Date: Thu, 11 Apr 2002 14:51:13 +0100 From: Simon Dick <simond@irrelevant.org> To: Andrew Gallatin <gallatin@cs.duke.edu> Cc: Denis Serenyi <dserenyi@panasas.com>, freebsd-hackers@freebsd.org Subject: Re: SSE bcopy Message-ID: <20020411135113.GG2916@irrelevant.org> In-Reply-To: <15541.37586.404951.505010@grasshopper.cs.duke.edu> References: <B3B2200B-4CD1-11D6-9B98-003065675568@panasas.com> <15541.37586.404951.505010@grasshopper.cs.duke.edu>
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On Thu, Apr 11, 2002 at 09:42:42AM -0400, Andrew Gallatin wrote: > > Denis Serenyi writes: > > I've been looking at adding an SSE bcopy that runs at user-level to a > > program that I'm working on. I'm using FreeBSD 4.3 currently. > > > > I wrote the routine, and when I execute it, I get an illegal instruction > > exception when I try to execute the first SSE instruction (movups). > > > > After searching the hackers archives, I'm guessing that this is because > > FreeBSD 4.3 does not execute the instructions at boot time to enable SSE > > instructions to be executed, and also because FreeBSD 4.3 does not save > > the 128-bit SIMD registers on context switches. > > > > Am I correct in this assessment? > > > > It also seems like this support has been added to FreeBSD 4.5. Is this > > correct? > > > > Assuming yes, in what release was SSE support added to FreeBSD? Has > > anyone done a patch that can be applied to FreeBSD 4.3, or are the > > changes non-trivial? > > > > As David says, have a look at > http://kobe1995.net/~kaz/FreeBSD/SSE.en.html There is a patch there > for 4.3. > > What are the performance implications to an SSE bcopy? How much > faster is it than a normal bcopy? > > Would you consider releasing your code under a BSD license so that > others could play with it, and possibly integrate it (or something > based on it) into FreeBSD? Also if he wants to check if OS SSE support is enabled, he can check if the hw.instruction_sse sysctl is set to 1, then he'll know if it's safe to use :) -- Simon Dick simond@irrelevant.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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