upstream/redis
1
0
Fork 0
mirror of https://github.com/redis/redis.git synced 2026-05-28 04:02:46 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

bitops: switch AVX2 scan to epi64 comparison for consistency

Browse source 
Use _mm256_cmpeq_epi64 + _mm256_movemask_pd in redisBitposScanAVX2,
matching the qword-granularity comparison style of the AVX512 path
which uses _mm512_cmpeq_epi64_mask.
This commit is contained in:
Martin Dimitrov 2026-05-19 20:42:37 -07:00
parent afb8a2bbc4
commit a4ad686ef3
1 changed files with 4 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
src/bitops.c
View file

@ -414,12 +414,13 @@ static unsigned long redisBitposScanAVX2(unsigned char *p,
unsigned long count, int bit) {
unsigned long scanned = 0;
__m256i skip = bit ? _mm256_setzero_si256()
: _mm256_set1_epi8((char)0xFF);
: _mm256_set1_epi64x(-1LL);
while (count >= 32) {
__m256i data = _mm256_loadu_si256((__m256i *)p);
int eq = _mm256_movemask_epi8(_mm256_cmpeq_epi8(data, skip));
if (eq != -1) break;
int eq = _mm256_movemask_pd(_mm256_castsi256_pd(
_mm256_cmpeq_epi64(data, skip)));
if (eq != 0xF) break;
p += 32;
count -= 32;
scanned += 32;