FDOT (4-way, multiple vectors)

Multi-vector 8-bit floating-point dot-product to single-precision

The instruction computes the fused sum-of-products of a group of four 8-bit floating-point values held in the corresponding 32-bit elements of the two or four first and second source vectors. The single-precision sum-of-products are scaled by 2^{-UInt(FPMR.LSCALE)}, before being destructively added without intermediate rounding to the corresponding single-precision elements of the ZA single-vector groups. The 8-bit floating-point encoding format for the elements of the first source vector and the second source vector is selected by FPMR.F8S1 and FPMR.F8S2 respectively.

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

The vector group symbol, VGx2 or VGx4, indicates that the ZA operand consists of two or four ZA single-vector groups respectively. The vector group symbol is preferred for disassembly, but optional in assembler source code.

This instruction is unpredicated.

It has encodings from 2 classes: Two ZA single-vectors and Four ZA single-vectors

Two ZA single-vectors
(FEAT_SME_F8F32)

if !IsFeatureImplemented(FEAT_SME_F8F32) then UNDEFINED; constant integer v = UInt('010':Rv); constant integer n = UInt(Zn:'0'); constant integer m = UInt(Zm:'0'); constant integer offset = UInt(off3); constant integer nreg = 2;

Four ZA single-vectors
(FEAT_SME_F8F32)

if !IsFeatureImplemented(FEAT_SME_F8F32) then UNDEFINED; constant integer v = UInt('010':Rv); constant integer n = UInt(Zn:'00'); constant integer m = UInt(Zm:'00'); constant integer offset = UInt(off3); constant integer nreg = 4;