_mm512_maskz_permutex_pd
Classification
AVX-512, Swizzle, CPUID Test: AVX512F
Header File
Instruction
VPERMPD zmm {z}, zmm, imm8
Synopsis
_mm512_maskz_permutex_pd(__mmask8 k, __m512d a, const int imm8);
Description
Shuffle double-precision (64-bit) floating-point elements in "a" within 256-bit lanes using the control in "imm8", and store the results in "dst" using zeromask "k" (elements are zeroed out 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])
tmp_dst[319:256] := SELECT4(a[511:256], imm8[1:0])
tmp_dst[383:320] := SELECT4(a[511:256], imm8[3:2])
tmp_dst[447:384] := SELECT4(a[511:256], imm8[5:4])
tmp_dst[511:448] := SELECT4(a[511:256], imm8[7:6])
FOR j := 0 to 7
i := j*64
IF k[j]
dst[i+63:i] := tmp_dst[i+63:i]
ELSE
dst[i+63:i] := 0
FI
ENDFOR
dst[MAX:512] := 0