Add a FileCheck test covering the 'expected at least one input' error in ReduceOp::verify(). The companion 'expected at least one output' check was dead code: SameVariadicOperandSize fires first whenever inputs.size() \!= inits.size(), and when both are empty the input check fires first; remove the unreachable branch. Assisted-by: Claude Code
Multi-Level Intermediate Representation
See https://mlir.llvm.org/ for more information.