On Wed, Jan 25, 2012 at 03:21:12PM +0100, Joachim Berdal Haga wrote: > Hi, > > I'm looking a bit on assembly performance at the moment. It looks like > a lot of time (almost 25% in poisson/linear lagrange) of the time is > spent in these two lines of GenericFunction::evaluate(): > > Array<double> _values(value_size(), values); > const Array<double> x(cell.geometric_dimension, > const_cast<double*>(coordinates)); > > This seems to be because of the instantiation of boost::shared_arrays. > The ownership of the array data is not transferred (the data will be > deleted by the caller of evaluate()), so this does not really add any > safety. > > I don't have a complete picture of how Array<> is used, does the > Python layer rely on the shared semantics (in other places)? If not, > it might be better to make them non-shared and create copies for use > in Python where needed.
Would it help if we do this: 1. Make GenericFunction::evaluate an inline function that just calls a new version of GenericFunction::eval. 2. The new version of GenericFunction::eval has the same implementation as the current evaluate() function. The result would be that we get two eval() functions, one with plain pointers and one with Array(). A C++ user (and the JIT-compiled expressions) would use the plain pointer version, while the Array version gets wrapped for Python subclassing (where I assume the extra cost will not make a difference). -- Anders _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
