print warning when GPU pair style increases the communication cutoff

doc/src/Errors_warnings.txt

@@ -390,6 +390,11 @@ have fully consistent image flags, since some bonds will cross
 periodic boundaries and connect two atoms with the same image
 flag. :dd
 
+{Increasing communication cutoff for GPU style} :dt
+
+The pair style has increased the communication cutoff to be consistent with
+the communication cutoff requirements for this pair style when run on the GPU. :dd
+
 {KIM Model does not provide 'energy'; Potential energy will be zero} :dt
 
 Self-explanatory. :dd

src/GPU/gpu_extra.h

@@ -133,4 +133,9 @@ E: Unknown error in GPU library
 
 Self-explanatory.
 
+W: Increasing communication cutoff for GPU style
+
+The pair style has increased the communication cutoff to be consistent with
+the communication cutoff requirements for this pair style when run on the GPU.
+
 */

src/GPU/pair_sw_gpu.cpp

@@ -206,8 +206,11 @@ void PairSWGPU::init_style()
     neighbor->requests[irequest]->ghost = 1;
   }
 
-  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin) )
+  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin)) {
     comm->cutghostuser=2.0*cutmax + neighbor->skin;
+    if (comm->me == 0)
+       error->warning(FLERR,"Increasing communication cutoff for GPU style");
+  }
 }
 
 /* ----------------------------------------------------------------------

src/GPU/pair_tersoff_gpu.cpp

@@ -240,8 +240,11 @@ void PairTersoffGPU::init_style()
     neighbor->requests[irequest]->ghost = 1;
   }
 
-  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin) )
+  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin)) {
     comm->cutghostuser = 2.0*cutmax + neighbor->skin;
+    if (comm->me == 0)
+       error->warning(FLERR,"Increasing communication cutoff for GPU style");
+  }
 }
 
 /* ----------------------------------------------------------------------

src/GPU/pair_tersoff_mod_gpu.cpp

@@ -232,8 +232,11 @@ void PairTersoffMODGPU::init_style()
     neighbor->requests[irequest]->ghost = 1;
   }
 
-  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin) )
+  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin)) {
     comm->cutghostuser = 2.0*cutmax + neighbor->skin;
+    if (comm->me == 0)
+       error->warning(FLERR,"Increasing communication cutoff for GPU style");
+  }
 }
 
 /* ----------------------------------------------------------------------

src/GPU/pair_tersoff_zbl_gpu.cpp

@@ -254,8 +254,11 @@ void PairTersoffZBLGPU::init_style()
     neighbor->requests[irequest]->ghost = 1;
   }
 
-  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin) )
+  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin)) {
     comm->cutghostuser = 2.0*cutmax + neighbor->skin;
+    if (comm->me == 0)
+       error->warning(FLERR,"Increasing communication cutoff for GPU style");
+  }
 }
 
 /* ----------------------------------------------------------------------

src/GPU/pair_vashishta_gpu.cpp

@@ -234,9 +234,11 @@ void PairVashishtaGPU::init_style()
     neighbor->requests[irequest]->ghost = 1;
   }
 
-  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin) )
+  if (comm->cutghostuser < (2.0*cutmax + neighbor->skin)) {
     comm->cutghostuser=2.0*cutmax + neighbor->skin;
-
+    if (comm->me == 0)
+       error->warning(FLERR,"Increasing communication cutoff for GPU style");
+  }
 }
 
 /* ----------------------------------------------------------------------