_mm_mask_lzcnt_epi32
Classification
AVX-512, Bit Manipulation, CPUID Test: AVX512CD
Header File
immintrin.h
Instruction
VPLZCNTD xmm {k}, xmm
Synopsis
 _mm_mask_lzcnt_epi32(__m128i src, __mmask8 k, __m128i a);
Description
Counts the number of leading zero bits in each packed 32-bit integer 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
FOR j := 0 to 3
	i := j*32
	IF k[j]
		tmp := 31
		dst[i+31:i] := 0
		DO WHILE (tmp >= 0 AND a[i+tmp] == 0)
			tmp := tmp - 1
			dst[i+31:i] := dst[i+31:i] + 1
		OD
	ELSE
		dst[i+31:i] := src[i+31:i]
	FI
ENDFOR
dst[MAX:128] := 0