$ sudo emerge -uavDN world

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

Calculating world dependencies... done!
[ebuild  NS   ] sys-devel/gcc-3.3.6-r1  USE="fortran gtk nls (-altivec) -bootstrap -boundschecking -build -doc -gcj (-hardened) -ip28 -ip32r10k (-multilib) -multislot (-n32) (-n64) -nocxx -nopie -nossp -objc -test -vanilla" 23,534 kB
[ebuild  N    ] virtual/libstdc++-3.3  0 kB

Total: 2 packages (1 new, 1 in new slot), Size of downloads: 23,534 kB