Create AllocationSite objects, pointed to by AllocationSiteInfo.

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 29a4be2140ffc629a81ab8d55b9a83a1d4a69536..1a1ec5cf6dc43180d5957c2a095c93093ff233a1 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -65,6 +65,16 @@ void FastCloneShallowObjectStub::InitializeInterfaceDescriptor(
 }
 
 
+void CreateAllocationSiteStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { ebx };
+  descriptor->register_param_count_ = 1;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ = NULL;
+}
+
+
 void KeyedLoadFastElementStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
@@ -4697,17 +4707,21 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   __ cmp(ecx, Immediate(TypeFeedbackCells::MegamorphicSentinel(isolate)));
   __ j(equal, &done);
 
+  /*
+    If we came here, we need to see if we are the array function.
+    If we didn't have a matching function, and we didn't find the megamorph
+    sentinel, then we have in the cell either some other function or an
+    AllocationSite. Do a map check on the object in ecx
+  */

[Hannes Payer (out of office), 2013/07/08 09:03:10]

It looks like that all comments in that file are of style
// foo
// bar
Let's continue doing that.

+  Handle<Map> allocation_site_map(
+      masm->isolate()->heap()->allocation_site_map(),
+      masm->isolate());
+  __ cmp(FieldOperand(ecx, 0), Immediate(allocation_site_map));
+  __ j(not_equal, &miss);
+
   // Special handling of the Array() function, which caches not only the
   // monomorphic Array function but the initial ElementsKind with special
   // sentinels

[Hannes Payer (out of office), 2013/07/08 09:03:10]

This comment can be removed.

-  __ JumpIfNotSmi(ecx, &miss);
-  if (FLAG_debug_code) {
-    Handle<Object> terminal_kind_sentinel =
-        TypeFeedbackCells::MonomorphicArraySentinel(masm->isolate(),
-                                                    LAST_FAST_ELEMENTS_KIND);
-    __ cmp(ecx, Immediate(terminal_kind_sentinel));
-    __ Assert(less_equal, "Array function sentinel is not an ElementsKind");
-  }
 
   // Load the global or builtins object from the current context
   __ LoadGlobalContext(ecx);
@@ -4739,14 +4753,22 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
                       Context::SlotOffset(Context::ARRAY_FUNCTION_INDEX)));
   __ j(not_equal, &not_array_function);
 
-  // The target function is the Array constructor, install a sentinel value in
-  // the constructor's type info cell that will track the initial ElementsKind
-  // that should be used for the array when its constructed.
-  Handle<Object> initial_kind_sentinel =
-      TypeFeedbackCells::MonomorphicArraySentinel(isolate,
-          GetInitialFastElementsKind());
-  __ mov(FieldOperand(ebx, Cell::kValueOffset),
-         Immediate(initial_kind_sentinel));
+  // The target function is the Array constructor,
+  // Create an AllocationSite if we don't already have it, store it in the cell
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+
+    __ push(eax);
+    __ push(edi);
+    __ push(ebx);
+
+    CreateAllocationSiteStub create_stub;
+    __ CallStub(&create_stub);
+
+    __ pop(ebx);
+    __ pop(edi);
+    __ pop(eax);
+  }
   __ jmp(&done);
 
   __ bind(&not_array_function);
@@ -4912,6 +4934,7 @@ void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
   // It is important that the store buffer overflow stubs are generated first.
   RecordWriteStub::GenerateFixedRegStubsAheadOfTime(isolate);
   ArrayConstructorStubBase::GenerateStubsAheadOfTime(isolate);
+  CreateAllocationSiteStub::GenerateAheadOfTime(isolate);
 }
 
 
@@ -7794,13 +7817,16 @@ static void CreateArrayDispatchOneArgument(MacroAssembler* masm) {
   __ cmp(ebx, Immediate(undefined_sentinel));
   __ j(equal, &normal_sequence);
 

[Hannes Payer (out of office), 2013/07/08 09:03:10]

Can we add there a comment?

-  // The type cell may have gone megamorphic, don't overwrite if so
-  __ mov(ecx, FieldOperand(ebx, kPointerSize));
-  __ JumpIfNotSmi(ecx, &normal_sequence);
+  __ mov(ecx, FieldOperand(ebx, Cell::kValueOffset));
+  Handle<Map> allocation_site_map(
+      masm->isolate()->heap()->allocation_site_map(),
+      masm->isolate());
+  __ cmp(FieldOperand(ecx, 0), Immediate(allocation_site_map));
+  __ j(not_equal, &normal_sequence);
 
   // Save the resulting elements kind in type info
   __ SmiTag(edx);
-  __ mov(FieldOperand(ebx, kPointerSize), edx);
+  __ mov(FieldOperand(ecx, AllocationSite::kPayloadOffset), edx);
   __ SmiUntag(edx);
 
   __ bind(&normal_sequence);
@@ -7829,7 +7855,7 @@ static void ArrayConstructorStubAheadOfTimeHelper(Isolate* isolate) {
     ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
     T stub(kind);
     stub.GetCode(isolate)->set_is_pregenerated(true);
-    if (AllocationSiteInfo::GetMode(kind) != DONT_TRACK_ALLOCATION_SITE) {
+    if (AllocationSite::GetMode(kind) != DONT_TRACK_ALLOCATION_SITE) {
       T stub1(kind, CONTEXT_CHECK_REQUIRED, DISABLE_ALLOCATION_SITES);
       stub1.GetCode(isolate)->set_is_pregenerated(true);
     }
@@ -7901,7 +7927,20 @@ void ArrayConstructorStub::Generate(MacroAssembler* masm) {
   __ cmp(ebx, Immediate(undefined_sentinel));
   __ j(equal, &no_info);
   __ mov(edx, FieldOperand(ebx, Cell::kValueOffset));
-  __ JumpIfNotSmi(edx, &no_info);
+
+  // The type cell may have undefined in its value.
+  __ cmp(edx, Immediate(undefined_sentinel));
+  __ j(equal, &no_info);
+
+  // We should have an allocation site object
+  if (FLAG_debug_code) {
+    __ cmp(FieldOperand(edx, 0),
+           Immediate(Handle<Map>(
+               masm->isolate()->heap()->allocation_site_map())));
+    __ Assert(equal, "Expected AllocationSite object in register edx");
+  }
+
+  __ mov(edx, FieldOperand(edx, AllocationSite::kPayloadOffset));
   __ SmiUntag(edx);
   __ jmp(&switch_ready);
   __ bind(&no_info);