I understand why you would not want to make the change global. But it might be that the other COBOL moves are executed much less frequently, in which case a global change might be acceptable.
Bill Fairchild Software Developer Rocket Software 275 Grove Street * Newton, MA 02466-2272 * USA Tel: +1.617.614.4503 * Mobile: +1.508.341.1715 Email: [email protected] Web: www.rocketsoftware.com -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Farley, Peter x23353 Sent: Friday, August 07, 2009 5:27 PM To: [email protected] Subject: Re: z10 and overlapping/destructive moves > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Bill Fairchild > Sent: Friday, August 07, 2009 5:50 PM > To: [email protected] > Subject: Re: z10 and overlapping/destructive moves > > I have no idea how to change the COBOL source code to accomplish my > suggestion. Assuming there is no easy way, then if the module has a patch > area, he can zap the load module with the necessary changes. Then test > the change for an improvement in performance. If there is an improvement, > he can complain to whatever vendor supplied him with his COBOL compiler. The vendor would be IBM, the compiler is Enterprise COBOL V3.4. I can try the ALLSPACE suggestion just to see if it makes a difference, but as was pointed out in another reply, doing that globally would not be optimal, at least not for storage utilization. Easily "fixed" by having just one large variable initialized to spaces, large enough to cover the largest variable that needs to be set to spaces. COBOL will use only the length needed for shorter moves. And once a variable is large enough that COBOL generates an MVCL instead of MVC's, it's probably cheaper to just use the compiler literal SPACES, given that MVCL supports a padding character. In this particular case, if it reduces the CPU spike at that place in the code as seen by Strobe, an extra 120 bytes of otherwise unused storage may be worth the performance increase, if there is one. I'll report back after I try it out. Thanks for your help. Peter This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
