Odds are good most programmers tinkering in machine code won't beat the performance of the compiler. That takes experience. It is a good rule of thumb.
I think it is easier to write smaller (size) code than a compiler, but when you measure performance it will beat you often until you get good. Alignment, x86 tricks... It takes a bit of knowledge to do well.
I think he was talking mostly about size.
Odds are good most programmers tinkering in machine code won't beat the performance of the compiler. That takes experience. It is a good rule of thumb.
I think it is easier to write smaller (size) code than a compiler, but when you measure performance it will beat you often until you get good. Alignment, x86 tricks... It takes a bit of knowledge to do well.