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: Id5ef1b317ab997010d4e3888e456c26bef1ab9c0

1 files changed, 64 insertions, 0 deletions

diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
new file mode 100644
index 0000000..2c1091c
--- /dev/null
+++ b/compiler/optimizing/builder.cc
@@ -0,0 +1,64 @@
+/*
+ *
+ * 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 "dex_instruction.h"
+#include "builder.h"
+#include "nodes.h"
+
+namespace art {
+
+HGraph* HGraphBuilder::BuildGraph(const uint16_t* code_ptr, const uint16_t* code_end) {
+  graph_ = new (arena_) HGraph(arena_);
+
+  entry_block_ = new (arena_) HBasicBlock(graph_);
+  graph_->AddBlock(entry_block_);
+
+  exit_block_ = new (arena_) HBasicBlock(graph_);
+  // The exit block is added at the end of this method to ensure
+  // its id is the greatest. This is needed for dominator computation.
+
+  entry_block_->AddInstruction(new (arena_) HGoto(entry_block_));
+
+  current_block_ = new (arena_) HBasicBlock(graph_);
+  graph_->AddBlock(current_block_);
+  entry_block_->AddSuccessor(current_block_);
+
+  while (code_ptr < code_end) {
+    const Instruction& instruction = *Instruction::At(code_ptr);
+    if (!AnalyzeDexInstruction(instruction)) return nullptr;
+    code_ptr += instruction.SizeInCodeUnits();
+  }
+
+  exit_block_->AddInstruction(new (arena_) HExit(exit_block_));
+  graph_->AddBlock(exit_block_);
+  return graph_;
+}
+
+bool HGraphBuilder::AnalyzeDexInstruction(const Instruction& instruction) {
+  switch (instruction.Opcode()) {
+    case Instruction::RETURN_VOID:
+      current_block_->AddInstruction(new (arena_) HReturnVoid(current_block_));
+      current_block_->AddSuccessor(exit_block_);
+      current_block_ = nullptr;
+      break;
+    default:
+      return false;
+  }
+  return true;
+}
+
+}  // namespace art