_mm256_lzcnt_epi64
Classification
AVX-512, Bit Manipulation, CPUID Test: AVX512CD
Header File
Instruction
VPLZCNTQ ymm, ymm
Synopsis
_mm256_lzcnt_epi64(__m256i a);
Description
Counts the number of leading zero bits in each packed 64-bit integer in "a", and store the results in "dst".
Operation
FOR j := 0 to 3
i := j*64
tmp := 63
dst[i+63:i] := 0
DO WHILE (tmp >= 0 AND a[i+tmp] == 0)
tmp := tmp - 1
dst[i+63:i] := dst[i+63:i] + 1
OD
ENDFOR
dst[MAX:256] := 0