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| author | Brotli <no-reply@google.com> | 2024-04-18 19:59:28 -0700 |
|---|---|---|
| committer | Copybara-Service <copybara-worker@google.com> | 2024-04-18 20:00:02 -0700 |
| commit | 1b3a5ccb6e7b9384b741437532f4dae0730c61f2 (patch) | |
| tree | 4fe4f6271a54307c9dce11b40d5ed9e71e37dda6 /c/enc/hash_longest_match_inc.h | |
| parent | 443af10a8001c5de7bab306d329de614c3defebc (diff) | |
| download | brotli-1b3a5ccb6e7b9384b741437532f4dae0730c61f2.zip brotli-1b3a5ccb6e7b9384b741437532f4dae0730c61f2.tar.gz brotli-1b3a5ccb6e7b9384b741437532f4dae0730c61f2.tar.bz2 | |
Prefetch the backreference hashtable bucket.
Place the prefetch before the last distance checks, to give the prefetch enough time to work.
PiperOrigin-RevId: 626228820
Diffstat (limited to 'c/enc/hash_longest_match_inc.h')
| -rw-r--r-- | c/enc/hash_longest_match_inc.h | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/c/enc/hash_longest_match_inc.h b/c/enc/hash_longest_match_inc.h index 4679dac..b744f4d 100644 --- a/c/enc/hash_longest_match_inc.h +++ b/c/enc/hash_longest_match_inc.h @@ -169,11 +169,17 @@ static BROTLI_INLINE void FN(FindLongestMatch)( score_t best_score = out->score; size_t best_len = out->len; size_t i; + /* Precalculate the hash key and prefetch the bucket. */ + const uint32_t key = + FN(HashBytes)(&data[cur_ix_masked], self->hash_shift_); + uint32_t* BROTLI_RESTRICT bucket = &buckets[key << self->block_bits_]; + PREFETCH_L1(bucket); + if (self->block_bits_ > 4) PREFETCH_L1(bucket + 16); + out->len = 0; + out->len_code_delta = 0; BROTLI_DCHECK(cur_ix_masked + max_length <= ring_buffer_mask); - out->len = 0; - out->len_code_delta = 0; /* Try last distance first. */ for (i = 0; i < (size_t)self->num_last_distances_to_check_; ++i) { const size_t backward = (size_t)distance_cache[i]; @@ -219,9 +225,6 @@ static BROTLI_INLINE void FN(FindLongestMatch)( best_len = 3; } { - const uint32_t key = - FN(HashBytes)(&data[cur_ix_masked], self->hash_shift_); - uint32_t* BROTLI_RESTRICT bucket = &buckets[key << self->block_bits_]; const size_t down = (num[key] > self->block_size_) ? (num[key] - self->block_size_) : 0u; for (i = num[key]; i > down;) { |