// SMPI_RMA_TAG has to be the smallest one, as it will be decremented for accumulate ordering.
constexpr int SMPI_RMA_TAG = -6666;
+#define MPI_REQUEST_IGNORED ((MPI_Request*)-100)
+
/* Convert between Fortran and C */
#define FORT_BOTTOM(addr) ((*(int*)addr) == -200 ? MPI_BOTTOM : (void*)addr)