src/gmxlib/nonbonded/nb_kernel_sse2_single/nb_kernel_ElecEwSw_VdwNone_GeomP1P1_sse2_single.c

   1 /*
   2  * Note: this file was generated by the Gromacs sse2_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_sse2_single.h"
  34 #include "kernelutil_x86_sse2_single.h"
  35
  36 /*
  37  * Gromacs nonbonded kernel:   nb_kernel_ElecEwSw_VdwNone_GeomP1P1_VF_sse2_single
  38  * Electrostatics interaction: Ewald
  39  * VdW interaction:            None
  40  * Geometry:                   Particle-Particle
  41  * Calculate force/pot:        PotentialAndForce
  42  */
  43 void
  44 nb_kernel_ElecEwSw_VdwNone_GeomP1P1_VF_sse2_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 refer to j loop unrolling done with SSE, e.g. for the four 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              j_coord_offsetA,j_coord_offsetB,j_coord_offsetC,j_coord_offsetD;
  62     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
  63     real             shX,shY,shZ,rcutoff_scalar;
  64     real             *shiftvec,*fshift,*x,*f;
  65     __m128           tx,ty,tz,fscal,rcutoff,rcutoff2,jidxall;
  66     int              vdwioffset0;
  67     __m128           ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
  68     int              vdwjidx0A,vdwjidx0B,vdwjidx0C,vdwjidx0D;
  69     __m128           jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
  70     __m128           dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00;
  71     __m128           velec,felec,velecsum,facel,crf,krf,krf2;
  72     real             *charge;
  73     __m128i          ewitab;
  74     __m128           ewtabscale,eweps,sh_ewald,ewrt,ewtabhalfspace,ewtabF,ewtabFn,ewtabD,ewtabV;
  75     real             *ewtab;
  76     __m128           rswitch,swV3,swV4,swV5,swF2,swF3,swF4,d,d2,sw,dsw;
  77     real             rswitch_scalar,d_scalar;
  78     __m128           dummy_mask,cutoff_mask;
  79     __m128           signbit = _mm_castsi128_ps( _mm_set1_epi32(0x80000000) );
  80     __m128           one     = _mm_set1_ps(1.0);
  81     __m128           two     = _mm_set1_ps(2.0);
  82     x                = xx[0];
  83     f                = ff[0];
  84
  85     nri              = nlist->nri;
  86     iinr             = nlist->iinr;
  87     jindex           = nlist->jindex;
  88     jjnr             = nlist->jjnr;
  89     shiftidx         = nlist->shift;
  90     gid              = nlist->gid;
  91     shiftvec         = fr->shift_vec[0];
  92     fshift           = fr->fshift[0];
  93     facel            = _mm_set1_ps(fr->epsfac);
  94     charge           = mdatoms->chargeA;
  95
  96     sh_ewald         = _mm_set1_ps(fr->ic->sh_ewald);
  97     ewtab            = fr->ic->tabq_coul_FDV0;
  98     ewtabscale       = _mm_set1_ps(fr->ic->tabq_scale);
  99     ewtabhalfspace   = _mm_set1_ps(0.5/fr->ic->tabq_scale);
 100
 101     /* When we use explicit cutoffs the value must be identical for elec and VdW, so use elec as an arbitrary choice */
 102     rcutoff_scalar   = fr->rcoulomb;
 103     rcutoff          = _mm_set1_ps(rcutoff_scalar);
 104     rcutoff2         = _mm_mul_ps(rcutoff,rcutoff);
 105
 106     rswitch_scalar   = fr->rcoulomb_switch;
 107     rswitch          = _mm_set1_ps(rswitch_scalar);
 108     /* Setup switch parameters */
 109     d_scalar         = rcutoff_scalar-rswitch_scalar;
 110     d                = _mm_set1_ps(d_scalar);
 111     swV3             = _mm_set1_ps(-10.0/(d_scalar*d_scalar*d_scalar));
 112     swV4             = _mm_set1_ps( 15.0/(d_scalar*d_scalar*d_scalar*d_scalar));
 113     swV5             = _mm_set1_ps( -6.0/(d_scalar*d_scalar*d_scalar*d_scalar*d_scalar));
 114     swF2             = _mm_set1_ps(-30.0/(d_scalar*d_scalar*d_scalar));
 115     swF3             = _mm_set1_ps( 60.0/(d_scalar*d_scalar*d_scalar*d_scalar));
 116     swF4             = _mm_set1_ps(-30.0/(d_scalar*d_scalar*d_scalar*d_scalar*d_scalar));
 117
 118     /* Avoid stupid compiler warnings */
 119     jnrA = jnrB = jnrC = jnrD = 0;
 120     j_coord_offsetA = 0;
 121     j_coord_offsetB = 0;
 122     j_coord_offsetC = 0;
 123     j_coord_offsetD = 0;
 124
 125     outeriter        = 0;
 126     inneriter        = 0;
 127
 128     /* Start outer loop over neighborlists */
 129     for(iidx=0; iidx<nri; iidx++)
 130     {
 131         /* Load shift vector for this list */
 132         i_shift_offset   = DIM*shiftidx[iidx];
 133         shX              = shiftvec[i_shift_offset+XX];
 134         shY              = shiftvec[i_shift_offset+YY];
 135         shZ              = shiftvec[i_shift_offset+ZZ];
 136
 137         /* Load limits for loop over neighbors */
 138         j_index_start    = jindex[iidx];
