Re: Why is GForth-ITC fast?

According to  <brian.fox@[EMAIL PROTECTED]
>:
> Is the C compiler smarter than we are?

As a rule, yes.

Well, it is not that the C compiler is really an intelligent being;
rather, processors evolve and the optimization rules tend to change over
time. An actually maintained C compiler (e.g. gcc) has dozens of
developers who keep track of that and update the compiler so that it
knows how to produce fast code on today's systems. Besides, when
processors evolve, then tend to do it in a way which favours compilers,
hence new optimization rules are more of the "can be applied
systematically" trend than the "are easy to hand-code by a human" way.

The idea that "the compiler knows better" has been actively sup****ted by
the processor vendors, so much that it really became a reality rather
than a fine dream. At least on those big desktop systems that we now
have.

For instance, the "string opcodes" such as lodsd were not often used by
compilers, hence Intel and AMD did not bother optimize them, and these
opcodes are not quite slow with regards to the other opcodes. It thus
pays off to replace them by equivalent sequences of simpler opcodes,
something which is tedious for a human programmer but easy for a dumb
compiler.


	--Thomas ****in