commit e144f3b71e64e01d6ffd247eb15ca1ff56f6287b
author Igor Sheludko <ishell@chromium.org> Fri Jun 02 12:49:41 2023
committer V8 LUCI CQ <v8-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Jun 02 13:48:27 2023
tree 7c41bace1951e2a6886260084db886c6e634364b
parent 4217c51611830d98d7fd7b8c922571942a87ad2e

[ic] Fix store handler selection for arguments objects

Drive-by: fix printing of handlers in --trace-feedback-updates mode.

Bug: chromium:1450481
Change-Id: I1c0084701f7f8959da508481cab7a81a2bca3c8d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4584248
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/main@{#88021}

src/diagnostics/objects-printer.cc

diff --git a/src/diagnostics/objects-printer.cc b/src/diagnostics/objects-printer.cc
index 47f90f8..63d7993 100644
--- a/src/diagnostics/objects-printer.cc
+++ b/src/diagnostics/objects-printer.cc
@@ -1338,12 +1338,18 @@
     case FeedbackSlotKind::kSetKeyedStrict: {
       os << InlineCacheState2String(ic_state());
       if (ic_state() == InlineCacheState::MONOMORPHIC) {
-        os << "\n   " << Brief(GetFeedback()) << ": ";
-        Object handler = GetFeedbackExtra().GetHeapObjectOrSmi();
-        if (handler.IsWeakFixedArray()) {
-          handler = WeakFixedArray::cast(handler).Get(0).GetHeapObjectOrSmi();
+        HeapObject feedback = GetFeedback().GetHeapObject();
+        HeapObject feedback_extra = GetFeedbackExtra().GetHeapObject();
+        if (feedback.IsName()) {
+          os << " with name " << Brief(feedback);
+          WeakFixedArray array = WeakFixedArray::cast(feedback_extra);
+          os << "\n   " << Brief(array.Get(0)) << ": ";
+          Object handler = array.Get(1).GetHeapObjectOrSmi();
+          StoreHandler::PrintHandler(handler, os);
+        } else {
+          os << "\n   " << Brief(feedback) << ": ";
+          StoreHandler::PrintHandler(feedback_extra, os);
         }
-        StoreHandler::PrintHandler(handler, os);
       } else if (ic_state() == InlineCacheState::POLYMORPHIC) {
         HeapObject feedback = GetFeedback().GetHeapObject();
         WeakFixedArray array;

src/ic/handler-configuration.cc

diff --git a/src/ic/handler-configuration.cc b/src/ic/handler-configuration.cc
index 29dd9fa..306ff49 100644
--- a/src/ic/handler-configuration.cc
+++ b/src/ic/handler-configuration.cc
@@ -596,8 +596,11 @@
     os << ", validity cell = ";
     store_handler.validity_cell().ShortPrint(os);
     os << ")" << std::endl;
+  } else if (handler.IsMap()) {
+    os << "StoreHandler(field transition to " << Brief(handler) << ")"
+       << std::endl;
   } else {
-    os << "StoreHandler(<unexpected>)(" << Brief(handler) << ")";
+    os << "StoreHandler(<unexpected>)(" << Brief(handler) << ")" << std::endl;
   }
 }
 

src/ic/ic.cc

diff --git a/src/ic/ic.cc b/src/ic/ic.cc
index 05ee161..3bc8653 100644
--- a/src/ic/ic.cc
+++ b/src/ic/ic.cc
@@ -2303,10 +2303,18 @@
              receiver_map->has_sealed_elements() ||
              receiver_map->has_nonextensible_elements() ||
              receiver_map->has_typed_array_or_rab_gsab_typed_array_elements()) {
+    // TODO(jgruber): Update counter name.
     TRACE_HANDLER_STATS(isolate(), KeyedStoreIC_StoreFastElementStub);
-    code = StoreHandler::StoreFastElementBuiltin(isolate(), store_mode);
-    if (receiver_map->has_typed_array_or_rab_gsab_typed_array_elements()) {
-      return code;
+    if (receiver_map->IsJSArgumentsObjectMap() &&
+        receiver_map->has_fast_packed_elements()) {
+      // Allow fast behaviour for in-bounds stores while making it miss and
+      // properly handle the out of bounds store case.
+      code = StoreHandler::StoreFastElementBuiltin(isolate(), STANDARD_STORE);
+    } else {
+      code = StoreHandler::StoreFastElementBuiltin(isolate(), store_mode);
+      if (receiver_map->has_typed_array_or_rab_gsab_typed_array_elements()) {
+        return code;
+      }
     }
   } else if (IsStoreInArrayLiteralIC()) {
     // TODO(jgruber): Update counter name.
@@ -2317,7 +2325,7 @@
     TRACE_HANDLER_STATS(isolate(), KeyedStoreIC_StoreElementStub);
     DCHECK(DICTIONARY_ELEMENTS == receiver_map->elements_kind() ||
            receiver_map->has_frozen_elements());
-    code = StoreHandler::StoreSlow(isolate(), store_mode);
+    return StoreHandler::StoreSlow(isolate(), store_mode);
   }
 
   if (IsAnyDefineOwn() || IsStoreInArrayLiteralIC()) return code;

src/objects/map-inl.h

diff --git a/src/objects/map-inl.h b/src/objects/map-inl.h
index 50b16f6..7eb247e 100644
--- a/src/objects/map-inl.h
+++ b/src/objects/map-inl.h
@@ -621,6 +621,10 @@
   return IsFastElementsKind(elements_kind());
 }
 
+bool Map::has_fast_packed_elements() const {
+  return IsFastPackedElementsKind(elements_kind());
+}
+
 bool Map::has_sloppy_arguments_elements() const {
   return IsSloppyArgumentsElementsKind(elements_kind());
 }

src/objects/map.h

diff --git a/src/objects/map.h b/src/objects/map.h
index 8718fac..af5e9ae 100644
--- a/src/objects/map.h
+++ b/src/objects/map.h
@@ -429,6 +429,7 @@
   inline bool has_fast_smi_or_object_elements() const;
   inline bool has_fast_double_elements() const;
   inline bool has_fast_elements() const;
+  inline bool has_fast_packed_elements() const;
   inline bool has_sloppy_arguments_elements() const;
   inline bool has_fast_sloppy_arguments_elements() const;
   inline bool has_fast_string_wrapper_elements() const;