anchor.diff:      ! wk(ik)=8.0,(ikx==iky >. wk(ik)=4.0)
       zfac=1.0d0/16d0
   
  +#ifdef _OPENACC
  +    call reduce_acc(zfac,zutmp,zu_NB,zrhotmp(:,0))
  +#endif
  +
   !$omp parallel private(tid)
   !$  tid=omp_get_thread_num()
  +
  +#ifndef _OPENACC
       call reduce(tid,zfac,zutmp,zu_NB)
  +#endif
   
   ! 1.T_3
   !$omp do OMP_SIMD
  
positive.code: 
      NVTX_BEG("sym1()",1)
  
  #ifndef _OPENACC
  !$omp parallel private(tid)
  !$  tid=omp_get_thread_num()
      call reduce(tid,1.0d0,zutmp,zu_NB)
  !$omp end parallel
  
      zrho_l(:) = zrhotmp(0:NL-1,0)
  #else
      !
      call reduce_acc(1.0d0, zutmp, zu_NB, zrho_l)
  #endif
  
      NVTX_END()
  
negative.code: 
      zfac=1.0d0/4d0
  
  #ifdef _OPENACC
      call reduce_acc(zfac,zutmp,zu_NB,zrhotmp(:,0))
  #endif
  
  !$omp parallel private(tid)
  !$  tid=omp_get_thread_num()
  
  #ifndef _OPENACC
      call reduce(tid,zfac,zutmp,zu_NB)
  #endif
  
  ! 1.T_3
  !$omp do OMP_SIMD
  