReference gc_count_address =
+        ExternalReference::gc_count_address(isolate());
+    Label continue_using, done;
+    __ movl(rax, masm()->ExternalOperand(gc_count_address));
+    __ cmpl(rax, Immediate(maxCount));
+    __ j(less, &continue_using);
+    FastLiteralHelper(instr, DONT_TRACK_ALLOCATION_SITE);
+    __ jmp(&done);
+    __ bind(&continue_using);
+    FastLiteralHelper(instr, TRACK_ALLOCATION_SITE);
+    __ bind(&done);
+  } else {
+    FastLiteralHelper(instr, DONT_TRACK_ALLOCATION_SITE);
+  }
+}
+
 
 void LCodeGen::DoObjectLiteral(LObjectLiteral* instr) {
   Handle<FixedArray> literals(instr->environment()->closure()->literals());
@@ -5374,6 +5405,10 @@ void LCodeGen::DoObjectLiteral(LObjectLiteral* instr) {
       ? ObjectLiteral::kHasFunction
       : ObjectLiteral::kNoFlags;
 
+  if (instr->hydrogen()->allocation_site_mode() == TRACK_ALLOCATION_SITE) {
+    flags |= ObjectLiteral::kCreateAllocationSiteInfos;
+  }
+
   // Set up the parameters to the stub/runtime call and pick the right
   // runtime function or stub to call.
   int properties_count = constant_properties->length() / 2;