Earlier quoted context omitted.
> Sometimes a big, fat block of code is just easier to understand. John Carmack made once the same comment: http://number-none.com/blow/blog/programming/2014/09/26/carm...
I haven't read that in awhile. But the argument was around optimisation rather how easy it is to understand.
> In no way, shape, or form am I making a case that avoiding function calls alone directly helps performance.
Rather, he argues that (among other things) this is a way to make current bugs more visible and to avoid future bugs by disallowing calling functions that should be inlined.