[nvptx] Handle assignment to gang-level reduction variable

2019-01-15  Tom de Vries  <tdevries@suse.de>

	PR target/80547
	* config/nvptx/nvptx.c (nvptx_goacc_reduction_init): Handle
	lhs == NULL_TREE for gang-level reduction.

	* testsuite/libgomp.oacc-c-c++-common/gang-reduction-var-assignment.c:
	New test.

From-SVN: r267934

gcc/ChangeLog

+2019-01-15  Tom de Vries  <tdevries@suse.de>
+
+	PR target/80547
+	* config/nvptx/nvptx.c (nvptx_goacc_reduction_init): Handle
+	lhs == NULL_TREE for gang-level reduction.
+
 2019-01-15  Richard Biener  <rguenther@suse.de>
 	    Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>
 

gcc/config/nvptx/nvptx.c

@@ -6242,7 +6242,8 @@ nvptx_goacc_reduction_init (gcall *call, offload_attrs *oa)
 	    init = var;
 	}
 
-      gimplify_assign (lhs, init, &seq);
+      if (lhs != NULL_TREE)
+	gimplify_assign (lhs, init, &seq);
     }
 
   pop_gimplify_context (NULL);

libgomp/ChangeLog

+2019-01-15  Tom de Vries  <tdevries@suse.de>
+
+	PR target/80547
+	* testsuite/libgomp.oacc-c-c++-common/gang-reduction-var-assignment.c:
+	New test.
+
 2019-01-12  Tom de Vries  <tdevries@suse.de>
 
 	* testsuite/libgomp.oacc-c-c++-common/pr85486-2.c: New test.

libgomp/testsuite/libgomp.oacc-c-c++-common/gang-reduction-var-assignment.c

+/* { dg-xfail-run-if "PR88852" { openacc_host_selected } } */
+
+int
+main (void)
+{
+  int x = 123;
+
+#pragma acc parallel num_gangs(1) reduction (+: x)
+  {
+    x = 23;
+  }
+  if (x != 146)
+    __builtin_abort();
+
+  return 0;
+}