diff options
Diffstat (limited to 'absl/hash/internal')
| -rw-r--r-- | absl/hash/internal/low_level_hash.cc | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/absl/hash/internal/low_level_hash.cc b/absl/hash/internal/low_level_hash.cc index c917457a..b5db0b89 100644 --- a/absl/hash/internal/low_level_hash.cc +++ b/absl/hash/internal/low_level_hash.cc @@ -15,6 +15,7 @@ #include "absl/hash/internal/low_level_hash.h" #include "absl/base/internal/unaligned_access.h" +#include "absl/base/prefetch.h" #include "absl/numeric/int128.h" namespace absl { @@ -29,6 +30,8 @@ static uint64_t Mix(uint64_t v0, uint64_t v1) { uint64_t LowLevelHash(const void* data, size_t len, uint64_t seed, const uint64_t salt[5]) { + // Prefetch the cacheline that data resides in. + PrefetchToLocalCache(data); const uint8_t* ptr = static_cast<const uint8_t*>(data); uint64_t starting_length = static_cast<uint64_t>(len); uint64_t current_state = seed ^ salt[0]; @@ -40,6 +43,9 @@ uint64_t LowLevelHash(const void* data, size_t len, uint64_t seed, uint64_t duplicated_state = current_state; do { + // Always prefetch the next cacheline. + PrefetchToLocalCache(ptr + ABSL_CACHELINE_SIZE); + uint64_t a = absl::base_internal::UnalignedLoad64(ptr); uint64_t b = absl::base_internal::UnalignedLoad64(ptr + 8); uint64_t c = absl::base_internal::UnalignedLoad64(ptr + 16); |