[fedora-java] Profiling ecj (was: Using the natively-built Eclipse compiler)

[Andrew Overholt]

Hi,

I decided to do something similar to what Ziga had done.  I took his
HelloWorld.java [1] and compiled it with three incarnations of ecj:

1. java-gcj-compat's javac
2. an ecj made as in [2]
3. an ecj made as in [3]

Quick and dirty results (see [4] for details):

(average of 5 runs)

       |  j-g-c's javac  |  ecj (from .java)  |  ecj (linked)
-------------------------------------------------------------
real   |     1.1724 s    |      0.2812 s      |   0.3804 s
user   |     1.0576 s    |      0.217 s       |   0.313 s
sys    |     0.1144 s    |      0.0636 s      |   0.0672 s

I've attached the raw output of the time commands for all three tests.

Andrew

[1]
http://www.bootchart.org/misc/ecj/HelloWorld.java

[2] Note:  this took a _long_ time ... maybe I did something wrong?
(in an exploded Eclipse source tree (after rpmbuild --short-circuit -bp on
our eclipse.spec) in plugins/org.eclipse.jdt.core/compiler:

gcj -o ecj -I. --main=org.eclipse.jdt.internal.compiler.batch.Main -O2 \
`find -name \*.java -print0 | xargs -0`

[3]
gcj -O2 --main=org.eclipse.jdt.internal.compiler.batch.Main \
-Wl,-R,/usr/lib/eclipse/plugins/org.eclipse.jdt.core_3.1.0 \
/usr/lib/eclipse/plugins/org.eclipse.jdt.core_3.1.0/jdtcore.jar.so \
/usr/lib/eclipse/plugins/org.eclipse.jdt.core_3.1.0/jdtCompilerAdapter.jar.so \
-o ecj.linked

[4]
export CLASSPATH=/usr/share/java/libgcj-4.0.0.jar
time <compiler> HelloWorld.java
-------------- next part --------------
real    0m0.379s
user    0m0.310s
sys     0m0.068s

real    0m0.381s
user    0m0.317s
sys     0m0.065s

real    0m0.384s
user    0m0.310s
sys     0m0.073s

real    0m0.383s
user    0m0.316s
sys     0m0.066s

real    0m0.375s
user    0m0.312s
sys     0m0.064s
-------------- next part --------------
real    0m0.277s
user    0m0.210s
sys     0m0.067s

real    0m0.277s
user    0m0.224s
sys     0m0.052s

real    0m0.279s
user    0m0.198s
sys     0m0.081s

real    0m0.278s
user    0m0.220s
sys     0m0.057s

real    0m0.295s
user    0m0.233s
sys     0m0.061s
-------------- next part --------------
real    0m1.146s
user    0m1.039s
sys     0m0.107s

real    0m1.170s
user    0m1.051s
sys     0m0.117s

real    0m1.154s
user    0m1.047s
sys     0m0.107s

real    0m1.159s
user    0m1.044s
sys     0m0.115s

real    0m1.233s
user    0m1.107s
sys     0m0.126s