Polynomial multiply long (bottom)
This instruction performs a polynomial multiplication over [0, 1] of the even-numbered elements of the first source vector by the corresponding elements of the second source vector, and places the results in the overlapping double-width elements of the destination vector. This instruction is unpredicated.
ID_AA64ZFR0_EL1.AES indicates whether the 128-bit element variant is implemented. The 128-bit element variant is legal when executed in Streaming SVE mode if one of the following is true:
It has encodings from 2 classes: 16-bit or 64-bit elements and 128-bit element
| 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 | != 00 | 0 | Zm | 0 | 1 | 1 | 0 | 1 | 0 | Zn | Zd | |||||||||||||
| size | op | U | T | ||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; if size[0] == '0' 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);
| 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 | 0 | 0 | 0 | Zm | 0 | 1 | 1 | 0 | 1 | 0 | Zn | Zd | ||||||||||||
| size | op | U | T | ||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE_PMULL128) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 128; let n : integer = UInt(Zn); let m : integer = UInt(Zm); let d : integer = UInt(Zd);
| <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. |
if esize == 128 then if IsFeatureImplemented(FEAT_SSVE_AES) then CheckSVEEnabled(); else CheckNonStreamingSVEEnabled(); end; else CheckSVEEnabled(); end; 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 element1 : bits(esize DIV 2) = operand1[(2*e + 0)*:(esize DIV 2)]; let element2 : bits(esize DIV 2) = operand2[(2*e + 0)*:(esize DIV 2)]; result[e*:esize] = PolynomialMult{esize DIV 2, esize DIV 2}(element1, element2); 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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