src/gromacs/gmxlib/nonbonded/nb_kernel_sse2_double/nb_kernel_ElecNone_VdwLJEw_GeomP1P1_sse2_double.cpp

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * Copyright (c) 2012,2013,2014,2015,2017,2018, by the GROMACS development team, led by
   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
   6  * and including many others, as listed in the AUTHORS file in the
   7  * top-level source directory and at http://www.gromacs.org.
   8  *
   9  * GROMACS is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * as published by the Free Software Foundation; either version 2.1
  12  * of the License, or (at your option) any later version.
  13  *
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  35 /*
  36  * Note: this file was generated by the GROMACS sse2_double kernel generator.
  37  */
  38 #include "gmxpre.h"
  39
  40 #include "config.h"
  41
  42 #include <math.h>
  43
  44 #include "../nb_kernel.h"
  45 #include "gromacs/gmxlib/nrnb.h"
  46
  47 #include "kernelutil_x86_sse2_double.h"
  48
  49 /*
  50  * Gromacs nonbonded kernel:   nb_kernel_ElecNone_VdwLJEw_GeomP1P1_VF_sse2_double
  51  * Electrostatics interaction: None
  52  * VdW interaction:            LJEwald
  53  * Geometry:                   Particle-Particle
  54  * Calculate force/pot:        PotentialAndForce
  55  */
  56 void
  57 nb_kernel_ElecNone_VdwLJEw_GeomP1P1_VF_sse2_double
  58                     (t_nblist                    * gmx_restrict       nlist,
  59                      rvec                        * gmx_restrict          xx,
  60                      rvec                        * gmx_restrict          ff,
  61                      struct t_forcerec           * gmx_restrict          fr,
  62                      t_mdatoms                   * gmx_restrict     mdatoms,
  63                      nb_kernel_data_t gmx_unused * gmx_restrict kernel_data,
  64                      t_nrnb                      * gmx_restrict        nrnb)
  65 {
  66     /* Suffixes 0,1,2,3 refer to particle indices for waters in the inner or outer loop, or
  67      * just 0 for non-waters.
  68      * Suffixes A,B refer to j loop unrolling done with SSE double precision, e.g. for the two different
  69      * jnr indices corresponding to data put in the four positions in the SIMD register.
  70      */
  71     int              i_shift_offset,i_coord_offset,outeriter,inneriter;
  72     int              j_index_start,j_index_end,jidx,nri,inr,ggid,iidx;
  73     int              jnrA,jnrB;
  74     int              j_coord_offsetA,j_coord_offsetB;
  75     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
  76     real             rcutoff_scalar;
  77     real             *shiftvec,*fshift,*x,*f;
  78     __m128d          tx,ty,tz,fscal,rcutoff,rcutoff2,jidxall;
  79     int              vdwioffset0;
  80     __m128d          ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
  81     int              vdwjidx0A,vdwjidx0B;
  82     __m128d          jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
  83     __m128d          dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00;
  84     int              nvdwtype;
  85     __m128d          rinvsix,rvdw,vvdw,vvdw6,vvdw12,fvdw,fvdw6,fvdw12,vvdwsum,sh_vdw_invrcut6;
  86     int              *vdwtype;
  87     real             *vdwparam;
  88     __m128d          one_sixth   = _mm_set1_pd(1.0/6.0);
