[turbofan] Split JSGlobalObjectSpecialization into separate class.

src/compiler/js-global-object-specialization.h

+// Copyright 2015 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_JS_GLOBAL_OBJECT_SPECIALIZATION_H_
+#define V8_COMPILER_JS_GLOBAL_OBJECT_SPECIALIZATION_H_
+
+#include "src/base/flags.h"
+#include "src/compiler/graph-reducer.h"
+
+namespace v8 {
+namespace internal {
+
+// Forward declarations.
+class CompilationDependencies;
+class ScriptContextTable;
+class TypeCache;
+
+
+namespace compiler {
+
+// Forward declarations.
+class CommonOperatorBuilder;
+class JSGraph;
+class JSOperatorBuilder;
+class SimplifiedOperatorBuilder;
+
+
+// Specializes a given JSGraph to a given global object, potentially constant
+// folding some {JSLoadGlobal} nodes or strength reducing some {JSStoreGlobal}
+// nodes.
+class JSGlobalObjectSpecialization final : public AdvancedReducer {
+ public:
+  // Flags that control the mode of operation.
+  enum Flag {
+    kNoFlags = 0u,
+    kDeoptimizationEnabled = 1u << 0,
+  };
+  typedef base::Flags<Flag> Flags;
+
+  JSGlobalObjectSpecialization(Editor* editor, JSGraph* jsgraph, Flags flags,
+                               Handle<JSGlobalObject> global_object,
+                               CompilationDependencies* dependencies);
+
+  Reduction Reduce(Node* node) final;
+
+ private:
+  Reduction ReduceJSLoadGlobal(Node* node);
+  Reduction ReduceJSStoreGlobal(Node* node);
+
+  struct ScriptContextTableLookupResult;
+  bool LookupInScriptContextTable(Handle<Name> name,
+                                  ScriptContextTableLookupResult* result);
+
+  Graph* graph() const;
+  JSGraph* jsgraph() const { return jsgraph_; }
+  Isolate* isolate() const;
+  CommonOperatorBuilder* common() const;
+  JSOperatorBuilder* javascript() const;
+  SimplifiedOperatorBuilder* simplified() const;
+  Flags flags() const { return flags_; }
+  Handle<JSGlobalObject> global_object() const { return global_object_; }
+  Handle<ScriptContextTable> script_context_table() const {
+    return script_context_table_;
+  }
+  CompilationDependencies* dependencies() const { return dependencies_; }
+
+  JSGraph* const jsgraph_;
+  Flags const flags_;
+  Handle<JSGlobalObject> global_object_;
+  Handle<ScriptContextTable> script_context_table_;
+  CompilationDependencies* const dependencies_;
+  TypeCache const& type_cache_;
+
+  DISALLOW_COPY_AND_ASSIGN(JSGlobalObjectSpecialization);
+};
+
+DEFINE_OPERATORS_FOR_FLAGS(JSGlobalObjectSpecialization::Flags)
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_JS_GLOBAL_OBJECT_SPECIALIZATION_H_