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| From | Piotr Wyderski <peter.pan@neverland.mil> |
|---|---|
| Newsgroups | comp.arch |
| Subject | Re: Why is complex lea slow? |
| Date | 2011-05-19 17:13 +0200 |
| Organization | CI TASK http://www.task.gda.pl/ |
| Message-ID | <ir3c25$c2p$1@news.task.gda.pl> (permalink) |
| References | <9ceb0829-013e-4ee4-8ab3-9378ae59fe37@glegroupsg2000goo.googlegroups.com> |
Paul A. Clayton wrote: > In the context of LEA, the shifts are always constant and > I was under the impression that variable shifts are > generally less common. The lea-related problem inspired me to do more detailed survey and it turns out that most useful instruction got slower on SandyBridge. Not only lea, but also bsf, bsr and even bt (!!!) have increased their latencies to 3 cycles. Since I am a heavy user of these, and they appear mostly in performance-critical code, the current path Intel decided to go, i.e. making useful instructions slow and adding tons of useless but fast "extensions" like pcmpestri or crc32 scares me. Best regards Piotr Wyderski
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Re: Why is complex lea slow? "Paul A. Clayton" <paaronclayton@gmail.com> - 2011-05-17 12:58 -0700
Re: Why is complex lea slow? Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-05-18 09:40 +0200
Re: Why is complex lea slow? "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-05-18 06:25 -0700
Re: Why is complex lea slow? "Andy \"Krazy\" Glew" <andy@SPAM.comp-arch.net> - 2011-05-18 06:39 -0700
Re: Why is complex lea slow? Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-05-18 20:49 +0200
Re: Why is complex lea slow? Andrew Reilly <areilly---@bigpond.net.au> - 2011-05-19 00:11 +0000
Re: Why is complex lea slow? MitchAlsup <MitchAlsup@aol.com> - 2011-05-24 13:44 -0700
Re: Why is complex lea slow? Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-05-25 08:43 +0200
Re: Why is complex lea slow? MitchAlsup <MitchAlsup@aol.com> - 2011-05-25 08:31 -0700
Re: Why is complex lea slow? timcaffrey@aol.com (Tim McCaffrey) - 2011-05-25 14:53 +0000
Re: Why is complex lea slow? MitchAlsup <MitchAlsup@aol.com> - 2011-05-25 08:31 -0700
Re: Why is complex lea slow? timcaffrey@aol.com (Tim McCaffrey) - 2011-05-26 19:45 +0000
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-26 20:01 +0000
Re: Why is complex lea slow? nmm1@cam.ac.uk - 2011-05-26 20:29 +0100
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-26 20:14 +0000
Re: Why is complex lea slow? nmm1@cam.ac.uk - 2011-05-26 21:04 +0100
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-26 20:55 +0000
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-26 20:57 +0000
Re: Why is complex lea slow? nmm1@cam.ac.uk - 2011-05-26 21:30 +0100
Re: Why is complex lea slow? Tom Gardner <spamjunk@blueyonder.co.uk> - 2011-05-26 22:57 +0100
Re: Why is complex lea slow? Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-05-27 07:42 +0200
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-27 06:11 +0000
Re: Why is complex lea slow? Tom Gardner <spamjunk@blueyonder.co.uk> - 2011-05-27 07:18 +0100
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-27 06:33 +0000
Re: Why is complex lea slow? Michael S <already5chosen@yahoo.com> - 2011-05-27 03:24 -0700
Re: Why is complex lea slow? Tom Gardner <spamjunk@blueyonder.co.uk> - 2011-05-27 22:24 +0100
Re: Why is complex lea slow? Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-05-28 13:51 +0200
Re: Why is complex lea slow? Quadibloc <jsavard@ecn.ab.ca> - 2011-05-27 17:42 -0700
Re: Why is complex lea slow? Quadibloc <jsavard@ecn.ab.ca> - 2011-05-27 17:40 -0700
Re: Why is complex lea slow? Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-05-27 08:55 +0200
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-27 07:42 +0000
Re: Why is complex lea slow? Tom Gardner <spamjunk@blueyonder.co.uk> - 2011-05-27 09:24 +0100
Re: Why is complex lea slow? nmm1@cam.ac.uk - 2011-05-27 08:55 +0100
Re: Why is complex lea slow? Tom Gardner <spamjunk@blueyonder.co.uk> - 2011-05-27 10:20 +0100
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-27 08:53 +0000
Re: Why is complex lea slow? Tom Gardner <spamjunk@blueyonder.co.uk> - 2011-05-27 10:23 +0100
Re: Why is complex lea slow? kenney@cix.compulink.co.uk - 2011-05-27 23:47 -0500
Re: Why is complex lea slow? Quadibloc <jsavard@ecn.ab.ca> - 2011-05-27 17:44 -0700
Re: Why is complex lea slow? Bill Findlay <yaldnif.w@blueyonder.co.uk> - 2011-05-28 02:12 +0100
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-28 02:57 +0000
Re: Why is complex lea slow? Tom Gardner <spamjunk@blueyonder.co.uk> - 2011-05-28 09:27 +0100
Algol hardware representations, was: Why is complex lea slow? Bill Findlay <yaldnif.w@blueyonder.co.uk> - 2011-05-28 15:26 +0100
Re: Why is complex lea slow? Quadibloc <jsavard@ecn.ab.ca> - 2011-05-28 08:57 -0700
Re: Why is complex lea slow? Chris Gray <cg@GraySage.com> - 2011-05-27 14:14 -0600
Re: Why is complex lea slow? timcaffrey@aol.com (Tim McCaffrey) - 2011-05-26 23:26 +0000
Re: Why is complex lea slow? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-05-26 21:41 -0600
Re: Why is complex lea slow? Terje Mathisen <"terje.mathisen at tmsw.no"> - 2011-05-27 07:37 +0200
Re: Why is complex lea slow? kym@kymhorsell.com - 2011-05-27 06:16 +0000
Re: Why is complex lea slow? Quadibloc <jsavard@ecn.ab.ca> - 2011-05-27 17:52 -0700
Re: Why is complex lea slow? Piotr Wyderski <peter.pan@neverland.mil> - 2011-05-19 17:13 +0200
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