_mm512_reduce_mul_pd
Classification
AVX-512, Arithmetic, CPUID Test: AVX512F
Header File
immintrin.h
Synopsis
 _mm512_reduce_mul_pd(__m512d a);
Description
Reduce the packed double-precision (64-bit) floating-point elements in "a" by multiplication. Returns the product of all 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)
}
dst[63:0] := REDUCE_MUL(a, 8)