Commit 14dc1c69 authored by Steve Plimpton's avatar Steve Plimpton Committed by GitHub
Browse files

Merge pull request #683 from wmbrownIntel/pppm_intel_fix

Fixing bug in pppm/intel for AVX-512 with single precision and ik diff.
parents a1f5693f 7e58f084
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+16 −264
Original line number Diff line number Diff line
@@ -66,11 +66,7 @@ PPPMIntel::PPPMIntel(LAMMPS *lmp, int narg, char **arg) : PPPM(lmp, narg, arg)
  rho_lookup = drho_lookup = NULL;
  rho_points = 0;

  vdxy_brick = vdz0_brick = NULL;
  work3 = NULL;
  cg_pack = NULL;

  _use_table = _use_packing = _use_lrt = 0;
  _use_table = _use_lrt = 0;
}

PPPMIntel::~PPPMIntel()
@@ -82,12 +78,6 @@ PPPMIntel::~PPPMIntel()

  memory->destroy(rho_lookup);
  memory->destroy(drho_lookup);

  memory->destroy3d_offset(vdxy_brick, nzlo_out, nylo_out, 2*nxlo_out);
  memory->destroy3d_offset(vdz0_brick, nzlo_out, nylo_out, 2*nxlo_out);
  memory->destroy(work3);

  delete cg_pack;
}

/* ----------------------------------------------------------------------
@@ -141,36 +131,6 @@ void PPPMIntel::init()
  if (order > INTEL_P3M_MAXORDER)
    error->all(FLERR,"PPPM order greater than supported by USER-INTEL\n");

  _use_packing = (order == 7) && (INTEL_VECTOR_WIDTH == 16)
                              && (sizeof(FFT_SCALAR) == sizeof(float))
                              && (differentiation_flag == 0);
  if (_use_packing) {
    memory->destroy3d_offset(vdx_brick,nzlo_out,nylo_out,nxlo_out);
    memory->destroy3d_offset(vdy_brick,nzlo_out,nylo_out,nxlo_out);
    memory->destroy3d_offset(vdz_brick,nzlo_out,nylo_out,nxlo_out);
    memory->destroy3d_offset(vdxy_brick, nzlo_out, nylo_out, 2*nxlo_out);
    create3d_offset(vdxy_brick, nzlo_out, nzhi_out+2,
		    nylo_out, nyhi_out, 2*nxlo_out, 2*nxhi_out+1,
		    "pppmintel:vdxy_brick");
    memory->destroy3d_offset(vdz0_brick, nzlo_out, nylo_out, 2*nxlo_out);
    create3d_offset(vdz0_brick, nzlo_out, nzhi_out+2,
		    nylo_out, nyhi_out, 2*nxlo_out, 2*nxhi_out+1,
		    "pppmintel:vdz0_brick");
    memory->destroy(work3);
    memory->create(work3, 2*nfft_both, "pppmintel:work3");

    // new communicator for the double-size bricks
    delete cg_pack;
    int (*procneigh)[2] = comm->procneigh;
    cg_pack = new GridComm(lmp,world,2,0, 2*nxlo_in,2*nxhi_in+1,nylo_in,
                           nyhi_in,nzlo_in,nzhi_in, 2*nxlo_out,2*nxhi_out+1,
                           nylo_out,nyhi_out,nzlo_out,nzhi_out,
                           procneigh[0][0],procneigh[0][1],procneigh[1][0],
                           procneigh[1][1],procneigh[2][0],procneigh[2][1]);

    cg_pack->ghost_notify();
    cg_pack->setup();
  }
}

/* ----------------------------------------------------------------------
@@ -272,18 +232,13 @@ void PPPMIntel::compute_first(int eflag, int vflag)
  // also performs per-atom calculations via poisson_peratom()

  if (differentiation_flag == 1) poisson_ad();
  else poisson_ik_intel();
  else poisson_ik();

  // all procs communicate E-field values
  // to fill ghost cells surrounding their 3d bricks

  if (differentiation_flag == 1) cg->forward_comm(this,FORWARD_AD);
  else {
    if (_use_packing)
      cg_pack->forward_comm(this,FORWARD_IK);
    else
      cg->forward_comm(this,FORWARD_IK);
  }
  else cg->forward_comm(this,FORWARD_IK);

