Ada Code Efficiency

[sampson@cod.nosc.mil (Charles H. Sampson)]

     A few weeks ago I used Cray Ada as an example to show that Ada is not an
inherently slow language; I said that the code produced by Cray Ada is outper-
forming that produced by Cray FORTRAN.

     This assessment was objected to by Phillipe Collard, the project manager
for Cray Ada at Telesoft.  He pointed out that in his presentation at Tri-Ada
'90 he only claimed that Cray Ada's code was outperforming Cray FORTRAN's on
two sets of benchmarks and that Cray Ada was still behind on scalar operations,
but catching up.  He furthermore stated that the primary thrust of the Cray Ada
effort to date has been to vectorize loops, which it is now doing as well as
Cray FORTRAN.  Only now are they beginning to concentrate on improving the
scalar code.

     It's certainly refreshing to meet someone so against vaporware that he
won't even let a disinterested third party do it for him, but I think Phil-
lipe's modesty is a bit excessive.  The two benchmarks in question are Whet-
stone and Dhrystone!

     I still think that Cray Ada is a good counterexample to the idea that Ada
code is inherently slow.  I'll wait for Telesoft to issue an official announce-
ment about the scalar code efficiency, rather than give out the current figure
that Phillipe gave me.  I see no reason why the final figure should be much
less than 100%.  If constraint checks are suppressed, to let Ada and FORTRAN
compete on equal terms, I would expect it to be so close to 100% that any dif-
ference is insignificant.

                               Charlie