Todd, My assembler-writing days started in 1967 when storage was not all that abundant and economy was paramount*. Concise coding became an ingrained habit and I was often upset by inefficient macro expansions. Thus I preferred, for example, to manipulate my register usage to fit what I knew was needed by the coming macro expansion. Finally, there was really no need for the macro at all - except to document the SVC call - just like WTO MF=(E,(1)) for SVC 35 below now I take a look at it. So I guess that's the diametric opposite of your approach :-)
* I was once on the edge of a project to create some spooling code for DOS - that's the VSE of today. The target was 4K since it was designed to be able to fit into a 32K - 64K if you were rich - System 360 Model 30 or 40. One suggestion from the "review panel" was to use the X'1A' of - I think - the AR instruction in place of a packed decimal 1 constant. Chris Mason ----- Original Message ----- From: "Todd Burch" <[EMAIL PROTECTED]> Newsgroups: bit.listserv.ibm-main To: <IBM-MAIN@BAMA.UA.EDU> Sent: Tuesday, 21 February, 2006 8:57 PM Subject: Re: z/Architecture Principles of Operation (SA22-7832-04) > Point taken, and I have to agree that your sample coding technique will work > just fine. > > However, I prefer to let the assembler work for me, and to not spend my time > manually coding up all the parms and bits and such for macros, so that when > they expand all that is left to expand is an SVC. > > Todd > > ----- Original Message ----- > From: "Robert A. Rosenberg" <[EMAIL PROTECTED]> > Newsgroups: bit.listserv.ibm-main > To: <IBM-MAIN@BAMA.UA.EDU> > Sent: Tuesday, February 21, 2006 1:40 PM > Subject: Re: z/Architecture Principles of Operation (SA22-7832-04) > > > > At 11:51 -0600 on 02/21/2006, Todd Burch wrote about Re: > > z/Architecture Principles of Operation (SA22-7832-04): > > > > >Certainly I can do that. And, when I do that, I have absolutely no need > for > > >the LDF instructions. > > > > > >The purpose of the Long Displacement Facility is to provide relief for > base > > >register constraint. Coding a "LAY R1" to get around a macro expansion, > and > > >taking up a base register to do that, doesn't buy me diddly squat in > terms > > >of "base register relief". > > > > R1 IS the register that is loaded by the MF=(E,LIST) parm. Thus > > loading it via a LAY and coding MF=(E,(1)) tells the Macro to not > > generate the LA 1,List (since R1 has already been loaded). There is > > no EXTRA register used. Here are the expansions for your review. > > > > 000000 00000 00014 1 TESTMF CSECT > > R:C 00000 2 USING *,12 > > 3 WTO MF=(E,LIST) > > 000000 4110 C010 00010 7+ LA 1,LIST > > 000004 0A23 8+ SVC 35 > > 000006 E310 C010 0071 00010 9 LAY 1,LIST > > 10 WTO MF=(E,(1)) > > 00000C 0A23 14+ SVC 35 > > 000010 15 LIST DS F > > 16 END ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
