Re: Bounds Check Overhead

[nospam@see.signature (Richard Maine)]

Nasser Abbasi <nma@12000.org> wrote:

> I do not think this is too hard for the compiler to check, but I can be
> wrong. I would have to assume then that this is a g95 issue where it just
> does not do this extra check if it is supposed to be part of the Fortran
> standard to try to check against loop counters updates.

I seem to be having some trouble communicating here. No it is not
"supposed to be part of the Fortran standard to try to check against
loop counters updates".

I will repeat for the 3rd time.

>> Compilers are not required to enforce that rule,

Am I not making this clear? I cannot come up with a simpler way of
stating it. As I also said

>> In terms of the standard, that is basically all there is to say.

Anything else on the subject is outside of the standard. Really. There
are other things to say on the subject, but not in the standard.

Also, there is almost nothing that the standard says that compilers are
supposed to "try" to do. To quote Yoda

  "Do or do not... there is no try."

There are plenty of things that the market (i.e. users) say that
compilers should try to do, but it is quite rare for the standard to say
things like that. There are a few cases where the standard has a
"recommendation", which could reasonably be interpreted as a suggestion
to try to do something that is not strictly required. But those are rare
and none of them are in this area.

-- 
Richard Maine                    | Good judgement comes from experience;
email: last name at domain . net | experience comes from bad judgement.
domain: summertriangle           |  -- Mark Twain