Runtime checking of OpenACC parallelism dimensions clauses

	libgomp/
	* testsuite/libgomp.oacc-c-c++-common/parallel-dims.c: Rewrite.
	* testsuite/lib/libgomp.exp
	(check_effective_target_openacc_nvidia_accel_configured): New
	proc.
	* testsuite/libgomp.oacc-c++/c++.exp (check_effective_target_c)
	(check_effective_target_c++): New procs.
	* testsuite/libgomp.oacc-c/c.exp (check_effective_target_c)
	(check_effective_target_c++): Likewise.

From-SVN: r248358

5 files changed, 548 insertions, 12 deletions

diff --git a/libgomp/ChangeLog b/libgomp/ChangeLog
index 8209f9f..8fd5f07 100644
--- a/libgomp/ChangeLog
+++ b/libgomp/ChangeLog
@@ -1,3 +1,14 @@
+2017-05-23  Thomas Schwinge  <thomas@codesourcery.com>
+
+	* testsuite/libgomp.oacc-c-c++-common/parallel-dims.c: Rewrite.
+	* testsuite/lib/libgomp.exp
+	(check_effective_target_openacc_nvidia_accel_configured): New
+	proc.
+	* testsuite/libgomp.oacc-c++/c++.exp (check_effective_target_c)
+	(check_effective_target_c++): New procs.
+	* testsuite/libgomp.oacc-c/c.exp (check_effective_target_c)
+	(check_effective_target_c++): Likewise.
+
 2017-05-22  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/80809
diff --git a/libgomp/testsuite/lib/libgomp.exp b/libgomp/testsuite/lib/libgomp.exp
index 501a860..ea3da2c 100644
--- a/libgomp/testsuite/lib/libgomp.exp
+++ b/libgomp/testsuite/lib/libgomp.exp
@@ -359,6 +359,18 @@ proc check_effective_target_offload_device_shared_as { } {
     } ]
 }
 
+# Return 1 if configured for nvptx offloading.
+
+proc check_effective_target_openacc_nvidia_accel_configured { } {
+    global offload_targets
+    if { ![string match "*,nvptx,*" ",$offload_targets,"] } {
+        return 0
+    }
+    # PR libgomp/65099: Currently, we only support offloading in 64-bit
+    # configurations.
+    return [is-effective-target lp64]
+}
+
 # Return 1 if at least one nvidia board is present.
 
 proc check_effective_target_openacc_nvidia_accel_present { } {
diff --git a/libgomp/testsuite/libgomp.oacc-c++/c++.exp b/libgomp/testsuite/libgomp.oacc-c++/c++.exp
index 608b298..9beadd6 100644
--- a/libgomp/testsuite/libgomp.oacc-c++/c++.exp
+++ b/libgomp/testsuite/libgomp.oacc-c++/c++.exp
@@ -4,6 +4,13 @@ load_lib libgomp-dg.exp
 load_gcc_lib gcc-dg.exp
 load_gcc_lib torture-options.exp
 
+proc check_effective_target_c { } {
+    return 0
+}
+proc check_effective_target_c++ { } {
+    return 1
+}
+
 global shlib_ext
 
