/* irecv for the first segment from i */
ptmp = (char*)rbuf + i * rcount * extent;
first_segment_req = Request::irecv(ptmp, first_segment_count, rdtype, i,
COLL_TAG_GATHER, comm
);
/* irecv for the first segment from i */
ptmp = (char*)rbuf + i * rcount * extent;
first_segment_req = Request::irecv(ptmp, first_segment_count, rdtype, i,
COLL_TAG_GATHER, comm
);