Fix the negative lookup stub to handle deleted entries in a

src/mips/code-stubs-mips.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 7052 matching lines @@
                                                         Label* miss,
                                                         Label* done,
                                                         Register receiver,
                                                         Register properties,
                                                         Handle<String> name,
                                                         Register scratch0) {
   // If names of slots in range from 1 to kProbes - 1 for the hash value are
   // not equal to the name and kProbes-th slot is not used (its name is the
   // undefined value), it guarantees the hash table doesn't contain the
   // property. It's true even if some slots represent deleted properties
-  // (their names are the null value).
+  // (their names are the hole value).
   for (int i = 0; i < kInlinedProbes; i++) {
     // scratch0 points to properties hash.
     // Compute the masked index: (hash + i + i * i) & mask.
     Register index = scratch0;
     // Capacity is smi 2^n.
     __ lw(index, FieldMemOperand(properties, kCapacityOffset));
     __ Subu(index, index, Operand(1));
     __ And(index, index, Operand(
         Smi::FromInt(name->Hash() + StringDictionary::GetProbeOffset(i))));
 
     // Scale the index by multiplying by the entry size.
     ASSERT(StringDictionary::kEntrySize == 3);
     __ sll(at, index, 1);
     __ Addu(index, index, at);
 
     Register entity_name = scratch0;
     // Having undefined at this place means the name is not contained.
     ASSERT_EQ(kSmiTagSize, 1);
     Register tmp = properties;
     __ sll(scratch0, index, 1);
     __ Addu(tmp, properties, scratch0);
     __ lw(entity_name, FieldMemOperand(tmp, kElementsStartOffset));
 
     ASSERT(!tmp.is(entity_name));
     __ LoadRoot(tmp, Heap::kUndefinedValueRootIndex);
     __ Branch(done, eq, entity_name, Operand(tmp));
 
     if (i != kInlinedProbes - 1) {
+      // Load the hole ready for use below:
+      __ LoadRoot(tmp, Heap::kTheHoleValueRootIndex);
+
       // Stop if found the property.
       __ Branch(miss, eq, entity_name, Operand(Handle<String>(name)));
 
+      Label the_hole;
+      __ Branch(&the_hole, eq, entity_name, Operand(tmp));
+
       // Check if the entry name is not a symbol.
       __ lw(entity_name, FieldMemOperand(entity_name, HeapObject::kMapOffset));
       __ lbu(entity_name,
              FieldMemOperand(entity_name, Map::kInstanceTypeOffset));
       __ And(scratch0, entity_name, Operand(kIsSymbolMask));
       __ Branch(miss, eq, scratch0, Operand(zero_reg));
 
+      __ bind(&the_hole);
+
       // Restore the properties.
       __ lw(properties,
             FieldMemOperand(receiver, JSObject::kPropertiesOffset));
     }
   }
 
   const int spill_mask =
       (ra.bit() | t2.bit() | t1.bit() | t0.bit() | a3.bit() |
        a2.bit() | a1.bit() | a0.bit() | v0.bit());
 
@@ skipping 522 matching lines @@
   __ Ret(USE_DELAY_SLOT);
   __ mov(v0, a0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS