First step in refactoring hydrogen control instructions.

src/lithium-allocator.cc

 // Copyright 2010 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 547 matching lines @@
   live_in_sets_.AddBlock(NULL, block_count);
 }
 
 
 BitVector* LAllocator::ComputeLiveOut(HBasicBlock* block) {
   // Compute live out for the given block, except not including backward
   // successor edges.
   BitVector* live_out = new BitVector(next_virtual_register_);
 
   // Process all successor blocks.
-  HBasicBlock* successor = block->end()->FirstSuccessor();
-  while (successor != NULL) {
+  for (HSuccessorIterator it(block->end()); it.HasNext(); it.Advance()) {
     // Add values live on entry to the successor. Note the successor's
     // live_in will not be computed yet for backwards edges.
+    HBasicBlock* successor = it.Next();
     BitVector* live_in = live_in_sets_[successor->block_id()];
     if (live_in != NULL) live_out->Union(*live_in);
 
     // All phi input operands corresponding to this successor edge are live
     // out from this block.
     int index = successor->PredecessorIndexOf(block);
     const ZoneList<HPhi*>* phis = successor->phis();
     for (int i = 0; i < phis->length(); ++i) {
       HPhi* phi = phis->at(i);
       if (!phi->OperandAt(index)->IsConstant()) {
         live_out->Add(phi->OperandAt(index)->id());
       }
     }
-
-    // Check if we are done with second successor.
-    if (successor == block->end()->SecondSuccessor()) break;
-
-    successor = block->end()->SecondSuccessor();
   }
 
   return live_out;
 }
 
 
 void LAllocator::AddInitialIntervals(HBasicBlock* block,
                                      BitVector* live_out) {
   // Add an interval that includes the entire block to the live range for
   // each live_out value.
@@ skipping 1514 matching lines @@
     LiveRange* current = live_ranges()->at(i);
     if (current != NULL) current->Verify();
   }
 }
 
 
 #endif
 
 
 } }  // namespace v8::internal