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

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] app-crypt/johntheripper-1.9.0::gentoo  USE="openmp -custom-cflags -verify-sig" CPU_FLAGS_X86="avx avx2 avx512f sse2 (-mmx) -xop" 8736 KiB

Total: 1 package (1 new), Size of downloads: 8736 KiB