 139         j_index_end      = jindex[iidx+1];
 140
 141         /* Get outer coordinate index */
 142         inr              = iinr[iidx];
 143         i_coord_offset   = DIM*inr;
 144
 145         /* Load i particle coords and add shift vector */
 146         ix0              = _mm_set1_ps(shX + x[i_coord_offset+DIM*0+XX]);
 147         iy0              = _mm_set1_ps(shY + x[i_coord_offset+DIM*0+YY]);
 148         iz0              = _mm_set1_ps(shZ + x[i_coord_offset+DIM*0+ZZ]);
 149
 150         fix0             = _mm_setzero_ps();
 151         fiy0             = _mm_setzero_ps();
 152         fiz0             = _mm_setzero_ps();
 153
 154         /* Load parameters for i particles */
 155         iq0              = _mm_mul_ps(facel,_mm_load1_ps(charge+inr+0));
 156
 157         /* Reset potential sums */
 158         velecsum         = _mm_setzero_ps();
 159
 160         /* Start inner kernel loop */
 161         for(jidx=j_index_start; jidx<j_index_end && jjnr[jidx+3]>=0; jidx+=4)
 162         {
 163
 164             /* Get j neighbor index, and coordinate index */
 165             jnrA             = jjnr[jidx];
 166             jnrB             = jjnr[jidx+1];
 167             jnrC             = jjnr[jidx+2];
 168             jnrD             = jjnr[jidx+3];
 169
 170             j_coord_offsetA  = DIM*jnrA;
 171             j_coord_offsetB  = DIM*jnrB;
 172             j_coord_offsetC  = DIM*jnrC;
 173             j_coord_offsetD  = DIM*jnrD;
 174
 175             /* load j atom coordinates */
 176             gmx_mm_load_1rvec_4ptr_swizzle_ps(x+j_coord_offsetA,x+j_coord_offsetB,
 177                                               x+j_coord_offsetC,x+j_coord_offsetD,
 178                                               &jx0,&jy0,&jz0);
 179
 180             /* Calculate displacement vector */
 181             dx00             = _mm_sub_ps(ix0,jx0);
 182             dy00             = _mm_sub_ps(iy0,jy0);
 183             dz00             = _mm_sub_ps(iz0,jz0);
 184
 185             /* Calculate squared distance and things based on it */
 186             rsq00            = gmx_mm_calc_rsq_ps(dx00,dy00,dz00);
 187
 188             rinv00           = gmx_mm_invsqrt_ps(rsq00);
 189
 190             rinvsq00         = _mm_mul_ps(rinv00,rinv00);
 191
 192             /* Load parameters for j particles */
 193             jq0              = gmx_mm_load_4real_swizzle_ps(charge+jnrA+0,charge+jnrB+0,
 194                                                               charge+jnrC+0,charge+jnrD+0);
 195
 196             /**************************
 197              * CALCULATE INTERACTIONS *
 198              **************************/
 199
 200             if (gmx_mm_any_lt(rsq00,rcutoff2))
 201             {
 202
 203             r00              = _mm_mul_ps(rsq00,rinv00);
 204
 205             /* Compute parameters for interactions between i and j atoms */
 206             qq00             = _mm_mul_ps(iq0,jq0);
 207
 208             /* EWALD ELECTROSTATICS */
 209
 210             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 211             ewrt             = _mm_mul_ps(r00,ewtabscale);
 212             ewitab           = _mm_cvttps_epi32(ewrt);
 213             eweps            = _mm_sub_ps(ewrt,_mm_cvtepi32_ps(ewitab));
 214             ewitab           = _mm_slli_epi32(ewitab,2);
 215             ewtabF           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,0) );
 216             ewtabD           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,1) );
 217             ewtabV           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,2) );
 218             ewtabFn          = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,3) );
 219             _MM_TRANSPOSE4_PS(ewtabF,ewtabD,ewtabV,ewtabFn);
 220             felec            = _mm_add_ps(ewtabF,_mm_mul_ps(eweps,ewtabD));
 221             velec            = _mm_sub_ps(ewtabV,_mm_mul_ps(_mm_mul_ps(ewtabhalfspace,eweps),_mm_add_ps(ewtabF,felec)));
 222             velec            = _mm_mul_ps(qq00,_mm_sub_ps(rinv00,velec));
 223             felec            = _mm_mul_ps(_mm_mul_ps(qq00,rinv00),_mm_sub_ps(rinvsq00,felec));
 224
 225             d                = _mm_sub_ps(r00,rswitch);
 226             d                = _mm_max_ps(d,_mm_setzero_ps());
 227             d2               = _mm_mul_ps(d,d);
 228             sw               = _mm_add_ps(one,_mm_mul_ps(d2,_mm_mul_ps(d,_mm_add_ps(swV3,_mm_mul_ps(d,_mm_add_ps(swV4,_mm_mul_ps(d,swV5)))))));
 229
 230             dsw              = _mm_mul_ps(d2,_mm_add_ps(swF2,_mm_mul_ps(d,_mm_add_ps(swF3,_mm_mul_ps(d,swF4)))));
 231
