alternate implementation of pair/only option (for KOKKOS and GPU)

src/GPU/fix_gpu.cpp

@@ -120,6 +120,7 @@ FixGPU::FixGPU(LAMMPS *lmp, int narg, char **arg) :
   double binsize = 0.0;
   char *opencl_flags = nullptr;
   int block_pair = -1;
+  int pair_only_flag = 0;
 
   int iarg = 4;
   while (iarg < narg) {
@@ -169,6 +170,12 @@ FixGPU::FixGPU(LAMMPS *lmp, int narg, char **arg) :
       if (iarg+2 > narg) error->all(FLERR,"Illegal package gpu command");
       block_pair = utils::inumeric(FLERR,arg[iarg+1],false,lmp);
       iarg += 2;
+    } else if (strcmp(arg[iarg],"pair/only") == 0) {
+      if (iarg+2 > narg) error->all(FLERR,"Illegal package gpu command");
+      if (strcmp(arg[iarg+1],"off") == 0) pair_only_flag = 0;
+      else if (strcmp(arg[iarg+1],"on") == 0) pair_only_flag = 1;
+      else error->all(FLERR,"Illegal package gpu command");
+      iarg += 2;
     } else error->all(FLERR,"Illegal package gpu command");
   }
 
@@ -186,6 +193,11 @@ FixGPU::FixGPU(LAMMPS *lmp, int narg, char **arg) :
   if (force->newton_pair || force->newton_bond) force->newton = 1;
   else force->newton = 0;
 
+  if (pair_only_flag) {
+    lmp->suffixp = lmp->suffix;
+    lmp->suffix = nullptr;
+  }
+
   // pass params to GPU library
   // change binsize default (0.0) to -1.0 used by GPU lib
 

src/KOKKOS/kokkos.cpp

@@ -301,6 +301,7 @@ KokkosLMP::~KokkosLMP()
 
 void KokkosLMP::accelerator(int narg, char **arg)
 {
+  int pair_only_flag = 0;
   int iarg = 0;
   while (iarg < narg) {
     if (strcmp(arg[iarg],"neigh") == 0) {
@@ -390,6 +391,12 @@ void KokkosLMP::accelerator(int narg, char **arg)
       else if (strcmp(arg[iarg+1],"on") == 0) gpu_aware_flag = 1;
       else error->all(FLERR,"Illegal package kokkos command");
       iarg += 2;
+    } else if (strcmp(arg[iarg],"pair/only") == 0) {
+      if (iarg+2 > narg) error->all(FLERR,"Illegal package kokkos command");
+      if (strcmp(arg[iarg+1],"off") == 0) pair_only_flag = 0;
+      else if (strcmp(arg[iarg+1],"on") == 0) pair_only_flag = 1;
+      else error->all(FLERR,"Illegal package kokkos command");
+      iarg += 2;
     } else if (strcmp(arg[iarg],"neigh/thread") == 0) {
       if (iarg+2 > narg) error->all(FLERR,"Illegal package kokkos command");
       if (strcmp(arg[iarg+1],"off") == 0) neigh_thread = 0;
@@ -452,6 +459,15 @@ void KokkosLMP::accelerator(int narg, char **arg)
   neighbor->binsize_user = binsize;
   if (binsize <= 0.0) neighbor->binsizeflag = 0;
   else neighbor->binsizeflag = 1;
+
+  if (pair_only_flag) {
+    lmp->suffixp = lmp->suffix;
+    lmp->suffix = new char[7];
+    strcpy(lmp->suffix,"kk/host");
+
+    exchange_comm_classic = forward_comm_classic = reverse_comm_classic = 1;
+    exchange_comm_on_host = forward_comm_on_host = reverse_comm_on_host = 0;
+  }
 }
 
 /* ----------------------------------------------------------------------

src/force.cpp

@@ -245,13 +245,22 @@ void Force::create_pair(const std::string &style, int trysuffix)
 /* ----------------------------------------------------------------------
    generate a pair class
    if trysuffix = 1, try first with suffix1/2 appended
-   return sflag = 0 for no suffix added, 1 or 2 for suffix1/2 added
+   return sflag = 0 for no suffix added, 1 or 2 or 3 for suffix1/2/p added
+   special case: if suffixp exists only try suffixp, not suffix
 ------------------------------------------------------------------------- */
 
 Pair *Force::new_pair(const std::string &style, int trysuffix, int &sflag)
 {
   if (trysuffix && lmp->suffix_enable) {
-    if (lmp->suffix) {
+    if (lmp->suffixp) {
+      sflag = 3;
+      std::string estyle = style + "/" + lmp->suffixp;
+      if (pair_map->find(estyle) != pair_map->end()) {
+        PairCreator &pair_creator = (*pair_map)[estyle];
+        return pair_creator(lmp);
+      }
+    }
+    if (lmp->suffix && !lmp->suffixp) {
       sflag = 1;
       std::string estyle = style + "/" + lmp->suffix;
       if (pair_map->find(estyle) != pair_map->end()) {
@@ -727,7 +736,7 @@ KSpace *Force::kspace_match(const std::string &word, int exact)
 /* ----------------------------------------------------------------------
    store style name in str allocated here
    if sflag = 0, no suffix
-   if sflag = 1/2, append suffix or suffix2 to style
+   if sflag = 1/2/3, append suffix or suffix2 or suffixp to style
 ------------------------------------------------------------------------- */
 
 void Force::store_style(char *&str, const std::string &style, int sflag)
@@ -736,6 +745,7 @@ void Force::store_style(char *&str, const std::string &style, int sflag)
 
   if (sflag == 1) estyle += std::string("/") + lmp->suffix;
   else if (sflag == 2) estyle += std::string("/") + lmp->suffix2;
+  else if (sflag == 3) estyle += std::string("/") + lmp->suffixp;
 
   str = new char[estyle.size()+1];
   strcpy(str,estyle.c_str());

src/input.cpp

@@ -1715,7 +1715,10 @@ void Input::pair_style()
     int match = 0;
     if (style == force->pair_style) match = 1;
     if (!match && lmp->suffix_enable) {
-      if (lmp->suffix)
+      if (lmp->suffixp)
+        if (style + "/" + lmp->suffixp == force->pair_style) match = 1;
+
+      if (lmp->suffix && !lmp->suffixp)
         if (style + "/" + lmp->suffix == force->pair_style) match = 1;
 
       if (lmp->suffix2)

src/lammps.cpp

@@ -173,7 +173,7 @@ LAMMPS::LAMMPS(int narg, char **arg, MPI_Comm communicator) :
   int citeflag = 1;
   int helpflag = 0;
 
-  suffix = suffix2 = nullptr;
+  suffix = suffix2 = suffixp = nullptr;
   suffix_enable = 0;
   if (arg) exename = arg[0];
   else exename = nullptr;
@@ -714,6 +714,7 @@ LAMMPS::~LAMMPS()
   delete kokkos;
   delete [] suffix;
   delete [] suffix2;
+  delete [] suffixp;
 
   // free the MPI comm created by -mpi command-line arg processed in constructor
   // it was passed to universe as if original universe world

src/lammps.h

@@ -51,7 +51,7 @@ class LAMMPS {
 
   double initclock;              // wall clock at instantiation
 
-  char *suffix,*suffix2;         // suffixes to add to input script style names
+  char *suffix,*suffix2,*suffixp;// suffixes to add to input script style names
   int suffix_enable;             // 1 if suffixes are enabled, 0 if disabled
   char *exename;                 // pointer to argv[0]
   char ***packargs;              // arguments for cmdline package commands