I feel that if you're one of the rare people who know how and when crafted assembly works better, it's almost always also a better use of your time to work on the compiler, rather than whatever you are working on.
Even years ago when the compilers were not as good this is exactly what most people did. Compile it look at the asm. Sometimes see better bits here and there and replace that function with an asm one. If you are in a space where that perf really maters you do this more often.
