src/gromacs/gmxlib/nonbonded/nb_kernel_avx_256_single/nb_kernel_ElecNone_VdwLJSw_GeomP1P1_avx_256_single.c

   1 /*
   2  * Note: this file was generated by the Gromacs avx_256_single kernel generator.
   3  *
   4  *                This source code is part of
   5  *
   6  *                 G   R   O   M   A   C   S
   7  *
   8  * Copyright (c) 2001-2012, The GROMACS Development Team
   9  *
  10  * Gromacs is a library for molecular simulation and trajectory analysis,
  11  * written by Erik Lindahl, David van der Spoel, Berk Hess, and others - for
  12  * a full list of developers and information, check out http://www.gromacs.org
  13  *
  14  * This program is free software; you can redistribute it and/or modify it under
  15  * the terms of the GNU Lesser General Public License as published by the Free
  16  * Software Foundation; either version 2 of the License, or (at your option) any
  17  * later version.
  18  *
  19  * To help fund GROMACS development, we humbly ask that you cite
  20  * the papers people have written on it - you can find them on the website.
  21  */
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <math.h>
  27
  28 #include "../nb_kernel.h"
  29 #include "types/simple.h"
  30 #include "vec.h"
  31 #include "nrnb.h"
  32
  33 #include "gmx_math_x86_avx_256_single.h"
  34 #include "kernelutil_x86_avx_256_single.h"
  35
  36 /*
  37  * Gromacs nonbonded kernel:   nb_kernel_ElecNone_VdwLJSw_GeomP1P1_VF_avx_256_single
  38  * Electrostatics interaction: None
  39  * VdW interaction:            LennardJones
  40  * Geometry:                   Particle-Particle
  41  * Calculate force/pot:        PotentialAndForce
  42  */
  43 void
  44 nb_kernel_ElecNone_VdwLJSw_GeomP1P1_VF_avx_256_single
  45                     (t_nblist * gmx_restrict                nlist,
  46                      rvec * gmx_restrict                    xx,
  47                      rvec * gmx_restrict                    ff,
  48                      t_forcerec * gmx_restrict              fr,
  49                      t_mdatoms * gmx_restrict               mdatoms,
  50                      nb_kernel_data_t * gmx_restrict        kernel_data,
  51                      t_nrnb * gmx_restrict                  nrnb)
  52 {
  53     /* Suffixes 0,1,2,3 refer to particle indices for waters in the inner or outer loop, or
  54      * just 0 for non-waters.
  55      * Suffixes A,B,C,D,E,F,G,H refer to j loop unrolling done with AVX, e.g. for the eight different
  56      * jnr indices corresponding to data put in the four positions in the SIMD register.
  57      */
  58     int              i_shift_offset,i_coord_offset,outeriter,inneriter;
  59     int              j_index_start,j_index_end,jidx,nri,inr,ggid,iidx;
  60     int              jnrA,jnrB,jnrC,jnrD;
  61     int              jnrE,jnrF,jnrG,jnrH;
  62     int              jnrlistA,jnrlistB,jnrlistC,jnrlistD;
  63     int              jnrlistE,jnrlistF,jnrlistG,jnrlistH;
  64     int              j_coord_offsetA,j_coord_offsetB,j_coord_offsetC,j_coord_offsetD;
  65     int              j_coord_offsetE,j_coord_offsetF,j_coord_offsetG,j_coord_offsetH;
  66     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
  67     real             rcutoff_scalar;
  68     real             *shiftvec,*fshift,*x,*f;
  69     real             *fjptrA,*fjptrB,*fjptrC,*fjptrD,*fjptrE,*fjptrF,*fjptrG,*fjptrH;
  70     real             scratch[4*DIM];
  71     __m256           tx,ty,tz,fscal,rcutoff,rcutoff2,jidxall;
  72     real *           vdwioffsetptr0;
  73     __m256           ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
  74     int              vdwjidx0A,vdwjidx0B,vdwjidx0C,vdwjidx0D,vdwjidx0E,vdwjidx0F,vdwjidx0G,vdwjidx0H;
  75     __m256           jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
  76     __m256           dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00;
  77     int              nvdwtype;
  78     __m256           rinvsix,rvdw,vvdw,vvdw6,vvdw12,fvdw,fvdw6,fvdw12,vvdwsum,sh_vdw_invrcut6;
  79     int              *vdwtype;
  80     real             *vdwparam;
  81     __m256           one_sixth   = _mm256_set1_ps(1.0/6.0);
  82     __m256           one_twelfth = _mm256_set1_ps(1.0/12.0);
  83     __m256           rswitch,swV3,swV4,swV5,swF2,swF3,swF4,d,d2,sw,dsw;
  84     real             rswitch_scalar,d_scalar;
  85     __m256           dummy_mask,cutoff_mask;
  86     __m256           signbit = _mm256_castsi256_ps( _mm256_set1_epi32(0x80000000) );
  87     __m256           one     = _mm256_set1_ps(1.0);
  88     __m256           two     = _mm256_set1_ps(2.0);
  89     x                = xx[0];
  90     f                = ff[0];
  91
  92     nri              = nlist->nri;
  93     iinr             = nlist->iinr;
  94     jindex           = nlist->jindex;
  95     jjnr             = nlist->jjnr;
  96     shiftidx         = nlist->shift;
  97     gid              = nlist->gid;
  98     shiftvec         = fr->shift_vec[0];