 set shlib_ext [get_shlib_extension]
diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c
index f5766a4..d8af546 100644
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c
@@ -1,25 +1,524 @@
-/* { dg-do run { target openacc_nvidia_accel_selected } } */
+/* OpenACC parallelism dimensions clauses: num_gangs, num_workers,
+   vector_length.  */
+
+#include <limits.h>
+#include <openacc.h>
+
+/* TODO: "(int) acc_device_*" casts because of the C++ acc_on_device wrapper
+   not behaving as expected for -O0.  */
+#pragma acc routine seq
+static unsigned int __attribute__ ((optimize ("O2"))) acc_gang ()
+{
+  if (acc_on_device ((int) acc_device_host))
+    return 0;
+  else if (acc_on_device ((int) acc_device_nvidia))
+    {
+      unsigned int r;
+      asm volatile ("mov.u32 %0,%%ctaid.x;" : "=r" (r));
+      return r;
+    }
+  else
+    __builtin_abort ();
+}
+
+#pragma acc routine seq
+static unsigned int __attribute__ ((optimize ("O2"))) acc_worker ()
+{
+  if (acc_on_device ((int) acc_device_host))
+    return 0;
+  else if (acc_on_device ((int) acc_device_nvidia))
+    {
+      unsigned int r;
+      asm volatile ("mov.u32 %0,%%tid.y;" : "=r" (r));
+      return r;
+    }
+  else
+    __builtin_abort ();
+}
+
+#pragma acc routine seq
+static unsigned int __attribute__ ((optimize ("O2"))) acc_vector ()
+{
+  if (acc_on_device ((int) acc_device_host))
+    return 0;
+  else if (acc_on_device ((int) acc_device_nvidia))
+    {
+      unsigned int r;
+      asm volatile ("mov.u32 %0,%%tid.x;" : "=r" (r));
+      return r;
+    }
+  else
+    __builtin_abort ();
+}
 
-/* Worker and vector size checks.  Picked an outrageously large
-   value. */
 
 int main ()
 {
-  int dummy[10];
+  acc_init (acc_device_default);
+
+  /* Non-positive value.  */
+
+  /* GR, WS, VS.  */
+  {
+#define GANGS 0 /* { dg-warning "'num_gangs' value must be positive" "" { target c } } */
+    int gangs_actual = GANGS;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (gangs_actual) \
+  reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max) \
+  num_gangs (GANGS) /* { dg-warning "'num_gangs' value must be positive" "" { target c++ } } */
+    {
+      /* We're actually executing with num_gangs (1).  */
+      gangs_actual = 1;
+      for (int i = 100 * gangs_actual; i > -100 * gangs_actual; --i)
+	{
+	  /* <https://gcc.gnu.org/PR80547>.  */
+#if 0
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+#else
+	  int gangs = acc_gang ();
+	  gangs_min = (gangs_min < gangs) ? gangs_min : gangs;
+	  gangs_max = (gangs_max > gangs) ? gangs_max : gangs;
+	  int workers = acc_worker ();
+	  workers_min = (workers_min < workers) ? workers_min : workers;
+	  workers_max = (workers_max > workers) ? workers_max : workers;
+	  int vectors = acc_vector ();
+	  vectors_min = (vectors_min < vectors) ? vectors_min : vectors;
+	  vectors_max = (vectors_max > vectors) ? vectors_max : vectors;
+#endif
+	}
+    }
+    if (gangs_actual != 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != gangs_actual - 1
+	|| workers_min != 0 || workers_max != 0
+	|| vectors_min != 0 || vectors_max != 0)
+      __builtin_abort ();
+#undef GANGS
+  }
+
+  /* GP, WS, VS.  */
+  {
+#define GANGS 0 /* { dg-warning "'num_gangs' value must be positive" "" { target c } } */
+    int gangs_actual = GANGS;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (gangs_actual) \
+  num_gangs (GANGS) /* { dg-warning "'num_gangs' value must be positive" "" { target c++ } } */
+    {
+      /* We're actually executing with num_gangs (1).  */
+      gangs_actual = 1;
+#pragma acc loop gang reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * gangs_actual; i > -100 * gangs_actual; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (gangs_actual != 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != gangs_actual - 1
+	|| workers_min != 0 || workers_max != 0
+	|| vectors_min != 0 || vectors_max != 0)
+      __builtin_abort ();
+#undef GANGS
+  }
+
+  /* GR, WP, VS.  */
+  {
+#define WORKERS 0 /* { dg-warning "'num_workers' value must be positive" "" { target c } } */
+    int workers_actual = WORKERS;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (workers_actual) \
+  num_workers (WORKERS) /* { dg-warning "'num_workers' value must be positive" "" { target c++ } } */
+    {
+      /* We're actually executing with num_workers (1).  */
+      workers_actual = 1;
+#pragma acc loop worker reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * workers_actual; i > -100 * workers_actual; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (workers_actual != 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != 0
+	|| workers_min != 0 || workers_max != workers_actual - 1
+	|| vectors_min != 0 || vectors_max != 0)
+      __builtin_abort ();
+#undef WORKERS
+  }
+
+  /* GR, WS, VP.  */
+  {
+#define VECTORS 0 /* { dg-warning "'vector_length' value must be positive" "" { target c } } */
+    int vectors_actual = VECTORS;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (vectors_actual) /* { dg-warning "using vector_length \\(32\\), ignoring 1" "" { target openacc_nvidia_accel_configured } } */ \
+  vector_length (VECTORS) /* { dg-warning "'vector_length' value must be positive" "" { target c++ } } */
+    {
+      /* We're actually executing with vector_length (1), just the GCC nvptx
+	 back end enforces vector_length (32).  */
+      if (acc_on_device (acc_device_nvidia))
+	vectors_actual = 32;
+      else
+	vectors_actual = 1;
+#pragma acc loop vector reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * vectors_actual; i > -100 * vectors_actual; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (acc_get_device_type () == acc_device_nvidia)
+      {
+	if (vectors_actual != 32)
+	  __builtin_abort ();
+      }
+    else
+      if (vectors_actual != 1)
+	__builtin_abort ();
+    if (gangs_min != 0 || gangs_max != 0
+	|| workers_min != 0 || workers_max != 0
+	|| vectors_min != 0 || vectors_max != vectors_actual - 1)
+      __builtin_abort ();
+#undef VECTORS
+  }
+
 
