Track representations of fields

src/stub-cache.cc

Index: src/stub-cache.cc
diff --git a/src/stub-cache.cc b/src/stub-cache.cc
index 396e92ce39a6601295a6632de73088a0e05fec2f..ae427ee8c9316b332986c8bc08ee28d305a58a95 100644
--- a/src/stub-cache.cc
+++ b/src/stub-cache.cc
@@ -421,7 +421,15 @@ Handle<Code> StubCache::ComputeStoreTransition(Handle<Name> name,
                                                StrictModeFlag strict_mode) {
   Handle<Code> stub = FindIC(
       name, receiver, Code::STORE_IC, Code::MAP_TRANSITION, strict_mode);
-  if (!stub.is_null()) return stub;
+  if (!stub.is_null()) {
+    MapHandleList embedded_maps;
+    stub->FindAllMaps(&embedded_maps);
+    for (int i = 0; i < embedded_maps.length(); i++) {
+      if (embedded_maps.at(i).is_identical_to(transition)) {
+        return stub;
+      }
+    }
+  }
 
   StoreStubCompiler compiler(isolate_, strict_mode);
   Handle<Code> code =
@@ -570,7 +578,15 @@ Handle<Code> StubCache::ComputeKeyedStoreTransition(
     StrictModeFlag strict_mode) {
   Handle<Code> stub = FindIC(
       name, receiver, Code::KEYED_STORE_IC, Code::MAP_TRANSITION, strict_mode);
-  if (!stub.is_null()) return stub;
+  if (!stub.is_null()) {
+    MapHandleList embedded_maps;
+    stub->FindAllMaps(&embedded_maps);
+    for (int i = 0; i < embedded_maps.length(); i++) {
+      if (embedded_maps.at(i).is_identical_to(transition)) {
+        return stub;
+      }
+    }
+  }
 
   KeyedStoreStubCompiler compiler(isolate(), strict_mode, STANDARD_STORE);
   Handle<Code> code =
@@ -917,10 +933,11 @@ Handle<Code> StubCache::ComputeLoadElementPolymorphic(
 
 Handle<Code> StubCache::ComputePolymorphicIC(MapHandleList* receiver_maps,
                                              CodeHandleList* handlers,
+                                             int number_of_valid_maps,
                                              Handle<Name> name) {
   LoadStubCompiler ic_compiler(isolate_);
-  Code::StubType type = handlers->length() == 1 ? handlers->at(0)->type()
-                                                : Code::NORMAL;
+  Code::StubType type = number_of_valid_maps == 1 ? handlers->at(0)->type()
+                                                  : Code::NORMAL;
   Handle<Code> ic = ic_compiler.CompilePolymorphicIC(
       receiver_maps, handlers, name, type, PROPERTY);
   return ic;