Supporting AllocationSiteInfo for Nested arrays

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 e8f96e42dc06c019690fd13b1d475413e6f72312..418734d9317bf0e1d1d4e74e666cc7919f8e432f 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -5722,6 +5722,10 @@ void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
     DeoptimizeIf(ne, instr->environment());
   }
 
+  int flags = allocation_site_mode == TRACK_ALLOCATION_SITE
+      ? ArrayLiteral::kCreateAllocationSiteInfos
+      : ArrayLiteral::kNoFlags;
+
   // Set up the parameters to the stub/runtime call.
   __ LoadHeapObject(r3, literals);
   __ mov(r2, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
@@ -5739,9 +5743,13 @@ 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);
+    __ mov(r0, Operand(Smi::FromInt(flags)));
+    __ push(r0);
+    CallRuntime(Runtime::kCreateArrayLiteral, 4, instr);
   } else if (length > FastCloneShallowArrayStub::kMaximumClonedLength) {
-    CallRuntime(Runtime::kCreateArrayLiteralShallow, 3, instr);
+    __ mov(r0, Operand(Smi::FromInt(flags)));
+    __ push(r0);
+    CallRuntime(Runtime::kCreateArrayLiteralShallow, 4, instr);
   } else {
     FastCloneShallowArrayStub::Mode mode =
         boilerplate_elements_kind == FAST_DOUBLE_ELEMENTS
@@ -5754,6 +5762,7 @@ void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
 
 
 void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
+                            Handle<JSObject> original_object,
                             Register result,
                             Register source,
                             int* offset,
@@ -5761,11 +5770,13 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
   ASSERT(!source.is(r2));
   ASSERT(!result.is(r2));
 
+  // 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();
 
@@ -5802,11 +5813,14 @@ 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()));
+
       __ add(r2, result, Operand(*offset));
       __ str(r2, FieldMemOperand(result, total_offset));
       __ 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(r2, Handle<HeapObject>::cast(value));
       __ str(r2, FieldMemOperand(result, total_offset));
@@ -5820,8 +5834,10 @@ void LCodeGen::EmitDeepCopy(Handle<JSObject> object,
   if (create_allocation_site_info) {
     __ mov(r2, Operand(Handle<Map>(isolate()->heap()->
                                    allocation_site_info_map())));
-    __ str(r2, FieldMemOperand(result, object_size));
-    __ str(source, FieldMemOperand(result, object_size + kPointerSize));
+    __ str(r2, FieldMemOperand(result, object_size + object_offset));
+    __ LoadHeapObject(r2, original_object);
+    __ str(r2, FieldMemOperand(result,
+                               object_size + object_offset + kPointerSize));
   }
 
   if (has_elements) {
@@ -5851,16 +5867,22 @@ 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()));
           __ add(r2, result, Operand(*offset));
           __ str(r2, FieldMemOperand(result, total_offset));
           __ 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(r2, Handle<HeapObject>::cast(value));
           __ str(r2, FieldMemOperand(result, total_offset));
@@ -5876,28 +5898,11 @@ 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();
+void LCodeGen::FastLiteralHelper(LFastLiteral* instr, AllocationSiteMode mode) {
+  int size = mode == DONT_TRACK_ALLOCATION_SITE
+      ? instr->hydrogen()->size_without_allocation_sites()
+      : instr->hydrogen()->total_size();
 
-  // 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(r1, instr->hydrogen()->boilerplate());
-    // Load map into r2.
-    __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
-    // Load the map's "bit field 2".
-    __ ldrb(r2, FieldMemOperand(r2, Map::kBitField2Offset));
-    // Retrieve elements_kind from bit field 2.
-    __ ubfx(r2, r2, Map::kElementsKindShift, Map::kElementsKindBitCount);
-    __ cmp(r2, Operand(boilerplate_elements_kind));
-    DeoptimizeIf(ne, instr->environment());
-  }
-
-  // Allocate all objects that are part of the literal in one big
   // allocation. This avoids multiple limit checks.
   Label allocated, runtime_allocate;
   __ Allocate(size, r0, r2, r3, &runtime_allocate, TAG_OBJECT);
@@ -5911,12 +5916,40 @@ void LCodeGen::DoFastLiteral(LFastLiteral* instr) {
   __ bind(&allocated);
   int offset = 0;
   __ LoadHeapObject(r1, instr->hydrogen()->boilerplate());
-  EmitDeepCopy(instr->hydrogen()->boilerplate(), r0, r1, &offset,
+  EmitDeepCopy(instr->hydrogen()->boilerplate(),
+               instr->hydrogen()->original_boilerplate(),
+               r0, r1, &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;
+    __ mov(r0, Operand(gc_count_address));
+    __ ldr(r0, MemOperand(r0));
+    __ cmp(r0, Operand(maxCount));
+    __ b(lt, &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());
   Handle<FixedArray> constant_properties =
@@ -5929,8 +5962,12 @@ void LCodeGen::DoObjectLiteral(LObjectLiteral* instr) {
   int flags = instr->hydrogen()->fast_elements()
       ? ObjectLiteral::kFastElements
       : ObjectLiteral::kNoFlags;
-  __ mov(r0, Operand(Smi::FromInt(flags)));
 
+  if (instr->hydrogen()->allocation_site_mode() == TRACK_ALLOCATION_SITE) {
+    flags |= ObjectLiteral::kCreateAllocationSiteInfos;
+  }
+
+  __ mov(r0, Operand(Smi::FromInt(flags)));
   // Pick the right runtime function or stub to call.
   int properties_count = constant_properties->length() / 2;
   if (instr->hydrogen()->depth() > 1) {