VMS Help MACRO, VAX MACRO Assembler, Instructions, TSTx  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Purpose:        Arithmetic compare of a scalar to 0.
    Format:         opcode src.rx
    Operation:      src - 0
    C. Codes:       N = {src LSS 0}, Z = {src EQL 0}, V = 0, C = 0
    Exceptions:     None (integer), reserved operand (floating)
    Opcodes:        95    TSTB     Test byte
                    B5    TSTW     Test word
                    D5    TSTL     Test long
                    53    TSTF     Test F_floating
                    73    TSTD     Test D_floating
                    53FD  TSTG     Test G_floating
                    73FD  TSTH     Test H_floating
    Description:    The condition codes are affected according to
                    the values of src.