/sys$common/syshlp/helplib.hlb MACRO, VAX MACRO Assembler, Instructions, SBWC  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Purpose:        Subtract with carry - perform extended-precision
                    subtraction
    Format:         opcode sub.rl,dif.ml
    Operation:      dif = dif - sub - C
    C. Codes:       N = {dif LSS 0}, Z = {dif EQL 0},
                    V = {integer overflow}, C = {borrow from MSB}
    Exceptions:     Integer overflow
    Opcode:         D9    SBWC     Subtract with carry