Yes, a partition can comply with Iraq's existing constitution, because the current constitution allows for a federalist system with many localities. While the constitution provides for partition, because of its intentional federalism, there are many that do not support partition. While partition is possible under the constitution, it might not be a viable option for lack of public support.
A partition of Iraq is impermissible under the country's current constitution, which was adopted in 2005. One of the central tenets of the Iraqi constitution is that Islam is the official religion of the country and is the basis for all of its laws. Therefore partition on religious grounds would violate the constitution.