Added pass framework

The patch adds a Middle-End pass system and normalizes the current
 passes into the pass framework.

Passes have:
 - A start, work, and end functions.
 - A gate to determine to apply the pass.
 - Can provide a CFG dump folder.

mir_dataflow.cc, mir_graph.cc, mir_optimization.cc, ssa_transformation.cc:
 - Changed due to moving code into bb_optimizations.cc.
 - Moved certain functions from private to public due to needed from the passes.

pass.cc, pass.h:
 - Pass base class

pass_driver.cc, pass_driver.h:
 - The pass driver implementation.

frontend.cc:
 - Replace the function calls to the passes with the pass driver.

Change-Id: I88cd82efbf6499df9e6c7f135d7e294dd724a079
Signed-off-by: Jean Christophe Beyler <jean.christophe.beyler@intel.com>
diff --git a/compiler/dex/bb_optimizations.cc b/compiler/dex/bb_optimizations.cc
new file mode 100644
index 0000000..f013067
--- /dev/null
+++ b/compiler/dex/bb_optimizations.cc
@@ -0,0 +1,121 @@
+/*
+ * 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 "bb_optimizations.h"
+#include "dataflow_iterator.h"
+#include "dataflow_iterator-inl.h"
+
+namespace art {
+
+/*
+ * Code Layout pass implementation start.
+ */
+bool CodeLayout::WalkBasicBlocks(CompilationUnit *cUnit, BasicBlock *bb) const {
+  cUnit->mir_graph->LayoutBlocks(bb);
+  // No need of repeating, so just return false.
+  return false;
+}
+
+/*
+ * SSATransformation pass implementation start.
+ */
+bool SSATransformation::WalkBasicBlocks(CompilationUnit *cUnit, BasicBlock *bb) const {
+  cUnit->mir_graph->InsertPhiNodeOperands(bb);
+  // No need of repeating, so just return false.
+  return false;
+}
+
+void SSATransformation::End(CompilationUnit *cUnit) const {
+  // Verify the dataflow information after the pass.
+  if (cUnit->enable_debug & (1 << kDebugVerifyDataflow)) {
+    cUnit->mir_graph->VerifyDataflow();
+  }
+}
+
+/*
+ * ConstantPropagation pass implementation start
+ */
+bool ConstantPropagation::WalkBasicBlocks(CompilationUnit *cUnit, BasicBlock *bb) const {
+  cUnit->mir_graph->DoConstantPropagation(bb);
+  // No need of repeating, so just return false.
+  return false;
+}
+
+/*
+ * MethodUseCount pass implementation start.
+ */
+bool MethodUseCount::Gate(const CompilationUnit *cUnit) const {
+  // First initialize the data.
+  cUnit->mir_graph->InitializeMethodUses();
+
+  // Now check if the pass is to be ignored.
+  bool res = ((cUnit->disable_opt & (1 << kPromoteRegs)) == 0);
+
+  return res;
+}
+
+bool MethodUseCount::WalkBasicBlocks(CompilationUnit *cUnit, BasicBlock *bb) const {
+  cUnit->mir_graph->CountUses(bb);
+  // No need of repeating, so just return false.
+  return false;
+}
+
+/*
+ * Null Check Elimination and Type Inference Initialization pass implementation start.
+ */
+
+bool NullCheckEliminationAndTypeInferenceInit::Gate(const CompilationUnit *cUnit) const {
+  // First check the ssa register vector
+  cUnit->mir_graph->CheckSSARegisterVector();
+
+  // Did we disable the pass?
+  bool performInit = ((cUnit->disable_opt & (1 << kNullCheckElimination)) == 0);
+
+  return performInit;
+}
+
+bool NullCheckEliminationAndTypeInferenceInit::WalkBasicBlocks(CompilationUnit *cUnit, BasicBlock *bb) const {
+  cUnit->mir_graph->NullCheckEliminationInit(bb);
+  // No need of repeating, so just return false.
+  return false;
+}
+
+/*
+ * BasicBlock Combine pass implementation start.
+ */
+bool BBCombine::WalkBasicBlocks(CompilationUnit *cUnit, BasicBlock *bb) const {
+  cUnit->mir_graph->CombineBlocks(bb);
+
+  // No need of repeating, so just return false.
+  return false;
+}
+
+/*
+ * BasicBlock Optimization pass implementation start.
+ */
+void BBOptimizations::Start(CompilationUnit *cUnit) const {
+  DCHECK_EQ(cUnit->num_compiler_temps, 0);
+
+  /*
+   * This pass has a different ordering depEnding on the suppress exception,
+   * so do the pass here for now:
+   *   - Later, the Start should just change the ordering and we can move the extended
+   *     creation into the pass driver's main job with a new iterator
+   */
+  cUnit->mir_graph->BasicBlockOptimization();
+}
+
+}  // namespace art