  89     __m128d          one_twelfth = _mm_set1_pd(1.0/12.0);
  90     __m128d           c6grid_00;
  91     __m128d           ewclj,ewclj2,ewclj6,ewcljrsq,poly,exponent,f6A,f6B,sh_lj_ewald;
  92     real             *vdwgridparam;
  93     __m128d           one_half = _mm_set1_pd(0.5);
  94     __m128d           minus_one = _mm_set1_pd(-1.0);
  95     __m128d          dummy_mask,cutoff_mask;
  96     __m128d          signbit   = gmx_mm_castsi128_pd( _mm_set_epi32(0x80000000,0x00000000,0x80000000,0x00000000) );
  97     __m128d          one     = _mm_set1_pd(1.0);
  98     __m128d          two     = _mm_set1_pd(2.0);
  99     x                = xx[0];
 100     f                = ff[0];
 101
 102     nri              = nlist->nri;
 103     iinr             = nlist->iinr;
 104     jindex           = nlist->jindex;
 105     jjnr             = nlist->jjnr;
 106     shiftidx         = nlist->shift;
 107     gid              = nlist->gid;
 108     shiftvec         = fr->shift_vec[0];
 109     fshift           = fr->fshift[0];
 110     nvdwtype         = fr->ntype;
 111     vdwparam         = fr->nbfp;
 112     vdwtype          = mdatoms->typeA;
 113     vdwgridparam     = fr->ljpme_c6grid;
 114     sh_lj_ewald      = _mm_set1_pd(fr->ic->sh_lj_ewald);
 115     ewclj            = _mm_set1_pd(fr->ic->ewaldcoeff_lj);
 116     ewclj2           = _mm_mul_pd(minus_one,_mm_mul_pd(ewclj,ewclj));
 117
 118     /* Avoid stupid compiler warnings */
 119     jnrA = jnrB = 0;
 120     j_coord_offsetA = 0;
 121     j_coord_offsetB = 0;
 122
 123     outeriter        = 0;
 124     inneriter        = 0;
 125
 126     /* Start outer loop over neighborlists */
 127     for(iidx=0; iidx<nri; iidx++)
 128     {
 129         /* Load shift vector for this list */
 130         i_shift_offset   = DIM*shiftidx[iidx];
 131
 132         /* Load limits for loop over neighbors */
 133         j_index_start    = jindex[iidx];
 134         j_index_end      = jindex[iidx+1];
 135
 136         /* Get outer coordinate index */
 137         inr              = iinr[iidx];
 138         i_coord_offset   = DIM*inr;
 139
 140         /* Load i particle coords and add shift vector */
 141         gmx_mm_load_shift_and_1rvec_broadcast_pd(shiftvec+i_shift_offset,x+i_coord_offset,&ix0,&iy0,&iz0);
 142
 143         fix0             = _mm_setzero_pd();
 144         fiy0             = _mm_setzero_pd();
 145         fiz0             = _mm_setzero_pd();
 146
 147         /* Load parameters for i particles */
 148         vdwioffset0      = 2*nvdwtype*vdwtype[inr+0];
 149
 150         /* Reset potential sums */
 151         vvdwsum          = _mm_setzero_pd();
 152
 153         /* Start inner kernel loop */
 154         for(jidx=j_index_start; jidx<j_index_end-1; jidx+=2)
 155         {
 156
 157             /* Get j neighbor index, and coordinate index */
 158             jnrA             = jjnr[jidx];
 159             jnrB             = jjnr[jidx+1];
 160             j_coord_offsetA  = DIM*jnrA;
 161             j_coord_offsetB  = DIM*jnrB;
 162
 163             /* load j atom coordinates */
 164             gmx_mm_load_1rvec_2ptr_swizzle_pd(x+j_coord_offsetA,x+j_coord_offsetB,
 165                                               &jx0,&jy0,&jz0);
 166
 167             /* Calculate displacement vector */
 168             dx00             = _mm_sub_pd(ix0,jx0);
