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

Calculating dependencies ... done!
Dependency resolution took 1.02 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/libpcre-8.45-r4:3::gentoo  USE="bzip2 cxx jit pcre16 readline (unicode) zlib -libedit -pcre32 -static-libs -valgrind" 1542 KiB
[ebuild  N     ] dev-lang/xsb-4.0.0-r4::gentoo  USE="pcre threads -curl -debug -iodbc -java -mariadb -mysql -odbc -xml" 14992 KiB

Total: 2 packages (2 new), Size of downloads: 16534 KiB