[KeyedLoadIC] Support Smi "handlers" for element loads

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/globals.h"
+#include "src/utils.h"
+
+namespace v8 {
+namespace internal {
+
+enum LoadHandlerType {
+  kLoadICHandlerForElements = 0,
+  kLoadICHandlerForProperties = 1
+};
+
+class LoadHandlerTypeBit : public BitField<bool, 0, 1> {};
+
+// Encoding for configuration Smis for property loads:
+class FieldOffsetIsInobject
+    : public BitField<bool, LoadHandlerTypeBit::kNext, 1> {};
+class FieldOffsetIsDouble
+    : public BitField<bool, FieldOffsetIsInobject::kNext, 1> {};
+class FieldOffsetOffset : public BitField<int, FieldOffsetIsDouble::kNext, 27> {
+};
+// Make sure we don't overflow into the sign bit.
+STATIC_ASSERT(FieldOffsetOffset::kNext <= kSmiValueSize - 1);
+
+// Encoding for configuration Smis for elements loads:
+class KeyedLoadIsJsArray : public BitField<bool, LoadHandlerTypeBit::kNext, 1> {
+};
+class KeyedLoadConvertHole
+    : public BitField<bool, KeyedLoadIsJsArray::kNext, 1> {};
+class KeyedLoadElementsKind
+    : public BitField<ElementsKind, KeyedLoadConvertHole::kNext, 8> {};
+// Make sure we don't overflow into the sign bit.
+STATIC_ASSERT(KeyedLoadElementsKind::kNext <= kSmiValueSize - 1);
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_IC_HANDLER_CONFIGURATION_H_