Also instructions that don't set the condition code preserve the existing condition code for following instructions.
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 Ed Jaffe <[email protected]> Sent: November 15, 2022 16:47 To: [email protected] <[email protected]> Subject: Re: ADD LOGICAL WITH SIGNED IMMEDIATE HIGH N On 11/15/2022 1:19 PM, Paul Gilmartin wrote: > > Is the hardware smart enough to bypass setting the condition code when > it's > not needed but might slow the pipeline? Maybe next year's model. It's not so much setting the condition code that slows the pipeline, it's waiting to check the condition code that slows the pipeline. For example, CLI/JNE. The JNE has to wait for the cc to be surfaced. That's why we mostly use CIJNE instead. -- Phoenix Software International Edward E. Jaffe 831 Parkview Drive North El Segundo, CA 90245 https://www.phoenixsoftware.com/ -------------------------------------------------------------------------------- This e-mail message, including any attachments, appended messages and the information contained therein, is for the sole use of the intended recipient(s). If you are not an intended recipient or have otherwise received this email message in error, any use, dissemination, distribution, review, storage or copying of this e-mail message and the information contained therein is strictly prohibited. If you are not an intended recipient, please contact the sender by reply e-mail and destroy all copies of this email message and do not otherwise utilize or retain this email message or any or all of the information contained therein. Although this email message and any attachments or appended messages are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by the sender for any loss or damage arising in any way from its opening or use.