-#pragma acc parallel num_workers (2<<20) /* { dg-error "using num_workers" } */
+  /* High value.  */
+  
+  /* GR, WS, VS.  */
   {
-#pragma acc loop worker
-    for (int  i = 0; i < 10; i++)
-      dummy[i] = i;
+    /* There is no actual limit for the number of gangs, so we try with a
+       rather high value.  */
+    int gangs = 12345;
+    int gangs_actual = gangs;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (gangs_actual) \
+  reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max) \
+  num_gangs (gangs)
+    {
+      if (acc_on_device (acc_device_host))
+	{
+	  /* We're actually executing with num_gangs (1).  */
+	  gangs_actual = 1;
+	}
+      /* As we're executing GR not GP, don't multiply with a "gangs_actual"
+	 factor.  */
+      for (int i = 100 /* * gangs_actual */; i > -100 /* * gangs_actual */; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (gangs_actual < 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != gangs_actual - 1
+	|| workers_min != 0 || workers_max != 0
+	|| vectors_min != 0 || vectors_max != 0)
+      __builtin_abort ();
   }
 
-#pragma acc parallel vector_length (2<<20) /* { dg-error "using vector_length" } */
+  /* GP, WS, VS.  */
   {
-#pragma acc loop vector
-    for (int  i = 0; i < 10; i++)
-      dummy[i] = i;
+    /* There is no actual limit for the number of gangs, so we try with a
+       rather high value.  */
+    int gangs = 12345;
+    int gangs_actual = gangs;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (gangs_actual) \
+  num_gangs (gangs)
+    {
+      if (acc_on_device (acc_device_host))
+	{
+	  /* We're actually executing with num_gangs (1).  */
+	  gangs_actual = 1;
+	}
+#pragma acc loop gang reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * gangs_actual; i > -100 * gangs_actual; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (gangs_actual < 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != gangs_actual - 1
+	|| workers_min != 0 || workers_max != 0
+	|| vectors_min != 0 || vectors_max != 0)
+      __builtin_abort ();
   }
 
