vpermq

Permute Quadword Integers

VPERMQ ymm1, ymm2/m256, imm8

Shuffles quadwords within 256-bit lanes using immediate.

Details

Shuffles four 64-bit quadword elements within each 256-bit lane using a 2-bit immediate index for each element. The immediate controls the permutation pattern within the two halves of the 256-bit operand independently. Does not affect CPU flags; operates on 256-bit YMM registers under AVX2.

Pseudocode Operation

for i = 0 to 3:
  index = (imm8 >> (2*i)) & 0x3
  dest[64*i : 64*i+63] ← src[64*index : 64*index+63]

Example

VPERMQ ymm1, ymm2/m256, 3

Encoding

Binary Layout

VEX

Format VEX

Opcode VEX.256.66.0F3A.W1 00 /r ib

Extension AVX2

Operands

dest
256-bit YMM AVX register
src1
256-bit YMM AVX register or Memory operand
src2
8-bit signed immediate

Reference (Intel® SDM)

Instruction Forms

Opcode	Instruction	Op/En	64/32-bit Mode	CPUID	Description
VEX.256.66.0F3A.W1 00 /r ib	VPERMQ ymm1, ymm2/m256, imm8	A	V/V	AVX2	Permute qwords in ymm2/m256 using indices in imm8 and store the result in ymm1.
EVEX.256.66.0F3A.W1 00 /r ib	VPERMQ ymm1 {k1}{z}, ymm2/m256/m64bcst, imm8	B	V/V	(AVX512VL AND AVX512F) OR AVX10.1	Permute qwords in ymm2/m256/m64bcst using indexes in imm8 and store the result in ymm1.
EVEX.512.66.0F3A.W1 00 /r ib	VPERMQ zmm1 {k1}{z}, zmm2/m512/m64bcst, imm8	B	V/V	AVX512F OR AVX10.1	Permute qwords in zmm2/m512/m64bcst using indices in imm8 and store the result in zmm1.
EVEX.256.66.0F38.W1 36 /r	VPERMQ ymm1 {k1}{z}, ymm2, ymm3/m256/m64bcst	C	V/V	(AVX512VL AND AVX512F) OR AVX10.1	Permute qwords in ymm3/m256/m64bcst using indexes in ymm2 and store the result in ymm1.
EVEX.512.66.0F38.W1 36 /r	VPERMQ zmm1 {k1}{z}, zmm2, zmm3/m512/m64bcst	C	V/V	AVX512F OR AVX10.1	Permute qwords in zmm3/m512/m64bcst using indices in zmm2 and store the result in zmm1.

Instruction Operand Encoding

Op/En	Tuple Type	Operand 1	Operand 2	Operand 3	Operand 4
A	N/A	ModRM:reg (w)	ModRM:r/m (r)	imm8	N/A
B	Full	ModRM:reg (w)	ModRM:r/m (r)	imm8	N/A
C	Full	ModRM:reg (w)	EVEX.vvvv (r)	ModRM:r/m (r)	N/A

Description

The imm8 version: Copies quadwords from the source operand (the second operand) to the destination operand (the first operand) according to the indices specified by the immediate operand (the third operand). Each two-bit value in the immediate byte selects a qword element in the source operand. VEX version: The source operand can be a YMM register or a memory location. Bits (MAXVL-1:256) of the corresponding destination register are zeroed. In EVEX.512 encoded version, The elements in the destination are updated using the writemask k1 and the imm8 bits are reused as control bits for the upper 256-bit half when the control bits are coming from immediate. The source operand can be a ZMM register, a 512-bit memory location or a 512-bit vector broadcasted from a 64-bit memory location. Immediate control versions: VEX.vvvv and EVEX.vvvv are reserved and must be 1111b otherwise instructions will #UD. The vector control version: Copies quadwords from the second source operand (the third operand) to the destination operand (the first operand) according to the indices in the first source operand (the second operand). The first 3 bits of each 64 bit element in the index operand selects which quadword in the second source operand to copy. The first and second operands are ZMM registers, the third operand can be a ZMM register, a 512-bit memory location or a 512-bit vector broadcasted from a 64-bit memory location. The elements in the destination are updated using the writemask k1. Note that this instruction permits a qword in the source operand to be copied to multiple locations in the destination operand. If VPERMPQ is encoded with VEX.L= 0 or EVEX.128, an attempt to execute the instruction will cause an #UD exception.

Operation

VPERMQ (EVEX - imm8 control forms)



VPERMQ—Qwords Element Permutation                                                                                                         Vol. 2C 5-529
(KL, VL) = (4, 256), (8, 512)
FOR j := 0 TO KL-1
i := j * 64
IF (EVEX.b = 1) AND (SRC *is memory*)
THEN TMP_SRC[i+63:i] := SRC[63:0];
ELSE TMP_SRC[i+63:i] := SRC[i+63:i];
FI;
ENDFOR;
TMP_DEST[63:0] := (TMP_SRC[255:0] >> (IMM8[1:0] * 64))[63:0];
TMP_DEST[127:64] := (TMP_SRC[255:0] >> (IMM8[3:2] * 64))[63:0];
TMP_DEST[191:128] := (TMP_SRC[255:0] >> (IMM8[5:4] * 64))[63:0];
TMP_DEST[255:192] := (TMP_SRC[255:0] >> (IMM8[7:6] * 64))[63:0];
IF VL >= 512
TMP_DEST[319:256] := (TMP_SRC[511:256] >> (IMM8[1:0] * 64))[63:0];
TMP_DEST[383:320] := (TMP_SRC[511:256] >> (IMM8[3:2] * 64))[63:0];
TMP_DEST[447:384] := (TMP_SRC[511:256] >> (IMM8[5:4] * 64))[63:0];
TMP_DEST[511:448] := (TMP_SRC[511:256] >> (IMM8[7:6] * 64))[63:0];
FI;
FOR j := 0 TO KL-1
i := j * 64
IF k1[j] OR *no writemask*
THEN DEST[i+63:i] := TMP_DEST[i+63:i]
ELSE
IF *merging-masking*                                 ; merging-masking
THEN *DEST[i+63:i] remains unchanged*
ELSE                                                         ; zeroing-masking
DEST[i+63:i] := 0                    ;zeroing-masking
FI;
FI;
ENDFOR
DEST[MAXVL-1:VL] := 0

