[turbofan] Add initial support for growing stores.

src/compiler/simplified-operator.h

 // 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.
 
 #ifndef V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 #define V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 
 #include <iosfwd>
 
 #include "src/compiler/operator.h"
@@ skipping 123 matching lines @@
   kCheckForMinusZero,
   kDontCheckForMinusZero,
 };
 
 size_t hash_value(CheckForMinusZeroMode);
 
 std::ostream& operator<<(std::ostream&, CheckForMinusZeroMode);
 
 CheckForMinusZeroMode CheckMinusZeroModeOf(const Operator*) WARN_UNUSED_RESULT;
 
+// A descriptor for growing elements backing stores.
+enum class GrowFastElementsFlag : uint8_t {
+  kNone = 0u,
+  kArrayObject = 1u << 0,     // Update JSArray::length field.
+  kHoleyElements = 1u << 1,   // Backing store is holey.
+  kDoubleElements = 1u << 2,  // Backing store contains doubles.
+};
+typedef base::Flags<GrowFastElementsFlag> GrowFastElementsFlags;
+
+DEFINE_OPERATORS_FOR_FLAGS(GrowFastElementsFlags)
+
+std::ostream& operator<<(std::ostream&, GrowFastElementsFlags);
+
+GrowFastElementsFlags GrowFastElementsFlagsOf(const Operator*)
+    WARN_UNUSED_RESULT;
+
 // A descriptor for elements kind transitions.
 enum class ElementsTransition : uint8_t {
   kFastTransition,  // simple transition, just updating the map.
   kSlowTransition   // full transition, round-trip to the runtime.
 };
 
 size_t hash_value(ElementsTransition);
 
 std::ostream& operator<<(std::ostream&, ElementsTransition);
 
@@ skipping 162 matching lines @@
   const Operator* ObjectIsCallable();
   const Operator* ObjectIsNumber();
   const Operator* ObjectIsReceiver();
   const Operator* ObjectIsSmi();
   const Operator* ObjectIsString();
   const Operator* ObjectIsUndetectable();
 
   // ensure-writable-fast-elements object, elements
   const Operator* EnsureWritableFastElements();
 
+  // maybe-grow-fast-elements object, elements, index, length
+  const Operator* MaybeGrowFastElements(GrowFastElementsFlags flags);
+
   // transition-elements-kind object, from-map, to-map
   const Operator* TransitionElementsKind(ElementsTransition transition);
 
   const Operator* Allocate(PretenureFlag pretenure = NOT_TENURED);
 
   const Operator* LoadField(FieldAccess const&);
   const Operator* StoreField(FieldAccess const&);
 
   // load-buffer buffer, offset, length
   const Operator* LoadBuffer(BufferAccess);
@@ skipping 20 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(SimplifiedOperatorBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_SIMPLIFIED_OPERATOR_H_