  99     fshift           = fr->fshift[0];
 100     nvdwtype         = fr->ntype;
 101     vdwparam         = fr->nbfp;
 102     vdwtype          = mdatoms->typeA;
 103
 104     rcutoff_scalar   = fr->rvdw;
 105     rcutoff          = _mm256_set1_ps(rcutoff_scalar);
 106     rcutoff2         = _mm256_mul_ps(rcutoff,rcutoff);
 107
 108     rswitch_scalar   = fr->rvdw_switch;
 109     rswitch          = _mm256_set1_ps(rswitch_scalar);
 110     /* Setup switch parameters */
 111     d_scalar         = rcutoff_scalar-rswitch_scalar;
 112     d                = _mm256_set1_ps(d_scalar);
 113     swV3             = _mm256_set1_ps(-10.0/(d_scalar*d_scalar*d_scalar));
 114     swV4             = _mm256_set1_ps( 15.0/(d_scalar*d_scalar*d_scalar*d_scalar));
 115     swV5             = _mm256_set1_ps( -6.0/(d_scalar*d_scalar*d_scalar*d_scalar*d_scalar));
 116     swF2             = _mm256_set1_ps(-30.0/(d_scalar*d_scalar*d_scalar));
 117     swF3             = _mm256_set1_ps( 60.0/(d_scalar*d_scalar*d_scalar*d_scalar));
 118     swF4             = _mm256_set1_ps(-30.0/(d_scalar*d_scalar*d_scalar*d_scalar*d_scalar));
 119
 120     /* Avoid stupid compiler warnings */
 121     jnrA = jnrB = jnrC = jnrD = jnrE = jnrF = jnrG = jnrH = 0;
 122     j_coord_offsetA = 0;
 123     j_coord_offsetB = 0;
 124     j_coord_offsetC = 0;
 125     j_coord_offsetD = 0;
 126     j_coord_offsetE = 0;
 127     j_coord_offsetF = 0;
 128     j_coord_offsetG = 0;
 129     j_coord_offsetH = 0;
 130
 131     outeriter        = 0;
 132     inneriter        = 0;
 133
 134     for(iidx=0;iidx<4*DIM;iidx++)
 135     {
 136         scratch[iidx] = 0.0;
 137     }
 138
 139     /* Start outer loop over neighborlists */
 140     for(iidx=0; iidx<nri; iidx++)
 141     {
 142         /* Load shift vector for this list */
 143         i_shift_offset   = DIM*shiftidx[iidx];
 144
 145         /* Load limits for loop over neighbors */
 146         j_index_start    = jindex[iidx];
 147         j_index_end      = jindex[iidx+1];
 148
 149         /* Get outer coordinate index */
 150         inr              = iinr[iidx];
 151         i_coord_offset   = DIM*inr;
 152
 153         /* Load i particle coords and add shift vector */
 154         gmx_mm256_load_shift_and_1rvec_broadcast_ps(shiftvec+i_shift_offset,x+i_coord_offset,&ix0,&iy0,&iz0);
 155
 156         fix0             = _mm256_setzero_ps();
 157         fiy0             = _mm256_setzero_ps();
 158         fiz0             = _mm256_setzero_ps();
 159
 160         /* Load parameters for i particles */
 161         vdwioffsetptr0   = vdwparam+2*nvdwtype*vdwtype[inr+0];
 162
 163         /* Reset potential sums */
 164         vvdwsum          = _mm256_setzero_ps();
 165
 166         /* Start inner kernel loop */
 167         for(jidx=j_index_start; jidx<j_index_end && jjnr[jidx+7]>=0; jidx+=8)
 168         {
 169
 170             /* Get j neighbor index, and coordinate index */
 171             jnrA             = jjnr[jidx];
 172             jnrB             = jjnr[jidx+1];
 173             jnrC             = jjnr[jidx+2];
 174             jnrD             = jjnr[jidx+3];
 175             jnrE             = jjnr[jidx+4];
 176             jnrF             = jjnr[jidx+5];
 177             jnrG             = jjnr[jidx+6];
 178             jnrH             = jjnr[jidx+7];
 179             j_coord_offsetA  = DIM*jnrA;
 180             j_coord_offsetB  = DIM*jnrB;
 181             j_coord_offsetC  = DIM*jnrC;
 182             j_coord_offsetD  = DIM*jnrD;
 183             j_coord_offsetE  = DIM*jnrE;
 184             j_coord_offsetF  = DIM*jnrF;
 185             j_coord_offsetG  = DIM*jnrG;
 186             j_coord_offsetH  = DIM*jnrH;
 187
 188             /* load j atom coordinates */
 189             gmx_mm256_load_1rvec_8ptr_swizzle_ps(x+j_coord_offsetA,x+j_coord_offsetB,
 190                                                  x+j_coord_offsetC,x+j_coord_offsetD,
 191                                                  x+j_coord_offsetE,x+j_coord_offsetF,
 192                                                  x+j_coord_offsetG,x+j_coord_offsetH,
 193                                                  &jx0,&jy0,&jz0);
 194
 195             /* Calculate displacement vector */
 196             dx00             = _mm256_sub_ps(ix0,jx0);
 197             dy00             = _mm256_sub_ps(iy0,jy0);
 198             dz00             = _mm256_sub_ps(iz0,jz0);
 199
 200             /* Calculate squared distance and things based on it */
 201             rsq00            = gmx_mm256_calc_rsq_ps(dx00,dy00,dz00);
 202
 203             rinv00           = gmx_mm256_invsqrt_ps(rsq00);
 204
 205             rinvsq00         = _mm256_mul_ps(rinv00,rinv00);
 206
 207             /* Load parameters for j particles */
 208             vdwjidx0A        = 2*vdwtype[jnrA+0];
 209             vdwjidx0B        = 2*vdwtype[jnrB+0];
 210             vdwjidx0C        = 2*vdwtype[jnrC+0];
 211             vdwjidx0D        = 2*vdwtype[jnrD+0];
