On 24 Apr 2013 10:26:34 -0700, in bit.listserv.ibm-main you wrote: >On 4/24/2013 11:01 AM, John Gilmore wrote: >> The PrOp says: >> >> | There are two signed-decimal formats, >> | signed-packed and unsigned-packed. >> >> This is clear. It is also clear that mixing them combined with >> data-type punning can lead to disaster. >> >> Finally, it is clear that Mr. Comstock is not so well read in the >> current, i.e., 2008, PrOp as he should be. He and others should do >> their homework before they pontificate. In one of John McCarthy's >> favorite apothegms: Do the math or shut up. >> > >Interesting defensive position, John. Attacking in defense >of your fastidiousness. I would not call my posts 'pontificating'; >I thought we were having a discussion, some give and take, >if you will. > >I actually had read that stuff about unsigned packed >decimal some years ago but decided to ignore it because >it was not practical from the standpoint of the audience >I work with, z/OS applications developers. > >Perhaps I was wrong in that perception. Let me put it >out now: > > how many people are using decimal floating point > in Assembler? > >I suppose there are some who use it from a high level >language, most likely Java, but I suspect it has not >caught on in a big way yet, in any language. > >Clearly the OP was not including what I think I will >start calling 'pseudo-packed-decimal' in his question.
Having read Principles of operation, I agree with your posting. The preferred and arithmetically generated (results of add, etc.) are x'C' and x'D' but the other values are valid signs. I think the COBOL IF NUMERIC tests recognize sign zones based on the NUMPROC option which affects at least how the x'F' value is treated. Unfortunately COBOL STILL does NOT recognize DFP. Talk about IBM not talking to IBM. Clark Morris ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