VPERMQ (EVEX - vector control forms)
(KL, VL) = (4, 256), (8, 512)
FOR j := 0 TO KL-1
i := j * 64
IF (EVEX.b = 1) AND (SRC2 *is memory*)
THEN TMP_SRC2[i+63:i] := SRC2[63:0];
ELSE TMP_SRC2[i+63:i] := SRC2[i+63:i];
FI;
ENDFOR;
IF VL = 256
TMP_DEST[63:0] := (TMP_SRC2[255:0] >> (SRC1[1:0] * 64))[63:0];
TMP_DEST[127:64] := (TMP_SRC2[255:0] >> (SRC1[65:64] * 64))[63:0];
TMP_DEST[191:128] := (TMP_SRC2[255:0] >> (SRC1[129:128] * 64))[63:0];
TMP_DEST[255:192] := (TMP_SRC2[255:0] >> (SRC1[193:192] * 64))[63:0];
FI;
IF VL = 512
TMP_DEST[63:0] := (TMP_SRC2[511:0] >> (SRC1[2:0] * 64))[63:0];
TMP_DEST[127:64] := (TMP_SRC2[511:0] >> (SRC1[66:64] * 64))[63:0];
TMP_DEST[191:128] := (TMP_SRC2[511:0] >> (SRC1[130:128] * 64))[63:0];
TMP_DEST[255:192] := (TMP_SRC2[511:0] >> (SRC1[194:192] * 64))[63:0];
TMP_DEST[319:256] := (TMP_SRC2[511:0] >> (SRC1[258:256] * 64))[63:0];
TMP_DEST[383:320] := (TMP_SRC2[511:0] >> (SRC1[322:320] * 64))[63:0];


VPERMQ—Qwords Element Permutation                                                                                                         Vol. 2C 5-530
TMP_DEST[447:384] := (TMP_SRC2[511:0] >> (SRC1[386:384] * 64))[63:0];
TMP_DEST[511:448] := (TMP_SRC2[511:0] >> (SRC1[450:448] * 64))[63:0];
FI;
FOR j := 0 TO KL-1
i := j * 64
IF k1[j] OR *no writemask*
THEN DEST[i+63:i] := TMP_DEST[i+63:i]
ELSE
IF *merging-masking*                                 ; merging-masking
THEN *DEST[i+63:i] remains unchanged*
ELSE                                                         ; zeroing-masking
DEST[i+63:i] := 0                    ;zeroing-masking
FI;
FI;
ENDFOR
DEST[MAXVL-1:VL] := 0

VPERMQ (VEX.256 encoded version)
DEST[63:0] := (SRC[255:0] >> (IMM8[1:0] * 64))[63:0];
DEST[127:64] := (SRC[255:0] >> (IMM8[3:2] * 64))[63:0];
DEST[191:128] := (SRC[255:0] >> (IMM8[5:4] * 64))[63:0];
DEST[255:192] := (SRC[255:0] >> (IMM8[7:6] * 64))[63:0];
DEST[MAXVL-1:256] := 0

Intel C/C++ Compiler Intrinsic Equivalent

VPERMQ __m512i _mm512_permutex_epi64( __m512i a, int imm);
VPERMQ __m512i _mm512_mask_permutex_epi64(__m512i s, __mmask8 k, __m512i a, int imm);
VPERMQ __m512i _mm512_maskz_permutex_epi64( __mmask8 k, __m512i a, int imm);
VPERMQ __m512i _mm512_permutexvar_epi64( __m512i a, __m512i b);
VPERMQ __m512i _mm512_mask_permutexvar_epi64(__m512i s, __mmask8 k, __m512i a, __m512i b);
VPERMQ __m512i _mm512_maskz_permutexvar_epi64( __mmask8 k, __m512i a, __m512i b);
VPERMQ __m256i _mm256_permutex_epi64( __m256i a, int imm);
VPERMQ __m256i _mm256_mask_permutex_epi64(__m256i s, __mmask8 k, __m256i a, int imm);
VPERMQ __m256i _mm256_maskz_permutex_epi64( __mmask8 k, __m256i a, int imm);
VPERMQ __m256i _mm256_permutexvar_epi64( __m256i a, __m256i b);
VPERMQ __m256i _mm256_mask_permutexvar_epi64(__m256i s, __mmask8 k, __m256i a, __m256i b);
VPERMQ __m256i _mm256_maskz_permutexvar_epi64( __mmask8 k, __m256i a, __m256i b);

Exceptions

SIMD Floating-Point Exceptions

None. VPERMQ—Qwords Element Permutation Vol. 2C 5-531

Other Exceptions

Non-EVEX-encoded instruction, see Table 2-21, “Type 4 Class Exception Conditions.” Additionally: #UD If VEX.L = 0. If VEX.vvvv != 1111B. EVEX-encoded instruction, see Table 2-52, “Type E4NF Class Exception Conditions.” Additionally: #UD If encoded with EVEX.128. If EVEX.vvvv != 1111B and with imm8. VPERMQ—Qwords Element Permutation Vol. 2C 5-532