 212             vdwjidx0E        = 2*vdwtype[jnrE+0];
 213             vdwjidx0F        = 2*vdwtype[jnrF+0];
 214             vdwjidx0G        = 2*vdwtype[jnrG+0];
 215             vdwjidx0H        = 2*vdwtype[jnrH+0];
 216
 217             /**************************
 218              * CALCULATE INTERACTIONS *
 219              **************************/
 220
 221             if (gmx_mm256_any_lt(rsq00,rcutoff2))
 222             {
 223
 224             r00              = _mm256_mul_ps(rsq00,rinv00);
 225
 226             /* Compute parameters for interactions between i and j atoms */
 227             gmx_mm256_load_8pair_swizzle_ps(vdwioffsetptr0+vdwjidx0A,
 228                                             vdwioffsetptr0+vdwjidx0B,
 229                                             vdwioffsetptr0+vdwjidx0C,
 230                                             vdwioffsetptr0+vdwjidx0D,
 231                                             vdwioffsetptr0+vdwjidx0E,
 232                                             vdwioffsetptr0+vdwjidx0F,
 233                                             vdwioffsetptr0+vdwjidx0G,
 234                                             vdwioffsetptr0+vdwjidx0H,
 235                                             &c6_00,&c12_00);
 236
 237             /* LENNARD-JONES DISPERSION/REPULSION */
 238
 239             rinvsix          = _mm256_mul_ps(_mm256_mul_ps(rinvsq00,rinvsq00),rinvsq00);
 240             vvdw6            = _mm256_mul_ps(c6_00,rinvsix);
 241             vvdw12           = _mm256_mul_ps(c12_00,_mm256_mul_ps(rinvsix,rinvsix));
 242             vvdw             = _mm256_sub_ps( _mm256_mul_ps(vvdw12,one_twelfth) , _mm256_mul_ps(vvdw6,one_sixth) );
 243             fvdw             = _mm256_mul_ps(_mm256_sub_ps(vvdw12,vvdw6),rinvsq00);
 244
 245             d                = _mm256_sub_ps(r00,rswitch);
 246             d                = _mm256_max_ps(d,_mm256_setzero_ps());
 247             d2               = _mm256_mul_ps(d,d);
 248             sw               = _mm256_add_ps(one,_mm256_mul_ps(d2,_mm256_mul_ps(d,_mm256_add_ps(swV3,_mm256_mul_ps(d,_mm256_add_ps(swV4,_mm256_mul_ps(d,swV5)))))));
 249
 250             dsw              = _mm256_mul_ps(d2,_mm256_add_ps(swF2,_mm256_mul_ps(d,_mm256_add_ps(swF3,_mm256_mul_ps(d,swF4)))));
 251
 252             /* Evaluate switch function */
 253             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 254             fvdw             = _mm256_sub_ps( _mm256_mul_ps(fvdw,sw) , _mm256_mul_ps(rinv00,_mm256_mul_ps(vvdw,dsw)) );
 255             vvdw             = _mm256_mul_ps(vvdw,sw);
 256             cutoff_mask      = _mm256_cmp_ps(rsq00,rcutoff2,_CMP_LT_OQ);
 257
 258             /* Update potential sum for this i atom from the interaction with this j atom. */
 259             vvdw             = _mm256_and_ps(vvdw,cutoff_mask);
 260             vvdwsum          = _mm256_add_ps(vvdwsum,vvdw);
 261
 262             fscal            = fvdw;
 263
 264             fscal            = _mm256_and_ps(fscal,cutoff_mask);
 265
 266             /* Calculate temporary vectorial force */
 267             tx               = _mm256_mul_ps(fscal,dx00);
 268             ty               = _mm256_mul_ps(fscal,dy00);
 269             tz               = _mm256_mul_ps(fscal,dz00);
 270
 271             /* Update vectorial force */
 272             fix0             = _mm256_add_ps(fix0,tx);
 273             fiy0             = _mm256_add_ps(fiy0,ty);
 274             fiz0             = _mm256_add_ps(fiz0,tz);
 275
 276             fjptrA             = f+j_coord_offsetA;
 277             fjptrB             = f+j_coord_offsetB;
 278             fjptrC             = f+j_coord_offsetC;
 279             fjptrD             = f+j_coord_offsetD;
 280             fjptrE             = f+j_coord_offsetE;
 281             fjptrF             = f+j_coord_offsetF;
 282             fjptrG             = f+j_coord_offsetG;
 283             fjptrH             = f+j_coord_offsetH;
 284             gmx_mm256_decrement_1rvec_8ptr_swizzle_ps(fjptrA,fjptrB,fjptrC,fjptrD,fjptrE,fjptrF,fjptrG,fjptrH,tx,ty,tz);
 285
 286             }
 287
 288             /* Inner loop uses 59 flops */
 289         }
 290
 291         if(jidx<j_index_end)
 292         {
 293
 294             /* Get j neighbor index, and coordinate index */
 295             jnrlistA         = jjnr[jidx];
 296             jnrlistB         = jjnr[jidx+1];
 297             jnrlistC         = jjnr[jidx+2];
 298             jnrlistD         = jjnr[jidx+3];
 299             jnrlistE         = jjnr[jidx+4];
 300             jnrlistF         = jjnr[jidx+5];
 301             jnrlistG         = jjnr[jidx+6];
 302             jnrlistH         = jjnr[jidx+7];
 303             /* Sign of each element will be negative for non-real atoms.
 304              * This mask will be 0xFFFFFFFF for dummy entries and 0x0 for real ones,
 305              * so use it as val = _mm_andnot_ps(mask,val) to clear dummy entries.
