You can use a little known, but extremely useful feature called "keep internal boundaries"...
Create a revolved shell feature, with the semicircle as a sketch. Revolved 360 degrees, and make sure you tick the box "Keep Internal Boundaries". This has the effect of partitioning the initial cube.
You can use this technique for any of the feature creation methods, loft, extrude etc... and if you are creative there are some very cool effects you can come up with.