Re: Run-time checking and speed

[mfeldman@seas.gwu.edu (Michael Feldman)]

In article <EACHUS.95Jan17151835@spectre.mitre.org>,
Robert I. Eachus <eachus@spectre.mitre.org> wrote:

> > Yes, compilers sometimes have command-line switch to suppress _all_
> > checks, _everywhere_. IMHO, using this is downright foolish.
>
>   Wow!  I never thought I would be saying something like this, but:
>
>   No, Mike, the switch is very useful during development.  It allows
>you to quickly determine which compilation units may deserve further
>study when doing this sort of optimization.

[snip]

>     So keep the switch, just require that it not be used in delivered
>code.  ;-)

Good point, Bob; I hadn't thought of it.  It;'s actually the opposite
of what one usually sees advocated: checks _on_ during development, then
_off_ for production. Uhhh, no.

It's interesting to contemplate just how little is to be saved by 
suppressing checks in a well-designed program that uses the (sub-)type 
system to advantage. The myth has always been that Ada does all these 
"extra" checks, but of course the number of checks is inversely proportional 
in some sense to the intelligent use of the type system. 

That being the case, because the compiler has (we hope) limited the checks
to those are really needed, the difference in suppressing those checks 
should be at the margin.

Mike Feldman