 306              */
 307             dummy_mask = gmx_mm256_set_m128(gmx_mm_castsi128_ps(_mm_cmplt_epi32(_mm_loadu_si128((const __m128i *)(jjnr+jidx+4)),_mm_setzero_si128())),
 308                                             gmx_mm_castsi128_ps(_mm_cmplt_epi32(_mm_loadu_si128((const __m128i *)(jjnr+jidx)),_mm_setzero_si128())));
 309
 310             jnrA       = (jnrlistA>=0) ? jnrlistA : 0;
 311             jnrB       = (jnrlistB>=0) ? jnrlistB : 0;
 312             jnrC       = (jnrlistC>=0) ? jnrlistC : 0;
 313             jnrD       = (jnrlistD>=0) ? jnrlistD : 0;
 314             jnrE       = (jnrlistE>=0) ? jnrlistE : 0;
 315             jnrF       = (jnrlistF>=0) ? jnrlistF : 0;
 316             jnrG       = (jnrlistG>=0) ? jnrlistG : 0;
 317             jnrH       = (jnrlistH>=0) ? jnrlistH : 0;
 318             j_coord_offsetA  = DIM*jnrA;
 319             j_coord_offsetB  = DIM*jnrB;
 320             j_coord_offsetC  = DIM*jnrC;
 321             j_coord_offsetD  = DIM*jnrD;
 322             j_coord_offsetE  = DIM*jnrE;
 323             j_coord_offsetF  = DIM*jnrF;
 324             j_coord_offsetG  = DIM*jnrG;
 325             j_coord_offsetH  = DIM*jnrH;
 326
 327             /* load j atom coordinates */
 328             gmx_mm256_load_1rvec_8ptr_swizzle_ps(x+j_coord_offsetA,x+j_coord_offsetB,
 329                                                  x+j_coord_offsetC,x+j_coord_offsetD,
 330                                                  x+j_coord_offsetE,x+j_coord_offsetF,
 331                                                  x+j_coord_offsetG,x+j_coord_offsetH,
 332                                                  &jx0,&jy0,&jz0);
 333
 334             /* Calculate displacement vector */
 335             dx00             = _mm256_sub_ps(ix0,jx0);
 336             dy00             = _mm256_sub_ps(iy0,jy0);
 337             dz00             = _mm256_sub_ps(iz0,jz0);
 338
 339             /* Calculate squared distance and things based on it */
 340             rsq00            = gmx_mm256_calc_rsq_ps(dx00,dy00,dz00);
 341
 342             rinv00           = gmx_mm256_invsqrt_ps(rsq00);
 343
 344             rinvsq00         = _mm256_mul_ps(rinv00,rinv00);
 345
 346             /* Load parameters for j particles */
 347             vdwjidx0A        = 2*vdwtype[jnrA+0];
 348             vdwjidx0B        = 2*vdwtype[jnrB+0];
 349             vdwjidx0C        = 2*vdwtype[jnrC+0];
 350             vdwjidx0D        = 2*vdwtype[jnrD+0];
 351             vdwjidx0E        = 2*vdwtype[jnrE+0];
 352             vdwjidx0F        = 2*vdwtype[jnrF+0];
 353             vdwjidx0G        = 2*vdwtype[jnrG+0];
 354             vdwjidx0H        = 2*vdwtype[jnrH+0];
 355
 356             /**************************
 357              * CALCULATE INTERACTIONS *
 358              **************************/
 359
 360             if (gmx_mm256_any_lt(rsq00,rcutoff2))
 361             {
 362
 363             r00              = _mm256_mul_ps(rsq00,rinv00);
 364             r00              = _mm256_andnot_ps(dummy_mask,r00);
 365
 366             /* Compute parameters for interactions between i and j atoms */
 367             gmx_mm256_load_8pair_swizzle_ps(vdwioffsetptr0+vdwjidx0A,
 368                                             vdwioffsetptr0+vdwjidx0B,
 369                                             vdwioffsetptr0+vdwjidx0C,
 370                                             vdwioffsetptr0+vdwjidx0D,
 371                                             vdwioffsetptr0+vdwjidx0E,
 372                                             vdwioffsetptr0+vdwjidx0F,
 373                                             vdwioffsetptr0+vdwjidx0G,
 374                                             vdwioffsetptr0+vdwjidx0H,
 375                                             &c6_00,&c12_00);
 376
 377             /* LENNARD-JONES DISPERSION/REPULSION */
 378
 379             rinvsix          = _mm256_mul_ps(_mm256_mul_ps(rinvsq00,rinvsq00),rinvsq00);
 380             vvdw6            = _mm256_mul_ps(c6_00,rinvsix);
 381             vvdw12           = _mm256_mul_ps(c12_00,_mm256_mul_ps(rinvsix,rinvsix));
 382             vvdw             = _mm256_sub_ps( _mm256_mul_ps(vvdw12,one_twelfth) , _mm256_mul_ps(vvdw6,one_sixth) );
 383             fvdw             = _mm256_mul_ps(_mm256_sub_ps(vvdw12,vvdw6),rinvsq00);
 384
 385             d                = _mm256_sub_ps(r00,rswitch);
 386             d                = _mm256_max_ps(d,_mm256_setzero_ps());
 387             d2               = _mm256_mul_ps(d,d);
 388             sw               = _mm256_add_ps(one,_mm256_mul_ps(d2,_mm256_mul_ps(d,_mm256_add_ps(swV3,_mm256_mul_ps(d,_mm256_add_ps(swV4,_mm256_mul_ps(d,swV5)))))));
 389
 390             dsw              = _mm256_mul_ps(d2,_mm256_add_ps(swF2,_mm256_mul_ps(d,_mm256_add_ps(swF3,_mm256_mul_ps(d,swF4)))));
 391
 392             /* Evaluate switch function */
 393             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 394             fvdw             = _mm256_sub_ps( _mm256_mul_ps(fvdw,sw) , _mm256_mul_ps(rinv00,_mm256_mul_ps(vvdw,dsw)) );
 395             vvdw             = _mm256_mul_ps(vvdw,sw);
 396             cutoff_mask      = _mm256_cmp_ps(rsq00,rcutoff2,_CMP_LT_OQ);
 397
 398             /* Update potential sum for this i atom from the interaction with this j atom. */
 399             vvdw             = _mm256_and_ps(vvdw,cutoff_mask);
 400             vvdw             = _mm256_andnot_ps(dummy_mask,vvdw);
 401             vvdwsum          = _mm256_add_ps(vvdwsum,vvdw);
 402
 403             fscal            = fvdw;
 404
 405             fscal            = _mm256_and_ps(fscal,cutoff_mask);
 406
