You don't have to. Static areas and code can share a cache line with no performance penalty. It's dynamic areas (and dynamic code) that should be isolated from static areas and static code.
Gary Weinhold Senior Application Architect DATAKINETICS | Data Performance & Optimization Phone:+1.613.523.5500 x216 Email: [email protected] Visit us online at www.DKL.com E-mail Notification: The information contained in this email and any attachments is confidential and may be subject to copyright or other intellectual property protection. If you are not the intended recipient, you are not authorized to use or disclose this information, and we request that you notify us by reply mail or telephone and delete the original message from your mail system. ________________________________ From: IBM Mainframe Assembler List <[email protected]> on behalf of Dave Clark <[email protected]> Sent: November 30, 2023 11:12 To: [email protected] <[email protected]> Subject: Re: BAKR/PR and Linkage Convenction "IBM Mainframe Assembler List" <[email protected]> wrote on 11/21/2023 04:49:37 PM: > On 11/21/23 14:32:27, Tom Marchant wrote: > > Modern processors use a 256-byte cache line, with separate caches for > > instructions and data. A cache line maps to 256 bytes of storage on a > > 256-byte boundary. There are performance penalties when the same line > > of storage needs to be in both the instruction cache and the data cache. > Is it recommended, then, to cache-line align LTORG so instructions > and data don't share a cache line. Is there an instruction that > will continue to do this for future hardware? So, how does one force a 256-byte alignment? I have LOCTR now placing all of my static data areas at the beginning of the program (after the initial jump to the start of the code area). How do I pad that data area so that the following code area starts on the next 256-byte boundary? Sincerely, Dave Clark -- int.ext: 91078 direct: (937) 531-6378 home: (937) 751-3300 Winsupply Group Services 3110 Kettering Boulevard Dayton, Ohio 45439 USA (937) 294-5331 ********************************************************************************************* This email message and any attachments is for use only by the named addressee(s) and may contain confidential, privileged and/or proprietary information. If you have received this message in error, please immediately notify the sender and delete and destroy the message and all copies. All unauthorized direct or indirect use or disclosure of this message is strictly prohibited. No right to confidentiality or privilege is waived or lost by any error in transmission. *********************************************************************************************
