Unpack and zero-extend multi-vector elements
This instruction unpacks and zero-extends elements from one or two source vectors, and writes the zero-extended values into double width elements of the two or four destination vectors. This instruction is unpredicated.
It has encodings from 2 classes: Two registers and Four registers
| 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 |
| 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | size | 1 | 0 | 0 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | Zn | Zd | 1 | ||||||||
| U | |||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SME2) then EndOfDecode(Decode_UNDEF); end; if size == '00' then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << UInt(size); let n : integer = UInt(Zn); let d : integer = UInt(Zd::'0'); let nreg : integer{} = 2; let unsigned : boolean = TRUE;
| 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 |
| 1 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | size | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | Zn | 0 | Zd | 0 | 1 | ||||||
| U | |||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SME2) then EndOfDecode(Decode_UNDEF); end; if size == '00' then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << UInt(size); let n : integer = UInt(Zn::'0'); let d : integer = UInt(Zd::'00'); let nreg : integer{} = 4; let unsigned : boolean = TRUE;
| <T> |
Is the size specifier,
encoded in
|
| <Zd2> |
Is the name of the second scalable vector register of the destination multi-vector group, encoded as "Zd" times 2 plus 1. |
| <Zn> |
Is the name of the source scalable vector register, encoded in the "Zn" field. |
| <Tb> |
Is the size specifier,
encoded in
|
| <Zd4> |
Is the name of the fourth scalable vector register of the destination multi-vector group, encoded as "Zd" times 4 plus 3. |
| <Zn1> |
Is the name of the first scalable vector register of the source multi-vector group, encoded as "Zn" times 2. |
| <Zn2> |
Is the name of the second scalable vector register of the source multi-vector group, encoded as "Zn" times 2 plus 1. |
CheckStreamingSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV esize; let hsize : integer{} = esize DIV 2; let sreg : integer = nreg DIV 2; var results : array [[4]] of bits(VL); for r = 0 to sreg-1 do let operand : bits(VL) = Z{}(n+r); for i = 0 to 1 do for e = 0 to elements-1 do let element : bits(hsize) = operand[(i*elements + e)*:hsize]; results[[2*r+i]][e*:esize] = Extend{esize}(element, unsigned); end; end; end; for r = 0 to nreg-1 do Z{VL}(d+r) = results[[r]]; end;
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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