Signed saturating rounding doubling multiply-add high (unpredicated)
This instruction multiplies the signed elements of the first source vector by the corresponding elements of the second source vector, and then doubles the result and destructively adds the rounded high half of each result to the corresponding elements of the addend and destination vector. Each destination element is saturated to the N-bit element's signed integer range -2(N-1) to (2(N-1))-1. 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 | 0 | size | 0 | Zm | 0 | 1 | 1 | 1 | 0 | 0 | Zn | Zda | |||||||||||||
| S | |||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << UInt(size); let n : integer = UInt(Zn); let m : integer = UInt(Zm); let da : integer = UInt(Zda);
| <Zda> |
Is the name of the third source and destination scalable vector register, encoded in the "Zda" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Zn> |
Is the name of the first source scalable vector register, encoded in the "Zn" field. |
| <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); let operand3 : bits(VL) = Z{}(da); var result : bits(VL); for e = 0 to elements-1 do let element1 : integer = SInt(operand1[e*:esize]); let element2 : integer = SInt(operand2[e*:esize]); let element3 : integer = SInt(operand3[e*:esize]); let res : integer = (element3 << esize) + (2 * element1 * element2); result[e*:esize] = SignedSat{esize}((res + (1 << (esize - 1))) >> esize); end; Z{VL}(da) = result;
This instruction is a data-independent-time instruction as described in About PSTATE.DIT.
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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