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/nodes.cc b/compiler/optimizing/nodes.cc
new file mode 100644
index 0000000..e7e9f47
--- /dev/null
+++ b/compiler/optimizing/nodes.cc
@@ -0,0 +1,60 @@
+/*
+ * 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.
+ */
+
+#include "nodes.h"
+#include "utils/growable_array.h"
+
+namespace art {
+
+void HGraph::AddBlock(HBasicBlock* block) {
+  block->set_block_id(blocks_.Size());
+  blocks_.Add(block);
+}
+
+void HBasicBlock::AddInstruction(HInstruction* instruction) {
+  if (first_instruction_ == nullptr) {
+    DCHECK(last_instruction_ == nullptr);
+    first_instruction_ = last_instruction_ = instruction;
+  } else {
+    last_instruction_->next_ = instruction;
+    instruction->previous_ = last_instruction_;
+    last_instruction_ = instruction;
+  }
+}
+
+#define DEFINE_ACCEPT(name)                                                    \
+void H##name::Accept(HGraphVisitor* visitor) {                                 \
+  visitor->Visit##name(this);                                                  \
+}
+
+FOR_EACH_INSTRUCTION(DEFINE_ACCEPT)
+
+#undef DEFINE_ACCEPT
+
+void HGraphVisitor::VisitInsertionOrder() {
+  const GrowableArray<HBasicBlock*>* blocks = graph_->blocks();
+  for (size_t i = 0 ; i < blocks->Size(); i++) {
+    VisitBasicBlock(blocks->Get(i));
+  }
+}
+
+void HGraphVisitor::VisitBasicBlock(HBasicBlock* block) {
+  for (HInstructionIterator it(block); !it.Done(); it.Advance()) {
+    it.Current()->Accept(this);
+  }
+}
+
+}  // namespace art