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

Calculating dependencies ... done!
Dependency resolution took 0.97 s (backtrack: 0/20).

[ebuild  N     ] media-libs/glm-1.0.3::gentoo  USE="-test" CPU_FLAGS_X86="avx avx2 sse2 sse3 sse4_1 sse4_2 ssse3" 4490 KiB

Total: 1 package (1 new), Size of downloads: 4490 KiB