  // extra per-atom energy/virial communication

@@ -604,7 +559,7 @@ void PPPMIntel::make_rho(IntelBuffers<flt_t,acc_t> *buffers)
   interpolate from grid to get electric field & force on my particles for ik
------------------------------------------------------------------------- */

template<class flt_t, class acc_t, int use_table, int use_packing>
template<class flt_t, class acc_t, int use_table>
void PPPMIntel::fieldforce_ik(IntelBuffers<flt_t,acc_t> *buffers)
{
  // loop over my charges, interpolate electric field from nearby grid points
@@ -649,9 +604,9 @@ void PPPMIntel::fieldforce_ik(IntelBuffers<flt_t,acc_t> *buffers)
      int ny = part2grid[i][1];
      int nz = part2grid[i][2];

      int nxsum = (use_packing ? 2 : 1) * (nx + nlower);
      int nxsum = nx + nlower;
      int nysum = ny + nlower;
      int nzsum = nz + nlower;;
      int nzsum = nz + nlower;

      FFT_SCALAR dx = nx+fshiftone - (x[i].x-lo0)*xi;
      FFT_SCALAR dy = ny+fshiftone - (x[i].y-lo1)*yi;
@@ -668,12 +623,7 @@ void PPPMIntel::fieldforce_ik(IntelBuffers<flt_t,acc_t> *buffers)
        #pragma simd
        #endif
        for (int k = 0; k < INTEL_P3M_ALIGNED_MAXORDER; k++) {
          if (use_packing) {
            rho0[2 * k] = rho_lookup[idx][k];
            rho0[2 * k + 1] = rho_lookup[idx][k];
          } else {
	  rho0[k] = rho_lookup[idx][k];
          }
          rho1[k] = rho_lookup[idy][k];
          rho2[k] = rho_lookup[idz][k];
        }
@@ -690,12 +640,7 @@ void PPPMIntel::fieldforce_ik(IntelBuffers<flt_t,acc_t> *buffers)
            r2 = rho_coeff[l][k] + r2*dy;
            r3 = rho_coeff[l][k] + r3*dz;
          }
          if (use_packing) {
            rho0[2 * (k-nlower)] = r1;
            rho0[2 * (k-nlower) + 1] = r1;
          } else {
	  rho0[k-nlower] = r1;
          }
          rho1[k-nlower] = r2;
          rho2[k-nlower] = r3;
        }
@@ -722,38 +667,24 @@ void PPPMIntel::fieldforce_ik(IntelBuffers<flt_t,acc_t> *buffers)
          #if defined(LMP_SIMD_COMPILER)
          #pragma simd
          #endif
          for (int l = 0; l < (use_packing ? 2 : 1) *
                 INTEL_P3M_ALIGNED_MAXORDER; l++) {
          for (int l = 0; l < INTEL_P3M_ALIGNED_MAXORDER; l++) {
            int mx = l+nxsum;
            FFT_SCALAR x0 = y0*rho0[l];
            if (use_packing) {
              ekxy_arr[l] -= x0*vdxy_brick[mz][my][mx];
              ekz0_arr[l] -= x0*vdz0_brick[mz][my][mx];
            } else {
	    ekx_arr[l] -= x0*vdx_brick[mz][my][mx];
	    eky_arr[l] -= x0*vdy_brick[mz][my][mx];
	    ekz_arr[l] -= x0*vdz_brick[mz][my][mx];
          }
        }
      }
      }

      FFT_SCALAR ekx, eky, ekz;
      ekx = eky = ekz = ZEROF;

      if (use_packing) {
        for (int l = 0; l < 2*order; l += 2) {
          ekx += ekxy_arr[l];
          eky += ekxy_arr[l+1];
          ekz += ekz0_arr[l];
        }
      } else {
      for (int l = 0; l < order; l++) {
	ekx += ekx_arr[l];
	eky += eky_arr[l];
	ekz += ekz_arr[l];
      }
      }

      // convert E-field to force

@@ -965,137 +896,6 @@ void PPPMIntel::fieldforce_ad(IntelBuffers<flt_t,acc_t> *buffers)
  }
}

/* ----------------------------------------------------------------------
   FFT-based Poisson solver for ik
   Does special things for packing mode to avoid repeated copies
------------------------------------------------------------------------- */

void PPPMIntel::poisson_ik_intel()
{
  if (_use_packing == 0) {
    poisson_ik();
    return;
  }

  int i,j,k,n;
  double eng;

