CHA guard optimization (elimination/hoisting).

Test: manual by checking the dump-cfg output.

Change-Id: I254e168b9a85d2d3d23e02eea7e129c1bc9ab920
diff --git a/compiler/optimizing/cha_guard_optimization.h b/compiler/optimizing/cha_guard_optimization.h
new file mode 100644
index 0000000..ba0cdb8
--- /dev/null
+++ b/compiler/optimizing/cha_guard_optimization.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_OPTIMIZING_CHA_GUARD_OPTIMIZATION_H_
+#define ART_COMPILER_OPTIMIZING_CHA_GUARD_OPTIMIZATION_H_
+
+#include "optimization.h"
+
+namespace art {
+
+/**
+ * Optimize CHA guards by removing/moving them.
+ */
+class CHAGuardOptimization : public HOptimization {
+ public:
+  explicit CHAGuardOptimization(HGraph* graph)
+      : HOptimization(graph, kCHAGuardOptimizationPassName) {}
+
+  void Run() OVERRIDE;
+
+  static constexpr const char* kCHAGuardOptimizationPassName = "cha_guard_optimization";
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CHAGuardOptimization);
+};
+
+}  // namespace art
+
+#endif  // ART_COMPILER_OPTIMIZING_CHA_GUARD_OPTIMIZATION_H_