[Mlir-commits] [mlir] [mlir][Transform] Add a transform.match.operation_empty op to allow s… (PR #68319)

[Oleksandr Alex Zinenko]

================
@@ -55,12 +89,15 @@ class SingleOpMatcherOpTrait
                                     TransformState &state) {
     Value operandHandle = cast<OpTy>(this->getOperation()).getOperandHandle();
     auto payload = state.getPayloadOps(operandHandle);
-    if (!llvm::hasSingleElement(payload)) {
+    if (!payload.empty() && !llvm::hasSingleElement(payload)) {
       return emitDefiniteFailure(this->getOperation()->getLoc())
-             << "SingleOpMatchOpTrait requires the operand handle to point to "
-                "a single payload op";
+             << "AtMostOneOpMatcherOpTrait requires the operand handle to "
+                "point to at most one payload op";
+    }
+    if (payload.empty()) {
+      return detail::matchOptionalOperation(cast<OpTy>(this->getOperation()),
----------------
ftynse wrote:

Since `this->getOperation()` isn't actually used in the call, we can just do explicit `detail::matchOptionalOperation<OpTy>(results, state)` here that will be shorter.

https://github.com/llvm/llvm-project/pull/68319