ART: Pass driver generalization

- Generalizing Pass Driver.
- Migrating ME Pass Driver to use the new generalized Pass Driver.

There will be some more changes after in the compiler code to generalize
 it a bit more by separating what is being done by the optimizing passes
 and post-pass cleanups.

Change-Id: I140a70e88483d7c3991b7d336bd593b2613ae194
Signed-off-by: James C Scott <james.c.scott@intel.com>
diff --git a/compiler/dex/pass_driver_me.cc b/compiler/dex/pass_driver_me.cc
new file mode 100644
index 0000000..d054500
--- /dev/null
+++ b/compiler/dex/pass_driver_me.cc
@@ -0,0 +1,170 @@
+/*
+ * 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 "base/macros.h"
+#include "bb_optimizations.h"
+#include "compiler_internals.h"
+#include "dataflow_iterator.h"
+#include "dataflow_iterator-inl.h"
+#include "pass_driver_me.h"
+
+namespace art {
+
+namespace {  // anonymous namespace
+
+void DoWalkBasicBlocks(PassMEDataHolder* data, const PassME* pass, DataflowIterator* iterator) {
+  // Paranoid: Check the iterator before walking the BasicBlocks.
+  DCHECK(iterator != nullptr);
+  bool change = false;
+  for (BasicBlock *bb = iterator->Next(change); bb != 0; bb = iterator->Next(change)) {
+    data->bb = bb;
+    change = pass->Worker(data);
+  }
+}
+
+template <typename Iterator>
+inline void DoWalkBasicBlocks(PassMEDataHolder* data, const PassME* pass) {
+  DCHECK(data != nullptr);
+  CompilationUnit* c_unit = data->c_unit;
+  DCHECK(c_unit != nullptr);
+  Iterator iterator(c_unit->mir_graph.get());
+  DoWalkBasicBlocks(data, pass, &iterator);
+}
+}  // anonymous namespace
+
+/*
+ * Create the pass list. These passes are immutable and are shared across the threads.
+ *
+ * Advantage is that there will be no race conditions here.
+ * Disadvantage is the passes can't change their internal states depending on CompilationUnit:
+ *   - This is not yet an issue: no current pass would require it.
+ */
+// The initial list of passes to be used by the PassDriveME.
+template<>
+const Pass* const PassDriver<PassDriverME>::g_passes[] = {
+  GetPassInstance<CacheFieldLoweringInfo>(),
+  GetPassInstance<CacheMethodLoweringInfo>(),
+  GetPassInstance<CallInlining>(),
+  GetPassInstance<CodeLayout>(),
+  GetPassInstance<SSATransformation>(),
+  GetPassInstance<ConstantPropagation>(),
+  GetPassInstance<InitRegLocations>(),
+  GetPassInstance<MethodUseCount>(),
+  GetPassInstance<NullCheckEliminationAndTypeInference>(),
+  GetPassInstance<ClassInitCheckElimination>(),
+  GetPassInstance<BBCombine>(),
+  GetPassInstance<BBOptimizations>(),
+};
+
+// The number of the passes in the initial list of Passes (g_passes).
+template<>
+uint16_t const PassDriver<PassDriverME>::g_passes_size = arraysize(PassDriver<PassDriverME>::g_passes);
+
+// The default pass list is used by the PassDriverME instance of PassDriver to initialize pass_list_.
+template<>
+std::vector<const Pass*> PassDriver<PassDriverME>::g_default_pass_list(PassDriver<PassDriverME>::g_passes, PassDriver<PassDriverME>::g_passes + PassDriver<PassDriverME>::g_passes_size);
+
+PassDriverME::PassDriverME(CompilationUnit* cu)
+    : PassDriver(), pass_me_data_holder_(), dump_cfg_folder_("/sdcard/") {
+  pass_me_data_holder_.bb = nullptr;
+  pass_me_data_holder_.c_unit = cu;
+}
+
+PassDriverME::~PassDriverME() {
+}
+
+void PassDriverME::DispatchPass(const Pass* pass) {
+  VLOG(compiler) << "Dispatching " << pass->GetName();
+  const PassME* me_pass = down_cast<const PassME*>(pass);
+
+  DataFlowAnalysisMode mode = me_pass->GetTraversal();
+
+  switch (mode) {
+    case kPreOrderDFSTraversal:
+      DoWalkBasicBlocks<PreOrderDfsIterator>(&pass_me_data_holder_, me_pass);
+      break;
+    case kRepeatingPreOrderDFSTraversal:
+      DoWalkBasicBlocks<RepeatingPreOrderDfsIterator>(&pass_me_data_holder_, me_pass);
+      break;
+    case kRepeatingPostOrderDFSTraversal:
+      DoWalkBasicBlocks<RepeatingPostOrderDfsIterator>(&pass_me_data_holder_, me_pass);
+      break;
+    case kReversePostOrderDFSTraversal:
+      DoWalkBasicBlocks<ReversePostOrderDfsIterator>(&pass_me_data_holder_, me_pass);
+      break;
+    case kRepeatingReversePostOrderDFSTraversal:
+      DoWalkBasicBlocks<RepeatingReversePostOrderDfsIterator>(&pass_me_data_holder_, me_pass);
+      break;
+    case kPostOrderDOMTraversal:
+      DoWalkBasicBlocks<PostOrderDOMIterator>(&pass_me_data_holder_, me_pass);
+      break;
+    case kAllNodes:
+      DoWalkBasicBlocks<AllNodesIterator>(&pass_me_data_holder_, me_pass);
+      break;
+    case kNoNodes:
+      break;
+    default:
+      LOG(FATAL) << "Iterator mode not handled in dispatcher: " << mode;
+      break;
+  }
+}
+
+bool PassDriverME::RunPass(const Pass* pass, bool time_split) {
+  // Paranoid: c_unit and pass cannot be nullptr, and the pass should have a name
+  DCHECK(pass != nullptr);
+  DCHECK(pass->GetName() != nullptr && pass->GetName()[0] != 0);
+  CompilationUnit* c_unit = pass_me_data_holder_.c_unit;
+  DCHECK(c_unit != nullptr);
+
+  // Do we perform a time split
+  if (time_split) {
+    c_unit->NewTimingSplit(pass->GetName());
+  }
+
+  // Check the pass gate first.
+  bool should_apply_pass = pass->Gate(&pass_me_data_holder_);
+  if (should_apply_pass) {
+    // Applying the pass: first start, doWork, and end calls.
+    ApplyPass(&pass_me_data_holder_, pass);
+
+    // Do we want to log it?
+    if ((c_unit->enable_debug&  (1 << kDebugDumpCFG)) != 0) {
+      // Do we have a pass folder?
+      const PassME* me_pass = (down_cast<const PassME*>(pass));
+      const char* passFolder = me_pass->GetDumpCFGFolder();
+      DCHECK(passFolder != nullptr);
+
+      if (passFolder[0] != 0) {
+        // Create directory prefix.
+        std::string prefix = GetDumpCFGFolder();
+        prefix += passFolder;
+        prefix += "/";
+
+        c_unit->mir_graph->DumpCFG(prefix.c_str(), false);
+      }
+    }
+  }
+
+  // If the pass gate passed, we can declare success.
+  return should_apply_pass;
+}
+
+const char* PassDriverME::GetDumpCFGFolder() const {
+  return dump_cfg_folder_;
+}
+
+
+}  // namespace art