Depending on how extensively commented and how much white space there is in the EXEC, you will see some improvement if you remove all but the executable code from the version being interpreted. True, it is probably a somewhat piddly amount, but piddly times millions can be pretty big.
-----Original Message----- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Alan Altmark Sent: Thursday, January 04, 2007 1:35 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: REXX compiling / EXECLOAD On Thursday, 01/04/2007 at 11:12 PST, Don Russell <[EMAIL PROTECTED]> wrote: > Is there any performance benefit to compiling a REXX EXEC if it will > be EXECLOAD'd for the lifetime of it's use? > > For example, I have a service machine which, upon startup, EXECLOADs > some EXECs it needs over and over. It/they remain EXECLOADd until the > service machine is shutdown. The EXEC is not particularly > complex/large, but does compiling it actually make any difference? The advantage of compilation is not really based on how long you use it, but on what you are doing and how often you are doing it. An exec that spends all of its time in CMS and CP commands (e.g. diag or pipes) will see very little improvement, if any, by compiling. If you do a lot of parsing, string manipulation, and arithmetic, then you'll see gains. EXECLOADing is useful when you run the exec repeatedly, avoiding reading it from disk every time. Obviously that's only meaningful if the disk I/Os are a problem. These are, of course, generalizations and my motto is "Never Generalize". Alan Altmark z/VM Development IBM Endicott
