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From: larry@VLSI.JPL.NASA.GOV
Newsgroups: comp.lang.ada
Subject: Slow parts of Ada?
Message-ID: <890329113329.353@VLSI.JPL.NASA.GOV>
Date: 29 Mar 89 19:33:29 GMT
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> Ada ... has been used to develop a shadow AIRBUS flight control system 
> to evaluate Ada.  The system turned out very slow so they used a
> faster CPU to ensure meeting deadlines (actually, 4 times faster).

With just what's said above, it seems no real attempt was made to evaluate 
Ada.  Rather than switching to a faster CPU, a profiler should have been 
used to find the performance bottlenecks.

Does anyone know why the system turned out so slow?  (My experience is 
that the features in the "Pascal subset" of Ada are about as fast as their 
equivalents in other Algol-like languages such as C.  Just as a guess I'd 
say they were over-using tasking.)

Has anyone done a study to identify features of Ada that are slow in most 
Ada compilers?  That are slow only in particular Ada compilers?

                               Larry @ VLSI.JPL.NASA.GOV