Unsigned add long (top)
This instruction adds the corresponding odd-numbered unsigned elements of the first and second source vectors, and places the results in the overlapping double-width elements of the destination vector. This instruction is unpredicated.
| 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 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | size | 0 | Zm | 0 | 0 | 0 | 0 | 1 | 1 | Zn | Zd | |||||||||||||
| op | S | U | T | ||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE2) && !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 m : integer = UInt(Zm); let d : integer = UInt(Zd); let sel1 : integer = 1; let sel2 : integer = 1; let unsigned : boolean = TRUE;
| <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 first source scalable vector register, encoded in the "Zn" field. |
| <Tb> |
Is the size specifier,
encoded in
|
| <Zm> |
Is the name of the second source scalable vector register, encoded in the "Zm" field. |
CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV esize; let operand1 : bits(VL) = Z{}(n); let operand2 : bits(VL) = Z{}(m); var result : bits(VL); for e = 0 to elements-1 do let op1elt : bits(esize DIV 2) = operand1[(2*e + sel1)*:(esize DIV 2)]; let op2elt : bits(esize DIV 2) = operand2[(2*e + sel2)*:(esize DIV 2)]; let element1 : integer = if unsigned then UInt(op1elt) else SInt(op1elt); let element2 : integer = if unsigned then UInt(op2elt) else SInt(op2elt); let res : integer = element1 + element2; result[e*:esize] = res[esize-1:0]; 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
Copyright © 2010-2026 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.