Re: Speed Impact experiment on GCJ

[Andrew Haley <aph at redhat dot com>]

Rui Wang writes:
 > Hi, 
 > 
 > I did a simple test to analyse the speed impact of using GCJ between
 > java bytecode and native machine code. 
 > But the result looks not very promising, the data below shows that there
 > is rather large decrease of speed instead of increase. 
 > I couldn't figure out why, any suggestions are appreciated. 

We can't figure out why either, becasue your test uses the files
task.test, servers.d, and result.d, none of which you provided.

 > For Impl.java
 > public class Impl implements IFace {
 >     public Impl(){
 >     }

It's quite possible that an optimizing compiler will be able to figure
out that this is not really a loop:

 >     public int ping(int i, int j) {
 > 	int count= 0;
 > 	for(int n = 0 ; n < i*j; n++)
 > 		count++;
 > 	return count;
 >     }
 > }

Andrew.