 169             dy00             = _mm_sub_pd(iy0,jy0);
 170             dz00             = _mm_sub_pd(iz0,jz0);
 171
 172             /* Calculate squared distance and things based on it */
 173             rsq00            = gmx_mm_calc_rsq_pd(dx00,dy00,dz00);
 174
 175             rinv00           = sse2_invsqrt_d(rsq00);
 176
 177             rinvsq00         = _mm_mul_pd(rinv00,rinv00);
 178
 179             /* Load parameters for j particles */
 180             vdwjidx0A        = 2*vdwtype[jnrA+0];
 181             vdwjidx0B        = 2*vdwtype[jnrB+0];
 182
 183             /**************************
 184              * CALCULATE INTERACTIONS *
 185              **************************/
 186
 187             r00              = _mm_mul_pd(rsq00,rinv00);
 188
 189             /* Compute parameters for interactions between i and j atoms */
 190             gmx_mm_load_2pair_swizzle_pd(vdwparam+vdwioffset0+vdwjidx0A,
 191                                          vdwparam+vdwioffset0+vdwjidx0B,&c6_00,&c12_00);
 192
 193             c6grid_00       = gmx_mm_load_2real_swizzle_pd(vdwgridparam+vdwioffset0+vdwjidx0A,
 194                                                                vdwgridparam+vdwioffset0+vdwjidx0B);
 195
 196             /* Analytical LJ-PME */
 197             rinvsix          = _mm_mul_pd(_mm_mul_pd(rinvsq00,rinvsq00),rinvsq00);
 198             ewcljrsq         = _mm_mul_pd(ewclj2,rsq00);
 199             ewclj6           = _mm_mul_pd(ewclj2,_mm_mul_pd(ewclj2,ewclj2));
 200             exponent         = sse2_exp_d(ewcljrsq);
 201             /* poly = exp(-(beta*r)^2) * (1 + (beta*r)^2 + (beta*r)^4 /2) */
 202             poly             = _mm_mul_pd(exponent,_mm_add_pd(_mm_sub_pd(one,ewcljrsq),_mm_mul_pd(_mm_mul_pd(ewcljrsq,ewcljrsq),one_half)));
 203             /* vvdw6 = [C6 - C6grid * (1-poly)]/r6 */
 204             vvdw6            = _mm_mul_pd(_mm_sub_pd(c6_00,_mm_mul_pd(c6grid_00,_mm_sub_pd(one,poly))),rinvsix);
 205             vvdw12           = _mm_mul_pd(c12_00,_mm_mul_pd(rinvsix,rinvsix));
 206             vvdw             = _mm_sub_pd(_mm_mul_pd(vvdw12,one_twelfth),_mm_mul_pd(vvdw6,one_sixth));
 207             /* fvdw = vvdw12/r - (vvdw6/r + (C6grid * exponent * beta^6)/r) */
 208             fvdw             = _mm_mul_pd(_mm_sub_pd(vvdw12,_mm_sub_pd(vvdw6,_mm_mul_pd(_mm_mul_pd(c6grid_00,one_sixth),_mm_mul_pd(exponent,ewclj6)))),rinvsq00);
 209
 210             /* Update potential sum for this i atom from the interaction with this j atom. */
 211             vvdwsum          = _mm_add_pd(vvdwsum,vvdw);
 212
 213             fscal            = fvdw;
 214
 215             /* Calculate temporary vectorial force */
 216             tx               = _mm_mul_pd(fscal,dx00);
 217             ty               = _mm_mul_pd(fscal,dy00);
 218             tz               = _mm_mul_pd(fscal,dz00);
 219
 220             /* Update vectorial force */
 221             fix0             = _mm_add_pd(fix0,tx);
 222             fiy0             = _mm_add_pd(fiy0,ty);
 223             fiz0             = _mm_add_pd(fiz0,tz);
 224
 225             gmx_mm_decrement_1rvec_2ptr_swizzle_pd(f+j_coord_offsetA,f+j_coord_offsetB,tx,ty,tz);
 226
 227             /* Inner loop uses 51 flops */
 228         }
 229
 230         if(jidx<j_index_end)
 231         {
 232
 233             jnrA             = jjnr[jidx];
