_mm_mask_alignr_epi8
Classification
AVX-512, Miscellaneous, CPUID Test: AVX512BW
Header File
Instruction
VPALIGNR xmm {k}, xmm, xmm, imm8
Synopsis
_mm_mask_alignr_epi8(__m128i src, __mmask16 k, __m128i a, __m128i b, const int imm8);
Description
Concatenate pairs of 16-byte blocks in "a" and "b" into a 32-byte temporary result, shift the result right by "imm8" bytes, and store the low 16 bytes in "dst" using writemask "k" (elements are copied from "src" when the corresponding mask bit is not set).
Operation
tmp_dst[255:0] := ((a[127:0] << 128)[255:0] OR b[127:0]) >> (imm8*8)
FOR j := 0 to 15
i := j*8
IF k[j]
dst[i+7:i] := tmp_dst[i+7:i]
ELSE
dst[i+7:i] := src[i+7:i]
FI
ENDFOR
dst[MAX:128] := 0