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| author |  Abseil Team <absl-team@google.com> | 2023-07-13 10:51:10 -0700 |
|---|---|---|
| committer |  Copybara-Service <copybara-worker@google.com> | 2023-07-13 10:52:00 -0700 |
| commit | b8ebbc2ecadb64239dc0767b55296ab9c4510b0f (patch) | |
| tree | 86a1a63c7745dc95e4ee9ecac89bde26a88675ce /absl/hash | |
| parent | 1adf896ec842bd9788a1bbede94a33e1402b8ecb (diff) | |
Adding sw prefetchers to absl::hash.
PiperOrigin-RevId: 547850162
Change-Id: I43208c7fa1eaa2a7acfad5891b80c150ee58c65f
Diffstat (limited to 'absl/hash')
| -rw-r--r-- | absl/hash/BUILD.bazel | 1 | ||||
| -rw-r--r-- | absl/hash/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | absl/hash/internal/low_level_hash.cc | 6 |
3 files changed, 8 insertions, 0 deletions
diff --git a/absl/hash/BUILD.bazel b/absl/hash/BUILD.bazel index 7f964ae7..4346fc49 100644 --- a/absl/hash/BUILD.bazel +++ b/absl/hash/BUILD.bazel @@ -183,6 +183,7 @@ cc_library( deps = [ "//absl/base:config", "//absl/base:endian", + "//absl/base:prefetch", "//absl/numeric:int128", ], ) diff --git a/absl/hash/CMakeLists.txt b/absl/hash/CMakeLists.txt index 1adce617..65fd2a5f 100644 --- a/absl/hash/CMakeLists.txt +++ b/absl/hash/CMakeLists.txt @@ -165,6 +165,7 @@ absl_cc_library( absl::config absl::endian absl::int128 + absl::prefetch ) absl_cc_test( 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); |