Exclude the GPU reporting if Cuda is not enabled

src/Cube.H

@@ -129,9 +129,11 @@ private:
 	std::cout << std::string(60, '=') << std::endl;
 	std::cout << "Time in CPU: "
 		  << duration0.count()-duration1.count() << std::endl;
+#if HAVE_LIBCUDA==1
 	if (c->cC->cudaDevice>=0) {
 	  std::cout << "Time in GPU: " << duration1.count() << std::endl;
 	}
+#endif
 	std::cout << std::string(60, '=') << std::endl;
       }
     }

src/Cube.cc

@@ -289,14 +289,14 @@ void * Cube::determine_acceleration_and_potential_thread(void * arg)
     double z = cC->Pos(i, 2);
 
     // Recursion multipliers
-    auto stepx = exp(kfac*x);
-    auto stepy = exp(kfac*y);
-    auto stepz = exp(kfac*z);
+    auto stepx = std::exp(kfac*x);
+    auto stepy = std::exp(kfac*y);
+    auto stepz = std::exp(kfac*z);
 
     // Initial values (note sign change)
-    auto startx = exp(-kfac*(x*nmaxx));
-    auto starty = exp(-kfac*(y*nmaxy));
-    auto startz = exp(-kfac*(z*nmaxz));
+    auto startx = std::exp(-kfac*(x*nmaxx));
+    auto starty = std::exp(-kfac*(y*nmaxy));
+    auto startz = std::exp(-kfac*(z*nmaxz));
 
     std::complex<double> facx, facy, facz;
     int ix, iy, iz;