[Bug libgomp/85649] New: [og7, nvptx, openacc] Too much workers chosen for launch

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85649

            Bug ID: 85649
           Summary: [og7, nvptx, openacc] Too much workers chosen for
                    launch
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vries at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---

On the og7 branch for Titan V, we run into this error message in testsuite
polybench for testcases covariance and lu:
...
libgomp: The Nvidia accelerator has insufficient resources to launch
'x$_omp_fn$0' with num_workers = 27 and vector_length = 32; recompile the
program with 'num_workers = x and vector_length = y' on that offloaded region
or '-fopenacc-dim=-:x:y' where x * y <= 768.
...

The problem here is that num_workers is chosen by libgomp, and instead of
giving the error, it should reduce the num_workers.