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Hi Richard, Where can I see the virtual address? I heard that the RPG ILE compiler no longer has an option to print the MI. Is a pointer a virtual address? If so, I could move the pointer to a 16-byte field and look at the low-order byte? Regards, Peter Dow Dow Software Services, Inc. 909 425-0194 voice 909 425-0196 fax ----- Original Message ----- From: "Richard Jackson" <richardjackson@richardjackson.net> To: <RPG400-L@midrange.com> Sent: Tuesday, October 10, 2000 4:05 PM Subject: RE: RPG400-L Digest V2 #357 > look at the virtual address of the object in storage. If the low-order byte > of the address is a zero, the object is 16-byte aligned. If the low order > address byte is even (0, 2, 4, ...) the object is at least 2-byte aligned. > And so forth. > > Richard Jackson > mailto:richardjackson@richardjackson.net > http://www.richardjacksonltd.com > Voice: 1 (303) 808-8058 > Fax: 1 (303) 663-4325 > > -|-----Original Message----- > -|From: owner-rpg400-l@midrange.com [mailto:owner-rpg400-l@midrange.com]On > -|Behalf Of Peter Dow > -|Sent: Tuesday, October 10, 2000 1:27 PM > -|To: RPG400-L@midrange.com > -|Subject: Re: RPG400-L Digest V2 #357 > -| > -| > -|Hi Ken, > -| > -|How can one tell what boundary a data structure, or any other > -|field for that > -|matter, is aligned on? > -| > -|Curious, > -|Peter Dow > -|Dow Software Services, Inc. > -|909 425-0194 voice > -|909 425-0196 fax > -| > -|----- Original Message ----- > -|From: "Sims, Ken" <KSIMS@SOUTHERNWINE.com> > -|To: <rpg400-l@midrange.com> > -|Sent: Tuesday, October 10, 2000 10:08 AM > -|Subject: RE: RPG400-L Digest V2 #357 > -| > -| > -|> Hi Peter - > -|> > -|> >The V4R4 RPG ILE manual says: > -|> ... > -|> >The position they're talking about is the position of the > -|subfield within > -|a > -|> >data structure, so if the above is true, one would have to assume that > -|the > -|> >data structure begins on a 16-byte boundary. It would be nice if they > -|> >explicitly said that, and assured us it won't change from release to > -|> >release. > -|> > -|> Based on my experimentation, since the compiler rejects pointers defined > -|> with from/to positioning that is not on a 16-byte boundary, it appears > -|that > -|> data structures with pointers are always aligned on a 16-byte boundary. > -|> Only pointer fields *have* to be aligned on a 16-byte boundary. > -| No other > -|> fields *have* to be aligned on any particular boundary, and no other > -|fields > -|> need a 16-byte alignment for best performance; therefore there > -|is nothing > -|to > -|> imply that any data structure not containing pointers is aligned on a > -|> 16-byte boundary. > -|> > -|> The data structure being discussed in this thread does not > -|contain actual > -|> pointer fields since it is an externally described data structure using > -|> character fields to hold pointers, therefore there is no reason > -|to assume > -|> any particular alignment. > -|> > -|> The use of the ALIGN keyword does not imply changing the data structure > -|> itself to ANY particular byte alignment, only to adding padding between > -|> individual fields in the data structure to align float, signed integer, > -|and > -|> unsigned integer fields for performance. > -|> > -|> Ken > -|> Southern Wine and Spirits of Nevada, Inc. > -|> Opinions expressed are my own and do not necessarily represent the views > -|of > -|> my employer or anyone in their right mind. > -|> > -|> +--- > -|> | This is the RPG/400 Mailing List! > -|> | To submit a new message, send your mail to RPG400-L@midrange.com. > -|> | To subscribe to this list send email to RPG400-L-SUB@midrange.com. > -|> | To unsubscribe from this list send email to > -|RPG400-L-UNSUB@midrange.com. > -|> | Questions should be directed to the list owner/operator: > -|david@midrange.com > -|> +--- > -| > -|+--- > -|| This is the RPG/400 Mailing List! > -|| To submit a new message, send your mail to RPG400-L@midrange.com. > -|| To subscribe to this list send email to RPG400-L-SUB@midrange.com. > -|| To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com. > -|| Questions should be directed to the list owner/operator: > -|david@midrange.com > -|+--- > > +--- > | This is the RPG/400 Mailing List! > | To submit a new message, send your mail to RPG400-L@midrange.com. > | To subscribe to this list send email to RPG400-L-SUB@midrange.com. > | To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com. > | Questions should be directed to the list owner/operator: david@midrange.com > +--- +--- | This is the RPG/400 Mailing List! | To submit a new message, send your mail to RPG400-L@midrange.com. | To subscribe to this list send email to RPG400-L-SUB@midrange.com. | To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com. | Questions should be directed to the list owner/operator: david@midrange.com +---
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