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

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

[ebuild  N     ] acct-group/oprofile-0-r3::gentoo  0 KiB
[ebuild  N     ] acct-user/oprofile-0-r3::gentoo  0 KiB
[ebuild  N     ] dev-util/oprofile-1.4.0-r1::gentoo  USE="-apidoc -java (-pch) -static-libs" 1522 KiB

Total: 3 packages (3 new), Size of downloads: 1522 KiB