Re: Efficiency of code generated by Ada compilers

["Elias Salomão Helou Neto" <eshneto@gmail.com>]

On Aug 13, 12:08 pm, Elias Salomão Helou Neto <eshn...@gmail.com>
wrote:
> On Aug 12, 5:21 pm, "(see below)" <yaldni...@blueyonder.co.uk> wrote:
>
>
>
>
>
> > On 12/08/2010 20:23, in article m28w4bfxdy....@pushface.org, "Simon Wright"
>
> > <si...@pushface.org> wrote:
> > > csamp...@inetworld.net (Charles H. Sampson) writes:
>
> > >> Simon Wright <si...@pushface.org> wrote:
>
> > >>> csamp...@inetworld.net (Charles H. Sampson) writes:
>
> > >>>>      I then overloaded "+" and "-" for (Bearing, Turn_Angle) arguments
> > >>>> and Bearing return value.  In those functions is where the mod 360
> > >>>> occurred.  (Actually, mod 360.0, as it were.)
>
> > >>> Depending on what is doing the turning, in our application that would
> > >>> in some cases have to be mod 720.0 ...
>
> > >>      I'm puzzled.  Unless you're very careful, intermediate calculations
> > >> could result in a quasi-Bearing of more than 360 degrees but I'm pretty
> > >> sure most programmers on my project would have been surprised to see a
> > >> real bearing of 360 degrees or more.
>
> > > A tracker radar like this one (hope the link will work) might be able to
> > > turn through an unlimited number of revolutions, or (with a more
> > > mechanical design) there might be a limit on how many revs it could
> > > manage. So if it's currently pointing 10 degrees to starboard, how much
> > > further can it go before having to unwind?
>
> > > I agree that this is Training, not Bearing, of course.
>
> > >http://www.artisan3d.co.uk/static/bae_cimg_radar_Fi_latestReleased_ba...
> > > dar_Fi_Web.jpg
>
> > I think quantum mechanics codes would require angles mod 720 for spin 1/2
> > particles. 8-)
>
> > --
> > Bill Findlay
> > <surname><forename> chez blueyonder.co.uk
>
> Well, we are definitely drifting away from the original question. So
> much that I am considering to give up reading answers from this
> post...
>
> Anyway, someone prematurely implied that I may be doing premature
> optimization. The fact is that I do know, from profiling, how
> important is _not_ to range check in my specific application, so I
> will try to give you a "bottom line" of what have been said that
> really matters to me.
>
> 1) You can, in more than one way, tell the compiler to suppress most
> (any?) checks, but people do not advise to do so. Even if I say that I
> do need that :(
>
> 2) It is not necessary for the compiler to actually suppress any
> checking! It seems that the LRM demands the compiler to allow you to
> misunderstood something here.
>
> I am having a fairly good impression of Ada's features, but the effort
> it would take to learn the language may eventually not pay off.
>
> Thank you,
> Elias.
>
> P.S: Multidimensional _arrays_ are not multidimensional _matrices_
> neither are them MD _images_. The two latter are far more specific
> classes and the last case even needs to be templated in, say, pixel
> type, etc.

Sorry, but where it is written

> ask for the suppression, but it does mandate the compiler to actually
> skip such checks. Well, this is, to say the least, funny - unless I

you should read


ask for the suppression, but it does NOT mandate the compiler to
actually
skip such checks. Well, this is, to say the least, funny - unless I

Sorry again,
Elias.