In other words, if one had to venture a *guess* it would be that the immediate instructions were in practice a heck of a lot faster.
(Don't know that this sort of issue is relevant to the relative versus branch/displacement comparison.) Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of John Ehrman Sent: Wednesday, July 10, 2013 10:22 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Benchmark of Relative instructions vers Base+displacement ones On Tue, 9 Jul 2013 15:30:12 -0400, Richard Verville <r.vervi...@videotron.ca> asked: > Has anyone done benchmarks on different scenarios with instructions > with immediate & relative instructions versus the old instructions. <snip> The more important issue is memory access: CPU speeds have increased much faster than memory speeds. There is no memory pentaly for immediate operands, while memory references can be quite costly: an item taken from memory can displace other items in the data cache, or they might cross a cache-line or memory-page boundary, or require paging. A memory reference can take anywhere from a few cycles to many thousands, so if your processor supports useful immediate operands, take advantage. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
