[nvptx] Don't emit barriers for empty loops -- test-cases

Add test-cases for PR85381.

2019-01-12  Tom de Vries  <tdevries@suse.de>

	PR target/85381
	* testsuite/libgomp.oacc-c-c++-common/pr85381-5.c: New test.
	* testsuite/libgomp.oacc-c-c++-common/pr85381.c: New test.

From-SVN: r267893

libgomp/ChangeLog

 2019-01-12  Tom de Vries  <tdevries@suse.de>
 
+	PR target/85381
+	* testsuite/libgomp.oacc-c-c++-common/pr85381-5.c: New test.
+	* testsuite/libgomp.oacc-c-c++-common/pr85381.c: New test.
+
+2019-01-12  Tom de Vries  <tdevries@suse.de>
+
 	* testsuite/libgomp.oacc-c-c++-common/vred2d-128.c: New test.
 	* testsuite/libgomp.oacc-fortran/gemm.f90: New test.
 	* testsuite/libgomp.oacc-c-c++-common/vector-length-128-10.c: New test.

libgomp/testsuite/libgomp.oacc-c-c++-common/pr85381-5.c

+/* { dg-additional-options "-save-temps" } */
+/* { dg-do run { target openacc_nvidia_accel_selected } }
+   { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+
+#define n 1024
+
+int
+main (void)
+{
+  #pragma acc parallel vector_length(128)
+  {
+    #pragma acc loop vector
+    for (int i = 0; i < n; i++)
+      ;
+
+    #pragma acc loop vector
+    for (int i = 0; i < n; i++)
+      ;
+  }
+
+  return 0;
+}
+
+/* { dg-final { scan-assembler-not "bar.sync" } } */

libgomp/testsuite/libgomp.oacc-c-c++-common/pr85381.c

+/* { dg-additional-options "-save-temps" } */
+/* { dg-do run { target openacc_nvidia_accel_selected } }
+   { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+
+int
+main (void)
+{
+  int v1;
+
+  #pragma acc parallel vector_length (128)
+  #pragma acc loop vector
+  for (v1 = 0; v1 < 20; v1 += 2)
+    ;
+
+  return 0;
+}
+
+/* { dg-final { scan-assembler-not "bar.sync" } } */