Half-precision dot product to single-precision
This instruction calculates the fused sum-of-products of a pair of half-precision values held in each 32-bit element of the first source and second source vectors, without intermediate rounding, and then destructively adds the single-precision sum-of-products to the corresponding single-precision element 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 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 1 | Zm | 1 | 0 | 0 | 0 | 0 | 0 | Zn | Zda | ||||||||||||
| op | o2 | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SME2) && !IsFeatureImplemented(FEAT_SVE2p1) then EndOfDecode(Decode_UNDEF); end; 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. |
| <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 32; 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 elt1_a : bits(16) = operand1[(2 * e + 0)*:16]; let elt1_b : bits(16) = operand1[(2 * e + 1)*:16]; let elt2_a : bits(16) = operand2[(2 * e + 0)*:16]; let elt2_b : bits(16) = operand2[(2 * e + 1)*:16]; var sum : bits(32) = operand3[e*:32]; sum = FPDotAdd(sum, elt1_a, elt1_b, elt2_a, elt2_b, FPCR()); result[e*:32] = sum; end; Z{VL}(da) = 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:
2025-09_diff_tag 2025-11-28 16:29:05
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