+  /* GR, WP, VS.  */
+  {
+    /* We try with an outrageously large value. */
+#define WORKERS 2 << 20
+    int workers_actual = WORKERS;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (workers_actual) /* { dg-warning "using num_workers \\(32\\), ignoring 2097152" "" { target openacc_nvidia_accel_configured } } */ \
+  num_workers (WORKERS)
+    {
+      if (acc_on_device (acc_device_host))
+	{
+	  /* We're actually executing with num_workers (1).  */
+	  workers_actual = 1;
+	}
+      else if (acc_on_device (acc_device_nvidia))
+	{
+	  /* The GCC nvptx back end enforces num_workers (32).  */
+	  workers_actual = 32;
+	}
+      else
+	__builtin_abort ();
+#pragma acc loop worker reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * workers_actual; i > -100 * workers_actual; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (workers_actual < 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != 0
+	|| workers_min != 0 || workers_max != workers_actual - 1
+	|| vectors_min != 0 || vectors_max != 0)
+      __builtin_abort ();
+#undef WORKERS
+  }
+
+  /* GR, WP, VS.  */
+  {
+    /* We try with an outrageously large value. */
+    int workers = 2 << 20;
+    /* For nvptx offloading, this one will not result in "using num_workers
+       (32), ignoring runtime setting", and will in fact try to launch with
+       "num_workers (workers)", which will run into "libgomp: cuLaunchKernel
+       error: invalid argument".  So, limit ourselves here.  */
+    if (acc_get_device_type () == acc_device_nvidia)
+      workers = 32;
+    int workers_actual = workers;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (workers_actual) \
+  num_workers (workers)
+    {
+      if (acc_on_device (acc_device_host))
+	{
+	  /* We're actually executing with num_workers (1).  */
+	  workers_actual = 1;
+	}
+      else if (acc_on_device (acc_device_nvidia))
+	{
+	  /* We're actually executing with num_workers (32).  */
+	  /* workers_actual = 32; */
+	}
+      else
+	__builtin_abort ();
+#pragma acc loop worker reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * workers_actual; i > -100 * workers_actual; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (workers_actual < 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != 0
+	|| workers_min != 0 || workers_max != workers_actual - 1
+	|| vectors_min != 0 || vectors_max != 0)
+      __builtin_abort ();
+  }
+
+  /* GR, WS, VP.  */
+  {
+    /* We try with an outrageously large value. */
+#define VECTORS 2 << 20
+    int vectors_actual = VECTORS;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (vectors_actual) /* { dg-warning "using vector_length \\(32\\), ignoring 2097152" "" { target openacc_nvidia_accel_configured } } */ \
+  vector_length (VECTORS)
+    {
+      if (acc_on_device (acc_device_host))
+	{
+	  /* We're actually executing with vector_length (1).  */
+	  vectors_actual = 1;
+	}
+      else if (acc_on_device (acc_device_nvidia))
+	{
+	  /* The GCC nvptx back end enforces vector_length (32).  */
+	  vectors_actual = 32;
+	}
+      else
+	__builtin_abort ();
+#pragma acc loop vector reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * vectors_actual; i > -100 * vectors_actual; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (vectors_actual < 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != 0
+	|| workers_min != 0 || workers_max != 0
+	|| vectors_min != 0 || vectors_max != vectors_actual - 1)
+      __builtin_abort ();
+#undef VECTORS
+  }
+
+  /* GR, WS, VP.  */
+  {
+    /* We try with an outrageously large value. */
+    int vectors = 2 << 20;
+    int vectors_actual = vectors;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (vectors_actual) /* { dg-warning "using vector_length \\(32\\), ignoring runtime setting" "" { target openacc_nvidia_accel_configured } } */ \
+  vector_length (vectors)
+    {
+      if (acc_on_device (acc_device_host))
+	{
+	  /* We're actually executing with vector_length (1).  */
+	  vectors_actual = 1;
+	}
+      else if (acc_on_device (acc_device_nvidia))
+	{
+	  /* The GCC nvptx back end enforces vector_length (32).  */