 234             j_coord_offsetA  = DIM*jnrA;
 235
 236             /* load j atom coordinates */
 237             gmx_mm_load_1rvec_1ptr_swizzle_pd(x+j_coord_offsetA,
 238                                               &jx0,&jy0,&jz0);
 239
 240             /* Calculate displacement vector */
 241             dx00             = _mm_sub_pd(ix0,jx0);
 242             dy00             = _mm_sub_pd(iy0,jy0);
 243             dz00             = _mm_sub_pd(iz0,jz0);
 244
 245             /* Calculate squared distance and things based on it */
 246             rsq00            = gmx_mm_calc_rsq_pd(dx00,dy00,dz00);
 247
 248             rinv00           = sse2_invsqrt_d(rsq00);
 249
 250             rinvsq00         = _mm_mul_pd(rinv00,rinv00);
 251
 252             /* Load parameters for j particles */
 253             vdwjidx0A        = 2*vdwtype[jnrA+0];
 254
 255             /**************************
 256              * CALCULATE INTERACTIONS *
 257              **************************/
 258
 259             r00              = _mm_mul_pd(rsq00,rinv00);
 260
 261             /* Compute parameters for interactions between i and j atoms */
 262             gmx_mm_load_1pair_swizzle_pd(vdwparam+vdwioffset0+vdwjidx0A,&c6_00,&c12_00);
 263
 264             c6grid_00       = gmx_mm_load_1real_pd(vdwgridparam+vdwioffset0+vdwjidx0A);
 265
 266             /* Analytical LJ-PME */
 267             rinvsix          = _mm_mul_pd(_mm_mul_pd(rinvsq00,rinvsq00),rinvsq00);
 268             ewcljrsq         = _mm_mul_pd(ewclj2,rsq00);
 269             ewclj6           = _mm_mul_pd(ewclj2,_mm_mul_pd(ewclj2,ewclj2));
 270             exponent         = sse2_exp_d(ewcljrsq);
 271             /* poly = exp(-(beta*r)^2) * (1 + (beta*r)^2 + (beta*r)^4 /2) */
 272             poly             = _mm_mul_pd(exponent,_mm_add_pd(_mm_sub_pd(one,ewcljrsq),_mm_mul_pd(_mm_mul_pd(ewcljrsq,ewcljrsq),one_half)));
 273             /* vvdw6 = [C6 - C6grid * (1-poly)]/r6 */
 274             vvdw6            = _mm_mul_pd(_mm_sub_pd(c6_00,_mm_mul_pd(c6grid_00,_mm_sub_pd(one,poly))),rinvsix);
 275             vvdw12           = _mm_mul_pd(c12_00,_mm_mul_pd(rinvsix,rinvsix));
 276             vvdw             = _mm_sub_pd(_mm_mul_pd(vvdw12,one_twelfth),_mm_mul_pd(vvdw6,one_sixth));
 277             /* fvdw = vvdw12/r - (vvdw6/r + (C6grid * exponent * beta^6)/r) */
 278             fvdw             = _mm_mul_pd(_mm_sub_pd(vvdw12,_mm_sub_pd(vvdw6,_mm_mul_pd(_mm_mul_pd(c6grid_00,one_sixth),_mm_mul_pd(exponent,ewclj6)))),rinvsq00);
 279
 280             /* Update potential sum for this i atom from the interaction with this j atom. */
 281             vvdw             = _mm_unpacklo_pd(vvdw,_mm_setzero_pd());
 282             vvdwsum          = _mm_add_pd(vvdwsum,vvdw);
 283
 284             fscal            = fvdw;
 285
 286             fscal            = _mm_unpacklo_pd(fscal,_mm_setzero_pd());
 287
 288             /* Calculate temporary vectorial force */
 289             tx               = _mm_mul_pd(fscal,dx00);
 290             ty               = _mm_mul_pd(fscal,dy00);
 291             tz               = _mm_mul_pd(fscal,dz00);
 292
 293             /* Update vectorial force */
 294             fix0             = _mm_add_pd(fix0,tx);
 295             fiy0             = _mm_add_pd(fiy0,ty);
 296             fiz0             = _mm_add_pd(fiz0,tz);
 297
