FDOT (2-way, vectors, FP16 to FP32)
Half-precision floating-point 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 and second source vectors, without intermediate rounding, and then destructively adds the single-precision sum-of-products to the corresponding single-precision element of the destination vector.
This instruction is unpredicated.
Green
False
True
0
1
1
0
0
1
0
0
0
0
1
1
0
0
0
0
0
FDOT <Zda>.S, <Zn>.H, <Zm>.H
if !IsFeatureImplemented(FEAT_SME2) && !IsFeatureImplemented(FEAT_SVE2p1) then UNDEFINED;
constant integer n = UInt(Zn);
constant integer m = UInt(Zm);
constant integer da = UInt(Zda);
<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, encoded in the "Zm" field.
CheckSVEEnabled();
constant integer VL = CurrentVL;
constant integer PL = VL DIV 8;
constant integer elements = VL 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 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 * e + 0, 16];
constant bits(16) elt2_b = Elem[operand2, 2 * e + 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;