_mm512_mask_reduce_mul_epi64
Classification
AVX-512, Arithmetic, CPUID Test: AVX512F
Header File
Synopsis
_mm512_mask_reduce_mul_epi64(__mmask8 k, __m512i a);
Description
Reduce the packed 64-bit integers in "a" by multiplication using mask "k". Returns the product of all active elements in "a".
Operation
DEFINE REDUCE_MUL(src, len) {
IF len == 2
RETURN src[63:0] * src[127:64]
FI
len := len / 2
FOR j:= 0 to (len-1)
i := j*64
src[i+63:i] := src[i+63:i] * src[i+64*len+63:i+64*len]
ENDFOR
RETURN REDUCE_MUL(src[64*len-1:0], len)
}
tmp := a
FOR j := 0 to 8
i := j*64
IF k[j]
tmp[i+63:i] := a[i+63:i]
ELSE
tmp[i+63:i] := 1
FI
ENDFOR
dst[63:0] := REDUCE_MUL(tmp, 8)