Reorder KeyedStoreIC MISS code to avoid unnecessary compilation.

src/ic/ic.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/ic/ic.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/base/bits.h"
@@ skipping 1833 matching lines @@
     case LookupIterator::INTEGER_INDEXED_EXOTIC:
     case LookupIterator::ACCESS_CHECK:
     case LookupIterator::JSPROXY:
     case LookupIterator::NOT_FOUND:
       UNREACHABLE();
   }
   return slow_stub();
 }
 
 
-Handle<Code> KeyedStoreIC::StoreElementStub(Handle<JSObject> receiver,
+Handle<Code> KeyedStoreIC::StoreElementStub(Handle<Map> receiver_map,
                                             KeyedAccessStoreMode store_mode) {
   // Don't handle megamorphic property accesses for INTERCEPTORS or
   // ACCESSOR_CONSTANT
   // via megamorphic stubs, since they don't have a map in their relocation info
   // and so the stubs can't be harvested for the object needed for a map check.
   if (target()->type() != Code::NORMAL) {
     TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "non-NORMAL target type");
     return megamorphic_stub();
   }
 
-  Handle<Map> receiver_map(receiver->map(), isolate());
   MapHandleList target_receiver_maps;
   TargetMaps(&target_receiver_maps);
   if (target_receiver_maps.length() == 0) {
     Handle<Map> monomorphic_map =
         ComputeTransitionedMap(receiver_map, store_mode);
     store_mode = GetNonTransitioningStoreMode(store_mode);
     return PropertyICCompiler::ComputeKeyedStoreMonomorphic(
         monomorphic_map, language_mode(), store_mode);
   }
 
@@ skipping 13 matching lines @@
     if ((receiver_map.is_identical_to(previous_receiver_map) &&
          IsTransitionStoreMode(store_mode)) ||
         IsTransitionOfMonomorphicTarget(*previous_receiver_map,
                                         *transitioned_receiver_map)) {
       // If the "old" and "new" maps are in the same elements map family, or
       // if they at least come from the same origin for a transitioning store,
       // stay MONOMORPHIC and use the map for the most generic ElementsKind.
       store_mode = GetNonTransitioningStoreMode(store_mode);
       return PropertyICCompiler::ComputeKeyedStoreMonomorphic(
           transitioned_receiver_map, language_mode(), store_mode);
-    } else if (*previous_receiver_map == receiver->map() &&
+    } else if (receiver_map.is_identical_to(previous_receiver_map) &&
                old_store_mode == STANDARD_STORE &&
                (store_mode == STORE_AND_GROW_NO_TRANSITION ||
                 store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS ||
                 store_mode == STORE_NO_TRANSITION_HANDLE_COW)) {
       // A "normal" IC that handles stores can switch to a version that can
       // grow at the end of the array, handle OOB accesses or copy COW arrays
       // and still stay MONOMORPHIC.
       return PropertyICCompiler::ComputeKeyedStoreMonomorphic(
           receiver_map, language_mode(), store_mode);
     }
@@ skipping 243 matching lines @@
     // Don't use ICs for maps of the objects in Array's prototype chain. We
     // expect to be able to trap element sets to objects with those maps in
     // the runtime to enable optimization of element hole access.
     Handle<HeapObject> heap_object = Handle<HeapObject>::cast(object);
     if (heap_object->map()->IsMapInArrayPrototypeChain()) {
       TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "map in array prototype");
       use_ic = false;
     }
   }
 
+  Handle<Map> old_receiver_map;
+  bool sloppy_arguments_elements = false;
+  bool key_is_valid_index = false;
+  KeyedAccessStoreMode store_mode = STANDARD_STORE;
+  if (use_ic && object->IsJSObject()) {
+    Handle<JSObject> receiver = Handle<JSObject>::cast(object);
+    old_receiver_map = handle(receiver->map(), isolate());
+    sloppy_arguments_elements =
+        !is_sloppy(language_mode()) &&
+        receiver->elements()->map() ==
+            isolate()->heap()->sloppy_arguments_elements_map();
+    if (!sloppy_arguments_elements) {
+      key_is_valid_index = key->IsSmi() && Smi::cast(*key)->value() >= 0;
+      if (key_is_valid_index) {
+        uint32_t index = static_cast<uint32_t>(Smi::cast(*key)->value());
+        store_mode = GetStoreMode(receiver, index, value);
+      }
+    }
+  }
+
+  DCHECK(store_handle.is_null());
+  ASSIGN_RETURN_ON_EXCEPTION(isolate(), store_handle,
+                             Runtime::SetObjectProperty(isolate(), object, key,
+                                                        value, language_mode()),
+                             Object);
+
   if (use_ic) {
-    if (object->IsJSObject()) {
-      Handle<JSObject> receiver = Handle<JSObject>::cast(object);
-      if (receiver->elements()->map() ==
-              isolate()->heap()->sloppy_arguments_elements_map() &&
-          !is_sloppy(language_mode())) {
+    if (!old_receiver_map.is_null()) {
+      if (sloppy_arguments_elements) {
         TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "arguments receiver");
-      } else if (key->IsSmi() && Smi::cast(*key)->value() >= 0) {
-        uint32_t index = static_cast<uint32_t>(Smi::cast(*key)->value());
+      } else if (key_is_valid_index) {
         // We should go generic if receiver isn't a dictionary, but our
         // prototype chain does have dictionary elements. This ensures that
         // other non-dictionary receivers in the polymorphic case benefit
         // from fast path keyed stores.
-        if (!receiver->map()->DictionaryElementsInPrototypeChainOnly()) {
-          KeyedAccessStoreMode store_mode =
-              GetStoreMode(receiver, index, value);
-          stub = StoreElementStub(receiver, store_mode);
+        if (!old_receiver_map->DictionaryElementsInPrototypeChainOnly()) {
+          stub = StoreElementStub(old_receiver_map, store_mode);
 
           // Validate that the store_mode in the stub can also be derived
           // from peeking in the code bits of the handlers.
           ValidateStoreMode(stub);
         } else {
           TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "dictionary prototype");
         }
       } else {
         TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "non-smi-like key");
       }
     } else {
       TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "non-JSObject receiver");
     }
   }
 
-  if (store_handle.is_null()) {
-    ASSIGN_RETURN_ON_EXCEPTION(
-        isolate(), store_handle,
-        Runtime::SetObjectProperty(isolate(), object, key, value,
-                                   language_mode()),
-        Object);
-  }
-
   if (FLAG_vector_stores) {
     if (!is_vector_set() || stub.is_null()) {
       Code* megamorphic = *megamorphic_stub();
       if (!stub.is_null() && (*stub == megamorphic || *stub == *slow_stub())) {
         ConfigureVectorState(MEGAMORPHIC);
         TRACE_GENERIC_IC(isolate(), "KeyedStoreIC",
                          *stub == megamorphic ? "set generic" : "slow stub");
       }
     }
   } else {
@@ skipping 907 matching lines @@
     KeyedLoadICNexus nexus(vector, vector_slot);
     KeyedLoadIC ic(IC::EXTRA_CALL_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(receiver, key));
   }
 
   return *result;
 }
 }  // namespace internal
 }  // namespace v8