I'm essentially interested in the functionality of the operators library, and mostly curious if I'm using it in a less than optimal way (ie. I need to #define something, or write my operator += in a different way). Is it possible that the old code is being autovectorized, while for some reason the new code can't be? I'm using gcc 4.1 on a linux system. Thanks, Brian On 5/8/06, Victor A. Wagner Jr. wrote:

At 23:05 2006-05-07, you wrote:

...

Hi all -

I just tried out the operators library for the first time today. I was quite happy with how easily it helped me implement my test class. Unfortunately, I'm running into some performance issues, in particular with operator +.

The interesting thing is that the new operator += is actually faster than my old += by about a factor of 2, but my operator + is slower than my old + by a factor of nearly 10!

I'm new here, and not really sure how much code is appropriate to post to the list, so here's a minimal rundown:

-------------------------------------------------------------------------- Old code:

template<typename real> Vector3<real> operator + (const Vector3<real> &a, const Vector3<real> &b);

template<typename real> class Vector3 { protected: real m_v[3]; .. .. friend Vector3 operator +<> (const Vector3 &a, const Vector3 &b); };

template<typename real> inline Vector3<real> operator + (const Vector3<real> &a, const Vector3<real> &b){ Vector3<real> t; t[0] = a[0] + b[0]; t[1] = a[1] + b[1]; t[2] = a[2] + b[2]; return t; }

------------------------------------------------------------------------------------------------- New code (note that the new code is templatized on size, and that my instantiations were of size 3 to match the above code):

template class vec : boost::additive< vec , boost::multiplicative< vec, T > > { private: typedef unsigned int uint; typedef const T &const_reference; typedef T &reference;

private: boost::array m_v;

template<typename U> vec &operator += (const vec &t){ for(uint i = 0; i < S; ++i){ m_v[i] += t.m_v[i]; } return *this; } };

Any ideas how to increase the performance of the new code here? A factor of 10 makes it seem like I am just missing something important.

you showed us the code that you claim is faster, what do you want us to do?

...

Thanks, Brian _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

Victor A. Wagner Jr. http://rudbek.com The five most dangerous words in the English language: "There oughta be a law"

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