[Bug middle-end/78266] New: broken openacc loop partitioning on nvptx offloading targets

[cesar at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78266

            Bug ID: 78266
           Summary: broken openacc loop partitioning on nvptx offloading
                    targets
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Keywords: openacc
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: cesar at gcc dot gnu.org
  Target Milestone: ---
            Target: x86_64-linux-gnu, nvptx-none

Created attachment 39999
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39999&action=edit
vprop.c

The attached test case demonstrates a situation where an acc 'gang worker'
partitioned loop encloses an acc vector partitioned loop fails to generate
correct code. I'm not sure if there is a problem in the nvptx backend
worker-state propagator, or if oaccdevlow is generating bad code.

This test case works fine if the outer loop is either gang or worker
partitioned, but not both.