The first, base code, is just the following to get the overhead of loop control;
TIMEUSED STORADR=STARTIME,CPU=TOD,LINKAGE=SYSTEM
LOOPB DS 0H
L R3,POOLADDR GET FROM ADDRESS
L R4,TOADDR GET TO ADDR
BCT R9,LOOPB LOOP THE NEEDED NUMBER OF TIMES
TIMEUSED STORADR=ENDTIME,CPU=TOD,LINKAGE=SYSTEM
SPACE 3
LA R1,=CL12'BASE CODE'
BAL R14,TIMEOUT
The second case was just a move of 1K using four MVC instructions in a row,
which is the fastest.
All the others are just $MVC macro vs MVCL instruction.
Chris Blaicher
Technical Architect
Precisely.com
-----Original Message-----
From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On
Behalf Of Mike Hochee
Sent: Tuesday, October 20, 2020 4:40 PM
To: ASSEMBLER-LIST@LISTSERV.UGA.EDU
Subject: Re: Conditional MVCL macro?
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Thanks for sharing your test results, although I had trouble explaining the
results of the first two tests, and maybe this is related to how the $MVC macro
does its thing.
Anyway, If you throw out the first two tests, the $MVC technique appears to be
250-300% more efficient than the MVCL technique with lengths between 4K-64K.
But with a length of 128K, $MVC efficiency drops down to only 60%. My guess is
that MVCL will eventually prove to be more efficient than $MVC with move
lengths in excess of 256K.
I don't know if moving to/from the same storage locations makes any difference
for this test, but assuming intentional for the purpose of controlling this as
a variable. There's already enough unknowns!
Again, thanks for sharing!
