From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=BAYES_00,INVALID_DATE autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,b19fa62fdce575f9 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 1994-12-22 02:20:42 PST Path: nntp.gmd.de!newsserver.jvnc.net!nntpserver.pppl.gov!princeton!rutgers!att-out!pacbell.com!decwrl!hookup!swrinde!pipex!uunet!earth.usa.net!earth!intros From: intros@earth (Introspect Technologies) Newsgroups: comp.lang.ada Subject: Re: Reaching traditional engineering Date: 22 Dec 1994 10:20:42 GMT Organization: Internet Express Message-ID: <3dbjtq$kfl@earth.usa.net> References: <9412061309.AA02026@ajpo.sei.cmu.edu> <3cv6el$5v1@felix.seas.gwu.edu> <3d03j7$q21@gnat.cs.nyu.edu> <3d9kf9$f1n@source.asset.com> NNTP-Posting-Host: earth.usa.net X-Newsreader: TIN [version 1.2 PL2] Date: 1994-12-22T10:20:42+00:00 List-Id: Kevin Weise (weisek@source.asset.com) wrote: : In article <3d03j7$q21@gnat.cs.nyu.edu>, : Robert Dewar wrote: : >I assume you are aware of the Cray/Ada effort which was certainly aimed : >at least partly at their Fortran community. : > : Well, I have to respond to this one. WADR, Robert, my wife has been doing : benchmarking of various Ada compilers on various target platforms for : some time now. My discussions with her lead me to conclude that the : Cray Ada effort was basically a token effort, possibly just done in : response to, or in anticipation of, a contract for a DoD contractor. I used Cray Ada for a couple of years at the National Test Facility. The primary motivation for the development of the Ada compiler was juicy DoD/SDI/R&D-type contracts. The NTF was (at the time) taking the mandate seriously and insisted that Cray provide an Ada compiler as a condition for keeping their machines on-site. I don't know whether the government provided any funding to Cray to help them along. The compiler development group was (is?) very dedicated to Ada and expressed their hopes that Ada would catch on in the scientific community. I don't think Cray put any marketing push behind it, however. : The compiler itself is easy to break (esp. with generics), I never saw this behavior. On the contrary, the compiler was reasonably robust. The biggest headaches were with the (very primitive) Telesoft library manager that they ported to the Cray. : and generates : poor code (yes, I know, it uses a common back end with all other : language translators). My benchmarks (remember, this is 2-3 years ago) showed that standard computations in Cray Ada (including range and bounds checking, etc) took approximately 10% longer than Cray C and 20% longer than Cray Fortran. This is certainly not "poor code". The optimizer worked fine and Cray taught a class in how to write vectorizable code. The Cray architecture is very peculiar and requires a specific (and unusual) style of coding. I can see how someone could get poor performance if they didn't know "the tricks". In fact, writing to get the best performance often necessitated writing Ada in a very "non-Ada" way (very frustrating!). : Unless they've fixed it recently, a delay statement : is guaranteed to result in a wait of *AT LEAST* 2.0 seconds, regardless : of the requested value. While all this is not illegal, it certainly does : not entice any engineer to switch to Ada. We never used Cray tasking or delays so I can't speak to this issue. : When it comes to Cray Ada, JUST SAY NO! (Actually, my personal opinion : is, when it comes to the Cray, just say SGI! And we know they have a : good Ada implementation!) IMHO, the problem with Cray Ada was the Cray machines, not Ada. The speed advantages of a vector-based architecture are not worth all the programming hoops you have to jump through, especially if your application doesn't lend itself to vectorization. I agree that SGI (and DEC and HP and other general-purpose computers) are more cost-effective and are better hosts and targets for Ada development. : ---------------------------------------------------------------- : Kevin J. Weise weisek@source.asset.com : COLSA Corporation Voice - (205) 922-1512 ext. 2115 : ---------------------------------------------------------------- : "Admire those who seek the truth; : avoid those who find it." Marcel Proust Douglas Arndt (member, Team Ada!) Introspect Technologies, Inc. PO Box 1135 Colorado Springs, CO 80901-1135 (719) 634-5744 (719) 634-1163 fax intros@usa.net --------------------------------------------------------------------------- "Facts are just facts. You can't have opinions about facts." - Professor Peter Schickele --------------------------------------------------------------------------- --