 232             /* Evaluate switch function */
 233             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 234             felec            = _mm_sub_ps( _mm_mul_ps(felec,sw) , _mm_mul_ps(rinv00,_mm_mul_ps(velec,dsw)) );
 235             velec            = _mm_mul_ps(velec,sw);
 236             cutoff_mask      = _mm_cmplt_ps(rsq00,rcutoff2);
 237
 238             /* Update potential sum for this i atom from the interaction with this j atom. */
 239             velec            = _mm_and_ps(velec,cutoff_mask);
 240             velecsum         = _mm_add_ps(velecsum,velec);
 241
 242             fscal            = felec;
 243
 244             fscal            = _mm_and_ps(fscal,cutoff_mask);
 245
 246             /* Calculate temporary vectorial force */
 247             tx               = _mm_mul_ps(fscal,dx00);
 248             ty               = _mm_mul_ps(fscal,dy00);
 249             tz               = _mm_mul_ps(fscal,dz00);
 250
 251             /* Update vectorial force */
 252             fix0             = _mm_add_ps(fix0,tx);
 253             fiy0             = _mm_add_ps(fiy0,ty);
 254             fiz0             = _mm_add_ps(fiz0,tz);
 255
 256             gmx_mm_decrement_1rvec_4ptr_swizzle_ps(f+j_coord_offsetA,f+j_coord_offsetB,
 257                                                    f+j_coord_offsetC,f+j_coord_offsetD,
 258                                                    tx,ty,tz);
 259
 260             }
 261
 262             /* Inner loop uses 65 flops */
 263         }
 264
 265         if(jidx<j_index_end)
 266         {
 267
 268             /* Get j neighbor index, and coordinate index */
 269             jnrA             = jjnr[jidx];
 270             jnrB             = jjnr[jidx+1];
 271             jnrC             = jjnr[jidx+2];
 272             jnrD             = jjnr[jidx+3];
 273
 274             /* Sign of each element will be negative for non-real atoms.
 275              * This mask will be 0xFFFFFFFF for dummy entries and 0x0 for real ones,
 276              * so use it as val = _mm_andnot_ps(mask,val) to clear dummy entries.
 277              */
 278             dummy_mask = gmx_mm_castsi128_ps(_mm_cmplt_epi32(_mm_loadu_si128((const __m128i *)(jjnr+jidx)),_mm_setzero_si128()));
 279             jnrA       = (jnrA>=0) ? jnrA : 0;
 280             jnrB       = (jnrB>=0) ? jnrB : 0;
 281             jnrC       = (jnrC>=0) ? jnrC : 0;
 282             jnrD       = (jnrD>=0) ? jnrD : 0;
 283
 284             j_coord_offsetA  = DIM*jnrA;
 285             j_coord_offsetB  = DIM*jnrB;
 286             j_coord_offsetC  = DIM*jnrC;
 287             j_coord_offsetD  = DIM*jnrD;
 288
 289             /* load j atom coordinates */
 290             gmx_mm_load_1rvec_4ptr_swizzle_ps(x+j_coord_offsetA,x+j_coord_offsetB,
 291                                               x+j_coord_offsetC,x+j_coord_offsetD,
 292                                               &jx0,&jy0,&jz0);
 293
 294             /* Calculate displacement vector */
 295             dx00             = _mm_sub_ps(ix0,jx0);
 296             dy00             = _mm_sub_ps(iy0,jy0);
 297             dz00             = _mm_sub_ps(iz0,jz0);
 298
 299             /* Calculate squared distance and things based on it */
 300             rsq00            = gmx_mm_calc_rsq_ps(dx00,dy00,dz00);
 301
 302             rinv00           = gmx_mm_invsqrt_ps(rsq00);
 303
 304             rinvsq00         = _mm_mul_ps(rinv00,rinv00);
 305
 306             /* Load parameters for j particles */
 307             jq0              = gmx_mm_load_4real_swizzle_ps(charge+jnrA+0,charge+jnrB+0,
 308                                                               charge+jnrC+0,charge+jnrD+0);
 309
 310             /**************************
 311              * CALCULATE INTERACTIONS *
 312              **************************/
 313
 314             if (gmx_mm_any_lt(rsq00,rcutoff2))
 315             {
 316
 317             r00              = _mm_mul_ps(rsq00,rinv00);
 318             r00              = _mm_andnot_ps(dummy_mask,r00);
 319
 320             /* Compute parameters for interactions between i and j atoms */
 321             qq00             = _mm_mul_ps(iq0,jq0);
 322
 323             /* EWALD ELECTROSTATICS */
 324
 325             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 326             ewrt             = _mm_mul_ps(r00,ewtabscale);
 327             ewitab           = _mm_cvttps_epi32(ewrt);
 328             eweps            = _mm_sub_ps(ewrt,_mm_cvtepi32_ps(ewitab));
 329             ewitab           = _mm_slli_epi32(ewitab,2);
 330             ewtabF           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,0) );
