Refactor: split sum_stoband to sum_stoband and cal_storho (#5600)

Author: Qianruipku

source/module_hamilt_pw/hamilt_stodft/sto_iter.cpp

@@ -479,8 +479,7 @@ void Stochastic_Iter<T, Device>::sum_stoband(Stochastic_WF<T, Device>& stowf,
 {
     ModuleBase::TITLE("Stochastic_Iter", "sum_stoband");
     ModuleBase::timer::tick("Stochastic_Iter", "sum_stoband");
-    int nrxx = wfc_basis->nrxx;
-    int npwx = wfc_basis->npwk_max;
+    const int npwx = wfc_basis->npwk_max;
     const int norder = p_che->norder;
 
     //---------------cal demet-----------------------
@@ -557,33 +556,53 @@ void Stochastic_Iter<T, Device>::sum_stoband(Stochastic_WF<T, Device>& stowf,
     MPI_Allreduce(MPI_IN_PLACE, &sto_eband, 1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
 #endif
     pes->f_en.eband += sto_eband;
-    //---------------------cal rho-------------------------
-    double* sto_rho = new double[nrxx];
+    ModuleBase::timer::tick("Stochastic_Iter", "sum_stoband");
+}
 
-    double dr3 = GlobalC::ucell.omega / wfc_basis->nxyz;
-    double tmprho, tmpne;
-    T outtem;
-    double sto_ne = 0;
-    ModuleBase::GlobalFunc::ZEROS(sto_rho, nrxx);
+template <typename T, typename Device>
+void Stochastic_Iter<T, Device>::cal_storho(Stochastic_WF<T, Device>& stowf,
+                                             elecstate::ElecStatePW<T, Device>* pes,
+                                             ModulePW::PW_Basis_K* wfc_basis)
+{
+    ModuleBase::TITLE("Stochastic_Iter", "cal_storho");
+    ModuleBase::timer::tick("Stochastic_Iter", "cal_storho");
+    //---------------------cal rho-------------------------
+    const int nrxx = wfc_basis->nrxx;
+    const int npwx = wfc_basis->npwk_max;
+    const int nspin = PARAM.inp.nspin;
 
     T* porter = nullptr;
     resmem_complex_op()(this->ctx, porter, nrxx);
-    double out2;
 
-    double* ksrho = nullptr;
-    if (PARAM.inp.nbands > 0 && GlobalV::MY_STOGROUP == 0)
+    std::vector<double*> sto_rho(nspin);
+    for(int is = 0; is < nspin; ++is)
+    {
+        sto_rho[is] = pes->charge->rho[is];
+    }
+    std::vector<double> _tmprho;
+    if (PARAM.inp.nbands > 0)
     {
-        ksrho = new double[nrxx];
-        ModuleBase::GlobalFunc::DCOPY(pes->charge->rho[0], ksrho, nrxx);
-        setmem_var_op()(this->ctx, pes->rho[0], 0, nrxx);
-        // ModuleBase::GlobalFunc::ZEROS(pes->charge->rho[0], nrxx);
+        // If there are KS orbitals, we need to allocate another memory for sto_rho
+        _tmprho.resize(nrxx * nspin);
+        for(int is = 0; is < nspin; ++is)
+        {
+            sto_rho[is] = _tmprho.data() + is * nrxx;
+        }
     }
 
