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. Green False True 0 1 1 0 0 1 0 0 0 0 1 0 1 0 0 0 0 FDOT <Zda>.S, <Zn>.H, <Zm>.H[<imm>] if !IsFeatureImplemented(FEAT_SME2) && !IsFeatureImplemented(FEAT_SVE2p1) then UNDEFINED; constant integer n = UInt(Zn); constant integer m = UInt(Zm); constant integer da = UInt(Zda); constant integer index = UInt(i2); <Zda> Is the name of the third source and destination scalable vector register, encoded in the "Zda" field. <Zn> Is the name of the first source scalable vector register, encoded in the "Zn" field. <Zm> Is the name of the second source scalable vector register Z0-Z7, encoded in the "Zm" field. <imm> Is the immediate index of a group of two 16-bit elements within each 128-bit vector segment, in the range 0 to 3, encoded in the "i2" field. CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV 32; constant integer eltspersegment = 128 DIV 32; constant bits(VL) operand1 = Z[n, VL]; constant bits(VL) operand2 = Z[m, VL]; constant bits(VL) operand3 = Z[da, VL]; bits(VL) result; for e = 0 to elements-1 constant integer segmentbase = e - (e MOD eltspersegment); constant integer s = segmentbase + index; constant bits(16) elt1_a = Elem[operand1, 2 * e + 0, 16]; constant bits(16) elt1_b = Elem[operand1, 2 * e + 1, 16]; constant bits(16) elt2_a = Elem[operand2, 2 * s + 0, 16]; constant bits(16) elt2_b = Elem[operand2, 2 * s + 1, 16]; bits(32) sum = Elem[operand3, e, 32]; sum = FPDotAdd(sum, elt1_a, elt1_b, elt2_a, elt2_b, FPCR); Elem[result, e, 32] = sum; Z[da, VL] = result;