 331             ewtabD           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,1) );
 332             ewtabV           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,2) );
 333             ewtabFn          = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,3) );
 334             _MM_TRANSPOSE4_PS(ewtabF,ewtabD,ewtabV,ewtabFn);
 335             felec            = _mm_add_ps(ewtabF,_mm_mul_ps(eweps,ewtabD));
 336             velec            = _mm_sub_ps(ewtabV,_mm_mul_ps(_mm_mul_ps(ewtabhalfspace,eweps),_mm_add_ps(ewtabF,felec)));
 337             velec            = _mm_mul_ps(qq00,_mm_sub_ps(rinv00,velec));
 338             felec            = _mm_mul_ps(_mm_mul_ps(qq00,rinv00),_mm_sub_ps(rinvsq00,felec));
 339
 340             d                = _mm_sub_ps(r00,rswitch);
 341             d                = _mm_max_ps(d,_mm_setzero_ps());
 342             d2               = _mm_mul_ps(d,d);
 343             sw               = _mm_add_ps(one,_mm_mul_ps(d2,_mm_mul_ps(d,_mm_add_ps(swV3,_mm_mul_ps(d,_mm_add_ps(swV4,_mm_mul_ps(d,swV5)))))));
 344
 345             dsw              = _mm_mul_ps(d2,_mm_add_ps(swF2,_mm_mul_ps(d,_mm_add_ps(swF3,_mm_mul_ps(d,swF4)))));
 346
 347             /* Evaluate switch function */
 348             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 349             felec            = _mm_sub_ps( _mm_mul_ps(felec,sw) , _mm_mul_ps(rinv00,_mm_mul_ps(velec,dsw)) );
 350             velec            = _mm_mul_ps(velec,sw);
 351             cutoff_mask      = _mm_cmplt_ps(rsq00,rcutoff2);
 352
 353             /* Update potential sum for this i atom from the interaction with this j atom. */
 354             velec            = _mm_and_ps(velec,cutoff_mask);
 355             velec            = _mm_andnot_ps(dummy_mask,velec);
 356             velecsum         = _mm_add_ps(velecsum,velec);
 357
 358             fscal            = felec;
 359
 360             fscal            = _mm_and_ps(fscal,cutoff_mask);
 361
 362             fscal            = _mm_andnot_ps(dummy_mask,fscal);
 363
 364             /* Calculate temporary vectorial force */
 365             tx               = _mm_mul_ps(fscal,dx00);
 366             ty               = _mm_mul_ps(fscal,dy00);
 367             tz               = _mm_mul_ps(fscal,dz00);
 368
 369             /* Update vectorial force */
 370             fix0             = _mm_add_ps(fix0,tx);
 371             fiy0             = _mm_add_ps(fiy0,ty);
 372             fiz0             = _mm_add_ps(fiz0,tz);
 373
 374             gmx_mm_decrement_1rvec_4ptr_swizzle_ps(f+j_coord_offsetA,f+j_coord_offsetB,
 375                                                    f+j_coord_offsetC,f+j_coord_offsetD,
 376                                                    tx,ty,tz);
 377
 378             }
 379
 380             /* Inner loop uses 66 flops */
 381         }
 382
 383         /* End of innermost loop */
 384
 385         gmx_mm_update_iforce_1atom_swizzle_ps(fix0,fiy0,fiz0,
 386                                               f+i_coord_offset,fshift+i_shift_offset);
 387
 388         ggid                        = gid[iidx];
 389         /* Update potential energies */
 390         gmx_mm_update_1pot_ps(velecsum,kernel_data->energygrp_elec+ggid);
 391
 392         /* Increment number of inner iterations */
 393         inneriter                  += j_index_end - j_index_start;
 394
 395         /* Outer loop uses 11 flops */
 396     }
 397
 398     /* Increment number of outer iterations */
 399     outeriter        += nri;
 400
 401     /* Update outer/inner flops */
 402
 403     inc_nrnb(nrnb,eNR_NBKERNEL_ELEC_VF,outeriter*11 + inneriter*66);
 404 }
 405 /*
 406  * Gromacs nonbonded kernel:   nb_kernel_ElecEwSw_VdwNone_GeomP1P1_F_sse2_single
 407  * Electrostatics interaction: Ewald
 408  * VdW interaction:            None
 409  * Geometry:                   Particle-Particle
 410  * Calculate force/pot:        Force
 411  */
 412 void
 413 nb_kernel_ElecEwSw_VdwNone_GeomP1P1_F_sse2_single
 414                     (t_nblist * gmx_restrict                nlist,
 415                      rvec * gmx_restrict                    xx,
 416                      rvec * gmx_restrict                    ff,
 417                      t_forcerec * gmx_restrict              fr,
 418                      t_mdatoms * gmx_restrict               mdatoms,
 419                      nb_kernel_data_t * gmx_restrict        kernel_data,
 420                      t_nrnb * gmx_restrict                  nrnb)
 421 {
 422     /* Suffixes 0,1,2,3 refer to particle indices for waters in the inner or outer loop, or
 423      * just 0 for non-waters.
