FDOT (4-way, by element)

8-bit floating-point dot product to single-precision (vector, by element). This instruction computes the fused sum-of-products of a group of four 8-bit floating-point values held in each 32-bit element of the first source vector and a group of four 8-bit floating-point values in an indexed 32-bit element of the second source vector. 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 destination vector.

The 8-bit floating-point groups within the second source vector are specified using an immediate index.

The 8-bit floating-point encoding format for the elements of the first source vector is selected by FPMR.F8S1. The 8-bit floating-point encoding format for the elements of the second source vector is selected by FPMR.F8S2.

Advanced SIMD
(FEAT_FP8DOT4)

if !IsFeatureImplemented(FEAT_FP8DOT4) then UNDEFINED; integer n = UInt(Rn); integer m = UInt(M:Rm); integer d = UInt(Rd); integer i = UInt(H:L); constant integer datasize = if Q == '1' then 128 else 64; constant integer esize = 32; constant integer elements = datasize DIV esize;