Why Const Doesn't Make C Code Faster
> This is true in practice because enough real-world C code has “I know what I’m doing” casting away of const.<p>I found this out the hard way when I implemented OptimumC, the first data flow analysis optimizer for DOS C compilers back in the 1980's.<p>I had to undo doing optimizations on const.<p>Anecdote: Optimum C blew away all the other C compilers on a magazine benchmark article because it figured out that the benchmark code did nothing and deleted it. The author didn't ask me about it, he just assumed the compiler was buggy and gave us a bad review. Sigh.<p>When other compilers did DFA, the benchmarks got changed.