From: "James E. Hopper" <hopperj@macconnect.com>
Subject: Re: GNAT & GCC performace (bad news)
Date: 1999/12/02
Date: 1999-12-02T00:00:00+00:00 [thread overview]
Message-ID: <021219992309319566%hopperj@macconnect.com> (raw)
In-Reply-To: B46CA6A1.2991%Harald.Schmidt@tomcat.de
Another thing that costs is exceptions. in all but the latest gnats
(and only on certain platforms) ust having an exception handler carries
a fair runtime penalty. I maintain the machten gnat and codebuilder
comes with gnat 3.10 which is two generations back. (go to
cs.nyu.edu/pub/gnat/powermac for latest version) also i did not
implement zero cost exceptions (a feature of newer gnats on solaris and
irix, and i belive other os's). peraps i will get around to it one of
these days. also older versions of gnat paid sever penalty for some
types of arrays. newer compilers have fixed most of that. so
1. turn off runtime checking
2. get newest version for nyu site
3. perhaps retry your benchparms on a platform with zero cost
exceptions [either that or comment out the exception handlers]
jim
In article <B46CA6A1.2991%Harald.Schmidt@tomcat.de>, Harald Schmidt
<Harald.Schmidt@tomcat.de> wrote:
> I am playing around with Ada95 since nearly two weeks
> for an upcoming project, trying to select the best
> language for a headless server application. I am using
> CodeBuilder from Feldman's Ada book which comes with
> gnat and gnu c. My experience while compiling and running
> the dhrystone benchmark was that the C version of the
> Dhrystone was nearly twice as fast as the Ada version, and
> this sounds really bad. Has anyone any idea why this
> is so and how to solve this problem. What I was expecting,
> because gnat isn't a compiler env. but a to-C(++) translator,
> the performance decrease about ten to twenty percent but
> not 50 percent.
next prev parent reply other threads:[~1999-12-02 0:00 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-12-02 0:00 GNAT & GCC performace (bad news) Harald Schmidt
1999-12-02 0:00 ` David Starner
1999-12-02 0:00 ` James E. Hopper [this message]
1999-12-03 0:00 ` Robert A Duff
1999-12-04 0:00 ` Robert Dewar
1999-12-04 0:00 ` Harald Schmidt
1999-12-02 0:00 ` nabbasi
1999-12-02 0:00 ` Tucker Taft
1999-12-02 0:00 ` Dmitriy Anisimkov
1999-12-03 0:00 ` Robert Dewar
1999-12-03 0:00 ` Geoff Bull
1999-12-03 0:00 ` Geoff Bull
1999-12-03 0:00 ` Larry Kilgallen
1999-12-06 0:00 ` Robert Dewar
1999-12-06 0:00 ` Larry Kilgallen
1999-12-06 0:00 ` Robert A Duff
1999-12-07 0:00 ` Robert Dewar
1999-12-07 0:00 ` Tucker Taft
1999-12-08 0:00 ` Robert Dewar
1999-12-08 0:00 ` Ada2001
1999-12-09 0:00 ` Wes Groleau
1999-12-10 0:00 ` Robert Dewar
1999-12-10 0:00 ` Arthur Evans Jr
1999-12-11 0:00 ` Robert Dewar
1999-12-17 0:00 ` Richard Kenner
1999-12-07 0:00 ` Robert Dewar
1999-12-03 0:00 ` Mats Weber
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