 424      * Suffixes A,B,C,D refer to j loop unrolling done with SSE, e.g. for the four different
 425      * jnr indices corresponding to data put in the four positions in the SIMD register.
 426      */
 427     int              i_shift_offset,i_coord_offset,outeriter,inneriter;
 428     int              j_index_start,j_index_end,jidx,nri,inr,ggid,iidx;
 429     int              jnrA,jnrB,jnrC,jnrD;
 430     int              j_coord_offsetA,j_coord_offsetB,j_coord_offsetC,j_coord_offsetD;
 431     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
 432     real             shX,shY,shZ,rcutoff_scalar;
 433     real             *shiftvec,*fshift,*x,*f;
 434     __m128           tx,ty,tz,fscal,rcutoff,rcutoff2,jidxall;
 435     int              vdwioffset0;
 436     __m128           ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
 437     int              vdwjidx0A,vdwjidx0B,vdwjidx0C,vdwjidx0D;
 438     __m128           jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
 439     __m128           dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00;
 440     __m128           velec,felec,velecsum,facel,crf,krf,krf2;
 441     real             *charge;
 442     __m128i          ewitab;
 443     __m128           ewtabscale,eweps,sh_ewald,ewrt,ewtabhalfspace,ewtabF,ewtabFn,ewtabD,ewtabV;
 444     real             *ewtab;
 445     __m128           rswitch,swV3,swV4,swV5,swF2,swF3,swF4,d,d2,sw,dsw;
 446     real             rswitch_scalar,d_scalar;
 447     __m128           dummy_mask,cutoff_mask;
 448     __m128           signbit = _mm_castsi128_ps( _mm_set1_epi32(0x80000000) );
 449     __m128           one     = _mm_set1_ps(1.0);
 450     __m128           two     = _mm_set1_ps(2.0);
 451     x                = xx[0];
 452     f                = ff[0];
 453
 454     nri              = nlist->nri;
 455     iinr             = nlist->iinr;
 456     jindex           = nlist->jindex;
 457     jjnr             = nlist->jjnr;
 458     shiftidx         = nlist->shift;
 459     gid              = nlist->gid;
 460     shiftvec         = fr->shift_vec[0];
 461     fshift           = fr->fshift[0];
 462     facel            = _mm_set1_ps(fr->epsfac);
 463     charge           = mdatoms->chargeA;
 464
 465     sh_ewald         = _mm_set1_ps(fr->ic->sh_ewald);
 466     ewtab            = fr->ic->tabq_coul_FDV0;
 467     ewtabscale       = _mm_set1_ps(fr->ic->tabq_scale);
 468     ewtabhalfspace   = _mm_set1_ps(0.5/fr->ic->tabq_scale);
 469
 470     /* When we use explicit cutoffs the value must be identical for elec and VdW, so use elec as an arbitrary choice */
 471     rcutoff_scalar   = fr->rcoulomb;
 472     rcutoff          = _mm_set1_ps(rcutoff_scalar);
 473     rcutoff2         = _mm_mul_ps(rcutoff,rcutoff);
 474
 475     rswitch_scalar   = fr->rcoulomb_switch;
 476     rswitch          = _mm_set1_ps(rswitch_scalar);
 477     /* Setup switch parameters */
 478     d_scalar         = rcutoff_scalar-rswitch_scalar;
 479     d                = _mm_set1_ps(d_scalar);
 480     swV3             = _mm_set1_ps(-10.0/(d_scalar*d_scalar*d_scalar));
 481     swV4             = _mm_set1_ps( 15.0/(d_scalar*d_scalar*d_scalar*d_scalar));
 482     swV5             = _mm_set1_ps( -6.0/(d_scalar*d_scalar*d_scalar*d_scalar*d_scalar));
 483     swF2             = _mm_set1_ps(-30.0/(d_scalar*d_scalar*d_scalar));
 484     swF3             = _mm_set1_ps( 60.0/(d_scalar*d_scalar*d_scalar*d_scalar));
 485     swF4             = _mm_set1_ps(-30.0/(d_scalar*d_scalar*d_scalar*d_scalar*d_scalar));
 486
 487     /* Avoid stupid compiler warnings */
 488     jnrA = jnrB = jnrC = jnrD = 0;
 489     j_coord_offsetA = 0;
 490     j_coord_offsetB = 0;
 491     j_coord_offsetC = 0;
 492     j_coord_offsetD = 0;
 493
 494     outeriter        = 0;
 495     inneriter        = 0;
 496
 497     /* Start outer loop over neighborlists */
 498     for(iidx=0; iidx<nri; iidx++)
 499     {
 500         /* Load shift vector for this list */
 501         i_shift_offset   = DIM*shiftidx[iidx];
 502         shX              = shiftvec[i_shift_offset+XX];
