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From: Joel Seidman <joel.seidman-nospam@trw.com>
Subject: Re: should I be interested in ada?
Date: 1999/02/18
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Date: 1999-02-18T00:00:00+00:00
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Nick Roberts wrote:
> 
> Jerry Petrey wrote in message <36CC11A1.C7A71642@hercii.mar.lmco.com>...
> [...]
> |> Fortran's array facilities as an example, in Fortran one can put:
> |>
> |>    real, dimension (1:10) :: x
> |>    ...
> |>    x = 1.0
> |>
> |> setting all the elements of x to 1.0 (a 'broadcast scalar'), whereas in
> Ada
> |> to do the same thing, you must code something like:
> |>
> |>    X: array (1..10) of Float;
> |>    ...
> |>    for i in X'Range loop X(i) := 1.0; end loop;
> |
> |
> |I think using an aggregate would be much better than a loop:
> |
> |X := (1 .. 10 => 1.0);
> 
> Precisely right, of course.
> 
Hmmmm. This raises a question about what "better" means. I have seen the
latter recommended for style, and it does read better to me. However,
when I applied this to large aggregates, stack utilization went throught
the roof. The compiler (VADS) created a temp and then moved it on top of
the target variable. I quickly learned to use this method only where the
aggregate couldn't be too large. I'm really not sure why VADS does this.
Is it typical of Ada compilers? Or was VADS failing to do a fairly
obvious optimization. (To be fair, this was an old version of VADS. I
haven't tried this with our current compiler.)

-- Joel