fix

gridder_cxx.h

@@ -969,7 +969,7 @@ template<typename T, typename Serv> void x2grid_c
       {
       complex<T> tmp(v*ku[cu]);
       size_t cv=0;
-      for (; cv<supp-3; cv+=4)
+      for (; cv+3<supp; cv+=4)
         {
         ptr[cv  ] += tmp*kv[cv  ];
         ptr[cv+1] += tmp*kv[cv+1];
@@ -1027,7 +1027,7 @@ template<typename T, typename Serv> void grid2x_c
       {
       complex<T> tmp(0);
       size_t cv=0;
-      for (; cv<supp-3; cv+=4)
+      for (; cv+3<supp; cv+=4)
         tmp += ptr[cv  ]*kv[cv  ]
              + ptr[cv+1]*kv[cv+1]
              + ptr[cv+2]*kv[cv+2]