Optimize conditional branches that have same true/false targets.

runtime/vm/flow_graph_compiler.cc

 // 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.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
@@ skipping 152 matching lines @@
 bool FlowGraphCompiler::CanOptimizeFunction() const {
   return CanOptimize() && !parsed_function().function().HasBreakpoint();
 }
 
 
 bool FlowGraphCompiler::CanOSRFunction() const {
   return FLAG_use_osr & CanOptimizeFunction() && !is_optimizing();
 }
 
 
-static bool IsEmptyBlock(BlockEntryInstr* block) {
-  return !block->HasParallelMove() &&
-         block->next()->IsGoto() &&
-         !block->next()->AsGoto()->HasParallelMove();
-}
-
-
 void FlowGraphCompiler::CompactBlock(BlockEntryInstr* block) {
   BlockInfo* block_info = block_info_[block->postorder_number()];
 
   if (block_info->is_marked()) {
     return;
   }
   block_info->mark();
 
-  if (IsEmptyBlock(block)) {
+  if (block->IsEmptyBlock()) {
     BlockEntryInstr* target = block->next()->AsGoto()->successor();
     CompactBlock(target);
     block_info->set_jump_label(GetJumpLabel(target));
   }
 }
 
 
 void FlowGraphCompiler::CompactBlocks() {
   Label* fallthrough_label = NULL;
   for (intptr_t i = block_order().length() - 1; i >= 1; --i) {
@@ skipping 943 matching lines @@
 
   for (int i = 0; i < len; i++) {
     sorted->Add(CidTarget(ic_data.GetReceiverClassIdAt(i),
                           &Function::ZoneHandle(ic_data.GetTargetAt(i)),
                           ic_data.GetCountAt(i)));
   }
   sorted->Sort(HighestCountFirst);
 }
 
 }  // namespace dart