The FLOAT option controls the use of the additional floating-point registers and whether Decimal Floating Point is supported.
.-NODFP-. >>-FLOAT--(--+-DFP---+--)--------------------------------------><
Under FLOAT(DFP), the following applies:
The use of the DECIMAL built-in function might help here: if the statement is changed to A = A + DEC(B);, the library calls will be eliminated. The library calls can also be eliminated by assigning B to a FLOAT DECIMAL temporary variable and then adding that temporary variable to A.