 407             fscal            = _mm256_andnot_ps(dummy_mask,fscal);
 408
 409             /* Calculate temporary vectorial force */
 410             tx               = _mm256_mul_ps(fscal,dx00);
 411             ty               = _mm256_mul_ps(fscal,dy00);
 412             tz               = _mm256_mul_ps(fscal,dz00);
 413
 414             /* Update vectorial force */
 415             fix0             = _mm256_add_ps(fix0,tx);
 416             fiy0             = _mm256_add_ps(fiy0,ty);
 417             fiz0             = _mm256_add_ps(fiz0,tz);
 418
 419             fjptrA             = (jnrlistA>=0) ? f+j_coord_offsetA : scratch;
 420             fjptrB             = (jnrlistB>=0) ? f+j_coord_offsetB : scratch;
 421             fjptrC             = (jnrlistC>=0) ? f+j_coord_offsetC : scratch;
 422             fjptrD             = (jnrlistD>=0) ? f+j_coord_offsetD : scratch;
 423             fjptrE             = (jnrlistE>=0) ? f+j_coord_offsetE : scratch;
 424             fjptrF             = (jnrlistF>=0) ? f+j_coord_offsetF : scratch;
 425             fjptrG             = (jnrlistG>=0) ? f+j_coord_offsetG : scratch;
 426             fjptrH             = (jnrlistH>=0) ? f+j_coord_offsetH : scratch;
 427             gmx_mm256_decrement_1rvec_8ptr_swizzle_ps(fjptrA,fjptrB,fjptrC,fjptrD,fjptrE,fjptrF,fjptrG,fjptrH,tx,ty,tz);
 428
 429             }
 430
 431             /* Inner loop uses 60 flops */
 432         }
 433
 434         /* End of innermost loop */
 435
 436         gmx_mm256_update_iforce_1atom_swizzle_ps(fix0,fiy0,fiz0,
 437                                                  f+i_coord_offset,fshift+i_shift_offset);
 438
 439         ggid                        = gid[iidx];
 440         /* Update potential energies */
 441         gmx_mm256_update_1pot_ps(vvdwsum,kernel_data->energygrp_vdw+ggid);
 442
 443         /* Increment number of inner iterations */
 444         inneriter                  += j_index_end - j_index_start;
 445
 446         /* Outer loop uses 7 flops */
 447     }
 448
 449     /* Increment number of outer iterations */
 450     outeriter        += nri;
 451
 452     /* Update outer/inner flops */
 453
 454     inc_nrnb(nrnb,eNR_NBKERNEL_VDW_VF,outeriter*7 + inneriter*60);
 455 }
 456 /*
 457  * Gromacs nonbonded kernel:   nb_kernel_ElecNone_VdwLJSw_GeomP1P1_F_avx_256_single
 458  * Electrostatics interaction: None
 459  * VdW interaction:            LennardJones
 460  * Geometry:                   Particle-Particle
 461  * Calculate force/pot:        Force
 462  */
 463 void
 464 nb_kernel_ElecNone_VdwLJSw_GeomP1P1_F_avx_256_single
 465                     (t_nblist * gmx_restrict                nlist,
 466                      rvec * gmx_restrict                    xx,
 467                      rvec * gmx_restrict                    ff,
 468                      t_forcerec * gmx_restrict              fr,
 469                      t_mdatoms * gmx_restrict               mdatoms,
 470                      nb_kernel_data_t * gmx_restrict        kernel_data,
 471                      t_nrnb * gmx_restrict                  nrnb)
 472 {
 473     /* Suffixes 0,1,2,3 refer to particle indices for waters in the inner or outer loop, or
 474      * just 0 for non-waters.
 475      * Suffixes A,B,C,D,E,F,G,H refer to j loop unrolling done with AVX, e.g. for the eight different
 476      * jnr indices corresponding to data put in the four positions in the SIMD register.
 477      */
 478     int              i_shift_offset,i_coord_offset,outeriter,inneriter;
 479     int              j_index_start,j_index_end,jidx,nri,inr,ggid,iidx;
 480     int              jnrA,jnrB,jnrC,jnrD;
 481     int              jnrE,jnrF,jnrG,jnrH;
 482     int              jnrlistA,jnrlistB,jnrlistC,jnrlistD;
 483     int              jnrlistE,jnrlistF,jnrlistG,jnrlistH;
 484     int              j_coord_offsetA,j_coord_offsetB,j_coord_offsetC,j_coord_offsetD;
 485     int              j_coord_offsetE,j_coord_offsetF,j_coord_offsetG,j_coord_offsetH;
 486     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
 487     real             rcutoff_scalar;
 488     real             *shiftvec,*fshift,*x,*f;
 489     real             *fjptrA,*fjptrB,*fjptrC,*fjptrD,*fjptrE,*fjptrF,*fjptrG,*fjptrH;
 490     real             scratch[4*DIM];
 491     __m256           tx,ty,tz,fscal,rcutoff,rcutoff2,jidxall;
 492     real *           vdwioffsetptr0;
 493     __m256           ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
 494     int              vdwjidx0A,vdwjidx0B,vdwjidx0C,vdwjidx0D,vdwjidx0E,vdwjidx0F,vdwjidx0G,vdwjidx0H;
 495     __m256           jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
 496     __m256           dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00;
 497     int              nvdwtype;
 498     __m256           rinvsix,rvdw,vvdw,vvdw6,vvdw12,fvdw,fvdw6,fvdw12,vvdwsum,sh_vdw_invrcut6;
 499     int              *vdwtype;
 500     real             *vdwparam;
 501     __m256           one_sixth   = _mm256_set1_ps(1.0/6.0);
 502     __m256           one_twelfth = _mm256_set1_ps(1.0/12.0);
 503     __m256           rswitch,swV3,swV4,swV5,swF2,swF3,swF4,d,d2,sw,dsw;
 504     real             rswitch_scalar,d_scalar;
 505     __m256           dummy_mask,cutoff_mask;
 506     __m256           signbit = _mm256_castsi256_ps( _mm256_set1_epi32(0x80000000) );
 507     __m256           one     = _mm256_set1_ps(1.0);
 508     __m256           two     = _mm256_set1_ps(2.0);
 509     x                = xx[0];
 510     f                = ff[0];
 511
 512     nri              = nlist->nri;
 513     iinr             = nlist->iinr;
 514     jindex           = nlist->jindex;
 515     jjnr             = nlist->jjnr;
