gcc/libgomp/testsuite/libgomp.oacc-c-c++-common/par-reduction-1.c

/* { dg-additional-options "-Wopenacc-parallelism" } for testing/documenting
   aspects of that functionality.  */

#include <assert.h>

/* Test of reduction on parallel directive.  */

#define ACTUAL_GANGS 256

int
main (int argc, char *argv[])
{
  int res, res1 = 0, res2 = 0;

#if defined(ACC_DEVICE_TYPE_host)
# define GANGS 1
#else
# define GANGS 256
#endif
  #pragma acc parallel num_gangs(GANGS) num_workers(32) vector_length(32) \
    reduction(+:res1) copy(res2, res1)
  /* { dg-bogus "warning: region is gang partitioned but does not contain gang partitioned code" "TODO 'reduction', 'atomic'" { xfail { ! openacc_host_selected } } .-2 } */
  /* { dg-warning "region is worker partitioned but does not contain worker partitioned code" "" { target *-*-* } .-3 } */
  /* { dg-warning "region is vector partitioned but does not contain vector partitioned code" "" { target *-*-* } .-4 } */
  {
    res1 += 5;

    #pragma acc atomic
    res2 += 5;
  }
  res = GANGS * 5;

  assert (res == res1);
  assert (res == res2);
#undef GANGS

  res = res1 = res2 = 1;

#if defined(ACC_DEVICE_TYPE_host)
# define GANGS 1
#else
# define GANGS 8
#endif
  #pragma acc parallel num_gangs(GANGS) num_workers(32) vector_length(32) \
    reduction(*:res1) copy(res1, res2)
  /* { dg-bogus "warning: region is gang partitioned but does not contain gang partitioned code" "TODO 'reduction', 'atomic'" { xfail { ! openacc_host_selected } } .-2 } */
  /* { dg-warning "region is worker partitioned but does not contain worker partitioned code" "" { target *-*-* } .-3 } */
  /* { dg-warning "region is vector partitioned but does not contain vector partitioned code" "" { target *-*-* } .-4 } */
  {
    res1 *= 5;

    #pragma acc atomic
    res2 *= 5;
  }
  for (int i = 0; i < GANGS; ++i)
    res *= 5;

  assert (res == res1);
  assert (res == res2);
#undef GANGS

  return 0;
}