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Date: Mon, 08 Aug 2005 10:04:00 -0000
From: "netzberg at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: java-prs@gcc.gnu.org
Message-ID: <20050808100453.23283.netzberg@gmail.com>
Reply-To: gcc-bugzilla@gcc.gnu.org
Subject: [Bug java/23283] New: Java interpreter significantly faster than gcc?!
X-Bugzilla-Reason: CC
X-SW-Source: 2005-q3/txt/msg00187.txt.bz2
List-Id: <java-prs.sourceware.org>

I have a very compact code example (10 lines) for which running java interpreter
on a class file takes 4.5s and executing optimized binary created from the class
file with gcj takes 5.5s. Something is funny here. Can anyone explain what's
happening?

% uname -a
Linux localdomain 2.6.12-1.1372_FC3 #1 Fri Jul 15 00:59:10 EDT 2005 i686 i686
i386 GNU/Linux

>>>>>>>>>>> The java code (X.java):
import java.lang.*;
import java.util.*;
import java.io.*;
public class X {
    public static void main(String[] args) {
	Random R = new Random();
	for (int i=0; i < 10000000; i++)
	    R.nextDouble();
    }
}
>>>>>>>>>>The Makefile
all:
	@javac X.java
	@echo "*** Interpreted:"
	@time java -classpath . X
	@gcj -O3 --main=X -o x X.java
	@echo "*** Compiled:"
	@time ./x
>>>>>>>>>>Here is the output:
*** Interpreted:
4.30user 0.02system 0:04.51elapsed 95%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (1major+2734minor)pagefaults 0swaps
*** Compiled:
5.55user 0.01system 0:05.58elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+2069minor)pagefaults 0swaps

-- 
           Summary: Java interpreter significantly faster than gcc?!
           Product: gcc
           Version: 3.4.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: java
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: netzberg at gmail dot com
                CC: gcc-bugs at gcc dot gnu dot org,java-prs at gcc dot gnu
                    dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23283