These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 0.97 s (backtrack: 0/20).

[ebuild  N     ] sci-libs/dmlc-core-0.5::gentoo  USE="openmp -doc -s3 -test" CPU_FLAGS_X86="sse2" 251 KiB

Total: 1 package (1 new), Size of downloads: 251 KiB