Fix bug in r10812.

src/hydrogen-instructions.cc

 // Copyright 2012 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 366 matching lines @@
   RegisterUse(index, value);
   InternalSetOperandAt(index, value);
 }
 
 
 void HValue::DeleteAndReplaceWith(HValue* other) {
   // We replace all uses first, so Delete can assert that there are none.
   if (other != NULL) ReplaceAllUsesWith(other);
   ASSERT(HasNoUses());
   // Clearing the operands includes going through the use list of each operand
-  // to remove this HValue, which can be expensive.  Instead, we simply mark it
-  // as dead and remove it lazily from the operands' use lists.
+  // to remove this HValue, which can be expensive.  Instead, we mark this as
+  // dead and only check the first item in the use list of each operand.
+  // For the following items in the use lists we rely on the tail() method to
+  // skip dead dead items and remove them lazily.
   SetFlag(kIsDead);
+  for (int i = 0; i < OperandCount(); ++i) {
+    HValue* operand = OperandAt(i);
+    HUseListNode* first = operand->use_list_;
+    if (first != NULL && first->index() == i && first->value() == this) {
+      operand->use_list_ = first->tail();
+    }
+  }
   DeleteFromGraph();
 }
 
 
 void HValue::ReplaceAllUsesWith(HValue* other) {
   while (use_list_ != NULL) {
     HUseListNode* list_node = use_list_;
     HValue* value = list_node->value();
     ASSERT(!value->block()->IsStartBlock());
     value->InternalSetOperandAt(list_node->index(), other);
@@ skipping 1839 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal