UZP1, UZP2 (vectors) -- A64

This instruction concatenates adjacent even or odd-numbered elements from the first and second source vectors, and places the values in the destination vector. This instruction is unpredicated.

Note: UZP1 is equivalent to truncating and packing each element from two source vectors into a single destination vector with elements of half the size.

The 128-bit element variant requires that the Effective SVE vector length is at least 256 bits. ID_AA64ZFR0_EL1.F64MM indicates whether the 128-bit element variant is implemented. The 128-bit element variant is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled.

Even
(FEAT_SVE || FEAT_SME)

Decode for this encoding

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << UInt(size); let n : integer = UInt(Zn); let m : integer = UInt(Zm); let d : integer = UInt(Zd); let part : integer = 0;

Even (quadwords)
(FEAT_F64MM)

Decode for this encoding

if !IsFeatureImplemented(FEAT_F64MM) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 128; let n : integer = UInt(Zn); let m : integer = UInt(Zm); let d : integer = UInt(Zd); let part : integer = 0;

Odd
(FEAT_SVE || FEAT_SME)

Decode for this encoding

Odd (quadwords)
(FEAT_F64MM)

Decode for this encoding

Assembler Symbols

<Zd>	Is the name of the destination scalable vector register, encoded in the "Zd" field.

<T>

Is the size specifier, encoded in size:

size	<T>
00	B
01	H
10	S
11	D

<Zn>	Is the name of the first source scalable vector register, encoded in the "Zn" field.

<Zm>	Is the name of the second source scalable vector register, encoded in the "Zm" field.

Operation

if esize < 128 then CheckSVEEnabled(); else CheckNonStreamingSVEEnabled(); end; let VL : integer{} = CurrentVL(); if VL < esize * 2 then EndOfDecode(Decode_UNDEF); end; let pairs : integer = VL DIV (esize * 2); let operand1 : bits(VL) = Z{}(n); let operand2 : bits(VL) = Z{}(m); var result : bits(VL) = Zeros{}; for p = 0 to pairs - 1 do result[p*:esize] = operand1[(2*p+part)*:esize]; end; for p = 0 to pairs - 1 do result[(pairs+p)*:esize] = operand2[(2*p+part)*:esize]; end; Z{VL}(d) = result;

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.

2026-03_rel 2026-03-26 20:48:11

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
0	0	0	0	0	1	0	1	size		1	Zm					0	1	1	0	1	0	Zn					Zd
																					H

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
0	0	0	0	0	1	0	1	1	0	1	Zm					0	0	0	0	1	0	Zn					Zd
																			opc		H

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
0	0	0	0	0	1	0	1	size		1	Zm					0	1	1	0	1	1	Zn					Zd
																					H

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
0	0	0	0	0	1	0	1	1	0	1	Zm					0	0	0	0	1	1	Zn					Zd
																			opc		H