 503         shY              = shiftvec[i_shift_offset+YY];
 504         shZ              = shiftvec[i_shift_offset+ZZ];
 505
 506         /* Load limits for loop over neighbors */
 507         j_index_start    = jindex[iidx];
 508         j_index_end      = jindex[iidx+1];
 509
 510         /* Get outer coordinate index */
 511         inr              = iinr[iidx];
 512         i_coord_offset   = DIM*inr;
 513
 514         /* Load i particle coords and add shift vector */
 515         ix0              = _mm_set1_ps(shX + x[i_coord_offset+DIM*0+XX]);
 516         iy0              = _mm_set1_ps(shY + x[i_coord_offset+DIM*0+YY]);
 517         iz0              = _mm_set1_ps(shZ + x[i_coord_offset+DIM*0+ZZ]);
 518
 519         fix0             = _mm_setzero_ps();
 520         fiy0             = _mm_setzero_ps();
 521         fiz0             = _mm_setzero_ps();
 522
 523         /* Load parameters for i particles */
 524         iq0              = _mm_mul_ps(facel,_mm_load1_ps(charge+inr+0));
 525
 526         /* Start inner kernel loop */
 527         for(jidx=j_index_start; jidx<j_index_end && jjnr[jidx+3]>=0; jidx+=4)
 528         {
 529
 530             /* Get j neighbor index, and coordinate index */
 531             jnrA             = jjnr[jidx];
 532             jnrB             = jjnr[jidx+1];
 533             jnrC             = jjnr[jidx+2];
 534             jnrD             = jjnr[jidx+3];
 535
 536             j_coord_offsetA  = DIM*jnrA;
 537             j_coord_offsetB  = DIM*jnrB;
 538             j_coord_offsetC  = DIM*jnrC;
 539             j_coord_offsetD  = DIM*jnrD;
 540
 541             /* load j atom coordinates */
 542             gmx_mm_load_1rvec_4ptr_swizzle_ps(x+j_coord_offsetA,x+j_coord_offsetB,
 543                                               x+j_coord_offsetC,x+j_coord_offsetD,
 544                                               &jx0,&jy0,&jz0);
 545
 546             /* Calculate displacement vector */
 547             dx00             = _mm_sub_ps(ix0,jx0);
 548             dy00             = _mm_sub_ps(iy0,jy0);
 549             dz00             = _mm_sub_ps(iz0,jz0);
 550
 551             /* Calculate squared distance and things based on it */
 552             rsq00            = gmx_mm_calc_rsq_ps(dx00,dy00,dz00);
 553
 554             rinv00           = gmx_mm_invsqrt_ps(rsq00);
 555
 556             rinvsq00         = _mm_mul_ps(rinv00,rinv00);
 557
 558             /* Load parameters for j particles */
 559             jq0              = gmx_mm_load_4real_swizzle_ps(charge+jnrA+0,charge+jnrB+0,
 560                                                               charge+jnrC+0,charge+jnrD+0);
 561
 562             /**************************
 563              * CALCULATE INTERACTIONS *
 564              **************************/
 565
 566             if (gmx_mm_any_lt(rsq00,rcutoff2))
 567             {
 568
 569             r00              = _mm_mul_ps(rsq00,rinv00);
 570
 571             /* Compute parameters for interactions between i and j atoms */
 572             qq00             = _mm_mul_ps(iq0,jq0);
 573
 574             /* EWALD ELECTROSTATICS */
 575
 576             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 577             ewrt             = _mm_mul_ps(r00,ewtabscale);
 578             ewitab           = _mm_cvttps_epi32(ewrt);
 579             eweps            = _mm_sub_ps(ewrt,_mm_cvtepi32_ps(ewitab));
 580             ewitab           = _mm_slli_epi32(ewitab,2);
 581             ewtabF           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,0) );
 582             ewtabD           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,1) );
 583             ewtabV           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,2) );
 584             ewtabFn          = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,3) );
 585             _MM_TRANSPOSE4_PS(ewtabF,ewtabD,ewtabV,ewtabFn);
 586             felec            = _mm_add_ps(ewtabF,_mm_mul_ps(eweps,ewtabD));
 587             velec            = _mm_sub_ps(ewtabV,_mm_mul_ps(_mm_mul_ps(ewtabhalfspace,eweps),_mm_add_ps(ewtabF,felec)));
