Ceretain of Bernd Oppolzer's concerns are addressed in the designs of both ANSI BFP and ANSI DFP and in their zArchitecture implementations. Ad hoc schemes are in fact replaced by hardware implemented ones.
One of their most interesting features is the support they provide for non-standard values: o min, o max o SNaN, Signaling Not a Number, o QNaN, Quiet Not a Number, each of which has a distinct bit configuration different from that of any supported numeric floating-point value. I have used SNaN to address Bernd's uninitialized-variable problem in both assembly language and PL/I. (Current HLASM and PL/I implementations support the use of these special values in effect by name; and PL/I provides execution-time BIFs for manipulating them.) There are [different] accessible chapters in the current PrOp that describe both BFP and DFP. Read them! John Gilmore, Ashland, MA 01721 - USA ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
