FDOT (2-way, indexed, FP16 to FP32)

Half-precision floating-point indexed dot product

This instruction computes the fused sum-of-products of a pair of half-precision floating-point values held in each 32-bit element of the first source vector and a pair of half-precision floating-point values in an indexed 32-bit element of the second source vector, without intermediate rounding, and then destructively adds the single-precision sum-of-products to the corresponding single-precision element of the destination vector.

The half-precision floating-point pairs within the second source vector are specified using an immediate index which selects the same pair position within each 128-bit vector segment. The index range is from 0 to 3.

This instruction is unpredicated.

SVE2
(FEAT_SVE2p1)

if !HaveSME2() && !HaveSVE2p1() then UNDEFINED; integer n = UInt(Zn); integer m = UInt(Zm); integer da = UInt(Zda); integer index = UInt(i2);