 516     shiftidx         = nlist->shift;
 517     gid              = nlist->gid;
 518     shiftvec         = fr->shift_vec[0];
 519     fshift           = fr->fshift[0];
 520     nvdwtype         = fr->ntype;
 521     vdwparam         = fr->nbfp;
 522     vdwtype          = mdatoms->typeA;
 523
 524     rcutoff_scalar   = fr->rvdw;
 525     rcutoff          = _mm256_set1_ps(rcutoff_scalar);
 526     rcutoff2         = _mm256_mul_ps(rcutoff,rcutoff);
 527
 528     rswitch_scalar   = fr->rvdw_switch;
 529     rswitch          = _mm256_set1_ps(rswitch_scalar);
 530     /* Setup switch parameters */
 531     d_scalar         = rcutoff_scalar-rswitch_scalar;
 532     d                = _mm256_set1_ps(d_scalar);
 533     swV3             = _mm256_set1_ps(-10.0/(d_scalar*d_scalar*d_scalar));
 534     swV4             = _mm256_set1_ps( 15.0/(d_scalar*d_scalar*d_scalar*d_scalar));
 535     swV5             = _mm256_set1_ps( -6.0/(d_scalar*d_scalar*d_scalar*d_scalar*d_scalar));
 536     swF2             = _mm256_set1_ps(-30.0/(d_scalar*d_scalar*d_scalar));
 537     swF3             = _mm256_set1_ps( 60.0/(d_scalar*d_scalar*d_scalar*d_scalar));
 538     swF4             = _mm256_set1_ps(-30.0/(d_scalar*d_scalar*d_scalar*d_scalar*d_scalar));
 539
 540     /* Avoid stupid compiler warnings */
 541     jnrA = jnrB = jnrC = jnrD = jnrE = jnrF = jnrG = jnrH = 0;
 542     j_coord_offsetA = 0;
 543     j_coord_offsetB = 0;
 544     j_coord_offsetC = 0;
 545     j_coord_offsetD = 0;
 546     j_coord_offsetE = 0;
 547     j_coord_offsetF = 0;
 548     j_coord_offsetG = 0;
 549     j_coord_offsetH = 0;
 550
 551     outeriter        = 0;
 552     inneriter        = 0;
 553
 554     for(iidx=0;iidx<4*DIM;iidx++)
 555     {
 556         scratch[iidx] = 0.0;
 557     }
 558
 559     /* Start outer loop over neighborlists */
 560     for(iidx=0; iidx<nri; iidx++)
 561     {
 562         /* Load shift vector for this list */
 563         i_shift_offset   = DIM*shiftidx[iidx];
 564
 565         /* Load limits for loop over neighbors */
 566         j_index_start    = jindex[iidx];
 567         j_index_end      = jindex[iidx+1];
 568
 569         /* Get outer coordinate index */
 570         inr              = iinr[iidx];
 571         i_coord_offset   = DIM*inr;
 572
 573         /* Load i particle coords and add shift vector */
 574         gmx_mm256_load_shift_and_1rvec_broadcast_ps(shiftvec+i_shift_offset,x+i_coord_offset,&ix0,&iy0,&iz0);
 575
 576         fix0             = _mm256_setzero_ps();
 577         fiy0             = _mm256_setzero_ps();
 578         fiz0             = _mm256_setzero_ps();
 579
 580         /* Load parameters for i particles */
 581         vdwioffsetptr0   = vdwparam+2*nvdwtype*vdwtype[inr+0];
 582
 583         /* Start inner kernel loop */
 584         for(jidx=j_index_start; jidx<j_index_end && jjnr[jidx+7]>=0; jidx+=8)
 585         {
 586
 587             /* Get j neighbor index, and coordinate index */
 588             jnrA             = jjnr[jidx];
 589             jnrB             = jjnr[jidx+1];
 590             jnrC             = jjnr[jidx+2];
 591             jnrD             = jjnr[jidx+3];
 592             jnrE             = jjnr[jidx+4];
 593             jnrF             = jjnr[jidx+5];
 594             jnrG             = jjnr[jidx+6];
 595             jnrH             = jjnr[jidx+7];
 596             j_coord_offsetA  = DIM*jnrA;
 597             j_coord_offsetB  = DIM*jnrB;
 598             j_coord_offsetC  = DIM*jnrC;
 599             j_coord_offsetD  = DIM*jnrD;
 600             j_coord_offsetE  = DIM*jnrE;
 601             j_coord_offsetF  = DIM*jnrF;
 602             j_coord_offsetG  = DIM*jnrG;
 603             j_coord_offsetH  = DIM*jnrH;
 604
 605             /* load j atom coordinates */
 606             gmx_mm256_load_1rvec_8ptr_swizzle_ps(x+j_coord_offsetA,x+j_coord_offsetB,
 607                                                  x+j_coord_offsetC,x+j_coord_offsetD,
 608                                                  x+j_coord_offsetE,x+j_coord_offsetF,
 609                                                  x+j_coord_offsetG,x+j_coord_offsetH,
 610                                                  &jx0,&jy0,&jz0);
 611
 612             /* Calculate displacement vector */
 613             dx00             = _mm256_sub_ps(ix0,jx0);
 614             dy00             = _mm256_sub_ps(iy0,jy0);
 615             dz00             = _mm256_sub_ps(iz0,jz0);
 616
 617             /* Calculate squared distance and things based on it */
 618             rsq00            = gmx_mm256_calc_rsq_ps(dx00,dy00,dz00);
 619
 620             rinv00           = gmx_mm256_invsqrt_ps(rsq00);
 621
 622             rinvsq00         = _mm256_mul_ps(rinv00,rinv00);
 623
 624             /* Load parameters for j particles */
 625             vdwjidx0A        = 2*vdwtype[jnrA+0];
 626             vdwjidx0B        = 2*vdwtype[jnrB+0];
 627             vdwjidx0C        = 2*vdwtype[jnrC+0];
 628             vdwjidx0D        = 2*vdwtype[jnrD+0];
 629             vdwjidx0E        = 2*vdwtype[jnrE+0];
 630             vdwjidx0F        = 2*vdwtype[jnrF+0];
 631             vdwjidx0G        = 2*vdwtype[jnrG+0];
 632             vdwjidx0H        = 2*vdwtype[jnrH+0];
 633
 634             /**************************
 635              * CALCULATE INTERACTIONS *
 636              **************************/
 637
 638             if (gmx_mm256_any_lt(rsq00,rcutoff2))
 639             {
 640
 641             r00              = _mm256_mul_ps(rsq00,rinv00);
 642
 643             /* Compute parameters for interactions between i and j atoms */
 644             gmx_mm256_load_8pair_swizzle_ps(vdwioffsetptr0+vdwjidx0A,