 298             gmx_mm_decrement_1rvec_1ptr_swizzle_pd(f+j_coord_offsetA,tx,ty,tz);
 299
 300             /* Inner loop uses 51 flops */
 301         }
 302
 303         /* End of innermost loop */
 304
 305         gmx_mm_update_iforce_1atom_swizzle_pd(fix0,fiy0,fiz0,
 306                                               f+i_coord_offset,fshift+i_shift_offset);
 307
 308         ggid                        = gid[iidx];
 309         /* Update potential energies */
 310         gmx_mm_update_1pot_pd(vvdwsum,kernel_data->energygrp_vdw+ggid);
 311
 312         /* Increment number of inner iterations */
 313         inneriter                  += j_index_end - j_index_start;
 314
 315         /* Outer loop uses 7 flops */
 316     }
 317
 318     /* Increment number of outer iterations */
 319     outeriter        += nri;
 320
 321     /* Update outer/inner flops */
 322
 323     inc_nrnb(nrnb,eNR_NBKERNEL_VDW_VF,outeriter*7 + inneriter*51);
 324 }
 325 /*
 326  * Gromacs nonbonded kernel:   nb_kernel_ElecNone_VdwLJEw_GeomP1P1_F_sse2_double
 327  * Electrostatics interaction: None
 328  * VdW interaction:            LJEwald
 329  * Geometry:                   Particle-Particle
 330  * Calculate force/pot:        Force
 331  */
 332 void
 333 nb_kernel_ElecNone_VdwLJEw_GeomP1P1_F_sse2_double
 334                     (t_nblist                    * gmx_restrict       nlist,
 335                      rvec                        * gmx_restrict          xx,
 336                      rvec                        * gmx_restrict          ff,
 337                      struct t_forcerec           * gmx_restrict          fr,
 338                      t_mdatoms                   * gmx_restrict     mdatoms,
 339                      nb_kernel_data_t gmx_unused * gmx_restrict kernel_data,
 340                      t_nrnb                      * gmx_restrict        nrnb)
 341 {
 342     /* Suffixes 0,1,2,3 refer to particle indices for waters in the inner or outer loop, or
 343      * just 0 for non-waters.
 344      * Suffixes A,B refer to j loop unrolling done with SSE double precision, e.g. for the two different
 345      * jnr indices corresponding to data put in the four positions in the SIMD register.
 346      */
 347     int              i_shift_offset,i_coord_offset,outeriter,inneriter;
 348     int              j_index_start,j_index_end,jidx,nri,inr,ggid,iidx;
 349     int              jnrA,jnrB;
 350     int              j_coord_offsetA,j_coord_offsetB;
 351     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
 352     real             rcutoff_scalar;
 353     real             *shiftvec,*fshift,*x,*f;
 354     __m128d          tx,ty,tz,fscal,rcutoff,rcutoff2,jidxall;
 355     int              vdwioffset0;
 356     __m128d          ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
 357     int              vdwjidx0A,vdwjidx0B;
 358     __m128d          jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
 359     __m128d          dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00;
 360     int              nvdwtype;
 361     __m128d          rinvsix,rvdw,vvdw,vvdw6,vvdw12,fvdw,fvdw6,fvdw12,vvdwsum,sh_vdw_invrcut6;
 362     int              *vdwtype;
 363     real             *vdwparam;
 364     __m128d          one_sixth   = _mm_set1_pd(1.0/6.0);
 365     __m128d          one_twelfth = _mm_set1_pd(1.0/12.0);
