Which MPI collective routine gathers data from all tasks and distributes it to all?MPI_BcastMPI_GatherMPI_AllgatherMPI_ReduceCancelSave & Next

To determine which MPI collective routine gathers data from all tasks and distributes it to all, we need to analyze the provided options:

1. MPI_Bcast: This routine broadcasts data from one process to all other processes. It does not gather data from all tasks, it only sends data to them.

2. MPI_Gather: This routine gathers data from all processes and sends it to a single process. It does not distribute this gathered data back to all processes.

3. MPI_Allgather: This routine gathers data from all processes and distributes the collected data back to all processes. This fits the requirement to gather data from all tasks and distribute it to all.

4. MPI_Reduce: This routine combines data from all processes and sends the result to one process. It does not distribute the gathered data to all.

Thus, the correct option, which gathers data from all tasks and distributes it to all, is:

Final Answer

MPI_Allgather