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

Calculating dependencies ... done!
Dependency resolution took 1.48 s (backtrack: 0/20).

[ebuild     UD ] dev-libs/xxhash-0.8.3::gentoo [0.8.3-r2::gentoo] USE="(-static-libs%)" 1121 KiB

Total: 1 package (1 downgrade), Size of downloads: 1121 KiB