VectorICs: VisitClassLiteral needs adjustment for IC slot usage.

src/compiler/js-generic-lowering.cc

 // Copyright 2014 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-factory.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 341 matching lines @@
     node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
     ReplaceWithStubCall(node, callable, flags);
   }
 }
 
 
 void JSGenericLowering::LowerJSStoreProperty(Node* node) {
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
   const StorePropertyParameters& p = StorePropertyParametersOf(node->op());
   LanguageMode language_mode = OpParameter<LanguageMode>(node);
-  Callable callable = CodeFactory::KeyedStoreICInOptimizedCode(
-      isolate(), language_mode, UNINITIALIZED);
+  InlineCacheState state = FLAG_vector_stores && p.feedback().index() == -1

[Michael Starzinger, 2015/07/24 11:51:30]

Can we restructure this a little to be more readable. I had a hard time
understanding it and would have come to the wrong conclusion without your
offline help. How about this ...

// We have a special case where we do keyed stores but don't have a type
// feedback vector slot allocated to support it. In this case, install
// the megamorphic keyed store stub which needs neither vector nor slot.
bool use_vector_slot = FLAG_vector_stores && p.feedback().index() != -1;
Callable callable = CodeFactory::KeyedStoreICInOptimizedCode(isolate(),
language_mode, use_vector_slot ? UNINITIALIZED : MEGAMORPHIC);
if (use_vector_slot) {
  node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
} else {
  node->RemoveInput(3);
}

[mvstanton, 2015/07/24 12:24:58]

Most wise, thanks!

+                               ? MEGAMORPHIC
+                               : UNINITIALIZED;
+  Callable callable =
+      CodeFactory::KeyedStoreICInOptimizedCode(isolate(), language_mode, state);
   if (FLAG_vector_stores) {
-    DCHECK(p.feedback().index() != -1);
-    node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
+    if (state == MEGAMORPHIC) {
+      // We have a special case where we do keyed stores but don't have a type
+      // feedback vector slot allocated to support it. In this case, install
+      // the megamorphic keyed store stub which needs neither vector nor slot.
+      node->RemoveInput(3);
+    } else {
+      DCHECK(p.feedback().index() != -1);
+      node->InsertInput(zone(), 3,
+                        jsgraph()->SmiConstant(p.feedback().index()));
+    }
   } else {
     node->RemoveInput(3);
   }
   ReplaceWithStubCall(node, callable,
                       CallDescriptor::kPatchableCallSite | flags);
 }
 
 
 void JSGenericLowering::LowerJSStoreNamed(Node* node) {
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
@@ skipping 464 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8