[This is preliminary documentation and is subject to change.]
Perform a parallel reduction operation that summarizes the results from the input provided
by all of the processes in the communicator. Semantically, this is equivalent to an
MPI_Reduce(IntPtr, IntPtr, Int32, Int32, Int32, Int32, Int32) to an arbitrary root followed by an MPI_Bcast(IntPtr, Int32, Int32, Int32, Int32) from
that process.
See Allreduce<(Of <(T>)>)(T, ReductionOperation<(Of <(T>)>))
Namespace:
MPIAssembly: MPI (in MPI.dll)
Version: 0.6.0.0 (0.6.0.0)
Syntax
| C# |
|---|
public static int MPI_Allreduce( IntPtr sendbuf, IntPtr recvbuf, int count, int datatype, int op, int comm ) |
| Visual Basic (Declaration) |
|---|
Public Shared Function MPI_Allreduce ( _ sendbuf As IntPtr, _ recvbuf As IntPtr, _ count As Integer, _ datatype As Integer, _ op As Integer, _ comm As Integer _ ) As Integer |
| Visual C++ |
|---|
public: static int MPI_Allreduce( IntPtr sendbuf, IntPtr recvbuf, int count, int datatype, int op, int comm ) |
Parameters
- sendbuf
- Type: System..::.IntPtr
Buffer containing the "outgoing" values contributed by the calling process to the reduction operation.
- recvbuf
- Type: System..::.IntPtr
Buffer that will receive the results of the parallel reduction.
- count
- Type: System..::.Int32
The number of elements in sendbuf and recvbuf.
- datatype
- Type: System..::.Int32
The type of data in sendbuf and recvbuf.
- op
- Type: System..::.Int32
The MPI reduction operation to use, which may be one of the predefined reduction operations or a user-defined operation created with MPI_Op_create(IntPtr, Int32, Int32%).
- comm
- Type: System..::.Int32
The communicator over which the reduction will occur.