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- To: eigen@xxxxxxxxxxxxxxxxxxx
- Subject: Re: [eigen] geometry module
- From: Gael Guennebaud <gael.guennebaud@xxxxxxxxx>
- Date: Wed, 8 Sep 2010 14:11:52 +0200
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On Wed, Sep 8, 2010 at 2:04 PM, Gael Guennebaud
<gael.guennebaud@xxxxxxxxx> wrote:
> The problem is not the copy which are well optimized away by gcc, but
> the extra 5 shuffling. Maybe some shuffling can be removed by directly
> vectorizing the quaternion * vector product (we currently vectorize
> quat*quat only).
>
sorry, there are not 5 extra shuffling only, but 7 (!), and gcc
already optimized out 2 of them. I'm wondering how this vectorized
cross3 function can be faster than a scalar cross product....
gael