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Subject: Re: Bounds Check Overhead
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Date: Sat, 27 May 2006 14:29:32 GMT
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Date: 2006-05-27T14:29:32+00:00
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"Simon Wright" <simon@pushface.org> wrote in message
news:m2mzd569l9.fsf@grendel.local...
> Bob Lidral <l1dralspamba1t@comcast.net> writes:
>
> > However, the performance hit of including explicit bounds checking
> > can be significant -- especially for code with extremely short loops
> > that are executed a lot of times.
>
> In Ada one should where possible use the 'Range attribute:

Ideally yes, but in practice, such as in sorting and averaging,
the loop is often one or two short of the number of elements in the array.

>    for I in Some_Array'Range loop
>       Process (Some_Array (I));
>    end loop;
>
> where I _can't_ exceeed the bounds, so it would be surprising if a
> compiler inserted bounds checks.