Reduce.splits: def of bendtorch-core@0.1.0.0
Import: import bendtorch-core@0.1.0.0/src/autograd/reduce.bend as Reduce
Lines 241-249 of bendtorch-core@0.1.0.0/src/autograd/reduce.bend: https://jend.leeeet.dev/read.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce.bend&start_line=241&end_line=249

import Base
import bendtorch-core@0.1.0.0/src/shape/core.bend as Shape
import bendtorch-core@0.1.0.0/src/tensor/matmul.bend as Matrix

# How many top levels of the target tree fork. Every fork clones the whole
# contribution. A target whose fibers are contiguous splits by work, as
# `Matrix.splits` does with the terms of a cell; a target with strided fibers
# never forks, since there the forked build ran slower at 8 and 24 threads
# than one thread. The proofs hold for any split.
def splits(+plan: Shape.BroadcastPlan, +depth: Nat, +length: Nat) -> Nat:
  +extents = Shape.extents(Shape.output_shape(plan))
  +rows = Shape.index_table(Shape.extents(Shape.left_shape(plan)), Shape.extents(Shape.right_shape(plan)), extents)
  Bool.pick(Nat, contiguous(rows, extents), Matrix.splits(depth, terms(plan, length)), 0n)

Uses (11):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.pick
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce.bend&name=contiguous
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/autograd/reduce.bend&name=terms
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=BroadcastPlan
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=extents
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=index_table
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=left_shape
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=output_shape
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/shape/core.bend&name=right_shape
  https://jend.leeeet.dev/definition.txt?path=bendtorch-core@0.1.0.0/src/tensor/matmul.bend&name=splits