zip2

SVE Zip 2

ZIP2 <Zd>.<T>, <Zn>.<T>, <Zm>.<T>

Interleaves elements from the upper halves.

Pseudocode Operation

half ← VL / (2 * esize)
for i = 0 to VL/esize-1 step 2
  Zd[i, esize] ← Zn[half + i/2, esize]
  Zd[i+1, esize] ← Zm[half + i/2, esize]

Example

ZIP2 z0.s.T, z1.s.T, z2.s.T

Encoding

Binary Layout

00000101

31:24

size

23:22

1

21

Zm

20:16

011

15:13

00

12:11

1

10

Zn

9:5

Zd

4:0

 

Format SVE Permute

Opcode 0x05206400

Extension SVE

Operands

• Zd
  Destination scalable vector register (SVE)
• Zn
  First source scalable vector register (SVE)
• Zm
  Second source scalable vector register (SVE)

Related

Other forms of zip2

• zip2 Vector Zip 2 (Interleave)

More in SVE

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0x05204400	ZIP2 <Pd>.<T>, <Pn>.<T>, <Pm>.<T>		A64		00000101 | size | 10 | Pm | 010 | 0 | 0 | 1 | 0 | Pn | 0 | Pd
0x05206400	ZIP2 <Zd>.<T>, <Zn>.<T>, <Zm>.<T>		A64		00000101 | size | 1 | Zm | 011 | 00 | 1 | Zn | Zd
0x05A00400	ZIP2 <Zd>.Q, <Zn>.Q, <Zm>.Q		A64		00000101101 | Zm | 000 | 0 | 0 | 1 | Zn | Zd
0x0E007800	ZIP2 <Vd>.<T>, <Vn>.<T>, <Vm>.<T>		A64		0 | Q | 001110 | size | 0 | Rm | 0 | 1 | 1110 | Rn | Rd

Description

Interleave alternating elements from the lowest or highest halves of the first and second source vectors and place in elements of the destination vector. This instruction is unpredicated. 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.

Operation

if esize < 128 then CheckSVEEnabled(); else CheckNonStreamingSVEEnabled();
constant integer VL = CurrentVL;
if VL < esize * 2 then UNDEFINED;
constant integer pairs = VL DIV (esize * 2);
bits(VL) operand1 = Z[n, VL];
bits(VL) operand2 = Z[m, VL];
bits(VL) result = Zeros(VL);

integer base = part * pairs;
for p = 0 to pairs-1
    Elem[result, 2*p+0, esize] = Elem[operand1, base+p, esize];
    Elem[result, 2*p+1, esize] = Elem[operand2, base+p, esize];

Z[d, VL] = result;