Re: [eigen] Vectorized quaternion multiplication. |

[ Thread Index | Date Index | More lists.tuxfamily.org/eigen Archives ]

*To*: eigen@xxxxxxxxxxxxxxxxxxx*Subject*: Re: [eigen] Vectorized quaternion multiplication.*From*: Rohit Garg <rpg.314@xxxxxxxxx>*Date*: Sat, 7 Mar 2009 17:30:06 +0530*Dkim-signature*: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=CpJKt8kvjLo4kwEoupsrKxMOCvn6CTC8w0v767e/N+o=; b=uuvEfoSqAUyj4/ja8n5qGuG+BFBeMO0atFQL+XMqbppVjlpAN4QkIasM0N0+aowiF+ gKelrCj71bnlHhbQwkZt9MCHocenFC/mDiijJTO2m/jqi6A/9Od6zniQ7QbD+KHXZ6op znhW2QxinJDFnHAiDIczcCrRSZQGmUg9AWPyA=*Domainkey-signature*: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=IeVRMUUn/b+/xaj82+IrjNx0Mp7/ZsQtzhaNoG7aLLDmwvopfF7qwSQDQn1Kj0MXat T8GPjYYAXDKAYqTIdibVy2nRAw38qf6shXjhmlSmzvdZYI/MFp9dEUjo7DpEn8jvTwy6 xiwWK+2GcNo0PY08Wejyc6b6IjGN7mGWPo7Kg=

When you put it in, please tell me. :) I posted this for feedback here and you may be interested. http://forum.beyond3d.com/showthread.php?t=52840 On Sat, Mar 7, 2009 at 5:16 PM, Gael Guennebaud <gael.guennebaud@xxxxxxxxx> wrote: > hi, > > thanks a lot, > > at a first glance I was not sure about the perf, because it needs a > lot of shuffle instructions which are quite costly, so benched, and on > my core2 your version is 1.5 times faster :) Then I changed the > shuffle_ps for the simpler PSHUFD instr. and now, it is almost 2x > faster, so really worth it :) > > FYI I only changed vec4f_swizzle like this: > > #define vec4f_swizzle(v,p,q,r,s) (_mm_castsi128_ps(_mm_shuffle_epi32( > _mm_castps_si128(v), \ > ((s)<<6|(r)<<4|(q)<<2|(p))))) Now I see. This instruction takes one operand alone so is perhaps faster (aka higher throughput). -- Rohit Garg http://rpg-314.blogspot.com/ Senior Undergraduate Department of Physics Indian Institute of Technology Bombay

**Follow-Ups**:**Re: [eigen] Vectorized quaternion multiplication.***From:*Rohit Garg

**References**:**[eigen] Vectorized quaternion multiplication.***From:*Rohit Garg

**Re: [eigen] Vectorized quaternion multiplication.***From:*Gael Guennebaud

**Messages sorted by:**[ date | thread ]- Prev by Date:
**Re: [eigen] Vectorized quaternion multiplication.** - Next by Date:
**Re: [eigen] Vectorized quaternion multiplication.** - Previous by thread:
**Re: [eigen] Vectorized quaternion multiplication.** - Next by thread:
**Re: [eigen] Vectorized quaternion multiplication.**

Mail converted by MHonArc 2.6.19+ | http://listengine.tuxfamily.org/ |