Re: gcj compiled executable performance
On 26-03-2010 17:18, Donkey Hottie wrote:
I have never earlier tested gcj as I thought it was obsolete in its Java
language support.
But now I tested it with one of my apps, and here is the result.
The application is a command line app, which processes files as input,
and produces one file as output. No GUI.
I did not compile from source, but passed the already compiled (with Sun
javac) jar-file. Compiled fine, and resulted as a Linux-executable.
The gcj-compiled version runs fine, and produces the output file fine,
no errors.
But the gcj-compiled version is SLOW.
Sun JRE 6:
real 0m33.512s
user 0m28.450s
sys 0m1.472s
GCJ-compiled
real 1m46.161s
user 1m32.082s
sys 0m2.468s
The java command gets option -Xmx256m, but the gcj-compiled did not get
any Java-specific options.
Is it possible to pass that heap instruction to the gcj-compiled
version? Does it help?
My test results were even worse for GCJ, but that was with 3.4.4.
Did you use -O3 ?
Or is gcj really THAT bad? If it is, I wonder why they bother with gcj
any more.
They apparently want a Java compiler in the collection.
Arne
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