  // transform charge density (r -> k)

  n = 0;
  for (i = 0; i < nfft; i++) {
    work1[n++] = density_fft[i];
    work1[n++] = ZEROF;
  }

  fft1->compute(work1,work1,1);

  // global energy and virial contribution

  double scaleinv = 1.0/(nx_pppm*ny_pppm*nz_pppm);
  double s2 = scaleinv*scaleinv;

  if (eflag_global || vflag_global) {
    if (vflag_global) {
      n = 0;
      for (i = 0; i < nfft; i++) {
        eng = s2 * greensfn[i] * (work1[n]*work1[n] +
                                  work1[n+1]*work1[n+1]);
        for (j = 0; j < 6; j++) virial[j] += eng*vg[i][j];
        if (eflag_global) energy += eng;
        n += 2;
      }
    } else {
      n = 0;
      for (i = 0; i < nfft; i++) {
        energy +=
          s2 * greensfn[i] * (work1[n]*work1[n] + work1[n+1]*work1[n+1]);
        n += 2;
      }
    }
  }

  // scale by 1/total-grid-pts to get rho(k)
  // multiply by Green's function to get V(k)

  n = 0;
  for (i = 0; i < nfft; i++) {
    work1[n++] *= scaleinv * greensfn[i];
    work1[n++] *= scaleinv * greensfn[i];
  }

  // extra FFTs for per-atom energy/virial

  if (evflag_atom) poisson_peratom();

  // triclinic system

  if (triclinic) {
    poisson_ik_triclinic();
    return;
  }

  // compute gradients of V(r) in each of 3 dims by transformimg -ik*V(k)
  // FFT leaves data in 3d brick decomposition
  // copy it into inner portion of vdx,vdy,vdz arrays

  // x direction gradient
  n = 0;
  for (k = nzlo_fft; k <= nzhi_fft; k++)
    for (j = nylo_fft; j <= nyhi_fft; j++)
      for (i = nxlo_fft; i <= nxhi_fft; i++) {
        work2[n] = fkx[i]*work1[n+1];
        work2[n+1] = -fkx[i]*work1[n];
        n += 2;
      }

  fft2->compute(work2,work2,-1);

  // y direction gradient

  n = 0;
  for (k = nzlo_fft; k <= nzhi_fft; k++)
    for (j = nylo_fft; j <= nyhi_fft; j++)
      for (i = nxlo_fft; i <= nxhi_fft; i++) {
        work3[n] = fky[j]*work1[n+1];
        work3[n+1] = -fky[j]*work1[n];
        n += 2;
      }

  fft2->compute(work3,work3,-1);

  n = 0;
  for (k = nzlo_in; k <= nzhi_in; k++)
    for (j = nylo_in; j <= nyhi_in; j++)
      for (i = nxlo_in; i <= nxhi_in; i++) {
        vdxy_brick[k][j][2*i] = work2[n];
        vdxy_brick[k][j][2*i+1] = work3[n];
        n += 2;
      }

  // z direction gradient

  n = 0;
  for (k = nzlo_fft; k <= nzhi_fft; k++)
    for (j = nylo_fft; j <= nyhi_fft; j++)
      for (i = nxlo_fft; i <= nxhi_fft; i++) {
        work2[n] = fkz[k]*work1[n+1];
        work2[n+1] = -fkz[k]*work1[n];
        n += 2;
      }

  fft2->compute(work2,work2,-1);

  n = 0;
  for (k = nzlo_in; k <= nzhi_in; k++)
    for (j = nylo_in; j <= nyhi_in; j++)
      for (i = nxlo_in; i <= nxhi_in; i++) {
        vdz0_brick[k][j][2*i] = work2[n];
        vdz0_brick[k][j][2*i+1] = 0.;
        n += 2;
      }
}

/* ----------------------------------------------------------------------
   precompute rho coefficients as a lookup table to save time in make_rho
   and fieldforce.  Instead of doing this polynomial for every atom 6 times
@@ -1141,46 +941,6 @@ void PPPMIntel::precompute_rho()
  }
}

