[Mlir-commits] [mlir] [MLIR][SliceAnalysis] Add comment and restore failure condition (PR #142223)

[William Moses]

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@@ -109,6 +109,8 @@ static LogicalResult getBackwardSliceImpl(Operation *op,
         if (parentOp->getNumRegions() == 1 &&
             llvm::hasSingleElement(parentOp->getRegion(0).getBlocks())) {
           return getBackwardSliceImpl(parentOp, backwardSlice, options);
+        } else {
+          return failure();
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wsmoses wrote:

hm somehow missed these comments/review. rebased the PR.

I'm not quite sure how to test this as the condition here is restore a broken condition from https://github.com/llvm/llvm-project/pull/142076 to ensure the analysis is conservative. 

Happy to add a test if you know a good way to add one.

That said given https://github.com/llvm/llvm-project/pull/163749 it may be prudent to add this to restore correctness

https://github.com/llvm/llvm-project/pull/142223