Alter the second hash used in StoreBuffer::Compact.

src/store-buffer.cc

 // Copyright 2011 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 670 matching lines @@
   for (Address* current = start_; current < top; current++) {
     ASSERT(!heap_->cell_space()->Contains(*current));
     ASSERT(!heap_->code_space()->Contains(*current));
     ASSERT(!heap_->old_data_space()->Contains(*current));
     uintptr_t int_addr = reinterpret_cast<uintptr_t>(*current);
     // Shift out the last bits including any tags.
     int_addr >>= kPointerSizeLog2;
     int hash1 =
         ((int_addr ^ (int_addr >> kHashMapLengthLog2)) & (kHashMapLength - 1));
     if (hash_map_1_[hash1] == int_addr) continue;
-    int hash2 =
-        ((int_addr - (int_addr >> kHashMapLengthLog2)) & (kHashMapLength - 1));
+    uintptr_t hash2 = (int_addr - (int_addr >> kHashMapLengthLog2));
     hash2 ^= hash2 >> (kHashMapLengthLog2 * 2);
+    hash2 &= (kHashMapLength - 1);
     if (hash_map_2_[hash2] == int_addr) continue;
     if (hash_map_1_[hash1] == 0) {
       hash_map_1_[hash1] = int_addr;
     } else if (hash_map_2_[hash2] == 0) {
       hash_map_2_[hash2] = int_addr;
     } else {
       // Rather than slowing down we just throw away some entries.  This will
       // cause some duplicates to remain undetected.
       hash_map_1_[hash1] = int_addr;
       hash_map_2_[hash2] = 0;
     }
     old_buffer_is_sorted_ = false;
     old_buffer_is_filtered_ = false;
     *old_top_++ = reinterpret_cast<Address>(int_addr << kPointerSizeLog2);
     ASSERT(old_top_ <= old_limit_);
   }
   heap_->isolate()->counters()->store_buffer_compactions()->Increment();
   CheckForFullBuffer();
 }
 
 
 void StoreBuffer::CheckForFullBuffer() {
   EnsureSpace(kStoreBufferSize * 2);
 }
 
 } }  // namespace v8::internal