[GSLL-devel] [Gsll-devel] Efficient access to externally generated double-float arrays?

[Liam Healy]

OK, I've now committed what I think is my last attempt at this.  This
latest version includes optimization of matrices and setting values in
foreign arrays.  This latter comes with a caveat however.  The
compiler will macroexpand setf, and for SBCL at least, that means
making temporary variables to bind the actual values.  Those variables
of course don't have any declarations, so no compiler macro expansion
is done.  They way around this is to funcall #'(setf gref*) instead of
using the setf macro, something that I bet most people won't want to
do.  If I get some more energy to pursue this, I could define a setf
macro to shadow cl:setf, but I think I'll let this be for now.

I've written a "timing test" function loosely based on yours.  It is
in foreign-array/tests/timing.lisp.  I hope in the next few days to
run a few of these tests to see the benefit of the optimizations that
have been put in place.  You can see I have commented out the funcall
#'(setf grid:gref*) form at the end; in this example there are so few
sets that the speed difference is undetectable.

Liam