[ic] Support data handlers that represent simple field stores.

src/ic/handler-configuration.h

 // Copyright 2016 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_IC_HANDLER_CONFIGURATION_H_
 #define V8_IC_HANDLER_CONFIGURATION_H_
 
 #include "src/elements-kind.h"
 #include "src/field-index.h"
 #include "src/globals.h"
@@ skipping 48 matching lines @@
   // Creates a Smi-handler for loading a constant from fast object.
   static inline Handle<Object> LoadConstant(Isolate* isolate, int descriptor);
 
   // Creates a Smi-handler for loading an element.
   static inline Handle<Object> LoadElement(Isolate* isolate,
                                            ElementsKind elements_kind,
                                            bool convert_hole_to_undefined,
                                            bool is_js_array);
 };
 
+// A set of bit fields representing Smi handlers for stores.
+class StoreHandler {
+ public:
+  enum Kind { kForElements, kForFields };
+  class KindBits : public BitField<Kind, 0, 1> {};
+
+  enum FieldRepresentation { kSmi, kDouble, kHeapObject, kTagged };
+
+  //
+  // Encoding when KindBits contains kForFields.
+  //
+  class IsInobjectBits : public BitField<bool, KindBits::kNext, 1> {};
+  class FieldRepresentationBits
+      : public BitField<FieldRepresentation, IsInobjectBits::kNext, 2> {};
+  // +2 here is because each descriptor entry occupies 3 slots in array.
+  class DescriptorValueIndexBits
+      : public BitField<unsigned, FieldRepresentationBits::kNext,
+                        kDescriptorIndexBitCount + 2> {};
+  // +1 here is to cover all possible JSObject header sizes.
+  class FieldOffsetBits
+      : public BitField<unsigned, DescriptorValueIndexBits::kNext,
+                        kDescriptorIndexBitCount + 1 + kPointerSizeLog2> {};
+  // Make sure we don't overflow the smi.
+  STATIC_ASSERT(FieldOffsetBits::kNext <= kSmiValueSize);
+
+  // Creates a Smi-handler for storing a field to fast object.
+  static inline Handle<Object> StoreField(Isolate* isolate, int descriptor,
+                                          FieldIndex field_index,
+                                          Representation representation);
+};
+
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_IC_HANDLER_CONFIGURATION_H_