[lno] we now intechange loops on a well known benchmark...

[Zdenek Dvorak]

Hello,

> This patch should do the work for interchanging loops on swim, and
> probably other non optimal code.  I have tested that the transform
> matrix is built and validated on a reduced testcase
> (aka. ssa-chrec-62.c) 
> 
> Some low level comments: the dependence on this testcase is tricky
> {{0, +, 1}_1, +, 1335}_2   vs.   {0, +, 1336}_1
> 
> and for getting it right one has to bound the dependence domain.  This
> is done by estimating the number of iterations in loops 1 and 2 by
> looking at the size of the data and at the access functions.  I will
> be grateful if somebody could comment on the way this information is
> extracted in estimate_niter_from_size_of_data.  This is probably not
> the best solution, but it works on that testcase...

> + 	* cfgloop.h (struct loop): New fields parallel_p, and 
> + 	estimated_nb_iterations.

we already have field for this -- loop->bounds.  It would be also nice
to put the related analysis to
tree-ssa-loop-niter.c:estimate_numbers_of_iterations_loop.

Zdenek