“The question was recently raised on the lkml why such a wide
range of GCC versions were being actively supported by the Linux
kernel. One reason offered was, ‘because the new compilers are a
lot slower,’ an argument that left some perplexed. ‘Why is this an
issue when compiling a kernel? How often do you compile your
kernel?’“Linux creator Linus Torvalds agreed that the speed of the
compiler was indeed one of the reasons that older versions are
still supported, ‘for some people that is literally where _most_ of
the CPU cycles go…'”