Allocation site support for monomorphic StringAdds in BinaryOps.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 5b5212c7e07c9cc2b2e8522897b11c600030a739..920843dfe3f77560dd7ac3fa5cab6a03f4877e97 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -180,18 +180,6 @@ void TransitionElementsKindStub::InitializeInterfaceDescriptor(
 }
 
 
-void BinaryOpICStub::InitializeInterfaceDescriptor(
-    Isolate* isolate,
-    CodeStubInterfaceDescriptor* descriptor) {
-  static Register registers[] = { rdx, rax };
-  descriptor->register_param_count_ = 2;
-  descriptor->register_params_ = registers;
-  descriptor->deoptimization_handler_ = FUNCTION_ADDR(BinaryOpIC_Miss);
-  descriptor->SetMissHandler(
-      ExternalReference(IC_Utility(IC::kBinaryOpIC_Miss), isolate));
-}
-
-
 static void InitializeArrayConstructorDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor,
@@ -339,6 +327,29 @@ void ElementsTransitionAndStoreStub::InitializeInterfaceDescriptor(
 }
 
 
+void BinaryOpICStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { rdx, rax };
+  descriptor->register_param_count_ = 2;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ = FUNCTION_ADDR(BinaryOpIC_Miss);
+  descriptor->SetMissHandler(
+      ExternalReference(IC_Utility(IC::kBinaryOpIC_Miss), isolate));
+}
+
+
+void BinaryOpWithAllocationSiteStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { rcx, rdx, rax };
+  descriptor->register_param_count_ = 3;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ =
+      FUNCTION_ADDR(BinaryOpIC_MissWithAllocationSite);
+}
+
+
 void NewStringAddStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
@@ -2483,6 +2494,7 @@ void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
   ArrayConstructorStubBase::GenerateStubsAheadOfTime(isolate);
   CreateAllocationSiteStub::GenerateAheadOfTime(isolate);
   BinaryOpICStub::GenerateAheadOfTime(isolate);
+  BinaryOpICWithAllocationSiteStub::GenerateAheadOfTime(isolate);
 }
 
 
@@ -4229,6 +4241,35 @@ void StringCompareStub::Generate(MacroAssembler* masm) {
 }
 
 
+void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- rdx    : left
+  //  -- rax    : right
+  //  -- rsp[0] : return address
+  // -----------------------------------
+  Isolate* isolate = masm->isolate();
+
+  // Load rcx with the allocation site.  We stick an undefined dummy value here
+  // and replace it with the real allocation site later when we instantiate this
+  // stub in BinaryOpICWithAllocationSiteStub::GetCodeCopyFromTemplate().
+  __ Move(rcx, handle(isolate->heap()->undefined_value()));
+
+  // Make sure that we actually patched the allocation site.
+  if (FLAG_debug_code) {
+    __ testb(rcx, Immediate(kSmiTagMask));
+    __ Assert(zero, kExpectedAllocationSite);
+    __ Cmp(FieldOperand(rcx, HeapObject::kMapOffset),
+           isolate->factory()->allocation_site_map());
+    __ Assert(equal, kExpectedAllocationSite);
+  }
+
+  // Tail call into the stub that handles binary operations with allocation
+  // sites.
+  BinaryOpWithAllocationSiteStub stub(state_);
+  __ TailCallStub(&stub);
+}
+
+
 void ICCompareStub::GenerateSmis(MacroAssembler* masm) {
   ASSERT(state_ == CompareIC::SMI);
   Label miss;