 366     __m128d           c6grid_00;
 367     __m128d           ewclj,ewclj2,ewclj6,ewcljrsq,poly,exponent,f6A,f6B,sh_lj_ewald;
 368     real             *vdwgridparam;
 369     __m128d           one_half = _mm_set1_pd(0.5);
 370     __m128d           minus_one = _mm_set1_pd(-1.0);
 371     __m128d          dummy_mask,cutoff_mask;
 372     __m128d          signbit   = gmx_mm_castsi128_pd( _mm_set_epi32(0x80000000,0x00000000,0x80000000,0x00000000) );
 373     __m128d          one     = _mm_set1_pd(1.0);
 374     __m128d          two     = _mm_set1_pd(2.0);
 375     x                = xx[0];
 376     f                = ff[0];
 377
 378     nri              = nlist->nri;
 379     iinr             = nlist->iinr;
 380     jindex           = nlist->jindex;
 381     jjnr             = nlist->jjnr;
 382     shiftidx         = nlist->shift;
 383     gid              = nlist->gid;
 384     shiftvec         = fr->shift_vec[0];
 385     fshift           = fr->fshift[0];
 386     nvdwtype         = fr->ntype;
 387     vdwparam         = fr->nbfp;
 388     vdwtype          = mdatoms->typeA;
 389     vdwgridparam     = fr->ljpme_c6grid;
 390     sh_lj_ewald      = _mm_set1_pd(fr->ic->sh_lj_ewald);
 391     ewclj            = _mm_set1_pd(fr->ic->ewaldcoeff_lj);
 392     ewclj2           = _mm_mul_pd(minus_one,_mm_mul_pd(ewclj,ewclj));
 393
 394     /* Avoid stupid compiler warnings */
 395     jnrA = jnrB = 0;
 396     j_coord_offsetA = 0;
 397     j_coord_offsetB = 0;
 398
 399     outeriter        = 0;
 400     inneriter        = 0;
 401
 402     /* Start outer loop over neighborlists */
 403     for(iidx=0; iidx<nri; iidx++)
 404     {
 405         /* Load shift vector for this list */
 406         i_shift_offset   = DIM*shiftidx[iidx];
 407
 408         /* Load limits for loop over neighbors */
 409         j_index_start    = jindex[iidx];
 410         j_index_end      = jindex[iidx+1];
 411
 412         /* Get outer coordinate index */
 413         inr              = iinr[iidx];
 414         i_coord_offset   = DIM*inr;
 415
 416         /* Load i particle coords and add shift vector */
 417         gmx_mm_load_shift_and_1rvec_broadcast_pd(shiftvec+i_shift_offset,x+i_coord_offset,&ix0,&iy0,&iz0);
 418
 419         fix0             = _mm_setzero_pd();
 420         fiy0             = _mm_setzero_pd();
 421         fiz0             = _mm_setzero_pd();
 422
 423         /* Load parameters for i particles */
 424         vdwioffset0      = 2*nvdwtype*vdwtype[inr+0];
 425
 426         /* Start inner kernel loop */
 427         for(jidx=j_index_start; jidx<j_index_end-1; jidx+=2)
 428         {
 429
 430             /* Get j neighbor index, and coordinate index */
 431             jnrA             = jjnr[jidx];
 432             jnrB             = jjnr[jidx+1];
 433             j_coord_offsetA  = DIM*jnrA;
 434             j_coord_offsetB  = DIM*jnrB;
 435
 436             /* load j atom coordinates */
 437             gmx_mm_load_1rvec_2ptr_swizzle_pd(x+j_coord_offsetA,x+j_coord_offsetB,
 438                                               &jx0,&jy0,&jz0);
 439
 440             /* Calculate displacement vector */
 441             dx00             = _mm_sub_pd(ix0,jx0);
 442             dy00             = _mm_sub_pd(iy0,jy0);
 443             dz00             = _mm_sub_pd(iz0,jz0);
 444
 445             /* Calculate squared distance and things based on it */
