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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham
	autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,e7e6e919cef50811
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-03-15 02:44:53 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!news.net.uni-c.dk!uninett.no!not-for-mail
From: Reinert Korsnes <reinert.korsnes@chello.no>
Newsgroups: comp.lang.ada
Subject: Re: comparing gnat/Ada95 and g77
Date: Fri, 15 Mar 2002 11:44:10 +0100
Organization: UNINETT news service
Message-ID: <a6sjb3$em8$1@snipp.uninett.no>
References: <a6prk9$jhc$1@snipp.uninett.no>
 <3c907c86.6094213@news.demon.co.uk>
NNTP-Posting-Host: sthrkou.ffi.no
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7Bit
X-Trace: snipp.uninett.no 1016189091 15048 193.156.99.159 (15 Mar 2002
 10:44:51 GMT)
X-Complaints-To: news-abuse@uninett.no
User-Agent: KNode/0.6.1
Xref: archiver1.google.com comp.lang.ada:21272
Date: 2002-03-15T11:44:10+01:00
List-Id: <comp.lang.ada>

Thanks all for response.

For the Ada95 program I used:

 gnatmake test1.adb -cargs -O3 -ffast-math 

and for the Fortran version I used:

  f77 -c -O3 -ffast-math test1.f (and f77 -o test1 test1.o)

Ada:    11.8 s

Fortran: 2.7 s

Maybe "-ffast-math" is silently ignored (not "legal") for gnat 
since it is "dirty" ?  Without "-ffast-math" the Fortran 
version takes about 10.3 s .

reinert

PS: yes, I did NOT try to make a program doing anything
    meaningful except for figuring out compile options. 



John McCabe wrote:

> On Thu, 14 Mar 2002 10:47:18 +0100, Reinert Korsnes
> <reinert.korsnes@chello.no> wrote:
> 
>>Hi,
>>
>>Could anybody try these two programs (Ada and Fortran)
>>and see if it is possible to make the Ada version (via compile
>>options) to run as fast as the Fortran version under Linux, gnat
>>and g77 ?
> 
> What do you mean by "as fast as"? Do you have some figures already?
> What are the differences?
> 
> I can't see any reason (other than constraint checking which can be
> switched off) why the actual calculations should be any different, but
> you might find that the IO takes longer in Ada than in Fortran because
> it is obviously a bit more complicated (3 subroutine calls instead of
> 1) and, as you're doing this within a *huge* loop, any slight
> degradation here will be significant.