Array bound checks removal increasing importance

[bearophile via Digitalmars-d]

Sorry for my slow answering, I'm trying to catch up.

Kagamin:

> Shouldn't optimization go a different route?
> 
> 1. Get annoying performance problem.
> 2. Diagnose it.
> 3. Optimize the hot spot.
> 
> Do you have 1?

That's a good strategy if you are optimizing user code. But even 
when you write library code you sometimes can't use that 
strategy, because you are not always sure the performance needs 
of the people that will use the library. That's why Phobos should 
be written to be efficient regardless of evidence of performance 
problems.

The same is true for compiler writers. If you compile D code that 
uses arrays a lot with and without "-noboundscheck" you see some 
run time difference. It's nice to think that the D compiler will 
remove part of such difference in all your future D programs that 
you have not yet written. Array bound checks removal was found to 
be a sufficiently important problem to solve even in Java, that 
is used for heavy array processing less than other languages like 
Fortran.

Bye,
bearophile