John G., Do you still have available those additional comments you mentioned in a private communication back in October regarding the use of dynamically created set symbols in support of structured flag bits? I am still looking forward to hearing whatever you have to say on the subject.
Regards, Peter > -----Original Message----- > From: IBM Mainframe Assembler List [mailto:ASSEMBLER- > l...@listserv.uga.edu] On Behalf Of Farley, Peter x23353 > Sent: Monday, October 06, 2014 11:46 AM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: Syntax for using created SET symbols in a SETC value? > > John, > > Good thoughts, I do see where you are going with that design. However, in > my particular case I don't *think* that I want the flag names ordered > lexicographically, since the flag names themselves are not a patterned set of > names but a wide range of vastly different names explicitly descriptive of the > "meaning" of each flag. I do want the flags to occur (i.e., be defined) in > precisely the order that I specify because flags likely to be tested or > set/unset/etc. together by the application code are currently already > grouped into the same flag byte. Unless I am misunderstanding your reason > for ordering the names lexicographically? > > John Erhman's SHARE presentation that Abe pointed out has a nearly > complete (minus some error checking) set of macros to do pretty much what > I envisioned doing. > > I think it is sufficient for my purposes to have a set of created GBLA > variables > whose name is the name of the flag and whose value is the byte number of > the flag byte array, thus permitting set/unset/etc. and test macros to use > that byte number as an offset into the flag byte array. > > However, if you have a better implementation of this concept I would be > very happy indeed to see it. > > Thanks again for your help. > > Peter > > -----Original Message----- > From: IBM Mainframe Assembler List [mailto:ASSEMBLER- > l...@listserv.uga.edu] On Behalf Of John Gilmore > Sent: Saturday, October 04, 2014 8:29 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: Syntax for using created SET symbols in a SETC value? > > Peter (again), > > Something to think about until I get back to you tomorrow. > > A set of flags Flag1, Flag2, . . . , Flag8 can be viewed as an array > > f(1) f(2) f(8) > | | | | > |bbbbbbbb|bbbbbbbb| . . . |bbbbbbbb| > > in each element of which the eight bit positions are labeled > > |b b b b b b b b| > 1 2 3 4 5 6 7 8 > > If then 0 < i <= 8 is a byte subscript and 0 < j <= 8 is a bit > subscript in some byte j can also be used to subscript an array of 8 > masks > > mask(1), BL1'10000000' > mask(2), BL1'01000000' > mask(3), BL1'00100000' > mask(4), BL1'00010000' > mask(5), BL1'00001000' > mask(6), BL1'00000100' > mask(7), BL1'00000010' > mask(8), BL1'00000001' > > usable to test any bit position in any byte-array element. > > If then having put flag names in ascending lexicographic sequence the > position p of a flag name in this (also one-origin) sequence > determines both i and j. We have > > i = floor[p/8] + 1 > j = mod(p,8) + 1 > > The construction of a one-origin lexicographically ordered sequence of > flag names is thus the only really interesting task here. > -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system.
