Absent EX how do you do a variable length PACK or MVO or ... Surely not with an MVI into the instruction stream ...
Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of John McKown Sent: Thursday, May 11, 2017 10:52 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Performance of Decimal Floating Point Instruction On Thu, May 11, 2017 at 12:32 PM, Charles Mills <charl...@mcn.org> wrote: > And one of these days the architecture starts allowing EX of an EX and > it fails the bite test. > I really doubt that IBM would make such a change to the existing EX instruction. IBM well knows that people (idiots? like me) use EX 0,* as a one instruction guaranteed abend. If they did do such a thing, I would expect them to deliberately check for that specific case and force a S0C3 (actually PIC 3 - not COBOL). I don't actually like the EX instructions. I remember the implementation of such in the Xerox Sigma series. Every instruction on it was 4 bytes long and so would fit into one of the general purpose registers. That would allow you to "execute" any
