lru_aarch64.c

uint8_t getMask(const int16_t hash, const int16x8_t LRU)
{
    // assert(hash & 0xF == 0);
    const int16x8_t hash8 = {hash, hash, hash, hash,
                            hash, hash, hash, hash};
    const int16x8_t LRUHashes = LRU & ~0xF;
    const int16x8_t matches = LRUHashes == hash8;
    // == sets the result element to 0xFF on match
    const int16x8_t multi = {1 << 0, 1 << 1, 1 << 2, 1 << 3,
                             1 << 4, 1 << 5, 1 << 6, 1 << 7};
    // horizontal add over all elements to get the result
    return vaddvq_s16(matches & multi);
}