FMOPA (widening, 4-way)

8-bit floating-point sum of outer products and accumulate

The 8-bit floating-point sum of outer products and accumulate instruction works with a 32-bit element ZA tile.

This instruction widens the SVL_S×4 sub-matrix of 8-bit floating-point values held in the first source vector to single-precision floating-point values and multiplies it by the widened 4×SVL_S sub-matrix of 8-bit floating-point values in the second source vector to single-precision floating-point values.

Each source vector is independently predicated by a corresponding governing predicate. When a 8-bit source element is Inactive it is treated as having the value +0.0, but if both groups of source vector elements that correspond to a 32-bit destination element contain Inactive elements, then the destination element remains unmodified.

The resulting SVL_S×SVL_S single-precision floating-point sum of outer products are scaled by 2^{-UInt(FPMR.LSCALE)}, before being destructively added to the single-precision floating-point destination tile. This is equivalent to performing a downscaled 4-way dot product and accumulate to each of the destination tile elements.

Each 32-bit container of the first source vector holds 4 consecutive column elements of each row of a SVL_S×4 sub-matrix. Similarly, each 32-bit container of the second source vector holds 4 consecutive row elements of each column of a 4×SVL_S sub-matrix.

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.

SME2
(FEAT_SME_F8F32)

if !IsFeatureImplemented(FEAT_SME_F8F32) then UNDEFINED; integer a = UInt(Pn); integer b = UInt(Pm); integer n = UInt(Zn); integer m = UInt(Zm); integer da = UInt(ZAda);