ZIP2

Zip vectors (secondary)

This instruction reads adjacent vector elements from the upper half of two source SIMD&FP registers as pairs, interleaves the pairs and places them into a vector, and writes the vector to the destination SIMD&FP register. The first pair from the first source register is placed into the two lowest vector elements, with subsequent pairs taken alternately from each source register.


Note

This instruction can be used with ZIP1 to interleave two vectors.


The following figure shows an example of the operation of ZIP1 and ZIP2 with the arrangement specifier 8B.
ZIP1 and ZIP2 with the arrangement specifier 8B

Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.

Advanced SIMD
(FEAT_AdvSIMD)

313029282726252423222120191817161514131211109876543210
0Q001110size0Rm011110RnRd
op

Encoding

ZIP2 <Vd>.<T>, <Vn>.<T>, <Vm>.<T>

Decode for this encoding

if !IsFeatureImplemented(FEAT_AdvSIMD) then EndOfDecode(Decode_UNDEF); end; if size::Q == '110' then EndOfDecode(Decode_UNDEF); end; let d : integer{} = UInt(Rd); let n : integer{} = UInt(Rn); let m : integer{} = UInt(Rm); let esize : integer{} = 8 << UInt(size); let datasize : integer{} = 64 << UInt(Q); let elements : integer = datasize DIV esize; let part : integer = UInt(op); let pairs : integer = elements DIV 2;

Assembler Symbols

<Vd>

Is the name of the SIMD&FP destination register, encoded in the "Rd" field.

<T>

Is an arrangement specifier, encoded in (size :: Q):

size Q <T>
00 0 8B
00 1 16B
01 0 4H
01 1 8H
10 0 2S
10 1 4S
11 0 RESERVED
11 1 2D
<Vn>

Is the name of the first SIMD&FP source register, encoded in the "Rn" field.

<Vm>

Is the name of the second SIMD&FP source register, encoded in the "Rm" field.

Operation

AArch64_CheckFPAdvSIMDEnabled(); let operand1 : bits(datasize) = V{}(n); let operand2 : bits(datasize) = V{}(m); var result : bits(datasize); let base : integer = part * pairs; for p = 0 to pairs-1 do result[(2*p+0)*:esize] = operand1[(base+p)*:esize]; result[(2*p+1)*:esize] = operand2[(base+p)*:esize]; end; V{datasize}(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

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