[mlir] NFC: void visitRegionSuccessors

[makslevental]

I would like to hook/override visitRegionSuccessors in sparse analyses that inherit from AbstractSparseForwardDataFlowAnalysis. This would allow me to control specifically how regions are analyzed (e.g., order and number of visits).

cc @antiagainst

[llvmbot]

@llvm/pr-subscribers-mlir

Author: Maksim Levental (makslevental)

Changes

I would like to hook/override visitRegionSuccessors in sparse analyses that inherit from AbstractSparseForwardDataFlowAnalysis. This would allow me to control specifically how regions are analyzed (e.g., number of visits).

---

Full diff: https://github.com/llvm/llvm-project/pull/125268.diff

1 Files Affected:

• (modified) mlir/include/mlir/Analysis/DataFlow/SparseAnalysis.h (+1-1)

diff --git a/mlir/include/mlir/Analysis/DataFlow/SparseAnalysis.h b/mlir/include/mlir/Analysis/DataFlow/SparseAnalysis.h
index 387b9ee707179bf..8c67c9dd75de598 100644
--- a/mlir/include/mlir/Analysis/DataFlow/SparseAnalysis.h
+++ b/mlir/include/mlir/Analysis/DataFlow/SparseAnalysis.h
@@ -255,7 +255,7 @@ class AbstractSparseForwardDataFlowAnalysis : public DataFlowAnalysis {
   /// operation `branch`, which can either be the entry block of one of the
   /// regions or the parent operation itself, and set either the argument or
   /// parent result lattices.
-  void visitRegionSuccessors(ProgramPoint *point,
+  virtual void visitRegionSuccessors(ProgramPoint *point,
                              RegionBranchOpInterface branch,
                              RegionBranchPoint successor,
                              ArrayRef<AbstractSparseLattice *> lattices);

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[joker-eph]

Making a method virtual is not a trivial change: it at minima deserves to update the document IMO.

In particular the dataflow framework is already a complex piece of of machinery that is hard to grasp, every new customization point increases the complexity, and should be described in terms of the invariant of the system (what is an implemented overriding this allowed to do here and for which purposes?).

[makslevental]

Add a note in the doc string (and the commit mesage) about invariants/responsibilities of overriding method.