_mm256_mask_reduce_mul_epi8
Classification
AVX-512, Arithmetic, CPUID Test: AVX512BW
Header File
Synopsis
_mm256_mask_reduce_mul_epi8(__mmask32 k, __m256i a);
Description
Reduce the packed 8-bit integers in "a" by multiplication using mask "k". Returns the sum of all active elements in "a".
Operation
DEFINE REDUCE_MUL(src, len) {
IF len == 2
RETURN src[7:0] * src[15:8]
FI
len := len / 2
FOR j:= 0 to (len-1)
i := j*8
src[i+7:i] := src[i+7:i] * src[i+8*len+7:i+8*len]
ENDFOR
RETURN REDUCE_MUL(src[8*len-1:0], len)
}
tmp := a
FOR j := 0 to 31
i := j*8
IF k[j]
tmp[i+7:i] := a[i+7:i]
ELSE
tmp[i+7:i] := 1
FI
ENDFOR
dst[7:0] := REDUCE_MUL(tmp, 32)