UVDOT (4-way)

Multi-vector unsigned integer vertical dot product by indexed element

This instruction calculates the vertical dot product of the corresponding four unsigned 8-bit or 16-bit integer values held in the four first source vectors and four unsigned 8-bit or 16-bit integer values in the corresponding indexed 32-bit or 64-bit element of the second source vector. The widened dot product results are destructively added to the corresponding 32-bit or 64-bit element of the ZA single-vector groups.

The groups within the second source vector are specified using an immediate element index that selects the same group position within each 128-bit vector segment. The index range is from 0 to one less than the number of groups per 128-bit segment.

The single-vector group within each quarter of the ZA array is selected by the sum of the vector select register and offset, modulo quarter the number of ZA array vectors.

The vector group symbol VGx4 indicates that the ZA operand consists of four ZA single-vector groups. The vector group symbol is preferred for disassembly, but optional in assembler source code.

This instruction is unpredicated.

ID_AA64SMFR0_EL1.I16I64 indicates whether the 16-bit integer variant is implemented.

It has encodings from 2 classes: 8-bit to 32-bit and 16-bit to 64-bit

8-bit to 32-bit
(FEAT_SME2)

Decode for this encoding

if !IsFeatureImplemented(FEAT_SME2) then EndOfDecode(Decode_UNDEF); end; let v : integer = UInt('010'::Rv); let esize : integer{} = 32; let n : integer = UInt(Zn::'00'); let m : integer = UInt('0'::Zm); let offset : integer = UInt(off3); let index : integer = UInt(i2);

16-bit to 64-bit
(FEAT_SME2 && FEAT_SME_I16I64)

Decode for this encoding

if !(IsFeatureImplemented(FEAT_SME2) && IsFeatureImplemented(FEAT_SME_I16I64)) then EndOfDecode(Decode_UNDEF); end; let v : integer = UInt('010'::Rv); let esize : integer{} = 64; let n : integer = UInt(Zn::'00'); let m : integer = UInt('0'::Zm); let offset : integer = UInt(off3); let index : integer = UInt(i1);