For PLAPACK, the calling sequences are given by place HR here

place HR here
The data type of the operands and parameters like vector length and stride are now passed as part of linear algebra
objects `x`, `xmax`, and `k`.
Instead of returning the result *k* as the function
value, it is returned in `k`. In addition, the value of *x*(*k*)
is returned.

When a node calls `PLA_Local_iamax`
the operation
is equivalent to
extracting the local information (data type, length, and pointer to the
buffers) and locally performing the appropriate operation.
The local dimensions of `xmax` and `k` must be ,
but they can be of any object type. The data type of `k` must
be integer (`MPI_INT`).
The local dimensions of `x` must be such
that the operation is well-defined. All objects must have the same datatype.
Notice: no communication is performed as part of this call.
Thus, all information must be locally available.

All nodes must simultaneously call `PLA_Iamax`, which performs
the BLAS call on the distributed objects.
Parameters `xmax` and `k` must
be multiscalars.
The datatype of `k` must be integer.
Parameter `x`
must be of object type vector or (duplicated) projected
vector.