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

Calculating dependencies ... done!
Dependency resolution took 0.99 s (backtrack: 0/20).

[ebuild  N     ] sys-apps/memtest86+-7.20::gentoo  USE="bios64 boot uefi64 (-bios32) (-iso32) -iso64 -secureboot (-uefi32)" 263 KiB

Total: 1 package (1 new), Size of downloads: 263 KiB