Use BitVector instead of handcrafted SparseSet.

src/hydrogen-gvn.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 350 matching lines @@
     }
   }
 }
 
 
 HGlobalValueNumberingPhase::HGlobalValueNumberingPhase(HGraph* graph)
       : HPhase("H_Global value numbering", graph),
         removed_side_effects_(false),
         block_side_effects_(graph->blocks()->length(), zone()),
         loop_side_effects_(graph->blocks()->length(), zone()),
-        visited_on_paths_(zone(), graph->blocks()->length()) {
+        visited_on_paths_(graph->blocks()->length(), zone()) {
     ASSERT(!AllowHandleAllocation::IsAllowed());
     block_side_effects_.AddBlock(GVNFlagSet(), graph->blocks()->length(),
                                  zone());
     loop_side_effects_.AddBlock(GVNFlagSet(), graph->blocks()->length(),
                                 zone());
   }
 
 void HGlobalValueNumberingPhase::Analyze() {
   removed_side_effects_ = false;
   ComputeBlockSideEffects();
@@ skipping 232 matching lines @@
 
 
 GVNFlagSet
 HGlobalValueNumberingPhase::CollectSideEffectsOnPathsToDominatedBlock(
     HBasicBlock* dominator, HBasicBlock* dominated) {
   GVNFlagSet side_effects;
   for (int i = 0; i < dominated->predecessors()->length(); ++i) {
     HBasicBlock* block = dominated->predecessors()->at(i);
     if (dominator->block_id() < block->block_id() &&
         block->block_id() < dominated->block_id() &&
-        visited_on_paths_.Add(block->block_id())) {
+        !visited_on_paths_.Contains(block->block_id())) {
+      visited_on_paths_.Add(block->block_id());
       side_effects.Add(block_side_effects_[block->block_id()]);
       if (block->IsLoopHeader()) {
         side_effects.Add(loop_side_effects_[block->block_id()]);
       }
       side_effects.Add(CollectSideEffectsOnPathsToDominatedBlock(
           dominator, block));
     }
   }
   return side_effects;
 }
@@ skipping 214 matching lines @@
                                                       dominated);
         successor_map->Kill(side_effects_on_all_paths);
         successor_dominators->Kill(side_effects_on_all_paths);
       }
     }
     current = next;
   }
 }
 
 } }  // namespace v8::internal