Reland of [interpreter] Add string type feedback to add

src/code-stubs.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-stubs.h"
 
 #include <sstream>
 
 #include "src/ast/ast.h"
 #include "src/bootstrapper.h"
@@ skipping 1014 matching lines @@
 compiler::Node* AddWithFeedbackStub::Generate(
     CodeStubAssembler* assembler, compiler::Node* lhs, compiler::Node* rhs,
     compiler::Node* slot_id, compiler::Node* type_feedback_vector,
     compiler::Node* context) {
   typedef CodeStubAssembler::Label Label;
   typedef compiler::Node Node;
   typedef CodeStubAssembler::Variable Variable;
 
   // Shared entry for floating point addition.
   Label do_fadd(assembler), end(assembler),
-      call_add_stub(assembler, Label::kDeferred);
+      do_add_any(assembler, Label::kDeferred), call_add_stub(assembler);
   Variable var_fadd_lhs(assembler, MachineRepresentation::kFloat64),
       var_fadd_rhs(assembler, MachineRepresentation::kFloat64),
       var_type_feedback(assembler, MachineRepresentation::kWord32),
       var_result(assembler, MachineRepresentation::kTagged);
 
   // Check if the {lhs} is a Smi or a HeapObject.
   Label if_lhsissmi(assembler), if_lhsisnotsmi(assembler);
   assembler->Branch(assembler->WordIsSmi(lhs), &if_lhsissmi, &if_lhsisnotsmi);
 
   assembler->Bind(&if_lhsissmi);
@@ skipping 27 matching lines @@
         assembler->Goto(&end);
       }
     }
 
     assembler->Bind(&if_rhsisnotsmi);
     {
       // Load the map of {rhs}.
       Node* rhs_map = assembler->LoadMap(rhs);
 
       // Check if the {rhs} is a HeapNumber.
-      assembler->GotoUnless(assembler->IsHeapNumberMap(rhs_map),
-                            &call_add_stub);
+      assembler->GotoUnless(assembler->IsHeapNumberMap(rhs_map), &do_add_any);
 
       var_fadd_lhs.Bind(assembler->SmiToFloat64(lhs));
       var_fadd_rhs.Bind(assembler->LoadHeapNumberValue(rhs));
       assembler->Goto(&do_fadd);
     }
   }
 
   assembler->Bind(&if_lhsisnotsmi);
   {
+    Label check_string(assembler);
+
     // Load the map of {lhs}.
     Node* lhs_map = assembler->LoadMap(lhs);
 
     // Check if {lhs} is a HeapNumber.
     Label if_lhsisnumber(assembler), if_lhsisnotnumber(assembler);
-    assembler->GotoUnless(assembler->IsHeapNumberMap(lhs_map), &call_add_stub);
+    assembler->GotoUnless(assembler->IsHeapNumberMap(lhs_map), &check_string);
 
     // Check if the {rhs} is Smi.
     Label if_rhsissmi(assembler), if_rhsisnotsmi(assembler);
     assembler->Branch(assembler->WordIsSmi(rhs), &if_rhsissmi, &if_rhsisnotsmi);
 
     assembler->Bind(&if_rhsissmi);
     {
       var_fadd_lhs.Bind(assembler->LoadHeapNumberValue(lhs));
       var_fadd_rhs.Bind(assembler->SmiToFloat64(rhs));
       assembler->Goto(&do_fadd);
     }
 
     assembler->Bind(&if_rhsisnotsmi);
     {
       // Load the map of {rhs}.
       Node* rhs_map = assembler->LoadMap(rhs);
 
       // Check if the {rhs} is a HeapNumber.
-      assembler->GotoUnless(assembler->IsHeapNumberMap(rhs_map),
-                            &call_add_stub);
+      assembler->GotoUnless(assembler->IsHeapNumberMap(rhs_map), &do_add_any);
 
       var_fadd_lhs.Bind(assembler->LoadHeapNumberValue(lhs));
       var_fadd_rhs.Bind(assembler->LoadHeapNumberValue(rhs));
       assembler->Goto(&do_fadd);
     }
+
+    assembler->Bind(&check_string);
+    {
+      // Check if the {rhs} is a smi, and exit the string check early if it is.
+      assembler->GotoIf(assembler->WordIsSmi(rhs), &do_add_any);
+
+      Node* lhs_instance_type = assembler->LoadMapInstanceType(lhs_map);
+
+      // Exit unless {lhs} is a string
+      assembler->GotoUnless(assembler->IsStringInstanceType(lhs_instance_type),
+                            &do_add_any);
+
+      Node* rhs_instance_type = assembler->LoadInstanceType(rhs);
+
+      // Exit unless {rhs} is a string
+      assembler->GotoUnless(assembler->IsStringInstanceType(rhs_instance_type),
+                            &do_add_any);
+
+      var_type_feedback.Bind(
+          assembler->Int32Constant(BinaryOperationFeedback::kString));
+      assembler->Goto(&call_add_stub);
+    }
   }
 
   assembler->Bind(&do_fadd);
   {
     var_type_feedback.Bind(
         assembler->Int32Constant(BinaryOperationFeedback::kNumber));
     Node* value =
         assembler->Float64Add(var_fadd_lhs.value(), var_fadd_rhs.value());
     Node* result = assembler->ChangeFloat64ToTagged(value);
     var_result.Bind(result);
     assembler->Goto(&end);
   }
 
+  assembler->Bind(&do_add_any);
+  {
+    var_type_feedback.Bind(
+        assembler->Int32Constant(BinaryOperationFeedback::kAny));
+    assembler->Goto(&call_add_stub);
+  }
+
   assembler->Bind(&call_add_stub);
   {
-    var_type_feedback.Bind(
-        assembler->Int32Constant(BinaryOperationFeedback::kAny));
     Callable callable = CodeFactory::Add(assembler->isolate());
     var_result.Bind(assembler->CallStub(callable, context, lhs, rhs));
     assembler->Goto(&end);
   }
 
   assembler->Bind(&end);
   assembler->UpdateFeedback(var_type_feedback.value(), type_feedback_vector,
                             slot_id);
   return var_result.value();
 }
@@ skipping 4674 matching lines @@
 
   if (type == MachineType::Pointer()) {
     return Representation::External();
   }
 
   return Representation::Tagged();
 }
 
 }  // namespace internal
 }  // namespace v8