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

Calculating dependencies ... done!
Dependency resolution took 1.01 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/libtommath-1.3.0::gentoo  USE="-doc -examples -static-libs" 628 KiB
[ebuild  N     ] dev-libs/libtomcrypt-1.18.2-r4:0/1::gentoo  USE="gmp libtommath -tomsfastmath" 2577 KiB

Total: 2 packages (2 new), Size of downloads: 3204 KiB