On Jan 12, 2012, at 08:32, McKown, John wrote:
> OK, I hope I'm not becoming wearisome with my yammering. But I am not too
> busy right now. And I still really like and respect the z architecture
> (despite its horrendous price).
>
Of course, that comes out of not our pocket, but your employers'.
An you've often mentioned how cost-conscious they are. So, then,
why are they not considering converting to Linux rather than to
Windows. OS software would be much cheaper; hardware should
be the same (literally); is this then offset by the cost of middleware
and application software?
> I ask about the CPU cost of an EX because that same program that I'm working
> on uses the EX a fair amount to move "variable length" strings into a
> blank-initialized area for reporting purposes. Instead of EX of an MVC, I
> could use MVCL or MVCLE. But many have said that EX of an MVC is less
> overhead than MVCL in many cases. Especially since I know that my length is
> always no more than 255 characters. I check and report an error if the length
> is 256 or more.
>
If EX is so bad, I wonder about a chain of:
TM COUNT,128
BNO *+18
MVC 0(DEST,128),0(SOURCE)
LA DEST,128(,DEST)
LA SOURCE,128(,SOURCE)
TM COUNT,64
BNO *+18
MVC 0(DEST,64),0(SOURCE)
LA DEST,64(,DEST)
LA SOURCE,64(,SOURCE)
...
TM COUNT,1
BNO *+10
MVC 0(DEST,1),0(SOURCE)
(Or wrap it in a loop)
(I haven't been an assembler programmer for three decades; fill
in the blanks.)
-- gil