 645                                             vdwioffsetptr0+vdwjidx0B,
 646                                             vdwioffsetptr0+vdwjidx0C,
 647                                             vdwioffsetptr0+vdwjidx0D,
 648                                             vdwioffsetptr0+vdwjidx0E,
 649                                             vdwioffsetptr0+vdwjidx0F,
 650                                             vdwioffsetptr0+vdwjidx0G,
 651                                             vdwioffsetptr0+vdwjidx0H,
 652                                             &c6_00,&c12_00);
 653
 654             /* LENNARD-JONES DISPERSION/REPULSION */
 655
 656             rinvsix          = _mm256_mul_ps(_mm256_mul_ps(rinvsq00,rinvsq00),rinvsq00);
 657             vvdw6            = _mm256_mul_ps(c6_00,rinvsix);
 658             vvdw12           = _mm256_mul_ps(c12_00,_mm256_mul_ps(rinvsix,rinvsix));
 659             vvdw             = _mm256_sub_ps( _mm256_mul_ps(vvdw12,one_twelfth) , _mm256_mul_ps(vvdw6,one_sixth) );
 660             fvdw             = _mm256_mul_ps(_mm256_sub_ps(vvdw12,vvdw6),rinvsq00);
 661
 662             d                = _mm256_sub_ps(r00,rswitch);
 663             d                = _mm256_max_ps(d,_mm256_setzero_ps());
 664             d2               = _mm256_mul_ps(d,d);
 665             sw               = _mm256_add_ps(one,_mm256_mul_ps(d2,_mm256_mul_ps(d,_mm256_add_ps(swV3,_mm256_mul_ps(d,_mm256_add_ps(swV4,_mm256_mul_ps(d,swV5)))))));
 666
 667             dsw              = _mm256_mul_ps(d2,_mm256_add_ps(swF2,_mm256_mul_ps(d,_mm256_add_ps(swF3,_mm256_mul_ps(d,swF4)))));
 668
 669             /* Evaluate switch function */
 670             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 671             fvdw             = _mm256_sub_ps( _mm256_mul_ps(fvdw,sw) , _mm256_mul_ps(rinv00,_mm256_mul_ps(vvdw,dsw)) );
 672             cutoff_mask      = _mm256_cmp_ps(rsq00,rcutoff2,_CMP_LT_OQ);
 673
 674             fscal            = fvdw;
 675
 676             fscal            = _mm256_and_ps(fscal,cutoff_mask);
 677
 678             /* Calculate temporary vectorial force */
 679             tx               = _mm256_mul_ps(fscal,dx00);
 680             ty               = _mm256_mul_ps(fscal,dy00);
 681             tz               = _mm256_mul_ps(fscal,dz00);
 682
 683             /* Update vectorial force */
 684             fix0             = _mm256_add_ps(fix0,tx);
 685             fiy0             = _mm256_add_ps(fiy0,ty);
 686             fiz0             = _mm256_add_ps(fiz0,tz);
 687
 688             fjptrA             = f+j_coord_offsetA;
 689             fjptrB             = f+j_coord_offsetB;
 690             fjptrC             = f+j_coord_offsetC;
 691             fjptrD             = f+j_coord_offsetD;
 692             fjptrE             = f+j_coord_offsetE;
 693             fjptrF             = f+j_coord_offsetF;
 694             fjptrG             = f+j_coord_offsetG;
 695             fjptrH             = f+j_coord_offsetH;
 696             gmx_mm256_decrement_1rvec_8ptr_swizzle_ps(fjptrA,fjptrB,fjptrC,fjptrD,fjptrE,fjptrF,fjptrG,fjptrH,tx,ty,tz);
 697
 698             }
 699
 700             /* Inner loop uses 56 flops */
 701         }
 702
 703         if(jidx<j_index_end)
 704         {
 705
 706             /* Get j neighbor index, and coordinate index */
 707             jnrlistA         = jjnr[jidx];
 708             jnrlistB         = jjnr[jidx+1];
 709             jnrlistC         = jjnr[jidx+2];
 710             jnrlistD         = jjnr[jidx+3];
 711             jnrlistE         = jjnr[jidx+4];
 712             jnrlistF         = jjnr[jidx+5];
 713             jnrlistG         = jjnr[jidx+6];
 714             jnrlistH         = jjnr[jidx+7];
 715             /* Sign of each element will be negative for non-real atoms.
 716              * This mask will be 0xFFFFFFFF for dummy entries and 0x0 for real ones,
 717              * so use it as val = _mm_andnot_ps(mask,val) to clear dummy entries.
 718              */
 719             dummy_mask = gmx_mm256_set_m128(gmx_mm_castsi128_ps(_mm_cmplt_epi32(_mm_loadu_si128((const __m128i *)(jjnr+jidx+4)),_mm_setzero_si128())),
 720                                             gmx_mm_castsi128_ps(_mm_cmplt_epi32(_mm_loadu_si128((const __m128i *)(jjnr+jidx)),_mm_setzero_si128())));
 721
 722             jnrA       = (jnrlistA>=0) ? jnrlistA : 0;
 723             jnrB       = (jnrlistB>=0) ? jnrlistB : 0;
 724             jnrC       = (jnrlistC>=0) ? jnrlistC : 0;
 725             jnrD       = (jnrlistD>=0) ? jnrlistD : 0;
 726             jnrE       = (jnrlistE>=0) ? jnrlistE : 0;
 727             jnrF       = (jnrlistF>=0) ? jnrlistF : 0;
 728             jnrG       = (jnrlistG>=0) ? jnrlistG : 0;
 729             jnrH       = (jnrlistH>=0) ? jnrlistH : 0;
 730             j_coord_offsetA  = DIM*jnrA;
 731             j_coord_offsetB  = DIM*jnrB;
 732             j_coord_offsetC  = DIM*jnrC;
 733             j_coord_offsetD  = DIM*jnrD;
 734             j_coord_offsetE  = DIM*jnrE;
 735             j_coord_offsetF  = DIM*jnrF;
 736             j_coord_offsetG  = DIM*jnrG;
 737             j_coord_offsetH  = DIM*jnrH;
 738
 739             /* load j atom coordinates */
 740             gmx_mm256_load_1rvec_8ptr_swizzle_ps(x+j_coord_offsetA,x+j_coord_offsetB,
 741                                                  x+j_coord_offsetC,x+j_coord_offsetD,
 742                                                  x+j_coord_offsetE,x+j_coord_offsetF,
 743                                                  x+j_coord_offsetG,x+j_coord_offsetH,
 744                                                  &jx0,&jy0,&jz0);
