Re: Interested about number crunching in Ada

[Gautier <gautier@fakeaddress.nil>]

anon wrote:

> As for F2A: 
> 
> Language converts are nice but in the GNU series they may add useless 
> code because of the number of steps take to convert the code from the 
> source to object code.
> 
> An example:

..

>    GNAT  -- to --> C then using GCC -- to --> asm 
>             asm then using GCC -- to --> object

<<In no sense does GNAT translate your Ada code into C code.>>
Robert Dewar
Ada Core Technologies (found in groups.google.com)

>    F2A -- to --> Ada then using GNAT -- to --> C
>             C using GCC -- to --> asm 
>             asm then using GCC -- to --> object

- The "step" asm to machine code in the object is trivial, asm is just a
human-readable writing for the machine code; no transformation there.
- The GNAT-to-C exists only in your imagination.
- F2A is not a Fortran preprocessor for using Ada as the back end; you use it
once and forget the Fortran code, and continue developing the Ada source.
At the end, you have one step. Sorry...

As for I/O, apart the LOW_LEVEL_IO you mention (never seen before!), the usual 
Text_IO, Direct_IO, Sequential_IO are perfectly compatible from Ada 83 through 
Ada 2005. Ada 95's Stream_IO works in Ada 2005 (would you expect the reverse 
?). Conversely, a SGI Fortran has slightly different I/O than a Lahey Fortran 
and DEC/HP Fortran is still a bit different on that point. The situation is 
just the reverse that you imagine.

As for HP Ada, I don't care about politics, only about performance :-).
______________________________________________________________
Gautier         -- http://www.mysunrise.ch/users/gdm/index.htm
Ada programming -- http://www.mysunrise.ch/users/gdm/gsoft.htm

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