[Bug target/99555] New: [OpenMP/nvptx] Execution-time hang for simple nested OpenMP 'target'/'parallel'/'task' constructs

[tschwinge at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99555

            Bug ID: 99555
           Summary: [OpenMP/nvptx] Execution-time hang for simple nested
                    OpenMP 'target'/'parallel'/'task' constructs
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: openmp
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tschwinge at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org, kcy at codesourcery dot com,
                    vries at gcc dot gnu.org
  Target Milestone: ---
            Target: nvptx

Discovered during OpenMP 'task' 'detach' development.  See PR98738,
<http://mid.mail-archive.com/e7796b0a-c8ee-e695-3775-9edfa254c552@codesourcery.com>;
when offloaded to nvptx, '-O0', the following hangs consistently:

    #pragma omp target
    #pragma omp parallel
    #pragma omp task
      ;

This doesn't hang when offloaded to GCN or the host device, or if
'num_threads(1)' is specified on the 'parallel'.

---

Not yet determined if this is a regression, when this started.