I suspect that the extra halfword has more impact on performance than the register, and I agree that the performance difference is probably negligible. Just curious.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Adam Johanson <[email protected]> Sent: Friday, November 10, 2023 12:26 PM To: [email protected] Subject: Re: LA vs LHI >I know that it's model dependent and also depends on the cache loading, but >are there cases where there is a measurable performance difference between >these? > > LAY Rx,4096 > LHI Rx,4096 One aspect of the differences between the two is that LAY has a larger footprint in the i-cache since it's a 6-byte instruction vs. the 4-byte LHI. Finding / constructing a use case where that makes a measurable performance difference could be an interesting exercise. =============================== Adam Johanson Broadcom Mainframe Software Division ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
