[openacc] Add oacc_get_default_dim

Expose oacc_default_dims to backends.

2018-12-17  Tom de Vries  <tdevries@suse.de>

	* omp-offload.c (oacc_get_default_dim): New function.
	* omp-offload.h (oacc_get_default_dim): Declare.

---
 gcc/omp-offload.c | 7 +++++++
 gcc/omp-offload.h | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/gcc/omp-offload.c b/gcc/omp-offload.c
index 4457e1a3079..9c7bd7328d1 100644
--- a/gcc/omp-offload.c
+++ b/gcc/omp-offload.c
@@ -573,6 +573,13 @@ oacc_xform_tile (gcall *call)
 static int oacc_default_dims[GOMP_DIM_MAX];
 static int oacc_min_dims[GOMP_DIM_MAX];
 
+int
+oacc_get_default_dim (int dim)
+{
+  gcc_assert (0 <= dim && dim < GOMP_DIM_MAX);
+  return oacc_default_dims[dim];
+}
+
 /* Parse the default dimension parameter.  This is a set of
    :-separated optional compute dimensions.  Each specified dimension
    is a positive integer.  When device type support is added, it is
diff --git a/gcc/omp-offload.h b/gcc/omp-offload.h
index 6186f03649e..14edcad8a7d 100644
--- a/gcc/omp-offload.h
+++ b/gcc/omp-offload.h
@@ -22,6 +22,8 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef GCC_OMP_DEVICE_H
 #define GCC_OMP_DEVICE_H
 
+extern int oacc_get_default_dim (int dim);
+
 extern GTY(()) vec<tree, va_gc> *offload_funcs;
 extern GTY(()) vec<tree, va_gc> *offload_vars;