 745
 746             /* Calculate displacement vector */
 747             dx00             = _mm256_sub_ps(ix0,jx0);
 748             dy00             = _mm256_sub_ps(iy0,jy0);
 749             dz00             = _mm256_sub_ps(iz0,jz0);
 750
 751             /* Calculate squared distance and things based on it */
 752             rsq00            = gmx_mm256_calc_rsq_ps(dx00,dy00,dz00);
 753
 754             rinv00           = gmx_mm256_invsqrt_ps(rsq00);
 755
 756             rinvsq00         = _mm256_mul_ps(rinv00,rinv00);
 757
 758             /* Load parameters for j particles */
 759             vdwjidx0A        = 2*vdwtype[jnrA+0];
 760             vdwjidx0B        = 2*vdwtype[jnrB+0];
 761             vdwjidx0C        = 2*vdwtype[jnrC+0];
 762             vdwjidx0D        = 2*vdwtype[jnrD+0];
 763             vdwjidx0E        = 2*vdwtype[jnrE+0];
 764             vdwjidx0F        = 2*vdwtype[jnrF+0];
 765             vdwjidx0G        = 2*vdwtype[jnrG+0];
 766             vdwjidx0H        = 2*vdwtype[jnrH+0];
 767
 768             /**************************
 769              * CALCULATE INTERACTIONS *
 770              **************************/
 771
 772             if (gmx_mm256_any_lt(rsq00,rcutoff2))
 773             {
 774
 775             r00              = _mm256_mul_ps(rsq00,rinv00);
 776             r00              = _mm256_andnot_ps(dummy_mask,r00);
 777
 778             /* Compute parameters for interactions between i and j atoms */
 779             gmx_mm256_load_8pair_swizzle_ps(vdwioffsetptr0+vdwjidx0A,
 780                                             vdwioffsetptr0+vdwjidx0B,
 781                                             vdwioffsetptr0+vdwjidx0C,
 782                                             vdwioffsetptr0+vdwjidx0D,
 783                                             vdwioffsetptr0+vdwjidx0E,
 784                                             vdwioffsetptr0+vdwjidx0F,
 785                                             vdwioffsetptr0+vdwjidx0G,
 786                                             vdwioffsetptr0+vdwjidx0H,
 787                                             &c6_00,&c12_00);
 788
 789             /* LENNARD-JONES DISPERSION/REPULSION */
 790
 791             rinvsix          = _mm256_mul_ps(_mm256_mul_ps(rinvsq00,rinvsq00),rinvsq00);
 792             vvdw6            = _mm256_mul_ps(c6_00,rinvsix);
 793             vvdw12           = _mm256_mul_ps(c12_00,_mm256_mul_ps(rinvsix,rinvsix));
 794             vvdw             = _mm256_sub_ps( _mm256_mul_ps(vvdw12,one_twelfth) , _mm256_mul_ps(vvdw6,one_sixth) );
 795             fvdw             = _mm256_mul_ps(_mm256_sub_ps(vvdw12,vvdw6),rinvsq00);
 796
 797             d                = _mm256_sub_ps(r00,rswitch);
 798             d                = _mm256_max_ps(d,_mm256_setzero_ps());
 799             d2               = _mm256_mul_ps(d,d);
 800             sw               = _mm256_add_ps(one,_mm256_mul_ps(d2,_mm256_mul_ps(d,_mm256_add_ps(swV3,_mm256_mul_ps(d,_mm256_add_ps(swV4,_mm256_mul_ps(d,swV5)))))));
 801
 802             dsw              = _mm256_mul_ps(d2,_mm256_add_ps(swF2,_mm256_mul_ps(d,_mm256_add_ps(swF3,_mm256_mul_ps(d,swF4)))));
 803
 804             /* Evaluate switch function */
 805             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 806             fvdw             = _mm256_sub_ps( _mm256_mul_ps(fvdw,sw) , _mm256_mul_ps(rinv00,_mm256_mul_ps(vvdw,dsw)) );
 807             cutoff_mask      = _mm256_cmp_ps(rsq00,rcutoff2,_CMP_LT_OQ);
 808
 809             fscal            = fvdw;
 810
 811             fscal            = _mm256_and_ps(fscal,cutoff_mask);
 812
 813             fscal            = _mm256_andnot_ps(dummy_mask,fscal);
 814
 815             /* Calculate temporary vectorial force */
 816             tx               = _mm256_mul_ps(fscal,dx00);
 817             ty               = _mm256_mul_ps(fscal,dy00);
 818             tz               = _mm256_mul_ps(fscal,dz00);
 819
 820             /* Update vectorial force */
 821             fix0             = _mm256_add_ps(fix0,tx);
 822             fiy0             = _mm256_add_ps(fiy0,ty);
 823             fiz0             = _mm256_add_ps(fiz0,tz);
 824
 825             fjptrA             = (jnrlistA>=0) ? f+j_coord_offsetA : scratch;
 826             fjptrB             = (jnrlistB>=0) ? f+j_coord_offsetB : scratch;
 827             fjptrC             = (jnrlistC>=0) ? f+j_coord_offsetC : scratch;
 828             fjptrD             = (jnrlistD>=0) ? f+j_coord_offsetD : scratch;
 829             fjptrE             = (jnrlistE>=0) ? f+j_coord_offsetE : scratch;
 830             fjptrF             = (jnrlistF>=0) ? f+j_coord_offsetF : scratch;
 831             fjptrG             = (jnrlistG>=0) ? f+j_coord_offsetG : scratch;
 832             fjptrH             = (jnrlistH>=0) ? f+j_coord_offsetH : scratch;
 833             gmx_mm256_decrement_1rvec_8ptr_swizzle_ps(fjptrA,fjptrB,fjptrC,fjptrD,fjptrE,fjptrF,fjptrG,fjptrH,tx,ty,tz);
 834
 835             }
 836
 837             /* Inner loop uses 57 flops */
 838         }
 839
 840         /* End of innermost loop */
 841
 842         gmx_mm256_update_iforce_1atom_swizzle_ps(fix0,fiy0,fiz0,
 843                                                  f+i_coord_offset,fshift+i_shift_offset);
 844
 845         /* Increment number of inner iterations */
 846         inneriter                  += j_index_end - j_index_start;
 847
 848         /* Outer loop uses 6 flops */
 849     }
 850
 851     /* Increment number of outer iterations */
 852     outeriter        += nri;
 853
 854     /* Update outer/inner flops */
 855
 856     inc_nrnb(nrnb,eNR_NBKERNEL_VDW_F,outeriter*6 + inneriter*57);
 857 }