Initial import of ChangeLowering.

src/compiler/change-lowering.h

Index: src/compiler/change-lowering.h
diff --git a/src/compiler/change-lowering.h b/src/compiler/change-lowering.h
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index 0000000000000000000000000000000000000000..3e16d800de73f76b3afa83c5692a4c783977444f
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+++ b/src/compiler/change-lowering.h
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+// 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_CHANGE_LOWERING_H_
+#define V8_COMPILER_CHANGE_LOWERING_H_
+
+#include "include/v8.h"
+#include "src/compiler/common-operator.h"
+#include "src/compiler/graph-reducer.h"
+#include "src/compiler/machine-operator.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+// Forward declarations.
+class CommonNodeCache;
+class Linkage;
+
+class ChangeLoweringBase : public Reducer {
+ public:
+  ChangeLoweringBase(Graph* graph, Linkage* linkage, CommonNodeCache* cache);
+  virtual ~ChangeLoweringBase();
+
+ protected:
+  Node* ExternalConstant(ExternalReference reference);
+  Node* HeapConstant(PrintableUnique<HeapObject> value);
+  Node* ImmovableHeapConstant(Handle<HeapObject> value);
+  Node* Int32Constant(int32_t value);
+  Node* NumberConstant(double value);
+  Node* CEntryStubConstant();
+  Node* TrueConstant();
+  Node* FalseConstant();
+
+  Reduction ChangeBitToBool(Node* val, Node* control);
+
+  Graph* graph() const { return graph_; }
+  Isolate* isolate() const { return isolate_; }
+  Linkage* linkage() const { return linkage_; }
+  CommonNodeCache* cache() const { return cache_; }
+  CommonOperatorBuilder* common() { return &common_; }
+  MachineOperatorBuilder* machine() { return &machine_; }
+
+ private:
+  Graph* graph_;
+  Isolate* isolate_;
+  Linkage* linkage_;
+  CommonNodeCache* cache_;
+  CommonOperatorBuilder common_;
+  MachineOperatorBuilder machine_;
+
+  SetOncePointer<Node> c_entry_stub_constant_;
+  SetOncePointer<Node> true_constant_;
+  SetOncePointer<Node> false_constant_;
+};
+
+
+template <size_t kPointerSize = kApiPointerSize>
+class ChangeLowering V8_FINAL : public ChangeLoweringBase {
+ public:
+  ChangeLowering(Graph* graph, Linkage* linkage);
+  ChangeLowering(Graph* graph, Linkage* linkage, CommonNodeCache* cache)
+      : ChangeLoweringBase(graph, linkage, cache) {}
+  virtual ~ChangeLowering() {}
+
+  virtual Reduction Reduce(Node* node) V8_OVERRIDE;
+
+ private:
+  Reduction ChangeBoolToBit(Node* val);
+  Reduction ChangeInt32ToTagged(Node* val, Node* effect, Node* control);
+  Reduction ChangeTaggedToFloat64(Node* val, Node* effect, Node* control);
+};
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_CHANGE_LOWERING_H_