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Re: [GSoC] generation of Gimple code from isl_ast_node_if

On 26/07/2014 16:16, Roman Gareev wrote:
I would still add a test case which does not contain a reduction (+=)
and where graphite is not duplicating pbbs.

Help for what? I was looking to create a simple test case. Is there still an
open bug?

Sorry, I thought, we should add this test case to be able to test
graphite without patch related to graphite-sese-to-poly.c (patch1).

Right. I think we should have a simple test case that does not trigger basic block duplication, which is basically triggered for reductions.

The test case:

static int __attribute__((noinline))
foo ()
  int i, res = 0;

  for (i = 0; i < 50; i++)
      if (i < 5)
        res += 1;

  return res;

that you just proposed contains again a reduction and yields several bbs that cause problems.

  for (int c1 = 0; c1 <= 49; c1 += 1) {
    for (int c2 = 0; c2 <= 1; c2 += 1)
    if (c1 <= 4)

I proposed a test case without a reduction (possibly a little bit more complex):

> > for i:
> >   A[i] = ...
> >
> > You could do the summation/verfication outside of the scop e.g. in
> > the main
> > function.
> It seems that it doesn't help (at least for now).

Can you explain why you believe it is hard/impossible to generate a test case without reduction?

Sorry Roman. I am still confused. Are we looking for a test case or are we
still trying to understand an issue. Specifically, do we still incorrectly
transform the code even after your isl_id_for_pbb() patch?

I gives a wrong answer without patch1. The code is transformed
correctly with this patch.

OK. So we don't need to solve another bug. That is good.


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