Hadrons: moving Hadrons to root directory, build system improvements

Grid/qcd/action/scalar/ScalarInteractionAction.h

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+/*************************************************************************************
+
+  Grid physics library, www.github.com/paboyle/Grid
+
+  Source file: ./lib/qcd/action/gauge/WilsonGaugeAction.h
+
+  Copyright (C) 2015
+
+  Author: Guido Cossu <guido,cossu@ed.ac.uk>
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License along
+  with this program; if not, write to the Free Software Foundation, Inc.,
+  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+  See the full license in the file "LICENSE" in the top level distribution
+directory
+  *************************************************************************************/
+/*  END LEGAL */
+
+#ifndef SCALAR_INT_ACTION_H
+#define SCALAR_INT_ACTION_H
+
+// Note: this action can completely absorb the ScalarAction for real float fields
+// use the scalarObjs to generalise the structure
+
+namespace Grid
+{
+// FIXME drop the QCD namespace everywhere here
+
+template <class Impl, int Ndim>
+class ScalarInteractionAction : public QCD::Action<typename Impl::Field>
+{
+public:
+  INHERIT_FIELD_TYPES(Impl);
+
+private:
+  RealD mass_square;
+  RealD lambda;
+  RealD g;
+  const unsigned int N = Impl::Group::Dimension;
+
+  typedef typename Field::vector_object vobj;
+  typedef CartesianStencil<vobj, vobj> Stencil;
+
+  SimpleCompressor<vobj> compressor;
+  int npoint = 2 * Ndim;
+  std::vector<int> directions;    //
+  std::vector<int> displacements; //
+
+public:
+  ScalarInteractionAction(RealD ms, RealD l, RealD gval) : mass_square(ms), lambda(l), g(gval), displacements(2 * Ndim, 0), directions(2 * Ndim, 0)
+  {
+    for (int mu = 0; mu < Ndim; mu++)
+    {
+      directions[mu] = mu;
+      directions[mu + Ndim] = mu;
+      displacements[mu] = 1;
+      displacements[mu + Ndim] = -1;
+    }
+  }
+
+  virtual std::string LogParameters()
+  {
+    std::stringstream sstream;
+    sstream << GridLogMessage << "[ScalarAction] lambda      : " << lambda << std::endl;
+    sstream << GridLogMessage << "[ScalarAction] mass_square : " << mass_square << std::endl;
+    sstream << GridLogMessage << "[ScalarAction] g           : " << g << std::endl;
+    return sstream.str();
+  }
+
+  virtual std::string action_name() { return "ScalarAction"; }
+
+  virtual void refresh(const Field &U, GridParallelRNG &pRNG) {}
+
+  virtual RealD S(const Field &p)
+  {
+    assert(p._grid->Nd() == Ndim);
+    static Stencil phiStencil(p._grid, npoint, 0, directions, displacements);
+    phiStencil.HaloExchange(p, compressor);
+    Field action(p._grid), pshift(p._grid), phisquared(p._grid);
+    phisquared = p * p;
+    action = (2.0 * Ndim + mass_square) * phisquared - lambda * phisquared * phisquared;
+    for (int mu = 0; mu < Ndim; mu++)
+    {
+      //  pshift = Cshift(p, mu, +1);  // not efficient, implement with stencils
+      parallel_for(int i = 0; i < p._grid->oSites(); i++)
+      {
+        int permute_type;
+        StencilEntry *SE;
+        vobj temp2;
+        const vobj *temp, *t_p;
+
+        SE = phiStencil.GetEntry(permute_type, mu, i);
+        t_p = &p._odata[i];
+        if (SE->_is_local)
+        {
+          temp = &p._odata[SE->_offset];
+          if (SE->_permute)
+          {
+            permute(temp2, *temp, permute_type);
+            action._odata[i] -= temp2 * (*t_p) + (*t_p) * temp2;
+          }
+          else
+          {
+            action._odata[i] -= (*temp) * (*t_p) + (*t_p) * (*temp);
+          }
+        }
+        else
+        {
+          action._odata[i] -= phiStencil.CommBuf()[SE->_offset] * (*t_p) + (*t_p) * phiStencil.CommBuf()[SE->_offset];
+        }
+      }
+      //  action -= pshift*p + p*pshift;
+    }
+    // NB the trace in the algebra is normalised to 1/2
+    // minus sign coming from the antihermitian fields
+    return -(TensorRemove(sum(trace(action)))).real() * N / g;
+  };
+
+  virtual void deriv(const Field &p, Field &force)
+  {
+    double t0 = usecond();
+    assert(p._grid->Nd() == Ndim);
+    force = (2. * Ndim + mass_square) * p - 2. * lambda * p * p * p;
+    double interm_t = usecond();
+
+    // move this outside
+    static Stencil phiStencil(p._grid, npoint, 0, directions, displacements);
+
+    phiStencil.HaloExchange(p, compressor);
+    double halo_t = usecond();
+    int chunk = 128;
+    //for (int mu = 0; mu < QCD::Nd; mu++) force -= Cshift(p, mu, -1) + Cshift(p, mu, 1);
+
+    // inverting the order of the loops slows down the code(! g++ 7)
+    // cannot try to reduce the number of  force writes by factor npoint...
+    // use cache blocking
+    for (int point = 0; point < npoint; point++)
+    {
+
+#pragma omp parallel 
+{
+        int permute_type;
+        StencilEntry *SE;
+        const vobj *temp;
+
+#pragma omp for schedule(static, chunk)
+      for (int i = 0; i < p._grid->oSites(); i++)
+      {
+        SE = phiStencil.GetEntry(permute_type, point, i);
+        // prefetch next p?
+
+        if (SE->_is_local)
+        {
+          temp = &p._odata[SE->_offset];
+      
+          if (SE->_permute)
+          {
+            vobj temp2;
+            permute(temp2, *temp, permute_type);
+            force._odata[i] -= temp2;
+          }
+          else
+          {
+            force._odata[i] -= *temp; // slow part. Dominated by this read/write (BW)
+          }
+        }
+        else
+        {
+          force._odata[i] -= phiStencil.CommBuf()[SE->_offset];
+        }
+      }
+
+    }
+  }
+  force *= N / g;
+
+  double t1 = usecond();
+  double total_time = (t1 - t0) / 1e6;
+  double interm_time = (interm_t - t0) / 1e6;
+  double halo_time = (halo_t - interm_t) / 1e6;
+  double stencil_time = (t1 - halo_t) / 1e6;
+  std::cout << GridLogIntegrator << "Total time for force computation (s)       : " << total_time << std::endl;
+  std::cout << GridLogIntegrator << "Intermediate time for force computation (s): " << interm_time << std::endl;
+  std::cout << GridLogIntegrator << "Halo time in force computation (s)         : " << halo_time << std::endl;
+  std::cout << GridLogIntegrator << "Stencil time in force computation (s)      : " << stencil_time << std::endl;
+  double flops = p._grid->gSites() * (14 * N * N * N + 18 * N * N + 2);
+  double flops_no_stencil = p._grid->gSites() * (14 * N * N * N + 6 * N * N + 2);
+  double Gflops = flops / (total_time * 1e9);
+  double Gflops_no_stencil = flops_no_stencil / (interm_time * 1e9);
+  std::cout << GridLogIntegrator << "Flops: " << flops << "  - Gflop/s : " << Gflops << std::endl;
+  std::cout << GridLogIntegrator << "Flops NS: " << flops_no_stencil << "  - Gflop/s NS: " << Gflops_no_stencil << std::endl;
+}
+};
+
+} // namespace Grid
+
+#endif // SCALAR_INT_ACTION_H