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/kissfft-131.2.0::gentoo  USE="openmp -alloca -double -int16 -int32 -test -tools" CPU_FLAGS_X86="sse" 52 KiB

Total: 1 package (1 new), Size of downloads: 52 KiB