implement accelerator introspection for GPU package

lib/gpu/lal_device.cpp

@@ -783,3 +783,39 @@ double lmp_gpu_forces(double **f, double **tor, double *eatom,
                       double **vatom, double *virial, double &ecoul) {
   return global_device.fix_gpu(f,tor,eatom,vatom,virial,ecoul);
 }
+
+bool lmp_gpu_config(const std::string &category, const std::string &setting)
+{
+  if (category == "api") {
+#if defined(USE_OPENCL)
+    return setting == "opencl";
+#elif defined(USE_HIP)
+    return setting == "hip";
+#elif defined(USE_CUDA)
+    return setting == "cuda";
+#endif
+    return false;
+  }
+  if (category == "precision") {
+    if (setting == "single") {
+#if defined(_SINGLE_SINGLE)
+      return true;
+#else
+      return false;
+#endif
+    } else if (setting == "mixed") {
+#if defined(_SINGLE_DOUBLE)
+      return true;
+#else
+      return false;
+#endif
+    } else if (setting == "double") {
+#if defined(_DOUBLE_DOUBLE)
+      return true;
+#else
+      return false;
+#endif
+    } else return false;
+  }
+  return false;
+}

src/info.cpp

@@ -94,6 +94,7 @@ enum {COMPUTES=1<<0,
       REGION_STYLES=1<<23,
       DUMP_STYLES=1<<24,
       COMMAND_STYLES=1<<25,
+      ACCELERATOR=1<<26,
       ALL=~0};
 
 static const int STYLES = ATOM_STYLES | INTEGRATE_STYLES | MINIMIZE_STYLES
@@ -198,6 +199,9 @@ void Info::command(int narg, char **arg)
     } else if (strncmp(arg[idx],"coeffs",3) == 0) {
       flags |= COEFFS;
       ++idx;
+    } else if (strncmp(arg[idx],"accelerator",3) == 0) {
+      flags |= ACCELERATOR;
+      ++idx;
     } else if (strncmp(arg[idx],"styles",3) == 0) {
       if (idx+1 < narg) {
         ++idx;
@@ -314,6 +318,22 @@ void Info::command(int narg, char **arg)
     fputs("\n",out);
   }
 
+  if (flags & ACCELERATOR) {
+    fputs("\nAccelerator configuration:\n\n",out);
+    std::string mesg;
+    if (has_package("GPU")) {
+      mesg = "GPU package API: ";
+      if (has_accelerator_feature("GPU","api","cuda"))   mesg += "CUDA\n";
+      if (has_accelerator_feature("GPU","api","hip"))    mesg += "HIP\n";
+      if (has_accelerator_feature("GPU","api","opencl")) mesg += "OpenCL\n";
+      mesg +=  "GPU package precision: ";
+      if (has_accelerator_feature("GPU","precision","single")) mesg += "single\n";
+      if (has_accelerator_feature("GPU","precision","mixed"))  mesg += "mixed\n";
+      if (has_accelerator_feature("GPU","precision","double")) mesg += "double\n";
+      fputs(mesg.c_str(),out);
+    }
+  }
+
   if (flags & MEMORY) {
     double meminfo[3];
 
@@ -1129,6 +1149,10 @@ bool Info::has_package(const std::string &package_name) {
   return false;
 }
 
+#if defined(LMP_GPU)
+extern bool lmp_gpu_config(const std::string &, const std::string &);
+#endif
+
 bool Info::has_accelerator_feature(const std::string &package,
                                    const std::string &category,
                                    const std::string &setting)
@@ -1143,6 +1167,7 @@ bool Info::has_accelerator_feature(const std::string &package,
 #endif
 #if defined(LMP_GPU)
   if (package == "GPU") {
+    return lmp_gpu_config(category,setting);
   }
 #endif
 #if defined(LMP_USER_OMP)