Unsigned unpack and extend half of vector
This instruction unpacks and zero-extends elements from the lowest or highest half of the source vector, and writes the zero-extended values into double-width elements of the destination vector. This instruction is unpredicated.
It has encodings from 2 classes: High half and Low half
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| 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | size | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | Zn | Zd | |||||||||
| U | H | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) 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); let unsigned : boolean = TRUE; let hi : boolean = TRUE;
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| 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | size | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | Zn | Zd | |||||||||
| U | H | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) 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); let unsigned : boolean = TRUE; let hi : boolean = FALSE;
| <Zd> |
Is the name of the destination scalable vector register, encoded in the "Zd" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Zn> |
Is the name of the source scalable vector register, encoded in the "Zn" field. |
| <Tb> |
Is the size specifier,
encoded in
|
CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV esize; let hsize : integer{} = esize DIV 2; let offset : integer = if hi then elements else 0; let operand : bits(VL) = Z{}(n); var result : bits(VL); for e = 0 to elements-1 do let element : bits(hsize) = operand[(e + offset)*:hsize]; result[e*:esize] = Extend{esize}(element, unsigned); end; Z{VL}(d) = result;
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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