 446             rsq00            = gmx_mm_calc_rsq_pd(dx00,dy00,dz00);
 447
 448             rinv00           = sse2_invsqrt_d(rsq00);
 449
 450             rinvsq00         = _mm_mul_pd(rinv00,rinv00);
 451
 452             /* Load parameters for j particles */
 453             vdwjidx0A        = 2*vdwtype[jnrA+0];
 454             vdwjidx0B        = 2*vdwtype[jnrB+0];
 455
 456             /**************************
 457              * CALCULATE INTERACTIONS *
 458              **************************/
 459
 460             r00              = _mm_mul_pd(rsq00,rinv00);
 461
 462             /* Compute parameters for interactions between i and j atoms */
 463             gmx_mm_load_2pair_swizzle_pd(vdwparam+vdwioffset0+vdwjidx0A,
 464                                          vdwparam+vdwioffset0+vdwjidx0B,&c6_00,&c12_00);
 465
 466             c6grid_00       = gmx_mm_load_2real_swizzle_pd(vdwgridparam+vdwioffset0+vdwjidx0A,
 467                                                                vdwgridparam+vdwioffset0+vdwjidx0B);
 468
 469             /* Analytical LJ-PME */
 470             rinvsix          = _mm_mul_pd(_mm_mul_pd(rinvsq00,rinvsq00),rinvsq00);
 471             ewcljrsq         = _mm_mul_pd(ewclj2,rsq00);
 472             ewclj6           = _mm_mul_pd(ewclj2,_mm_mul_pd(ewclj2,ewclj2));
 473             exponent         = sse2_exp_d(ewcljrsq);
 474             /* poly = exp(-(beta*r)^2) * (1 + (beta*r)^2 + (beta*r)^4 /2) */
 475             poly             = _mm_mul_pd(exponent,_mm_add_pd(_mm_sub_pd(one,ewcljrsq),_mm_mul_pd(_mm_mul_pd(ewcljrsq,ewcljrsq),one_half)));
 476             /* f6A = 6 * C6grid * (1 - poly) */
 477             f6A              = _mm_mul_pd(c6grid_00,_mm_sub_pd(one,poly));
 478             /* f6B = C6grid * exponent * beta^6 */
 479             f6B              = _mm_mul_pd(_mm_mul_pd(c6grid_00,one_sixth),_mm_mul_pd(exponent,ewclj6));
 480             /* fvdw = 12*C12/r13 - ((6*C6 - f6A)/r6 + f6B)/r */
 481             fvdw              = _mm_mul_pd(_mm_add_pd(_mm_mul_pd(_mm_sub_pd(_mm_mul_pd(c12_00,rinvsix),_mm_sub_pd(c6_00,f6A)),rinvsix),f6B),rinvsq00);
 482
 483             fscal            = fvdw;
 484
 485             /* Calculate temporary vectorial force */
 486             tx               = _mm_mul_pd(fscal,dx00);
 487             ty               = _mm_mul_pd(fscal,dy00);
 488             tz               = _mm_mul_pd(fscal,dz00);
 489
 490             /* Update vectorial force */
 491             fix0             = _mm_add_pd(fix0,tx);
 492             fiy0             = _mm_add_pd(fiy0,ty);
 493             fiz0             = _mm_add_pd(fiz0,tz);
 494
 495             gmx_mm_decrement_1rvec_2ptr_swizzle_pd(f+j_coord_offsetA,f+j_coord_offsetB,tx,ty,tz);
 496
 497             /* Inner loop uses 46 flops */
 498         }
 499
 500         if(jidx<j_index_end)
 501         {
 502
 503             jnrA             = jjnr[jidx];
 504             j_coord_offsetA  = DIM*jnrA;
 505
 506             /* load j atom coordinates */
 507             gmx_mm_load_1rvec_1ptr_swizzle_pd(x+j_coord_offsetA,
 508                                               &jx0,&jy0,&jz0);
 509
 510             /* Calculate displacement vector */
 511             dx00             = _mm_sub_pd(ix0,jx0);
 512             dy00             = _mm_sub_pd(iy0,jy0);
