All I can say is WOW, also. There are only two reasons I can think of to have it cost that much. 1) It is a milli-code instruction, or 2) It purges the pipeline.
If that time is for each instruction, then I tend to think it is milli-code. If the time is for a SAM64/SAM31 pair, then I think it is a hardware level instruction that happens to purge the instruction pipeline. Ed, you were not clear on if that time was for a single SAMxx instruction or a SAM64/SAM31 pair. Chris Blaicher Technical Architect Mainframe Development Syncsort Incorporated 50 Tice Boulevard, Woodcliff Lake, NJ 07677 P: 201-930-8234 | M: 512-627-3803 E: cblaic...@syncsort.com www.syncsort.com -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Charles Mills Sent: Wednesday, May 4, 2016 5:23 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: How expensive is AMODE switching? Wow! Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Ed Jaffe Sent: Wednesday, May 04, 2016 2:08 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: How expensive is AMODE switching? On 5/4/2016 1:49 PM, Jerry Callen wrote: > Before I sit down and write a test program to time it, can anyone tell me how > expensive the AMODE switching instructions are (SAM31/SAM64)? Our zHISR benchmark averages the time required to switch from 31-bit mode to 64-bit mode and back again, back-to-back. (It does not time the case where the target mode is the same as the current mode.) The result here suggests that a 'SAMnn' instruction is approximately equal to 34 'L' instructions on a z13s. YMMV. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ________________________________ ATTENTION: ----- The information contained in this message (including any files transmitted with this message) may contain proprietary, trade secret or other confidential and/or legally privileged information. Any pricing information contained in this message or in any files transmitted with this message is always confidential and cannot be shared with any third parties without prior written approval from Syncsort. This message is intended to be read only by the individual or entity to whom it is addressed or by their designee. If the reader of this message is not the intended recipient, you are on notice that any use, disclosure, copying or distribution of this message, in any form, is strictly prohibited. If you have received this message in error, please immediately notify the sender and/or Syncsort and destroy all copies of this message in your possession, custody or control. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
