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=3.8 required=5.0 tests=BAYES_00,INVALID_MSGID,
	RATWARE_MS_HASH,RATWARE_OUTLOOK_NONAME autolearn=no autolearn_force=no
	version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 109fba,baaf5f793d03d420
X-Google-Attributes: gid109fba,public
X-Google-Thread: 103376,97188312486d4578
X-Google-Attributes: gid103376,public
X-Google-Thread: fc89c,97188312486d4578
X-Google-Attributes: gidfc89c,public
X-Google-Thread: 1014db,6154de2e240de72a
X-Google-Attributes: gid1014db,public
From: "Tim Behrendsen" <tim@airshields.com>
Subject: Re: What's the best language to start with? [was: Re: Should I learn
 C or Pascal?]
Date: 1996/08/09
Message-ID: <01bb85ff$b4d78b00$87ee6fce@timpent.airshields.com>#1/1
X-Deja-AN: 173149994
references: <31FBC584.4188@ivic.qc.ca>
 <01bb83ad$29c3cfa0$87ee6fce@timpent.airshields.com>
 <4u89c4$p7p@solutions.solon.com>
 <01bb83f5$923391e0$87ee6fce@timpent.airshields.com>
 <4uah1k$b2o@solutions.solon.com>
 <01bb853b$ca4c8e00$87ee6fce@timpent.airshields.com>
 <4udjki$2l8@cnn.Princeton.EDU>
content-type: text/plain; charset=ISO-8859-1
organization: A-SIS
mime-version: 1.0
newsgroups: comp.lang.c,comp.lang.c++,comp.unix.programmer,comp.lang.ada
Date: 1996-08-09T00:00:00+00:00
List-Id: <comp.lang.ada>


telnet user <tim@franck> wrote in article <4udjki$2l8@cnn.Princeton.EDU>...
> Tim Behrendsen (tim@airshields.com) wrote:
> 
> : This is an interesting case, because it is somewhat inefficently
> : implemented.  If you're interested in speed, you would do...
> 
> : int gcd(int x, int y) {
> :     int z;
> :     while (y != 0)
> :         z = y; y = x % y; x = z;
> :     return(y);
> : }
> 
> However if you are interested in correctness, you use braces for the
> loop.  I think this case where you write assembly in C, get it wrong,
> and ...
> : Using my AIX compiler, I get a nominal improvement of about
> : 10%, mostly because the speed of the modulo is much slower
> : than the inefficiency of recursion.
> 
> only achieve a 10% speedup proves everyone else's point, and is an
> appropriate place to end this thread.

Yes, with *this* algorithm, on *this* computer, I only got a
10% improvement.  I rewrote an algorithm to be non-recrursive
that was published in CUJ and got a 40% improvement.  This is
the reality of what happens when you let the compiler to do the
thinking.

-- Tim Behrendsen (tim@airshields.com)