[Mlir-commits] [mlir] [mlir][ArmSME] Use liveness information in the tile allocator (PR #90448)

[Benjamin Maxwell]

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@@ -116,4 +116,50 @@ VectorType getSMETileTypeForElement(Type elementType) {
   return VectorType::get({minNumElts, minNumElts}, elementType, {true, true});
 }
 
+void eraseTriviallyDeadTileOps(IRRewriter &rewriter,
+                               FunctionOpInterface function) {
+  SmallVector<Operation *> worklist;
+  function->walk([&](Operation *op) {
+    auto armSMEOp = dyn_cast<arm_sme::ArmSMETileOpInterface>(op);
+    if (armSMEOp && isOpTriviallyDead(armSMEOp))
+      worklist.push_back(armSMEOp);
+  });
+  while (!worklist.empty()) {
+    Operation *op = worklist.pop_back_val();
+    if (!isOpTriviallyDead(op))
+      continue;
----------------
MacDue wrote:

It's simpler to implement this way. An operand of the trivially dead operation won't become trivially dead until after the `eraseOp()` call, which would delete the operation (making it a use-after-free to iterate over the operands). 

https://github.com/llvm/llvm-project/pull/90448