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

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 208bd91a0db7cc6a74fc879e681a8bece0e930e6..305a6d854c34a3e370610ac4f719f139bc271e87 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -342,6 +342,17 @@ void BinaryOpICStub::InitializeInterfaceDescriptor(
 }
 
 
+void BinaryOpWithAllocationSiteStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { ecx, edx, eax };
+  descriptor->register_param_count_ = 3;
+  descriptor->register_params_ = registers;
+  descriptor->deoptimization_handler_ =
+      FUNCTION_ADDR(BinaryOpIC_MissWithAllocationSite);
+}
+
+
 void NewStringAddStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
@@ -2652,8 +2663,10 @@ void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
   if (Serializer::enabled()) {
     PlatformFeatureScope sse2(SSE2);
     BinaryOpICStub::GenerateAheadOfTime(isolate);
+    BinaryOpICWithAllocationSiteStub::GenerateAheadOfTime(isolate);
   } else {
     BinaryOpICStub::GenerateAheadOfTime(isolate);
+    BinaryOpICWithAllocationSiteStub::GenerateAheadOfTime(isolate);
   }
 }
 
@@ -4385,6 +4398,35 @@ void StringCompareStub::Generate(MacroAssembler* masm) {
 }
 
 
+void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- edx    : left
+  //  -- eax    : right
+  //  -- esp[0] : return address
+  // -----------------------------------
+  Isolate* isolate = masm->isolate();
+
+  // Load ecx 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().
+  __ mov(ecx, handle(isolate->heap()->undefined_value()));
+
+  // Make sure that we actually patched the allocation site.
+  if (FLAG_debug_code) {
+    __ test(ecx, Immediate(kSmiTagMask));
+    __ Assert(not_equal, kExpectedAllocationSite);
+    __ cmp(FieldOperand(ecx, 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;