On Sun, Jul 29, 2012 at 7:33 PM, Gary Funck <g...@intrepid.com> wrote:
>
> I have been experimenting with the graphite optimizer, based on GCC trunk, and
> cloog-isl. I started with the attached simple "C" program, which has this
> basic structure.
>
> #define N 20000
> int a[N][N], b[N], c[N];
> [...]
> for (i = 0; i < N; i++)
> {
> b[i] = i;
> c[i] = i + N;
> }
> for (i = 0; i < N; i++)
> for (j = 0; j < N; j++)
> a[j][i] = b[i] + c[j];
>
> (Attached, is the full test case.)
>
> And compiled it with: -O3 -floop-block.
>
> Couple of questions:
> 1) What option should I supply to confirm that the graphite optimizer ran and
> determine (i) did it in fact perform any optimizations, and (ii) which
> optimizations did it perform?
You have to look at dump files.
> 2) If -floop-block couldn't optimize this program, what is the likely reason?
> 3) Would you please offer pointers to example "C" programs that highlight
> graphite-cloog-isl optimizations?
Look at the gcc.dg/graphite/ testsuite.
> Thanks,
> - Gary