+	  vectors_actual = 32;
+	}
+      else
+	__builtin_abort ();
+#pragma acc loop vector reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * vectors_actual; i > -100 * vectors_actual; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (vectors_actual < 1)
+      __builtin_abort ();
+    if (gangs_min != 0 || gangs_max != 0
+	|| workers_min != 0 || workers_max != 0
+	|| vectors_min != 0 || vectors_max != vectors_actual - 1)
+      __builtin_abort ();
+  }
+
+
+  /* Composition of GP, WP, VP.  */
+  {
+    int gangs = 12345;
+    /* With nvptx offloading, multi-level reductions apparently are very slow
+       in the following case.  So, limit ourselves here.  */
+    if (acc_get_device_type () == acc_device_nvidia)
+      gangs = 3;
+    int gangs_actual = gangs;
+#define WORKERS 3
+    int workers_actual = WORKERS;
+#define VECTORS 11
+    int vectors_actual = VECTORS;
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc parallel copy (gangs_actual, workers_actual, vectors_actual) /* { dg-warning "using vector_length \\(32\\), ignoring 11" "" { target openacc_nvidia_accel_configured } } */ \
+  num_gangs (gangs) \
+  num_workers (WORKERS) \
+  vector_length (VECTORS)
+    {
+      if (acc_on_device (acc_device_host))
+	{
+	  /* We're actually executing with num_gangs (1), num_workers (1),
+	     vector_length (1).  */
+	  gangs_actual = 1;
+	  workers_actual = 1;
+	  vectors_actual = 1;
+	}
+      else if (acc_on_device (acc_device_nvidia))
+	{
+	  /* The GCC nvptx back end enforces vector_length (32).  */
+	  vectors_actual = 32;
+	}
+      else
+	__builtin_abort ();
+#pragma acc loop gang reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100 * gangs_actual; i > -100 * gangs_actual; --i)
+#pragma acc loop worker reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+	for (int j = 100 * workers_actual; j > -100 * workers_actual; --j)
+#pragma acc loop vector reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+	  for (int k = 100 * vectors_actual; k > -100 * vectors_actual; --k)
+	    {
+	      gangs_min = gangs_max = acc_gang ();
+	      workers_min = workers_max = acc_worker ();
+	      vectors_min = vectors_max = acc_vector ();
+	    }
+    }
+    if (gangs_min != 0 || gangs_max != gangs_actual - 1
+	|| workers_min != 0 || workers_max != workers_actual - 1
+	|| vectors_min != 0 || vectors_max != vectors_actual - 1)
+      __builtin_abort ();
+#undef VECTORS
+#undef WORKERS
+  }
+
+
+  /* We can't test parallelized OpenACC kernels constructs in this way: use of
+     the acc_gang, acc_worker, acc_vector functions will make the construct
+     unparallelizable.  */
+
+
+  /* Unparallelized OpenACC kernels constructs must get launched as 1 x 1 x 1
+     kernels.  */
+  {
+    int gangs_min, gangs_max, workers_min, workers_max, vectors_min, vectors_max;
+    gangs_min = workers_min = vectors_min = INT_MAX;
+    gangs_max = workers_max = vectors_max = INT_MIN;
+#pragma acc kernels
+    {
+      /* This is to make the OpenACC kernels construct unparallelizable.  */
+      asm volatile ("" : : : "memory");
+
+#pragma acc loop reduction (min: gangs_min, workers_min, vectors_min) reduction (max: gangs_max, workers_max, vectors_max)
+      for (int i = 100; i > -100; --i)
+	{
+	  gangs_min = gangs_max = acc_gang ();
+	  workers_min = workers_max = acc_worker ();
+	  vectors_min = vectors_max = acc_vector ();
+	}
+    }
+    if (gangs_min != 0 || gangs_max != 1 - 1
+	|| workers_min != 0 || workers_max != 1 - 1
+	|| vectors_min != 0 || vectors_max != 1 - 1)
+      __builtin_abort ();
+  }
+
+
   return 0;
 }
diff --git a/libgomp/testsuite/libgomp.oacc-c/c.exp b/libgomp/testsuite/libgomp.oacc-c/c.exp
index b509a10..4475bf5 100644
--- a/libgomp/testsuite/libgomp.oacc-c/c.exp
+++ b/libgomp/testsuite/libgomp.oacc-c/c.exp
@@ -15,6 +15,13 @@ load_lib libgomp-dg.exp
 load_gcc_lib gcc-dg.exp
 load_gcc_lib torture-options.exp
 
+proc check_effective_target_c { } {
+    return 1
+}
+proc check_effective_target_c++ { } {
+    return 0
+}
+
 # Initialize dg.
 dg-init
 torture-init