legate.core.Runtime.tree_reduce#

Runtime.tree_reduce(
self,
Library library,
_LocalTaskID task_id,
LogicalStore store,
int64_t radix=4,
) → LogicalStore#

Performs a user-defined reduction by building a tree of reduction tasks. At each step, the reducer task gets up to radix input stores and is supposed to produce outputs in a single unbound store.

Parameters:

  • library (Library) – Library to which the task id belongs

  • task_id (LocalTaskID) – Id of the reducer task

  • store (LogicalStore) – LogicalStore to perform reductions on

  • radix (int) – Fan-in of each reducer task. If the store is partitioned into \(N\) sub-stores by the runtime, then the first level of reduction tree has \(\\ceil{N / \\mathtt{radix}}\) reducer tasks.

Returns:

LogicalStore that contains reduction results

Return type:

LogicalStore

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