Enable optimizer pipeline for DBC.

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 8170 matching lines @@
                        Definition* result) const;
 
   void PrintTo(BufferFormatter* f) const;
   const char* ToCString() const;
 
   // Deep copy an environment.  The 'length' parameter may be less than the
   // environment's length in order to drop values (e.g., passed arguments)
   // from the copy.
   Environment* DeepCopy(Zone* zone, intptr_t length) const;
 
+#if defined(TARGET_ARCH_DBC)
+  // Return/ReturnTOS instruction drops incoming arguments so
+  // we have to drop outgoing arguments from the innermost environment.
+  // On all other architectures caller drops outgoing arguments itself
+  // hence the difference.
+  // Note: this method can only be used at the code generation stage because
+  // it mutates environment in unsafe way (e.g. does not update def-use
+  // chains).
+  void DropArguments(intptr_t argc) {

[Florian Schneider, 2016/05/19 13:21:40]

Maybe put only a declaration here, and put the definition into
intermediate_language_dbc.cc.

[Vyacheslav Egorov (Google), 2016/05/19 15:19:40]

Done.

+#if defined(DEBUG)
+    // Check that we are in the backend - register allocation has been run.
+    ASSERT(locations_ != NULL);
+
+    // Check that we are only dropping PushArgument instructions from the
+    // environment.
+    ASSERT(argc <= values_.length());
+    for (intptr_t i = 0; i < argc; i++) {
+      ASSERT(values_[values_.length() - i - 1]->definition()->IsPushArgument());
+    }
+#endif
+    values_.TruncateTo(values_.length() - argc);
+  }
+#endif
+
  private:
   friend class ShallowIterator;
 
   Environment(intptr_t length,
               intptr_t fixed_parameter_count,
               intptr_t deopt_id,
               const ParsedFunction& parsed_function,
               Environment* outer)
       : values_(length),
         locations_(NULL),
@@ skipping 54 matching lines @@
   LocationSummary* Name::MakeLocationSummary(Zone* zone, bool opt) const {    \
     UNIMPLEMENTED();                                                          \
     return NULL;                                                              \
   }                                                                           \
   void Name::EmitNativeCode(FlowGraphCompiler* compiler) { UNIMPLEMENTED(); }
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_