op.getOperation()->getOperand(to));
    }
    BitVector operands_to_erase(op->getNumOperands());
    int args_start = op->getNumOperands()
                         ? op.getArgOperands().getBase()->getOperandNumber()
                         : 0;
    operands_to_erase |= args_to_erase.lookup(func);
    operands_to_erase <<= args_start;
    op->eraseOperands(operands_to_erase);