VectorICs: megamorphic keyed loads in crankshaft don't need a vector.

src/hydrogen.cc

 // Copyright 2013 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/hydrogen.h"
 
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 5388 matching lines @@
         }
       } else {
         HValue* global_object = Add<HLoadNamedField>(
             context(), nullptr,
             HObjectAccess::ForContextSlot(Context::GLOBAL_OBJECT_INDEX));
         HLoadGlobalGeneric* instr =
             New<HLoadGlobalGeneric>(global_object,
                                     variable->name(),
                                     ast_context()->is_for_typeof());
         if (FLAG_vector_ics) {
-          Handle<SharedFunctionInfo> current_shared =
-              function_state()->compilation_info()->shared_info();
-          instr->SetVectorAndSlot(
-              handle(current_shared->feedback_vector(), isolate()),
-              expr->VariableFeedbackSlot());
+          instr->SetVectorAndSlot(handle(current_feedback_vector(), isolate()),
+                                  expr->VariableFeedbackSlot());
         }
         return ast_context()->ReturnInstruction(instr, expr->id());
       }
     }
 
     case Variable::PARAMETER:
     case Variable::LOCAL: {
       HValue* value = LookupAndMakeLive(variable);
       if (value == graph()->GetConstantHole()) {
         DCHECK(IsDeclaredVariableMode(variable->mode()) &&
@@ skipping 1470 matching lines @@
     Handle<String> name, HValue* value, bool is_uninitialized) {
   if (is_uninitialized) {
     Add<HDeoptimize>(
         Deoptimizer::kInsufficientTypeFeedbackForGenericNamedAccess,
         Deoptimizer::SOFT);
   }
   if (access_type == LOAD) {
     HLoadNamedGeneric* result =
         New<HLoadNamedGeneric>(object, name, PREMONOMORPHIC);
     if (FLAG_vector_ics) {
-      Handle<SharedFunctionInfo> current_shared =
-          function_state()->compilation_info()->shared_info();
       Handle<TypeFeedbackVector> vector =
-          handle(current_shared->feedback_vector(), isolate());
+          handle(current_feedback_vector(), isolate());
       FeedbackVectorICSlot slot = expr->AsProperty()->PropertyFeedbackSlot();
       result->SetVectorAndSlot(vector, slot);
     }
     return result;
   } else {
     return New<HStoreNamedGeneric>(object, name, value,
                                    function_language_mode(), PREMONOMORPHIC);
   }
 }
 
 
 
 HInstruction* HOptimizedGraphBuilder::BuildKeyedGeneric(
     PropertyAccessType access_type,
     Expression* expr,
     HValue* object,
     HValue* key,
     HValue* value) {
   if (access_type == LOAD) {
-    HLoadKeyedGeneric* result =
-        New<HLoadKeyedGeneric>(object, key, PREMONOMORPHIC);
-    if (FLAG_vector_ics) {
-      Handle<SharedFunctionInfo> current_shared =
-          function_state()->compilation_info()->shared_info();
-      Handle<TypeFeedbackVector> vector =
-          handle(current_shared->feedback_vector(), isolate());
-      FeedbackVectorICSlot slot = expr->AsProperty()->PropertyFeedbackSlot();
-      result->SetVectorAndSlot(vector, slot);
-    }
+    // HLoadKeyedGeneric with vector ics benefits from being encoded as
+    // MEGAMORPHIC because the vector/slot combo becomes unnecessary.
+    HLoadKeyedGeneric* result = New<HLoadKeyedGeneric>(
+        object, key, FLAG_vector_ics ? MEGAMORPHIC : PREMONOMORPHIC);
     return result;
   } else {
     return New<HStoreKeyedGeneric>(object, key, value, function_language_mode(),
                                    PREMONOMORPHIC);
   }
 }
 
 
 LoadKeyedHoleMode HOptimizedGraphBuilder::BuildKeyedHoleMode(Handle<Map> map) {
   // Loads from a "stock" fast holey double arrays can elide the hole check.
@@ skipping 2371 matching lines @@
       call = BuildCallConstantFunction(expr->target(), argument_count);
     } else {
       PushArgumentsFromEnvironment(argument_count);
       HCallFunction* call_function =
           New<HCallFunction>(function, argument_count);
       call = call_function;
       if (expr->is_uninitialized() &&
           expr->IsUsingCallFeedbackICSlot(isolate())) {
         // We've never seen this call before, so let's have Crankshaft learn
         // through the type vector.
-        Handle<SharedFunctionInfo> current_shared =
-            function_state()->compilation_info()->shared_info();
         Handle<TypeFeedbackVector> vector =
-            handle(current_shared->feedback_vector(), isolate());
+            handle(current_feedback_vector(), isolate());
         FeedbackVectorICSlot slot = expr->CallFeedbackICSlot();
         call_function->SetVectorAndSlot(vector, slot);
       }
     }
   }
 
   Drop(1);  // Drop the function.
   return ast_context()->ReturnInstruction(call, expr->id());
 }
 
@@ skipping 3618 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal