Floating-point add pairwise
This instruction adds pairs of adjacent floating-point elements within each source vector, and interleaves the results from corresponding lanes. The interleaved result values are destructively placed in the first source vector.
| 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 | 1 | 0 | 0 | 1 | 0 | 0 | size | 0 | 1 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | Pg | Zm | Zdn | |||||||||||
| opc | |||||||||||||||||||||||||||||||
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 g : integer = UInt(Pg); let m : integer = UInt(Zm); let dn : integer = UInt(Zdn);
| <Zdn> |
Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Pg> |
Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. |
| <Zm> |
Is the name of the second source scalable vector register, encoded in the "Zm" field. |
CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let PL : integer{} = VL DIV 8; let elements : integer = VL DIV esize; let mask : bits(PL) = P{}(g); let operand1 : bits(VL) = Z{}(dn); let operand2 : bits(VL) = if AnyActiveElement{PL}(mask, esize) then Z{VL}(m) else Zeros{VL}; var result : bits(VL) = Z{}(dn); var element1 : bits(esize); var element2 : bits(esize); for e = 0 to elements-1 do if ActivePredicateElement{PL}(mask, e, esize) then if IsEven(e) then element1 = operand1[(e + 0)*:esize]; element2 = operand1[(e + 1)*:esize]; else element1 = operand2[(e - 1)*:esize]; element2 = operand2[(e + 0)*:esize]; end; result[e*:esize] = FPAdd{esize}(element1, element2, FPCR()); end; end; Z{VL}(dn) = result;
This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is CONSTRAINED UNPREDICTABLE:
2026-03_rel 2026-03-26 20:48:11
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