+    // pes->rho is a device memory, and when using cpu and double, we donot need to allocate memory for pes->rho 
+    if (PARAM.inp.device != "gpu" && PARAM.inp.precision != "single") {
+        pes->rho = reinterpret_cast<Real **>(sto_rho.data());
+    }
+    for (int is = 0; is < nspin; is++)
+    {
+        setmem_var_op()(this->ctx, pes->rho[is], 0, nrxx);
+    }
     for (int ik = 0; ik < this->pkv->get_nks(); ++ik)
     {
         const int nchip_ik = nchip[ik];
         int current_spin = 0;
-        if (PARAM.inp.nspin == 2)
+        if (nspin == 2)
         {
             current_spin = this->pkv->isk[ik];
         }
@@ -602,27 +621,50 @@ void Stochastic_Iter<T, Device>::sum_stoband(Stochastic_WF<T, Device>& stowf,
         }
     }
     if (PARAM.inp.device == "gpu" || PARAM.inp.precision == "single") {
-        for (int ii = 0; ii < PARAM.inp.nspin; ii++) {
-            castmem_var_d2h_op()(this->cpu_ctx, this->ctx, pes->charge->rho[ii], pes->rho[ii], nrxx);
+        for(int is = 0; is < nspin; ++is)
+        {
+            castmem_var_d2h_op()(this->cpu_ctx, this->ctx, sto_rho[is], pes->rho[is], nrxx);
         }
     }
+    else
+    {
+        // We need to set pes->rho back to the original value
+        pes->rho = reinterpret_cast<Real **>(pes->charge->rho);
+    }
+
     delmem_complex_op()(this->ctx, porter);
 #ifdef __MPI
-    // temporary, rho_mpi should be rewrite as a tool function! Now it only treats pes->charge->rho
-    pes->charge->rho_mpi();
+    if(GlobalV::KPAR > 1)
+    {
+        for (int is = 0; is < nspin; ++is)
+        {
+            pes->charge->reduce_diff_pools(sto_rho[is]);
+        }
+    }
 #endif
-    for (int ir = 0; ir < nrxx; ++ir)
+
+    double sto_ne = 0;
+    for(int is = 0; is < nspin; ++is)
     {
-        tmprho = pes->charge->rho[0][ir] / GlobalC::ucell.omega;
-        sto_rho[ir] = tmprho;
-        sto_ne += tmprho;
+#ifdef _OPENMP
+#pragma omp parallel for reduction(+ : sto_ne)
+#endif
+        for (int ir = 0; ir < nrxx; ++ir)
+        {
+            sto_rho[is][ir] /= GlobalC::ucell.omega;
+            sto_ne += sto_rho[is][ir];
+        }
     }
-    sto_ne *= dr3;
+
+    sto_ne *= GlobalC::ucell.omega / wfc_basis->nxyz;
 
 #ifdef __MPI
     MPI_Allreduce(MPI_IN_PLACE, &sto_ne, 1, MPI_DOUBLE, MPI_SUM, POOL_WORLD);
     MPI_Allreduce(MPI_IN_PLACE, &sto_ne, 1, MPI_DOUBLE, MPI_SUM, PARAPW_WORLD);
-    MPI_Allreduce(MPI_IN_PLACE, sto_rho, nrxx, MPI_DOUBLE, MPI_SUM, PARAPW_WORLD);
+    for(int is = 0; is < nspin; ++is)
+    {
+        MPI_Allreduce(MPI_IN_PLACE, sto_rho[is], nrxx, MPI_DOUBLE, MPI_SUM, PARAPW_WORLD);
+    }
 #endif
     double factor = targetne / (KS_ne + sto_ne);
     if (std::abs(factor - 1) > 1e-10)
@@ -635,32 +677,32 @@ void Stochastic_Iter<T, Device>::sum_stoband(Stochastic_WF<T, Device>& stowf,
         factor = 1;
     }
 
-    if (GlobalV::MY_STOGROUP == 0)
+    for (int is = 0; is < 1; ++is)
     {
         if (PARAM.inp.nbands > 0)
         {
-            ModuleBase::GlobalFunc::DCOPY(ksrho, pes->charge->rho[0], nrxx);
+#ifdef _OPENMP
+#pragma omp parallel for
+#endif
+            for (int ir = 0; ir < nrxx; ++ir)
+            {
+                pes->charge->rho[is][ir] += sto_rho[is][ir];
+                pes->charge->rho[is][ir] *= factor;
+            }
         }
         else
         {
-            ModuleBase::GlobalFunc::ZEROS(pes->charge->rho[0], nrxx);
-        }
-    }
-
-    if (GlobalV::MY_STOGROUP == 0)
-    {
-        for (int is = 0; is < 1; ++is)
-        {
+#ifdef _OPENMP
+#pragma omp parallel for
+#endif
             for (int ir = 0; ir < nrxx; ++ir)
             {
-                pes->charge->rho[is][ir] += sto_rho[ir];
                 pes->charge->rho[is][ir] *= factor;
             }
         }
     }
-    delete[] sto_rho;
-    delete[] ksrho;
-    ModuleBase::timer::tick("Stochastic_Iter", "sum_stoband");
+
+    ModuleBase::timer::tick("Stochastic_Iter", "cal_storho");
     return;
 }
 

source/module_hamilt_pw/hamilt_stodft/sto_iter.h

@@ -44,19 +44,72 @@ class Stochastic_Iter
               StoChe<Real, Device>& stoche,
               hamilt::HamiltSdftPW<T, Device>* p_hamilt_sto);
 
