_mm512_mask_popcnt_epi64
Classification
AVX-512, Bit Manipulation, CPUID Test: AVX512VPOPCNTDQ
Header File
Instruction
VPOPCNTQ zmm {k}, zmm
Synopsis
_mm512_mask_popcnt_epi64(__m512i src, __mmask8 k, __m512i a);
Description
Count the number of logical 1 bits in packed 64-bit integers in "a", and store the results in "dst" using writemask "k" (elements are copied from "src" when the corresponding mask bit is not set).
Operation
DEFINE POPCNT(a) {
count := 0
DO WHILE a > 0
count += a[0]
a >>= 1
OD
RETURN count
}
FOR j := 0 to 7
i := j*64
IF k[j]
dst[i+63:i] := POPCNT(a[i+63:i])
ELSE
dst[i+63:i] := src[i+63:i]
FI
ENDFOR
dst[MAX:512] := 0