src/gromacs/mdlib/nbnxn_kernels/nbnxn_kernel_common.cpp

   1 /*
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  35 #include "gmxpre.h"
  36
  37 #include "nbnxn_kernel_common.h"
  38
  39 #include "gromacs/pbcutil/ishift.h"
  40
  41 static void
  42 clear_f_all(const nbnxn_atomdata_t *nbat, real *f)
  43 {
  44     int i;
  45
  46     for (i = 0; i < nbat->natoms*nbat->fstride; i++)
  47     {
  48         f[i] = 0;
  49     }
  50 }
  51
  52 static void
  53 clear_f_flagged(const nbnxn_atomdata_t *nbat, int output_index, real *f)
  54 {
  55     const nbnxn_buffer_flags_t *flags;
  56     gmx_bitmask_t               our_flag;
  57     int                         b, a0, a1, i;
  58
  59     flags = &nbat->buffer_flags;
  60
  61     bitmask_init_bit(&our_flag, output_index);
  62
  63     for (b = 0; b < flags->nflag; b++)
  64     {
  65         if (!bitmask_is_disjoint(flags->flag[b], our_flag))
  66         {
  67             a0 = b*NBNXN_BUFFERFLAG_SIZE;
  68             a1 = a0 + NBNXN_BUFFERFLAG_SIZE;
  69             for (i = a0*nbat->fstride; i < a1*nbat->fstride; i++)
  70             {
  71                 f[i] = 0;
  72             }
  73         }
  74     }
  75 }
  76
  77 void
  78 clear_f(const nbnxn_atomdata_t *nbat, int output_index, real *f)
  79 {
  80     if (nbat->bUseBufferFlags)
  81     {
  82         clear_f_flagged(nbat, output_index, f);
  83     }
  84     else
  85     {
  86         clear_f_all(nbat, f);
  87     }
  88 }
  89
  90 void
  91 clear_fshift(real *fshift)
  92 {
  93     int i;
  94
  95     for (i = 0; i < SHIFTS*DIM; i++)
  96     {
  97         fshift[i] = 0;
  98     }
  99 }
 100
 101 void
 102 reduce_energies_over_lists(const nbnxn_atomdata_t     *nbat,
 103                            int                         nlist,
 104                            real                       *Vvdw,
 105                            real                       *Vc)
 106 {
 107     int nb;
 108     int i, j, ind, indr;
 109
 110     for (nb = 0; nb < nlist; nb++)
 111     {
 112         for (i = 0; i < nbat->nenergrp; i++)
 113         {
 114             /* Reduce the diagonal terms */
 115             ind        = i*nbat->nenergrp + i;
 116             Vvdw[ind] += nbat->out[nb].Vvdw[ind];
 117             Vc[ind]   += nbat->out[nb].Vc[ind];
 118
 119             /* Reduce the off-diagonal terms */
 120             for (j = i+1; j < nbat->nenergrp; j++)
 121             {
 122                 /* The output should contain only one off-diagonal part */
 123                 ind        = i*nbat->nenergrp + j;
 124                 indr       = j*nbat->nenergrp + i;
 125                 Vvdw[ind] += nbat->out[nb].Vvdw[ind] + nbat->out[nb].Vvdw[indr];
 126                 Vc[ind]   += nbat->out[nb].Vc[ind]   + nbat->out[nb].Vc[indr];
 127             }
 128         }
 129     }
 130 }