[Mlir-commits] [mlir] Extend `getBackwardSlice` to track values captured from above (PR #113478)

[Ian Wood]

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@@ -115,6 +116,19 @@ static void getBackwardSliceImpl(Operation *op,
     }
   }
 
+  // Visit values that are defined above.
+  if (!options.omitUsesFromAbove) {
+    visitUsedValuesDefinedAbove(op->getRegions(), [&](OpOperand *operand) {
+      if (Operation *definingOp = operand->get().getDefiningOp()) {
+        getBackwardSliceImpl(definingOp, backwardSlice, options);
+        return;
+      }
+      Operation *bbAargOwner =
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IanWood1 wrote:

I realized that I was duplicating all the logic within the for loop going over the operands. Instead, I changed it to iterate over a SetVector of the operands + used values defined above, which decreases logic duplication. However, this does mean we have to allocate space to store the operands in the `SetVector`. But _maybe_ this is fine?

https://github.com/llvm/llvm-project/pull/113478