On Thu, 14 Jan 2016, Jakub Jelinek wrote:
> That is weird, because c is also a firstprivate var in target and
> (implicitly) shared in teams, so if omp lowering/expansion is not buggy,
> you should see the exactly same problem with that.
> Wonder if we use GOMP_MAP_FIRSTPRIVATE_INT when we shouldn't (the var really
> should be addressable because of the atomics and atomics would be the only
> way to observe some changes on it (or teams reduction?)).
I see that there's stack var 'c' initialized from omp_data_i->c in
main._omp_fn.0, which makes a per-team copy of 'c'. Thus I think it's a
lowering/expansion issue. I didn't dig further.
> That said, for the testcase, as it is num_teams(4), I think I'd prefer
> #pragma omp atomic read c, g[0] and g[1] into temporaries and verify if they
> are one of the possible values.
Done in the below patch.
> > Second, there are failures on libgomp.c/examples-4/teams-{3,4}.c and their
> > Fortran counterparts. The issue is that 'sum' is not reduced across all
> > teams, but only across loop iterations within each team. I'm using the
> > following patch to add the missing reduction. Is that correct?
>
> Yes, but we need to report it upstream, the bug is on the OpenMP Examples
> side.
> Let me do it now.
Thanks! Do you want me to repost that patch with the Fortran bits updated?
Alexander
diff --git a/libgomp/testsuite/libgomp.c/target-31.c
b/libgomp/testsuite/libgomp.c/target-31.c
index 255327c..27f9410 100644
--- a/libgomp/testsuite/libgomp.c/target-31.c
+++ b/libgomp/testsuite/libgomp.c/target-31.c
@@ -36,7 +36,18 @@ main ()
u3[i] = k + i;
#pragma omp parallel num_threads (1)
{
- if (c != 3 || d != 4 || g[0] != 9 || g[1] != 10 || h[0] != 11 || h[1] !=
12 || k != 14 || m[0] != 17 || m[1] != 18)
+ int v1, v2, v3;
+ #pragma omp atomic read
+ v1 = c;
+ #pragma omp atomic read
+ v2 = g[0];
+ #pragma omp atomic read
+ v3 = g[1];
+ if ((v1 != 3 && v1 != 4 && v1 != 5 && v1 != 6)
+ || d != 4
+ || (v2 != 9 && v2 != 11 && v2 != 13 && v2 != 15)
+ || (v3 != 10 && v3 != 13 && v3 != 16 && v3 != 19)
+ || h[0] != 11 || h[1] != 12 || k != 14 || m[0] != 17 || m[1] != 18)
#pragma omp atomic write
err = 1;
b = omp_get_team_num ();
