[all-commits] [llvm/llvm-project] 4b9e2f: [MLIR][Affine] Make fusion helper check method sig...

[Uday Bondhugula via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4b9e2f8fe0fcb1d104fd10a149372aaf7ca99af2
      https://github.com/llvm/llvm-project/commit/4b9e2f8fe0fcb1d104fd10a149372aaf7ca99af2
  Author: Uday Bondhugula <uday at polymagelabs.com>
  Date:   2022-12-29 (Thu, 29 Dec 2022)

  Changed paths:
    M mlir/lib/Dialect/Affine/Transforms/LoopFusion.cpp

  Log Message:
  -----------
  [MLIR][Affine] Make fusion helper check method significantly more efficient

The `hasDependencePath` method in affine fusion is quite inefficient as
it does a DFS on the complete graph for what is a small part of the
checks before fusion can be performed. Make this efficient by using the
fact that the nodes involved are all at the top-level of the same block.
With this change, for large graphs with about 10,000 nodes, the check
runs in a few seconds instead of not terminating even in a few hours.

This is NFC from a functionality standpoint; it only leads to an
improvement in pass running time on large IR.

Differential Revision: https://reviews.llvm.org/D140522