mapping.map(op->getOperand(arg.index()), arg.value());
  }
  return builder.clone(*op, mapping)->getResults();
}

FailureOr<int32_t> CastI64ToI32(const int64_t value) {
  if (!llvm::isInt<32>(value)) {
    DEBUG_WITH_TYPE(
        "mlir-quant-attrs-and-constraints",
        llvm::dbgs()
            << "Tried to cast " << value
            << "from int64 to int32, but lies out of range of int32.\n");
    return failure();
  }

// the cast attempt as `name`.
template <typename T>
FailureOr<T> TryCast(Operation* op, const StringRef name) {
  auto cast_op = dyn_cast_or_null<T>(op);
  if (cast_op) {
    return cast_op;
  } else {
    DEBUG_WITH_TYPE("mlir-quant-attrs-and-constraints",
                    llvm::dbgs() << "Failed to match " << name << " ("
                                 << T::getOperationName() << ").\n");
    return failure();
  }
}