Gcj binaries performance (arm-linux)

Fri May 9 08:53:00 GMT 2008

Andrew John Hughes wrote:
> 2008年4月29日 ffileppo <ffileppo@libero.it>:
>> >
>> > aph@debian:~$ /home/aph/gcc-4.3.0-RC-20080301-install/bin/gcj MyPanel.class -O --main=MyPanel
>> > aph@debian:~$ ./a.out
>> > Test "Bubble Sort" (Num loop: 100)
>> > First loop time: 22
>> > Total time elapsed: 2197
>> >
>> > aph@debian:~$ /home/aph/gcc-4.3.0-RC-20080301-install/bin/gcj MyPanel.class -O2 --main=MyPanel
>> > aph@debian:~$ ./a.out
>> > Test "Bubble Sort" (Num loop: 100)
>> > First loop time: 20
>> > Total time elapsed: 1943

>>>> Thanks for your help Andrew,
>> I'm getting good performance on target using -O / -O2

>> So does gcj default to no optimisation? This is what these results
> suggest, as the -O version is about 18 times quicker.

Yes, of course. That's standard for UNIX, as far as I'm aware: I don't
think I've ever come across a compiler that optimized unless it was
asked to.
Andrew.