Re-apply: Initial check-in of an optimizing compiler.

The classes and the names are very much inspired by V8/Dart.
It currently only supports the RETURN_VOID dex instruction,
and there is a pretty printer to check if the building of the
graph is correct.

Change-Id: I28e125dfee86ae6ec9b3fec6aa1859523b92a893
diff --git a/compiler/optimizing/pretty_printer.h b/compiler/optimizing/pretty_printer.h
new file mode 100644
index 0000000..62a5a2c
--- /dev/null
+++ b/compiler/optimizing/pretty_printer.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2014 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_PRETTY_PRINTER_H_
+#define ART_COMPILER_OPTIMIZING_PRETTY_PRINTER_H_
+
+#include "nodes.h"
+
+namespace art {
+
+class HPrettyPrinter : public HGraphVisitor {
+ public:
+  explicit HPrettyPrinter(HGraph* graph) : HGraphVisitor(graph) { }
+
+  virtual void VisitInstruction(HInstruction* instruction) {
+    PrintString("  ");
+    PrintString(instruction->DebugName());
+    PrintNewLine();
+  }
+
+  virtual void VisitBasicBlock(HBasicBlock* block) {
+    PrintString("BasicBlock ");
+    PrintInt(block->block_id());
+    PrintNewLine();
+    HGraphVisitor::VisitBasicBlock(block);
+  }
+
+  virtual void PrintNewLine() = 0;
+  virtual void PrintInt(int value) = 0;
+  virtual void PrintString(const char* value) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(HPrettyPrinter);
+};
+
+}  // namespace art
+
+#endif  // ART_COMPILER_OPTIMIZING_PRETTY_PRINTER_H_