+    /**
+     * @brief sum demet and eband energies for each k point and each band
+     * 
+     * @param stowf stochastic wave function
+     * @param pes elecstate
+     * @param pHamilt hamiltonian
+     * @param wfc_basis wfc pw basis
+     */
     void sum_stoband(Stochastic_WF<T, Device>& stowf,
                      elecstate::ElecStatePW<T, Device>* pes,
                      hamilt::Hamilt<T, Device>* pHamilt,
                      ModulePW::PW_Basis_K* wfc_basis);
 
+    /**
+     * @brief calculate the density
+     * 
+     * @param stowf stochastic wave function
+     * @param pes elecstate
+     * @param wfc_basis wfc pw basis
+     */
+    void cal_storho(Stochastic_WF<T, Device>& stowf,
+                    elecstate::ElecStatePW<T, Device>* pes,
+                    ModulePW::PW_Basis_K* wfc_basis);
+
+    /**
+     * @brief calculate total number of electrons
+     * 
+     * @param pes elecstate
+     * @return double 
+     */
     double calne(elecstate::ElecState* pes);
 
+    /**
+     * @brief solve ne(mu) = ne_target and get chemical potential mu
+     * 
+     * @param iter scf iteration index
+     * @param pes elecstate
+     */
     void itermu(const int iter, elecstate::ElecState* pes);
 
+    /**
+     * @brief orthogonalize stochastic wave functions with KS wave functions
+     * 
+     * @param ik k point index
+     * @param psi KS wave functions
+     * @param stowf stochastic wave functions
+     */
     void orthog(const int& ik, psi::Psi<T, Device>& psi, Stochastic_WF<T, Device>& stowf);
 
+    /**
+     * @brief check emax and emin
+     * 
+     * @param ik k point index
+     * @param istep ion step index
+     * @param iter scf iteration index
+     * @param stowf stochastic wave functions
+     */
     void checkemm(const int& ik, const int istep, const int iter, Stochastic_WF<T, Device>& stowf);
 
+    /**
+     * @brief check precision of Chebyshev expansion
+     * 
+     * @param ref reference value
+     * @param thr threshold
+     * @param info information
+     */
     void check_precision(const double ref, const double thr, const std::string info);
 
     ModuleBase::Chebyshev<double, Device>* p_che = nullptr;

source/module_hsolver/hsolver_pw_sdft.cpp

@@ -128,15 +128,10 @@ void HSolverPW_SDFT<T, Device>::solve(hamilt::Hamilt<T, Device>* pHamilt,
         MPI_Bcast(&pes->f_en.eband, 1, MPI_DOUBLE, 0, PARAPW_WORLD);
 #endif
     }
-    else
-    {
-        for (int is = 0; is < this->nspin; is++)
-        {
-            setmem_var_op()(this->ctx, pes_pw->rho[is], 0, pes_pw->charge->nrxx);
-        }
-    }
+    
     // calculate stochastic rho
     stoiter.sum_stoband(stowf, pes_pw, pHamilt, wfc_basis);
+    stoiter.cal_storho(stowf, pes_pw, wfc_basis);
 
     // will do rho symmetry and energy calculation in esolver
     ModuleBase::timer::tick("HSolverPW_SDFT", "solve");

source/module_hsolver/test/test_hsolver_sdft.cpp

@@ -151,6 +151,13 @@ void Stochastic_Iter<T, Device>::sum_stoband(Stochastic_WF<T, Device>& stowf,
     return;
 }
 
+template <typename T, typename Device>
+void Stochastic_Iter<T, Device>::cal_storho(Stochastic_WF<T, Device>& stowf,
+                                             elecstate::ElecStatePW<T, Device>* pes,
+                                             ModulePW::PW_Basis_K* wfc_basis)
+{
+}
+
 Charge::Charge(){};
 Charge::~Charge(){};