 513             dz00             = _mm_sub_pd(iz0,jz0);
 514
 515             /* Calculate squared distance and things based on it */
 516             rsq00            = gmx_mm_calc_rsq_pd(dx00,dy00,dz00);
 517
 518             rinv00           = sse2_invsqrt_d(rsq00);
 519
 520             rinvsq00         = _mm_mul_pd(rinv00,rinv00);
 521
 522             /* Load parameters for j particles */
 523             vdwjidx0A        = 2*vdwtype[jnrA+0];
 524
 525             /**************************
 526              * CALCULATE INTERACTIONS *
 527              **************************/
 528
 529             r00              = _mm_mul_pd(rsq00,rinv00);
 530
 531             /* Compute parameters for interactions between i and j atoms */
 532             gmx_mm_load_1pair_swizzle_pd(vdwparam+vdwioffset0+vdwjidx0A,&c6_00,&c12_00);
 533
 534             c6grid_00       = gmx_mm_load_1real_pd(vdwgridparam+vdwioffset0+vdwjidx0A);
 535
 536             /* Analytical LJ-PME */
 537             rinvsix          = _mm_mul_pd(_mm_mul_pd(rinvsq00,rinvsq00),rinvsq00);
 538             ewcljrsq         = _mm_mul_pd(ewclj2,rsq00);
 539             ewclj6           = _mm_mul_pd(ewclj2,_mm_mul_pd(ewclj2,ewclj2));
 540             exponent         = sse2_exp_d(ewcljrsq);
 541             /* poly = exp(-(beta*r)^2) * (1 + (beta*r)^2 + (beta*r)^4 /2) */
 542             poly             = _mm_mul_pd(exponent,_mm_add_pd(_mm_sub_pd(one,ewcljrsq),_mm_mul_pd(_mm_mul_pd(ewcljrsq,ewcljrsq),one_half)));
 543             /* f6A = 6 * C6grid * (1 - poly) */
 544             f6A              = _mm_mul_pd(c6grid_00,_mm_sub_pd(one,poly));
 545             /* f6B = C6grid * exponent * beta^6 */
 546             f6B              = _mm_mul_pd(_mm_mul_pd(c6grid_00,one_sixth),_mm_mul_pd(exponent,ewclj6));
 547             /* fvdw = 12*C12/r13 - ((6*C6 - f6A)/r6 + f6B)/r */
 548             fvdw              = _mm_mul_pd(_mm_add_pd(_mm_mul_pd(_mm_sub_pd(_mm_mul_pd(c12_00,rinvsix),_mm_sub_pd(c6_00,f6A)),rinvsix),f6B),rinvsq00);
 549
 550             fscal            = fvdw;
 551
 552             fscal            = _mm_unpacklo_pd(fscal,_mm_setzero_pd());
 553
 554             /* Calculate temporary vectorial force */
 555             tx               = _mm_mul_pd(fscal,dx00);
 556             ty               = _mm_mul_pd(fscal,dy00);
 557             tz               = _mm_mul_pd(fscal,dz00);
 558
 559             /* Update vectorial force */
 560             fix0             = _mm_add_pd(fix0,tx);
 561             fiy0             = _mm_add_pd(fiy0,ty);
 562             fiz0             = _mm_add_pd(fiz0,tz);
 563
 564             gmx_mm_decrement_1rvec_1ptr_swizzle_pd(f+j_coord_offsetA,tx,ty,tz);
 565
 566             /* Inner loop uses 46 flops */
 567         }
 568
 569         /* End of innermost loop */
 570
 571         gmx_mm_update_iforce_1atom_swizzle_pd(fix0,fiy0,fiz0,
 572                                               f+i_coord_offset,fshift+i_shift_offset);
 573
 574         /* Increment number of inner iterations */
 575         inneriter                  += j_index_end - j_index_start;
 576
 577         /* Outer loop uses 6 flops */
 578     }
 579
 580     /* Increment number of outer iterations */
 581     outeriter        += nri;
 582
 583     /* Update outer/inner flops */
 584
 585     inc_nrnb(nrnb,eNR_NBKERNEL_VDW_F,outeriter*6 + inneriter*46);
 586 }