Ah. I get what you are saying. That would be cool -- an "EXG," that would execute the contents of a grande register. You could build (reentrantly) any instruction you wanted. How about EXMG, that would execute the contents of a series of multiple adjacent registers, analogous to LMG?
Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of John McKown Sent: Thursday, May 11, 2017 11:39 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Performance of Decimal Floating Point Instruction On Thu, May 11, 2017 at 1:28 PM, Charles Mills <charl...@mcn.org> wrote: > Absent EX how do you do a variable length PACK or MVO or ... > I said that I didn't _like_ EX. Not that I didn't _use_ it. I'd prefer to "synthesize" an instruction into a 64 bit GPR and then "EX" the contents of the GPR. That would allow me to do more than just modify the value in second byte of the instruction. I understand why EX exists (just as you have pointed out) and why it does what it does. But a more generalized facility would be, to me, "nicer". But, in reality (which stinks in some ways), I understand that IBM won't create a new instruction "because John thinks it would be nice". [grin] > Surely not with an MVI into the instruction stream ... > > Charles > > -- Advertising is a valuable economic factor because it is the cheapest way of selling goods, particularly if the goods are worthless. -- Sinclair Lewis Maranatha! <>< John McKown
