Re: Is the "Ada mandate" being reconsidered?

[dewar@cs.nyu.edu (Robert Dewar)]

Tom Robinson says

"I am interested in what measure you are using for quality.  From the small
snipits I have read on the net it is not clear that the generated code
quality  of gnat is quite up to current standards yet.  Am I missing something
here?  Has anyone done ACEC or PIWG comparisons yet?"

As for most compilers, GNAT does some things well, and some things not
as well. For some programs, GNAT is the fastest Ada compiler around (in
terms of generated code), these are programs for which the backend of GCC
(which is very highly optimized) can generate really good code.

For some Ada specific constructs (notably check generation, aggregates,
exception handling and unconstrained array handling), there is a way to go,
but look to see major improvements in GNAT in all these areas in the near
future.

If you benchmark GNAT against other compilers, you will find that some
things are faster, some are slower. Overall, the results are pretty
comparable, which is quite interesting considering that in these cases
you are typically comparing an old technology where a LOT of effort has
been put into improving the quality of code in general (and the PIWG's
in particular) with a new technology where so far almost no effort has
been put into improving efficiency of generated code (we have been much
more concerned with functionality and reliability).

Robert Dewar
ACT