Reland "Allocation site support for monomorphic StringAdds in BinaryOps".

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index f658291f84cefb3f4d0d92324f6e6c1eededb2e0..f70271bd506ecb9148a7773dc566c3f379b6c63c 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -193,18 +193,6 @@ void CompareNilICStub::InitializeInterfaceDescriptor(
 }
 
 
-void BinaryOpICStub::InitializeInterfaceDescriptor(
-    Isolate* isolate,
-    CodeStubInterfaceDescriptor* descriptor) {
-  static Register registers[] = { r1, r0 };
-  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[] = { r1, r0 };
+  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[] = { r2, r1, r0 };
+  descriptor->register_param_count_ = 3;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ =
+      FUNCTION_ADDR(BinaryOpIC_MissWithAllocationSite);
+}
+
+
 void NewStringAddStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
@@ -1442,6 +1453,7 @@ void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
   ArrayConstructorStubBase::GenerateStubsAheadOfTime(isolate);
   CreateAllocationSiteStub::GenerateAheadOfTime(isolate);
   BinaryOpICStub::GenerateAheadOfTime(isolate);
+  BinaryOpICWithAllocationSiteStub::GenerateAheadOfTime(isolate);
 }
 
 
@@ -4162,6 +4174,38 @@ void StringCompareStub::Generate(MacroAssembler* masm) {
 }
 
 
+void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- r1    : left
+  //  -- r0    : right
+  //  -- lr    : return address
+  // -----------------------------------
+  Isolate* isolate = masm->isolate();
+
+  // Load r2 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(r2, handle(isolate->heap()->undefined_value()));
+
+  // Make sure that we actually patched the allocation site.
+  if (FLAG_debug_code) {
+    __ tst(r2, Operand(kSmiTagMask));
+    __ Assert(ne, kExpectedAllocationSite);
+    __ push(r2);
+    __ ldr(r2, FieldMemOperand(r2, HeapObject::kMapOffset));
+    __ LoadRoot(ip, Heap::kAllocationSiteMapRootIndex);
+    __ cmp(r2, ip);
+    __ pop(r2);
+    __ Assert(eq, kExpectedAllocationSite);
+  }
+
+  // Tail call into the stub that handles binary operations with allocation
+  // sites.
+  BinaryOpWithAllocationSiteStub stub(state_);
+  __ TailCallStub(&stub);
+}
+
+
 void StringAddStub::Generate(MacroAssembler* masm) {
   Label call_runtime, call_builtin;
   Builtins::JavaScript builtin_id = Builtins::ADD;