/* ----------------------------------------------------------------------
   pack own values to buf to send to another proc
------------------------------------------------------------------------- */

void PPPMIntel::pack_forward(int flag, FFT_SCALAR *buf, int nlist, int *list)
{
  int n = 0;

  if ((flag == FORWARD_IK) && _use_packing) {
    FFT_SCALAR *xsrc = &vdxy_brick[nzlo_out][nylo_out][2*nxlo_out];
    FFT_SCALAR *zsrc = &vdz0_brick[nzlo_out][nylo_out][2*nxlo_out];
    for (int i = 0; i < nlist; i++) {
      buf[n++] = xsrc[list[i]];
      buf[n++] = zsrc[list[i]];
    }
  } else {
    PPPM::pack_forward(flag, buf, nlist, list);
  }
}

/* ----------------------------------------------------------------------
   unpack another proc's own values from buf and set own ghost values
------------------------------------------------------------------------- */

void PPPMIntel::unpack_forward(int flag, FFT_SCALAR *buf, int nlist, int *list)
{
  int n = 0;

  if ((flag == FORWARD_IK) && _use_packing) {
    FFT_SCALAR *xdest = &vdxy_brick[nzlo_out][nylo_out][2*nxlo_out];
    FFT_SCALAR *zdest = &vdz0_brick[nzlo_out][nylo_out][2*nxlo_out];
    for (int i = 0; i < nlist; i++) {
      xdest[list[i]] = buf[n++];
      zdest[list[i]] = buf[n++];
    }
  } else {
    PPPM::unpack_forward(flag, buf, nlist, list);
  }
}

/* ----------------------------------------------------------------------
   memory usage of local arrays
------------------------------------------------------------------------- */
@@ -1201,14 +961,6 @@ double PPPMIntel::memory_usage()
      bytes += rho_points * INTEL_P3M_ALIGNED_MAXORDER * sizeof(FFT_SCALAR);
    }
  }
  if (_use_packing) {
    bytes += 2 * (nzhi_out + 2 - nzlo_out + 1) * (nyhi_out - nylo_out + 1)
               * (2 * nxhi_out + 1 - 2 * nxlo_out + 1) * sizeof(FFT_SCALAR);
    bytes -= 3 * (nxhi_out - nxlo_out + 1) * (nyhi_out - nylo_out + 1)
               * (nzhi_out - nzlo_out + 1) * sizeof(FFT_SCALAR);
    bytes += 2 * nfft_both * sizeof(FFT_SCALAR);
    bytes += cg_pack->memory_usage();
  }
  return bytes;
}

+3 −20
Original line number Diff line number Diff line
@@ -38,8 +38,6 @@ class PPPMIntel : public PPPM {
  virtual ~PPPMIntel();
  virtual void init();
  virtual void compute(int, int);
  virtual void pack_forward(int, FFT_SCALAR *, int, int *);
  virtual void unpack_forward(int, FFT_SCALAR *, int, int *);
  virtual double memory_usage();
  void compute_first(int, int);
  void compute_second(int, int);
@@ -64,12 +62,6 @@ class PPPMIntel : public PPPM {
  FFT_SCALAR **drho_lookup;
  FFT_SCALAR half_rho_scale, half_rho_scale_plus;

  int _use_packing;
  FFT_SCALAR ***vdxy_brick;
  FFT_SCALAR ***vdz0_brick;
  FFT_SCALAR *work3;
  class GridComm *cg_pack;

  #ifdef _LMP_INTEL_OFFLOAD
  int _use_base;
  #endif
@@ -92,23 +84,14 @@ class PPPMIntel : public PPPM {
      make_rho<flt_t,acc_t,0>(buffers);
    }
  }
  void poisson_ik_intel();
  template<class flt_t, class acc_t, int use_table, int use_packing>
  template<class flt_t, class acc_t, int use_table>
  void fieldforce_ik(IntelBuffers<flt_t,acc_t> *buffers);
  template<class flt_t, class acc_t>
  void fieldforce_ik(IntelBuffers<flt_t,acc_t> *buffers) {
    if (_use_table == 1) {
      if (_use_packing == 1) {
        fieldforce_ik<flt_t, acc_t, 1, 1>(buffers);
      } else {
        fieldforce_ik<flt_t, acc_t, 1, 0>(buffers);
      }
    } else {
      if (_use_packing == 1) {
        fieldforce_ik<flt_t, acc_t, 0, 1>(buffers);
      fieldforce_ik<flt_t, acc_t, 1>(buffers);
    } else {
        fieldforce_ik<flt_t, acc_t, 0, 0>(buffers);
      }
      fieldforce_ik<flt_t, acc_t, 0>(buffers);
    }
  }
  template<class flt_t, class acc_t, int use_table>