[PATCH] [og10] OpenACC: Turn off worker partitioning if num_workers==1

[Julian Brown]

This patch turns off the middle-end worker-partitioning support if the
number of workers for an outlined offload function is one.  In that case,
we do not need to perform the broadcasting/neutering code transformation.

OK for og10 branch?

Julian

ChangeLog

        gcc/
        * omp-offload.c (pass_oacc_gimple_workers::gate): Disable worker
        partitioning if num_workers is 1.
---
 gcc/omp-offload.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/gcc/omp-offload.c b/gcc/omp-offload.c
index bf72782ba4ce..2b730d057781 100644
--- a/gcc/omp-offload.c
+++ b/gcc/omp-offload.c
@@ -2165,7 +2165,20 @@ public:
   /* opt_pass methods: */
   virtual bool gate (function *)
   {
-    return flag_openacc && targetm.goacc.worker_partitioning;
+    if (!flag_openacc || !targetm.goacc.worker_partitioning)
+      return false;
+
+    tree attr = oacc_get_fn_attrib (current_function_decl);
+
+    if (!attr)
+      /* Not an offloaded function.  */
+      return false;
+
+    int worker_dim
+      = oacc_get_fn_dim_size (current_function_decl, GOMP_DIM_WORKER);
+
+    /* No worker partitioning if we know the number of workers is 1.  */
+    return worker_dim != 1;
   };
 
   virtual unsigned int execute (function *)
-- 
2.23.0