 588             velec            = _mm_mul_ps(qq00,_mm_sub_ps(rinv00,velec));
 589             felec            = _mm_mul_ps(_mm_mul_ps(qq00,rinv00),_mm_sub_ps(rinvsq00,felec));
 590
 591             d                = _mm_sub_ps(r00,rswitch);
 592             d                = _mm_max_ps(d,_mm_setzero_ps());
 593             d2               = _mm_mul_ps(d,d);
 594             sw               = _mm_add_ps(one,_mm_mul_ps(d2,_mm_mul_ps(d,_mm_add_ps(swV3,_mm_mul_ps(d,_mm_add_ps(swV4,_mm_mul_ps(d,swV5)))))));
 595
 596             dsw              = _mm_mul_ps(d2,_mm_add_ps(swF2,_mm_mul_ps(d,_mm_add_ps(swF3,_mm_mul_ps(d,swF4)))));
 597
 598             /* Evaluate switch function */
 599             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 600             felec            = _mm_sub_ps( _mm_mul_ps(felec,sw) , _mm_mul_ps(rinv00,_mm_mul_ps(velec,dsw)) );
 601             cutoff_mask      = _mm_cmplt_ps(rsq00,rcutoff2);
 602
 603             fscal            = felec;
 604
 605             fscal            = _mm_and_ps(fscal,cutoff_mask);
 606
 607             /* Calculate temporary vectorial force */
 608             tx               = _mm_mul_ps(fscal,dx00);
 609             ty               = _mm_mul_ps(fscal,dy00);
 610             tz               = _mm_mul_ps(fscal,dz00);
 611
 612             /* Update vectorial force */
 613             fix0             = _mm_add_ps(fix0,tx);
 614             fiy0             = _mm_add_ps(fiy0,ty);
 615             fiz0             = _mm_add_ps(fiz0,tz);
 616
 617             gmx_mm_decrement_1rvec_4ptr_swizzle_ps(f+j_coord_offsetA,f+j_coord_offsetB,
 618                                                    f+j_coord_offsetC,f+j_coord_offsetD,
 619                                                    tx,ty,tz);
 620
 621             }
 622
 623             /* Inner loop uses 62 flops */
 624         }
 625
 626         if(jidx<j_index_end)
 627         {
 628
 629             /* Get j neighbor index, and coordinate index */
 630             jnrA             = jjnr[jidx];
 631             jnrB             = jjnr[jidx+1];
 632             jnrC             = jjnr[jidx+2];
 633             jnrD             = jjnr[jidx+3];
 634
 635             /* Sign of each element will be negative for non-real atoms.
 636              * This mask will be 0xFFFFFFFF for dummy entries and 0x0 for real ones,
 637              * so use it as val = _mm_andnot_ps(mask,val) to clear dummy entries.
 638              */
 639             dummy_mask = gmx_mm_castsi128_ps(_mm_cmplt_epi32(_mm_loadu_si128((const __m128i *)(jjnr+jidx)),_mm_setzero_si128()));
 640             jnrA       = (jnrA>=0) ? jnrA : 0;
 641             jnrB       = (jnrB>=0) ? jnrB : 0;
 642             jnrC       = (jnrC>=0) ? jnrC : 0;
 643             jnrD       = (jnrD>=0) ? jnrD : 0;
 644
 645             j_coord_offsetA  = DIM*jnrA;
 646             j_coord_offsetB  = DIM*jnrB;
 647             j_coord_offsetC  = DIM*jnrC;
 648             j_coord_offsetD  = DIM*jnrD;
 649
 650             /* load j atom coordinates */
 651             gmx_mm_load_1rvec_4ptr_swizzle_ps(x+j_coord_offsetA,x+j_coord_offsetB,
 652                                               x+j_coord_offsetC,x+j_coord_offsetD,
 653                                               &jx0,&jy0,&jz0);
 654
 655             /* Calculate displacement vector */
 656             dx00             = _mm_sub_ps(ix0,jx0);
 657             dy00             = _mm_sub_ps(iy0,jy0);
 658             dz00             = _mm_sub_ps(iz0,jz0);
 659
 660             /* Calculate squared distance and things based on it */
 661             rsq00            = gmx_mm_calc_rsq_ps(dx00,dy00,dz00);
 662
 663             rinv00           = gmx_mm_invsqrt_ps(rsq00);
 664
 665             rinvsq00         = _mm_mul_ps(rinv00,rinv00);
 666
 667             /* Load parameters for j particles */
 668             jq0              = gmx_mm_load_4real_swizzle_ps(charge+jnrA+0,charge+jnrB+0,
 669                                                               charge+jnrC+0,charge+jnrD+0);
 670
