_mm256_mask_permutex_epi64
Classification
AVX-512, Miscellaneous, CPUID Test: AVX512F
Header File
Instruction
VPERMQ ymm {k}, ymm, imm8
Synopsis
_mm256_mask_permutex_epi64(__m256i src, __mmask8 k, __m256i a, const int imm8);
Description
Shuffle 64-bit integers in "a" across lanes lanes using the control in "imm8", and store the results in "dst" using writemask "k" (elements are copied from "src" when the corresponding mask bit is not set).
Operation
DEFINE SELECT4(src, control) {
CASE(control[1:0]) OF
0: tmp[63:0] := src[63:0]
1: tmp[63:0] := src[127:64]
2: tmp[63:0] := src[191:128]
3: tmp[63:0] := src[255:192]
ESAC
RETURN tmp[63:0]
}
tmp_dst[63:0] := SELECT4(a[255:0], imm8[1:0])
tmp_dst[127:64] := SELECT4(a[255:0], imm8[3:2])
tmp_dst[191:128] := SELECT4(a[255:0], imm8[5:4])
tmp_dst[255:192] := SELECT4(a[255:0], imm8[7:6])
FOR j := 0 to 3
i := j*64
IF k[j]
dst[i+63:i] := tmp_dst[i+63:i]
ELSE
dst[i+63:i] := src[i+63:i]
FI
ENDFOR
dst[MAX:256] := 0