diff options
| -rw-r--r-- | apt-pkg/pkgcache.cc | 58 |
1 files changed, 51 insertions, 7 deletions
diff --git a/apt-pkg/pkgcache.cc b/apt-pkg/pkgcache.cc index 058e389a5..12c116901 100644 --- a/apt-pkg/pkgcache.cc +++ b/apt-pkg/pkgcache.cc @@ -231,10 +231,54 @@ map_id_t pkgCache::sHash(const char *Str) const return Hash % HeaderP->GetHashTableSize(); } +#if defined(__GNUC__) + +#if defined(__x86_64__) +__attribute__((target("sse4.2"))) static int hash32(int crc32, const unsigned char *input, size_t size) +{ + if (input == nullptr) + return 0; + + crc32 ^= 0xffffffffU; + while (size >= 8) { + crc32 = __builtin_ia32_crc32di(crc32, *(uint64_t *)input); + input += 8; + size -= 8; + } + + if (size >= 4) { + crc32 = __builtin_ia32_crc32si(crc32, *(uint32_t *)input); + input += 4; + size -= 4; + } + + if (size >= 2) { + crc32 = __builtin_ia32_crc32hi(crc32, *(uint16_t *)input); + input += 2; + size -= 2; + } + + if (size >= 1) { + crc32 = __builtin_ia32_crc32qi(crc32, *(uint8_t *)input); + input += 1; + size -= 1; + } + crc32 ^= 0xffffffffU; + return crc32; +} +#endif + +__attribute__((target("default"))) +#endif +static int hash32(int crc32, const unsigned char *input, size_t size) +{ + return adler32(crc32, input, size); +} + uint32_t pkgCache::CacheHash() { pkgCache::Header header = {}; - uLong adler = adler32(0L, Z_NULL, 0); + uLong adler = hash32(0L, Z_NULL, 0); if (Map.Size() < sizeof(header)) return adler; @@ -243,14 +287,14 @@ uint32_t pkgCache::CacheHash() header.Dirty = false; header.CacheFileSize = 0; - adler = adler32(adler, - reinterpret_cast<const unsigned char *>(&header), - sizeof(header)); + adler = hash32(adler, + reinterpret_cast<const unsigned char *>(&header), + sizeof(header)); if (Map.Size() > sizeof(header)) { - adler = adler32(adler, - static_cast<const unsigned char *>(GetMap().Data()) + sizeof(header), - GetMap().Size() - sizeof(header)); + adler = hash32(adler, + static_cast<const unsigned char *>(GetMap().Data()) + sizeof(header), + GetMap().Size() - sizeof(header)); } return adler; |