 671             /**************************
 672              * CALCULATE INTERACTIONS *
 673              **************************/
 674
 675             if (gmx_mm_any_lt(rsq00,rcutoff2))
 676             {
 677
 678             r00              = _mm_mul_ps(rsq00,rinv00);
 679             r00              = _mm_andnot_ps(dummy_mask,r00);
 680
 681             /* Compute parameters for interactions between i and j atoms */
 682             qq00             = _mm_mul_ps(iq0,jq0);
 683
 684             /* EWALD ELECTROSTATICS */
 685
 686             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 687             ewrt             = _mm_mul_ps(r00,ewtabscale);
 688             ewitab           = _mm_cvttps_epi32(ewrt);
 689             eweps            = _mm_sub_ps(ewrt,_mm_cvtepi32_ps(ewitab));
 690             ewitab           = _mm_slli_epi32(ewitab,2);
 691             ewtabF           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,0) );
 692             ewtabD           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,1) );
 693             ewtabV           = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,2) );
 694             ewtabFn          = _mm_load_ps( ewtab + gmx_mm_extract_epi32(ewitab,3) );
 695             _MM_TRANSPOSE4_PS(ewtabF,ewtabD,ewtabV,ewtabFn);
 696             felec            = _mm_add_ps(ewtabF,_mm_mul_ps(eweps,ewtabD));
 697             velec            = _mm_sub_ps(ewtabV,_mm_mul_ps(_mm_mul_ps(ewtabhalfspace,eweps),_mm_add_ps(ewtabF,felec)));
 698             velec            = _mm_mul_ps(qq00,_mm_sub_ps(rinv00,velec));
 699             felec            = _mm_mul_ps(_mm_mul_ps(qq00,rinv00),_mm_sub_ps(rinvsq00,felec));
 700
 701             d                = _mm_sub_ps(r00,rswitch);
 702             d                = _mm_max_ps(d,_mm_setzero_ps());
 703             d2               = _mm_mul_ps(d,d);
 704             sw               = _mm_add_ps(one,_mm_mul_ps(d2,_mm_mul_ps(d,_mm_add_ps(swV3,_mm_mul_ps(d,_mm_add_ps(swV4,_mm_mul_ps(d,swV5)))))));
 705
 706             dsw              = _mm_mul_ps(d2,_mm_add_ps(swF2,_mm_mul_ps(d,_mm_add_ps(swF3,_mm_mul_ps(d,swF4)))));
 707
 708             /* Evaluate switch function */
 709             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 710             felec            = _mm_sub_ps( _mm_mul_ps(felec,sw) , _mm_mul_ps(rinv00,_mm_mul_ps(velec,dsw)) );
 711             cutoff_mask      = _mm_cmplt_ps(rsq00,rcutoff2);
 712
 713             fscal            = felec;
 714
 715             fscal            = _mm_and_ps(fscal,cutoff_mask);
 716
 717             fscal            = _mm_andnot_ps(dummy_mask,fscal);
 718
 719             /* Calculate temporary vectorial force */
 720             tx               = _mm_mul_ps(fscal,dx00);
 721             ty               = _mm_mul_ps(fscal,dy00);
 722             tz               = _mm_mul_ps(fscal,dz00);
 723
 724             /* Update vectorial force */
 725             fix0             = _mm_add_ps(fix0,tx);
 726             fiy0             = _mm_add_ps(fiy0,ty);
 727             fiz0             = _mm_add_ps(fiz0,tz);
 728
 729             gmx_mm_decrement_1rvec_4ptr_swizzle_ps(f+j_coord_offsetA,f+j_coord_offsetB,
 730                                                    f+j_coord_offsetC,f+j_coord_offsetD,
 731                                                    tx,ty,tz);
 732
 733             }
 734
 735             /* Inner loop uses 63 flops */
 736         }
 737
 738         /* End of innermost loop */
 739
 740         gmx_mm_update_iforce_1atom_swizzle_ps(fix0,fiy0,fiz0,
 741                                               f+i_coord_offset,fshift+i_shift_offset);
 742
 743         /* Increment number of inner iterations */
 744         inneriter                  += j_index_end - j_index_start;
 745
 746         /* Outer loop uses 10 flops */
 747     }
 748
 749     /* Increment number of outer iterations */
 750     outeriter        += nri;
 751
 752     /* Update outer/inner flops */
 753
 754     inc_nrnb(nrnb,eNR_NBKERNEL_ELEC_F,outeriter*10 + inneriter*63);
 755 }