Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cwjcc!gatech!horus!snm
From: snm@horus.gatech.edu (Sathis Menon)
Newsgroups: comp.lang.c++
Subject: Re: C++ : A free lunch ?
Message-ID: <17558@gatech.edu>
Date: 28 Oct 88 14:15:47 GMT
References: <133@icarus.kulcs.uucp> <77300014@p.cs.uiuc.edu>
Sender: news@gatech.edu
Reply-To: snm@horus.UUCP (Sathis Menon)
Organization: The Clouds Project, Georgia Tech
Lines: 25

In article <77300014@p.cs.uiuc.edu> johnson@p.cs.uiuc.edu writes:
>
>C++ is just as fast as C (within + or - 2%).  We have written an
>operating system (Choices) in C++ and are getting very good performance
>figures from it.  There is essentially no performance overhead in
>using C++.

OK., you are getting good performance figures from your OS using C++, but
did you have a parallel implementation in C to compare it?. Are you
implying that the "very good performance figures" that you mention
are attibuted to C++ (at least partly)?

The distributed OS project that I am working on (Clouds Project at
Georgia Tech) is using g++ (GNU C++) to implement the kernel and
system objects (essential system services). Unfortunately, the
optimizer that we got from GNU folks assumed a little too much,
which doesn't go hand in hand with low level coding. Hence, we don't
optimize the code right now and the code generated is worse than C code
(by checking the assembler listing, of course).

One of these days, we have to muster up the courage to give it another
shot ...

Sathis Menon
snm@gatech.edu