From: Isaac Gouy <igouy@...>
Date: 2006-08-04T02:20:12+09:00
Subject: Re: For performance, fix the Java program


Peter Hickman wrote:
> Isaac Gouy wrote:
> > 1) Over the past 3 or 4 days, people have said what's wrong with the
> > way you're producing output in Java, and suggested what you should do
> > instead. Is it that you don't know enough Java to follow their
> > suggestions and fix the program?
> >
> So far the only language that has come close to running as fast as the C
> is the Ocaml version and since then I have found other ways to speed up
> the C version. Just as I have posted the Ruby and Ocaml version if any
> certified Java expert cares to show me how it should be done (*cough*
> Charles O Nutter *cough*) then I will be happy to time it and check the
> output and report the results.

So you don't know enough Java?

> That way we can get away from all this
> stupidity like the fact that I didn't use the correct naming convention.
> Which we all know hugely affects performance. But remember that the
> timings will be based on a program that produces output.
> > A couple of days ago single measurements on my machine gave
> > 0.820s user+sys, gcc -pipe -Wall -O3 -fomit-frame-pointer
> > -funroll-loops -march=pentium4
> > 4.444s user+sys, sun-jdk-1.5.0.07
> >
> > Simply writing Java that converts the double-byte Unicode Java
> > outputStrings to single-byte /once/ instead of everytime there's a
> > print statement, and following the usual Java pattern of wrapping
> > output with a BufferedOutputStream, reduces that to
> >
> > 1.396s user+sys, sun-jdk-1.5.0.07
> >
> > Yesterday I emailed you another version of your Java generating Perl
> > script that fixes those print problems, the output matches the C
> > program output.
> >
> If it was the email I replied to yesterday then reason that it got close
> to the speed of the C version was because it didn't do any output. Once
> I put the output back in it was only around 5 seconds faster than my own
> Java version and around 15 seconds slower than the C version. Hardly
> encouragement to drop C and pursue Java. Remember I am running the
> program to get the output.

If it didn't produce any output I would have mentioned that, as I have
before.

Check your email - the subject line reads " For performance use ascii
output"