diff options
Diffstat (limited to 'deps/v8/src/store-buffer.cc')
| -rw-r--r-- | deps/v8/src/store-buffer.cc | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/deps/v8/src/store-buffer.cc b/deps/v8/src/store-buffer.cc index 66488ae50..8a6916403 100644 --- a/deps/v8/src/store-buffer.cc +++ b/deps/v8/src/store-buffer.cc @@ -687,10 +687,15 @@ void StoreBuffer::Compact() { 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 >> kHashSetLengthLog2)) & (kHashSetLength - 1)); + // The upper part of an address is basically random because of ASLR and OS + // non-determinism, so we use only the bits within a page for hashing to + // make v8's behavior (more) deterministic. + uintptr_t hash_addr = + int_addr & (Page::kPageAlignmentMask >> kPointerSizeLog2); + int hash1 = ((hash_addr ^ (hash_addr >> kHashSetLengthLog2)) & + (kHashSetLength - 1)); if (hash_set_1_[hash1] == int_addr) continue; - uintptr_t hash2 = (int_addr - (int_addr >> kHashSetLengthLog2)); + uintptr_t hash2 = (hash_addr - (hash_addr >> kHashSetLengthLog2)); hash2 ^= hash2 >> (kHashSetLengthLog2 * 2); hash2 &= (kHashSetLength - 1); if (hash_set_2_[hash2] == int_addr) continue; |