gcc

module (bold = default) build dependencies
gcc/4.7.2/b1 gcc 4.4.7
gcc/4.7.2/b2 gcc 4.4.7
gcc/4.7.2/b3 gcc 4.4.7
gcc/4.8.2 gcc 4.4.7
gcc/4.9.3 gcc 4.7.2
gcc/4.9.4 gcc 4.9.3
gcc/5.2.0 gcc 4.8.2
gcc/5.3.0 gcc 5.3.0
gcc/5.4.0 gcc 5.4.0

also see Using Software.