anchor.diff:  
       NVTX_BEG("sym1()",1)
   
  -#ifndef _OPENACC
  +#ifdef _OPENACC
  +    call reduce_acc(1.0d0,zutmp,zu_NB,zrho_l)
  +#else
   !$omp parallel private(tid)
   !$  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()
  
positive.code: !$omp end do OMP_SIMD
  !$omp end parallel
    end subroutine
    !====== tetragonal(8) structure =========================!
    subroutine sym8_tetragonal(zutmp,zu_NB,zrho_l,zrhotmp1,zrhotmp2)
      use global_variables
  
negative.code:     ! wk(ik)=8.0,(ikx==iky >. wk(ik)=4.0)
      zfac=1.0d0/32d0
  
  #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_4
  !$omp do OMP_SIMD
  