is a simple wrapper around MPI_Recv. Its main purpose is
to allow for some experimentation / tuning of this simple routine.
Successful completion is indicated by the returned error code
HPL_SUCCESS. In the case of messages of length less than or equal to
zero, this function returns immediately.
RBUF (local output) double *
On entry, RBUF specifies the starting address of buffer to be
RCOUNT (local input) int
On entry, RCOUNT specifies the number of double precision
entries in RBUF. RCOUNT must be at least zero.
SRC (local input) int
On entry, SRC specifies the rank of the sending process in
the communication space defined by COMM.
RTAG (local input) int
On entry, STAG specifies the message tag to be used for this
COMM (local input) MPI_Comm
The MPI communicator identifying the communication space.