New hydrogen instruction to reduce cost of growing an array on keyed stores.

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 1313 matching lines @@
     PropertyAccessType access_type) {
   IfBuilder length_checker(this);
 
   Token::Value token = IsHoleyElementsKind(kind) ? Token::GTE : Token::EQ;
   length_checker.If<HCompareNumericAndBranch>(key, length, token);
 
   length_checker.Then();
 
   HValue* current_capacity = AddLoadFixedArrayLength(elements);
 
-  IfBuilder capacity_checker(this);
-
-  capacity_checker.If<HCompareNumericAndBranch>(key, current_capacity,
-                                                Token::GTE);
-  capacity_checker.Then();
-
-  // BuildCheckAndGrowElementsCapacity could de-opt without profitable feedback
-  // therefore we defer calling it to a stub in optimized functions. It is
-  // okay to call directly in a code stub though, because a bailout to the
-  // runtime is tolerable in the corner cases.
   if (top_info()->IsStub()) {
+    IfBuilder capacity_checker(this);
+    capacity_checker.If<HCompareNumericAndBranch>(key, current_capacity,
+                                                  Token::GTE);
+    capacity_checker.Then();
     HValue* new_elements = BuildCheckAndGrowElementsCapacity(
         object, elements, kind, length, current_capacity, key);
     environment()->Push(new_elements);
+    capacity_checker.Else();
+    environment()->Push(elements);
+    capacity_checker.End();
   } else {
-    GrowArrayElementsStub stub(isolate(), is_js_array, kind);
-    GrowArrayElementsDescriptor descriptor(isolate());
-    HConstant* target = Add<HConstant>(stub.GetCode());
-    HValue* op_vals[] = {context(), object, key, current_capacity};
-    HValue* new_elements = Add<HCallWithDescriptor>(
-        target, 0, descriptor, Vector<HValue*>(op_vals, 4));
-    // If the object changed to a dictionary, GrowArrayElements will return a
-    // smi to signal that deopt is required.
-    Add<HCheckHeapObject>(new_elements);
-    environment()->Push(new_elements);
+    HValue* result = Add<HMaybeGrowElements>(
+        object, elements, key, current_capacity, is_js_array, kind);
+    environment()->Push(result);
   }
 
-  capacity_checker.Else();
-
-  environment()->Push(elements);
-  capacity_checker.End();
-
   if (is_js_array) {
     HValue* new_length = AddUncasted<HAdd>(key, graph_->GetConstant1());
     new_length->ClearFlag(HValue::kCanOverflow);
 
     Add<HStoreNamedField>(object, HObjectAccess::ForArrayLength(kind),
                           new_length);
   }
 
   if (access_type == STORE && kind == FAST_SMI_ELEMENTS) {
     HValue* checked_elements = environment()->Top();
@@ skipping 11771 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal