I don't object to MVC:2 although I don't need it and it seems almost everyone has a solution already. regarding CLC:2 if you know the second operand is shorter make it the first operand - that problem is solved.
Gregg -----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of Tony Thigpen Sent: Tuesday, May 22, 2012 9:45 PM To: [email protected] Subject: Re: MVC with 2nd operand length After reading this over the last few days, I got to ask: Why is everyone so concerned about validating the move to length when nobody is concerned about the move from length? Let's get real here. Almost everything we move is within a dsect along with other fields both before and after it. This means that should we move something too long, we just wipe out some of our other fields and get strange errors. On the other hand, move a short field to a longer field and we also get errors when we throw garbage into our data. For example, how is: MVC FLDA,FLDB (receiver too short) any worse than MVC FLDC,FLDD (sender too short) FLDA DS CL10 FLDB DS CL20 FLDC DS CL20 FLDD DS CL10 Both are bugs that will have to be chased down. So, if we are willing to put up with the first error because it's been that way for 40 years, why all the 'horror' at MVC:2 FLDA,FLDB Be consistent. Also, what ever is proposed for MVC needs to be also made available for CLC and other instructions. Tony Thigpen -----Original Message ----- From: robin Sent: 05/22/2012 09:21 PM > From: Gainsford, Allen > Sent: Tuesday, 22 May 2012 8:37 AM > >> Agreed. I'd suggest that an instruction tag (like the :ASM and :MAC tags >> that HLASM already supports) might be a good syntax to allow this. For >> example: > >> MVC DEST,SRCE USE DEST LENGTH >> MVC:2 DEST,SRCE USE SRCE LENGTH > > And MVC DEST,SRCS() > > However, as I said before, better to use a defined constant > having a clear unequivocal length a la CLx. > > To avoid errors, probably even better to use a macro that checks that > DEST is not shorter than SRCE. > >
